Ex., A001 01, N6 K2 K, Monganstown1, Co. Westmeath Eap Journal

Issue 3 [ISSN 2009-2237]

Archaeological Excavation ReportE2771 - Monganstown 1, Co. Westmeath

Metalworking site

Eachtra Journal

The Forge,Innishannon, Co. Cork.Tel.: 021 470 16 16Fax: 021 470 16 28E-mail: [email protected] Site: www.eachtra.ie

Contact details:

August 2009

Written by:

Client:

Final Archaeological Excavation Report,Monganstown 1N6 Kinnegad to KilbegganCo. Westmeath

Metalworking site

Westmeath County CouncilCulleen BegMullingarCo. Westmeath

A001/01

John Lehane

John Lehane and Penny Johnston

Ministerial Order No.:

Licensee:

E2771E Number:

Permalink: http://eachtra.ie/index.php/journal/e2771-monganstown-1-co-westmeath/

Monganstown 1, Co. Westmeath ISSUE 3: Eachtra Journal - ISSN 2009-2237E2771 | A001/01

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Table of Contents

Acknowledgements ..................................................................................................... iv

1 Non-Technical Summary ....................................................................................1

2 Scope of the Project ............................................................................................1

3 Receiving Environment ......................................................................................2

3.1 Geology ........................................................................................................2

3.2 Soils and their uses .......................................................................................2

3.3 Topography ..................................................................................................2

4 Archaeological and Historical Background .........................................................3

4.1 Bronze Age c. 2500-500 BC .........................................................................3

4.2 Iron Age c. 500 BC-500 AD ........................................................................3

4.3 Early Medieval c. 500-1100 AD ...................................................................3

4.4 Later Medieval c. 1100-1650 AD ..................................................................4

4.5 Post-medieval c. 1650-20th century ...............................................................5

4.6 Placenames and Townlands ..........................................................................5

5 Site location and topography ...............................................................................6

6 Results of the Excavation ....................................................................................6

6.1 Area 1 ..........................................................................................................6

7 Artefactual Remains .......................................................................................... 10

8 Environmental Remains .................................................................................... 11

9 Industrial Residues ............................................................................................ 11

10 Discussion .........................................................................................................12

11 Conclusion ......................................................................................................... 13

12 Bibliography ......................................................................................................14

13 Figures ............................................................................................................... 15

14 Plates .................................................................................................................21

15 Appendices ........................................................................................................27

15.1 Appendix 1: Context Register ......................................................................27

15.2 Appendix 2: Stratigraphic Matrix ................................................................33

15.3 Appendix 3: Radiocarbon dates from Monganstown 1 ................................34

15.4 Appendix 4: Assessment of Industrial Residues from Excavations at Monganstown 1 ........................................................................................................................ 35

15.5 Appendix 5: Charred plant remains and charcoal from Monganstown 1 .....54



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15.6 Appendix 6: Analysis of charcoal assemblages from Monganstown 1 ...........59

15.7 Appendix 7: Chemical analysis of industrial residues ...................................67

15.8 Appendix 8: Lithics Finds Report for A001/01 – Monganstown 1, Co. West-meath ....................................................................................................................73

Table of contents cont.



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Acknowledgements

Senior Archaeologist: John TierneyLicensee: John Lehane Field staff: Ray Riordan, Caroline Healy, Helen Butler, Julian Stroud, Deidre Gleeson, Christina MurphyAdditional Post-Excavation Work: Antonia Doolan, Sara Camplese, Illustrations: Enda O’Mahony, Deidre GleesonText: John Lehane, Áine Richardson, Antonia Doolan, Penny JohnstonSpecialists: Neil Fairburn, Marcos Martinón-Torres, Abigail Brewer, Penny Johnston, Mary Dillon, Farina Sternke, Queen’s University Belfast 14Chrono Centre

Works were carried out on behalf of Westmeath County Council and were funded by the National Roads Authority under the National Development Plan 2000 - 2006.



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List of FiguresFigure 1: General situation of site along the route of the new road N6 Kinnegad to Kilbeggan Discovery Series Map ............................................................................................................................................15

Figure 2: Monganstown 1 in relation to trenches of archaeological centreline testing that was carried out along the route of the new road .............................................................................................................16

Figure 3: RMP sites near the route of the new road N6 Kinnegad to Kilbeggan ...................................17

Figure 4: The excavated site showing three areas of excavation (Areas 1, 2 and 3) at Monganstown 1, Co. Westmeath (A001/01) ...........................................................................................................................18

Figure 5: Area of excavation in Area 1 at Monganstown 1 ....................................................................19

Figure 6: Sections through furnaces C.57, C.60 and C.63 ................................................................... 20

List of PlatesPlate 1: General site photograph ............................................................................................................21

Plate 2: General site photograph ............................................................................................................21

Plate 3: C.24 post-excavation ................................................................................................................22

Plate 4: C.63 mid-excavation ................................................................................................................22

Plate 5: C.40 post-excavation ................................................................................................................23

Plate 6: C.15 post-excavation .................................................................................................................23

Plate 7: C.2 post-excavation ................................................................................................................. 24

Plate 8: C.66 mid-excavation ............................................................................................................... 24

Plate 9: C.50 mid-excavation.................................................................................................................25

Plate 10: Flint A001/01:13:1 ..................................................................................................................25

Plate 11: An example of clay wall remains within furnace C.63 ............................................................26



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1 Non-Technical SummaryThis report details the results of archaeological excavations carried out at Monganstown townland, along the line of the N6 realignment between Kinnegad and Kilbeggan (Figure 1). Situated approxi-mately 2 km west of Kinnegad, the site is one of fourteen new archaeological sites identified during test excavations carried out in 2004. Following the identification of archaeological remains in situ during the testing phase, it was recommended that preservation by record would be required.The main concentration of archaeological features was confined to an area of approximately 15 m2

and was excavated under ministerial order A001/001. Evidence was recovered showing the existence of early medieval charcoal production pits, and Iron Age ironworking features, as well as other possible smelting and smithing furnaces close by. Several other pits were excavated, and had been used for the disposal of slag, although they may have originally had a different function.

2 Scope of the ProjectThis archaeological services project was carried out on behalf of Westmeath County Council, County Buildings, Mullingar, Co. Westmeath. The project was funded by the National Roads Authority under the National Development Plan 2000-2006. The purpose of the project was to conduct archaeological site investigations within the lands made available for the scheme and to assess the nature and extent of any new or potential archaeological sites uncovered. There were two contracts; Contract 1 (Kinnegad to Tyrellspass) undertaken by Eachtra Archaeological Projects and Contract 2 (Tyrellspass to Kilbeg-gan) carried out by Valerie J. Keeley Ltd. and Cultural Resource Development Services Ltd.This report covers results from Contract 1, Kinnegad to Tyrellspass. Phase 1 of the project (archaeo-logical centreline testing of the route) was carried out in June and July 2004 under licence (04E0908) issued by the Department of the Environment, Heritage and Local Government (DoEHLG). The principal aim of this phase of the project was to investigate known and possible sites of archaeological interest along the route of the proposed road scheme and to investigate the remainder of the route. This was done by a programme of centreline and offset testing (Figure 2). In addition Phase 2 included the resolution of identified sites which were excavated in the townlands of Monganstown, Farthingstown, Kiltotan Collinstown and Rattin. This phase of the project was carried out between January and March 2005 and excavations were carried out by two licensed directors under the direction of a senior archaeologist. In total fourteen sites were excavated during this phase of works and were carried out under Ministerial Order. The sites were situated near the western end of the scheme, in County West-meath, and were found in the townlands of Farthingstown and Kiltotan Collinstown (in the Barony of Fartullagh) and Monganstown and Rattin (in the Barony of Farbill).



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3 Receiving Environment

3.1 GeologyThe bedrock geology is mostly comprised of Lower Carboniferous rocks, mainly limestone, which overlies Devonian Old Red Sandstone (Holland 1981; Riada Consult 2003, 58). Some sills of Carbon-iferous volcanic rocks also pass through the bedrock sequences. The dominant topographical feature of Croghan Hill, 7 km southeast of Tyrrellspass, is comprised of shallow intrusive basaltic and dolamitic rocks formed by volcanic activity (Riada Consult 2003, 59).Superficial drift deposits overly the bedrock, varying from impermeable clay to permeable gravel (Ria-da Consult 2003). Glacial features such as eskers and kames dominate an otherwise flat landscape; the eskers are punctuated by sand and gravel quarries that provide good quality building materials (Casey 2002).

3.2 Soils and their usesThe soil type encountered in the area (Grey-Brown Podzolic) covers 3.43 % of Ireland, on the southern limit of the north to west Drumlin belt across the northern half of the country (Gardiner and Radford 1980, 91). The lighter Grey Brown Podzolics are ‘good all-purpose soils’ and the heavier Grey Brown Podzolics are better for pasture production (Ibid., 27). Although the soil is technically a fertile type, it has a high clay content which results in poor drainage and peat accumulation in the area is widespread. This is particularly the case along the western portion of the road route, (where the sites from this project were found), which has been covered by the growth of fens and raised bog. These peat lands have generally been worked and, while residual peats are often present, they do not tend to exceed 1 m thickness (Riada Consult 2003, 61).

3.3 TopographyThe landscape followed by the route of the new road from Kinnegad to Athlone is generally lowlying, ranging from the low undulating drift cover east of Athlone to the flat plains of the central boglands and moraine near Kinnegad. Only a 4 km stretch of the corridor east of Tyrellspass rises above 100 m in height, most of the land undulating gently along the northern extremities of the Bog of Allen. Outside the area of bogland the landscape is typified by regular enclosed fields, bordered by densely overgrown banks with mature hedgerows of ash, elder and hawthorn. This uniform landscape is bro-ken up by streams, eskers and rivers; the River Brosna and its tributaries drain the western part of the study area, while the land east of Rochfortbridge is drained by the Yellow River and other smaller tributaries of the River Boyne (Casey 2002). The moist climate combined with the low-lying condition of much of the area ensures seasonal flood-ing, limiting the land-use capability to livestock grazing punctuated by infrequent tillage. In areas of marginal land close to the edges of the raised bogs the pasture is criss-crossed by drainage ditches without the usual accompanying enclosing bank (Casey 2002).



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4 Archaeological and Historical Background(based on an Archaeological and Historical Background by Orlaith Egan)The sites within this study area are located in a rich multi-period archaeological landscape (Figure 3) and several monuments have already been assessed in the original EIS report (Riada Consult 2003). Recent excavations along the routes of new roads have added significantly to the list of known sites and the newly discovered sites from this part of the N6 road will add further knowledge to the overall understanding of the area. The area is associated with ancient routeways of unknown date; a large togher discovered by R.A. S Macalister in the nearby townland of Baltigeer in the 1930s may possibly have linked up with the Slighe Dala or Slí Asail, two ancient routeways which led to Tara and Connacht. One of the five great ancient roads of Ireland, the Slí Mór, is also thought to have passed through the area. The earliest indication of archaeological activity within the area was the recovery of a stray Mesolithic Bann flake (IAWU 2002) and a stone axe (SA 1989:17), potentially of Neolithic date (c. 4000-2500 BC), found in the townland of Rattin (IAWU 2001). However, all the archaeological sites excavated in the area have been identified as of Bronze Age date or later.

4.1 Bronze Age c. 2500-500 BCThe earliest known evidence of settlement is represented by an Early Bronze Age (c. 2500-1500 BC) togher discovered by the Irish Archaeological Wetland Unit in the townland of Rattin (IAWU 2001). Finds from the area include a socketed bronze axe head from the Late Bronze Age (1936:1873 NMI) which was recovered near Kinnegad townland (exact location unknown). Bronze Age burnt mounds are also reasonably common; one definite example (CHS 20) and several potential sites were discovered during fieldwalking of the proposed route (Riada Consult 2003, 247). A burnt mound was excavated at Kiltotan Collinstown 12 and at Kiltotan Collinstown 13 an anomalous pit produced a Middle-Late Bronze Age radiocarbon date.

4.2 Iron Age c. 500 BC-500 ADThere is a general dearth of evidence from this period in the Irish archaeological record. However, two Iron Age radiocarbon dates from iron smelting pits were produced at this site at Monganstown 1.

4.3 Early Medieval c. 500-1100 ADThe record of Early Historic activity in the study area and the surrounding countryside is rich. An ancient monastic site founded at Clonfad (WM27: 067, WM27: 066) to north of the townland of Rattin, consisted of a possible church site, a rectangular enclosure, a graveyard, crosses, and Bishop’s grave. St. Etchen was bishop of Clonfad or Cluain-fota-Baethain in the sixth century and the annals of Ulster record his death between 578-84 AD. He is reputed to have ordained St. Columcille and St. Colmáin mac Lúacháin of Lynn and many others. The monastery survived into the eight century AD as Blahmac, an abbott of Clonfad was killed in 799 AD (Gwynn & Hadcock 1970). Sites with evidence for craft/industry from this period include charcoal/metalworking pits at Monganstown 1, which produced two Early Historic radiocarbon dates, and material from a small metalworking pit at



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Kiltotan Collinstown 14, which also returned an Early Historic date.The most common settlement monuments of this period are ringforts (also known as rath or lios). These are interpreted as enclosed farmsteads and they generally consist of a circular ditch outside an earthen bank (constructed with the upcast from the excavation of the ditch). Larger examples may have more than one ditch and a bank forming the enclosure. At Kiltotan Collinstown 14 there are four ringforts located within 1 km of the site. The nearest, WM033-061, is situated just 350 m to the north. East of the site are WM033-065 and WM033-066, at distances of 700 m and 400 m respectively. The fourth ringfort, WM033-062, is about 840 m north-northeast of the site. Also within 1 km of the site is a fifth recorded monument, WM033-068, listed as an earthwork. At Monganstown 1 a further two ringforts (WM 027:069 and WM 027:070) are located in the area between the site and the town of Kinnegad, with one, just 500 m from the site. The evidence suggests that the area was quite intensely settled during the Early Historic period.

4.4 Later Medieval c. 1100-1650 ADThe villages of Tyrrellspass and Rochfortbridge both date from the medieval period and are located near the sites examined in this project. Rochfortbridge is located 11 km southwest of Kinnegad within the Barony of Fartullagh. The village is named after the Rochforts, a French family who settled in Ireland in 1243. Before the Rochforts established themselves in the area the Tyrrells, a powerful An-glo-Norman family, held the Barony of Fartullagh. This included the lands around Rochfortbridge and the parish of Castlelost. In the 13th century (c. 1411) the Tyrrells built a castle that consisted of a motte and bailey (a stone castle came later) in Tyrrellspass, to the northwest of the town. It guarded the western entrance to the Barony of Fartullagh and it remained the centre of power for the Tyrrells until the Cromwellian Invasions (1650). They also built a semi-fortified manorial church on the castle lands which contained an effigy of armoured Knight John Tyrell dating to 1607. The site of another castle (WM 027: 071) and a bridge (WM 028: 003), reflecting further settlement in the later medieval period, are located in the townland of Kinnegad.A defensive castle was also constructed in Rattin (WM34: 008), built to defend extensive Anglo-Nor-man territories in the midlands. The lands were owned by Hugh de Lacy but passed into the possession of Sir John Darcy and his descendents when he became Chamberlain and Steward of the household of King Edward ΙΙΙ, Chief justice of England and Peer of the realm. In the Insurrection of 1641 Nicholas Darcy forfeited Rattin and the greater part of his estates (Bardon 1913). The remains of a sixteenth century towerhouse (called Rattin Castle) are found in the townland today. Test trenches c. 1500 m to the northwest of the castle failed to produce any archaeological remains (Conway 1999, 298). How-ever, phase 1 test excavations north of Rattin towerhouse found the remains of a probable timber and brushwood trackway. There is also a recorded earthwork site (WM 34:007) located to the west of the castle but its function and date are unknown. The only excavated site from this project that dated to the Medieval period was a small furnace at Kil-totan Collinstown 14 which produced a fifteenth century radiocarbon date.



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4.5 Post-medieval c. 1650-20th centuryThe post-medieval archaeology examined during the project included the remains of field systems and vernacular architecture. Post-medieval field boundaries and ditches were excavated at Farthingstown 009, Farthingstown 011, Monganstown 2, Kiltotan Collinstown 12, Kiltotan Collinstown 13 and Kil-totan Collinstown 14. The field systems at Kiltotan Collinstown are probably related to a nineteenth century farmstead pictured on the 1st Edition OS map and located immediately adjacent to the site at Kiltotan Collinstown 12. Vernacular architecture was also examined at the site of Rattin 4, where a nineteenth century farmhouse was tested and recorded prior to road construction. South of Rattin 4 the post-medieval Clonfad mill still stands. This mill has been subjected to a standing building survey and has been reported separately.In addition there are two demesnes located within the study area (Farthingstown House and Side-brook House), both found in the townland of Farthingstown. The term ‘demesne’ originates from Norman French and indicates the portion of an estate retained by a feudal lord for his own use. The term is also used to indicate the extent of a wealthy landowners post-medieval landholding, imme-diately adjacent to their home. Most Irish examples typically consist of a big house with associated buildings, ornamental and recreational grounds, and perhaps the remains of an elaborate boundary wall (Riada Consult 2003, 249).

4.6 Placenames and TownlandsThe sites were excavated in the townlands of Farthingstown, Kiltotan Collinstown, Rattin and Mon-ganstown. The townland of Farthingstown lies in the parish of Castlelost in the barony of Fartullagh. It covers a substantial area containing c. 1802 acres. It is known in Irish as Baile na Feóirlinge meaning ‘town of the farthing’ (Walsh 1957). It was known as ‘Ballyneforlin alias Fardingston’ in the inquisi-tions of the seventeenth century (Inq. Car. Ι no. 129). The townland of Kiltotan and Collinstown is also located within the parish of Castlelost and the Barony of Fartullagh. It lies south and southeast of the old mail coach road from Tyrrellspass to Dublin and borders part of the County of Offaly. In 1837 it consisted of c. 320 acres, which was mainly of arable and pastureland but included a narrow stretch of bog, which bordered the parish of Newtown. Kiltotan is known in Irish as Cill Toiteáin meaning ‘the church of the conflagration’. Collinstown is known as Baile Choileáin translated as ‘the town of Collins’. (OS Namebooks). The townland of Rattin is located in the west of the parish of Killucan within the barony of Farbill. It is known in Irish as Rath Aitinne meaning ‘Rath of the furze’. The lands of Rattin were formerly part of the lands of Clonfad, situated to the west. The name Monganstown is derived from ‘the town of the Mongans’ and the townland covers an area of 483 acres.



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5 Site location and topographyThe site is situated approximately 2 km west of Kinnegad town, near the eastern end of the new route (Figures 1-3). It is 500 m south of the current N6, at Chainage 57240 (field 123/National Grid Co-or-dinates 258000/244650), in the townland of Monganstown, in the parish of Killucan and the barony of Farbill. The excavation was located 150 m north of, and in the flood plain of, the Kinnegad River, which forms the county boundary between Westmeath and Meath. It is on a slightly raised ridge in a level boggy field, which has been in use as pasture for cattle and sheep. It appears that the drier ground of the raised ridge would have attracted occupation in the past. The Boyne Valley Drainage Scheme in the 1950’s is responsible for the presence of deep field drains up to 3 m in depth close to the site.

6 Results of the ExcavationThree separate areas (Area 1 to 3) were stripped of topsoil during the original test excavations of the new route (Figure 4). Area 1 was the largest, being 53 m long (east to west) and 20 m wide, though of an irregular shape. The features identified included two charcoal production pits, six furnaces and several other pits and postholes (Figure 5, Plates 1 and 2).Area 2 was located 19 m west of Area 1 and just 4.4 m west of Area 3. It was 20 m long (northeast to southwest) and 10 m wide. The area was opened in order to uncover a possible linear feature identified during the testing phase but the only features visible were the remnants of a lazy-bed system. Area 3 was then opened between Areas 1 and 2, 4.4 m to the east of Area 2. It measured 20 m by 4 m with a long-axis running northeast to southwest. No archaeological evidence was uncovered in this area.A full record of the excavated contexts is presented in the context register in Appendix 1 while the stratigraphic matrix is presented in Appendix 2.

6.1 Area 1

6.1.1 Charcoal pits

Two large charcoal production pits (C.21 and C.24) were identified during excavations. The pits had a similar morphology, being sub-rectangular in plan with almost vertical sides and flat bases. Both pits were almost 3 m long, between 1.2 m and 1.3 m wide and 0.2 m deep, with C.21 the larger of the two. A large amount of charcoal remained in situ in both pits.The larger of these pits (C.21) measured 2.85 m north-south x 1.3 m in width x 0.26 in depth. It was situated in a corner of the site, approximately 20 m northwest of the main concentration of features and 14 m from the other charcoal pit (C.24). It contained an undisturbed charcoal rich fill (C.14) which was interpreted as the original fill of the pit following charcoal manufacture. Analysis of this material has shown that oak was the main raw material used for the manufacture of this charcoal and it has produced an Early Historic radiocarbon date of AD 898-920. There was no indication why this material was not utilised following its production.The second pit (C.24) measured 2.8 m northwest-southeast by 1.2 m in width and a maximum of 0.2 m in depth (Plate 3). This pit was identified during the test excavation and the upper fill (C.25) was material that was re-deposited as a result of archaeological test trenching. This overlay the original



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charcoal fill (C.13) which contained a piece of burnt struck flint (A001/001:13:1). The charcoal was identified as oak and it yielded an Early Historic radiocarbon date of AD 897-1024. The orientation of the individual wood pieces could be discerned lying along a northwest-southeast alignment, the same orientation as the pit itself.

6.1.2 Furnaces

Six furnaces were excavated on the site; C.40, C.47, C.57, C.60, C.63 and C.74. Four of these (fur-naces C.47, C.57, C.60 and C.63) were situated roughly in the centre of the site (Figure 5). The most southerly furnace (C.47) measured 0.54 m in length and 0.5 m in width. The lower fill (C.46) was composed of burnt clays that were interpreted as being part of the superstructure of the furnace. A total of 8 kg of slag were also retrieved from this deposit and chemical analysis indicated that this slag was from a bloomery furnace (Appendix 7). The second fill (C.48) was topsoil-like and probably accumulated in the furnace after the original furnace contents were removed.The smallest furnace on the site (C.57, Figure 6) measured 0.4 m by 0.3 m in plan. It contained two fills (C.58 and C.59); the lower fill (C.59) consisted of various slag and oak charcoal elements. The up-per fill (C.58) was a layer of slumped topsoil that filled the furnace following removal of the original contents. Two furnaces (C.60 and C.63) were of similar size and morphology; both were sub-circular with aver-age dimensions of 0.78 m by 0.61 m by 0.42 m. The furnace C.60 contained two fills (C.61 and C.62). The basal fill (C.62) was a charcoal-rich deposit found at the base of the cut (Figure 6) and interpreted as the remnants of the original charcoal (identified as ash) used as fuel in the furnace to attain the high temperature necessary for smelting. A total of 9 kg of slag were retrieved from this deposit. The upper fill (C.61) was similar to the upper fills of other furnaces, and contained topsoil-like sediments as well as 12 kg of slag. The furnace C.63 (Plate 4) differed from all the other furnaces in that it contained three fills (C.64, C.65 and C.75). The basal fill (C.75) was a layer of nearly pure charcoal that was recorded at the bottom of the cut (Figure 6) and it contained 14 kg of slag. It was similar to C.62, the basal fill in furnace C.60. This basal layer was overlain by a deposit of burnt clay (C.65) with possible structural elements (burnt clay and charcoal) that may imply a domed superstructure that collapsed into the furnace when it was broken to extract smelted ores. A total of 15 kg of slag remained in the deposit. The uppermost fill of this furnace (C.64) contained small amounts of slag and some oak char-coal and was probably disturbed furnace fill that accumulated in the furnace after its use. The largest furnace was C.74/C.40. This was an elongated, sub-rectangular pit/furnace (C.74) with a small circular furnace (C.40) at its southern end (Plate 5). This was found on the western edge of the main grouping of features in the centre of the site. C.40 was c. 0.55 m in diameter and 0.32 m in depth and it contained two fills (C.39 and C.38). The primary fill (C.39) was a dark slag rich mix, with 15 kg of slag retrieved along with charcoal from a diffuse-porous wood type. This context returned an Iron Age radiocarbon date of BC 361-113 (UB 6940, see Appendix 3). The upper fill of the furnace (C.38) was interpreted as a mix of topsoil and collapsed materials (including 3 kg of slag and ash, hazel and yew charcoal) that filled the furnace subsequent to the use of the feature. Recovered from this fill were two large pieces of vitrified clay lining that were originally part of the furnace; they may have formed



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part of a shaft (see Appendix 4) or they may have been from the clay walls of a bloomery furnace. One of these pieces has a small round hole towards its base for the insertion of bellows. The edges of C.74 extended northwards from this circular bowl, approximately 1.3 m in length by 0.5 m in width. These dimensions made it roughly 1 m longer than the other furnaces. This part of the furnace was filled by two deposits (C.72 and C.73), the basal fill (C.73) being very disturbed and composed of burnt clays (some possible fragments of superstructure), slag pieces (13 kg), charcoal and topsoil-like mate-rial. The presence of topsoil-like material in these fills may indicate some disturbance by ploughing in the general area, which resulted in the formation of homogenous brown fills mixed with debris from the furnace which had been dismantled to remove the processed ores. The upper fill (C.72) was clayey sand topsoil that probably slumped into the furnace void following a period of disuse. The irregular morphology of this feature implies that it was severely disturbed after smelting/smithing.

Furnace cut Length Width Depth Fuel/Charcoal type Clay walls present

Vitrified clay lin-ing present

C.47 0.54 0.5 Oak and yew Yes (in C.46) NoC.57 0.4 0.3 Oak No NoC.60 0.8 0.6 0.35 Ash No Yes (in C.61)C.63 0.76 0.62 0.5 Oak Yes (in C.65) Yes (in C.65 and

C.75)C.74/C.40(diameter of C.40 0.55 m)

1.3 0.55 0.32 Ash, hazel and yew Yes (in C.73 and C.38)

Yes (in C.38 and C.39)

6.1.3 Stakeholes

One stakehole (C.6) was situated in the southeast corner of the site. It had only one fill (C.5) indicating that it was formed by a driven post/large stake, which was subsequently removed. A similar stakehole (C.15, filled by C.16) was situated in the northwest corner of the site (Plate 6). The charcoal from this stakehole was identified as oak (Appendix 6) and it probably represents the remains of a burnt post (Appendix 6). Whether these two features formed part of larger structures is unknown, but there is no evidence for associated stakes or postholes. However, it is quite likely that some form of shelter was erected around the metal working site as this would have been necessary to protect against the ele-ments.

6.1.4 Clay Extraction Pits

Six pits (C.2, C.23, C.45, C.52, C.66 and C.79) were excavated on the site. They ranged in size from 4 m to 0.80 m in length, with depths of between 0.67 m and 0.10 m. The first pit (C.2) was an irregular cut and measured 3.84 m northwest-southeast x 0.80 m in width x 0.58 m in depth. It was situated in the northeast corner of the site (Plate 7). The primary fill (C.4) con-tained oak and hazel/alder charcoal, fragments of clay and 5 kg of slag waste. The other fills (C.1 and C.3) both contained charcoal (including oak, ash and elm) and slag, with most slag being retrieved from C.1, where 2 kg of slag was found. The oak charcoal identified from C.1 returned an Iron Age radiocarbon date of BC 338-46 (UB 6940, see Appendix 3). This pit was probably originally used as a quarry pit, for extracting clay that was used to build the superstructure of the nearby furnaces. It



9

was evidently later backfilled with waste material from the iron-working process taking place in the surrounding area. A similar pit (C.69) was situated approximately 1 m southwest of C.2. It measured 3.3 m southeast-northwest x 0.8 m x 0.4 m in depth and it had two fills (C.70 and C.71). The basal fill of the pit (C.71) contained small to moderate slag and oak charcoal inclusions (see Appendix 6 for charcoal identifica-tions) and it represents deliberate deposition of waste material from furnace activities. One fragment of a hazelnut shell was recovered from this context, indicating that waste from domestic activities may have been used to set the furnaces alight (Appendix 5). The upper fill (C.70) consisted of a mix of redeposited material that included topsoil. This pit was interpreted as a quarry pit and, like the other quarry pit C.2 and the disused furnaces, it was backfilled with waste from metalworking that was car-ried out at the site.Another linear quarry pit (C.45) was found 2 m south of C.2 and C.69, and it was located beside a deposit of orangey gravely clay. It measured 3.8 m east-west x 0.8 m x 0.4 m in depth and it had three fills (C.44, C.56 and C.55). The basal fill (C.44) contained frequent charcoal and slag inclusions as well as some plant remains. It was overlain by C.56, a deposit of red burnt clay, probably the lining of a furnace. This deposit also produced plant remains. The plant remains from both contexts were in a poor state of preservation but may represent domestic material that was used as tinder for the furnace fires; C.44 produced one charred unidentified seed, one stem or straw fragment, and one indetermi-nate fruit stone and C.56 produced one hazelnut shell fragment during plant remains analysis (Ap-pendix 5). Both of these deposits evidently represented redeposited furnace waste. The uppermost fill (C.55) contained only small amounts of charcoal, probably re-deposited from the surrounding area, and no industrial residues and may have been a result of natural silting.

Another pit (C.23) was situated at the southeast edge of the main body of features and to the south of the pit C.45. There was no evidence of burning in situ or any other indicator of use. It had four fills (C.31, C.30, C.22 and C.32). The primary fill of the cut (C.32) seemed to represent a deliberate back-filling episode. Other small deposits such as C.22 and C.30 contained small amounts of slag (there was 1 kg in C.22) and represented rubbish deposited in the pit. The uppermost fill (C.31) may have been the result of natural silting.The remaining pits were centrally located and they produced the most complex stratigraphy on the site. The earliest pit was C.79 which was situated next to one of the charcoal pits (C.24) at the northwest corner of the main concentration of the archaeology. The pit (C.79) measured 2.9 m northwest-south-east x 1.78 m x 0.67 m in depth. It had two fills (C.68 and C.29). The lowest was C.68, a deposit of silty sand with 10 kg of slag, interpreted as a layer of disposed slag. This underlay a spread of dark sediment with frequent charcoal inclusions (C.29) and it filled the pit and spread outside its confines, covering an area of approximately 3.2 m by 1.3 m. This spread (C.29) was also cut by another pit (C.66) which measured 2.5 m north-south x 0.85 m x 0.23 m in depth and was filled by C.67, a silty sand with occasional slag and charcoal (Plate 8). This pit (C.66) was in turn cut by a crescent-shaped pit (C.52) which was situated in the centre of the site. It measured 3.5 m east-west x 1.1 m x 0.3 m in depth and it followed and respected the edge of a natural deposit of orange gravely clay. It was filled by



10

layers C.53 and C.54, both of which had inclusions of slag and charcoal pieces. The charcoal-rich spread (C.29) that partially filled the earliest pit (C.79), was overlain by a thin layer of re-deposited industrial waste material (C.33) where charred seeds and hazel nut shell fragments were found (Appendix 5) along with fragments of oak charcoal (Appendix 6). This spread had dimensions of 1.0 m north-south x 0.4 m x 0.1 m and it was cut by another pit (C.36) which measured 1.5 m east-west x 1.45 m x 0.16 m and was filled by C.34, which contained frequent slag and moderate charcoal inclusions. It was cut by another pit (C.37) which measured 0.8 m north-south x 0.5 m x 0.1 m, and was filled with a layer of slag-rich industrial waste (C.35). It was postulated during excavation that some of these pits were dug for the purpose of extracting deposits of ore from the subsoil, as many of the pits were situated in proximity to natural deposits of orange gravely clay. Small lumps or nodules of possible iron ore and manganese deposits were identi-fied along the sides of natural deposits during the excavation and it was surmised that higher concen-trations were mined out at the time the site was in use. However, it is extremely unlikely that these pits could have produced anything near the amount of ore required for smelting purposes (Neil Fairburn, pers. comm.). The pits were found adjacent to the furnaces and their positions appear deliberate. It is therefore possible that some of the pits were excavated in order to extract clay for the manufacture of the furnace superstructures, for example clay domes, and were later utilised for the disposal of the industrial waste.

6.1.5 Pits of unknown function

A shallow depression or possible pit (C.10) was located in the southeast corner of the site and may have been associated with a nearby stakehole (C.6). It was irregular in plan and measured 0.5 m east-west x 0.45 m x 0.07 m in depth and had one charcoal-flecked fill (C.9). Another shallow pit (C.50) was located to the west of the main concentration of archaeological features (Plate 9), it measured 0.54 m east-west x 0.5 m x 0.15 m and it had only one fill (C.51). A third pit (C.78) situated nearby, measur-ing 2.05 m southwest-northeast x 1.1 m x 0.21 m and containing two fills (C.76 and C.77). The lower fill (C.76) consisted of a thin layer of charcoal while the upper fill (C.77) represented deliberate back-filling. The absence of evidence for burning in situ suggested that the charcoal production occurred elsewhere.

7 Artefactual RemainsOnly one find was recovered from this site, a burnt flint (A001/01:13:1, Plate 10) which was examined by Farina Sternke (Appendix 8). It was a type that was probably made in the Early Mesolithic or the Neolithic, although the find spot is probably typically Mesolithic (an island of raised ground sur-rounded by marchland). This is an early find that has evidently been disturbed and incorporated into deposits associated with later archaeological activity.



11

8 Environmental RemainsTwenty-one bulk soil samples and thirteen charcoal samples were analysed for the retrieval of charred seeds and charcoal. The flots for charred seeds were examined by Penny Johnston and Abigail Brewer (Appendix 5) and the charcoal from the site was examined by Mary Dillon (Appendix 6). Charred seeds were only found in six samples, these were mostly fragments from hazel nut shells. Most of the charcoal from the site was identified as oak, but ash and yew were also significant elements of the as-semblage.

9 Industrial ResiduesVisual inspection of the industrial residues from the site was carried out by Neil Fairburn (Appendix 4) and chemical analysis of three samples was carried out by Marcos Martinón-Torres at the Archaeo-logical Science Laboratories at the Institute of Archaeology in London (Appendix 7). Several of the samples resembled tap slag which suggested that the smelting occurred in a shaft furnace. If this was the case it is one of the earliest examples known from Ireland, where iron smelting technology is gen-erally considered deeply conservative (see Appendix 4). Chemical analysis suggested that the material, although visually resembling tap slag, was actually material that accumulated at the bottom or around the walls of a bloomery furnace (Appendix 7). The composition may be because this slag was a by-product, rather than a product, of the smelt (Appendix 4). Chemical analysis also indicated that the ore source was high in manganese and that the smelting process was quite efficient. High manganese (Mn), strontium (Sr) and barium (Br) are the indicators that could help to identify the potential ore source in the vicinity.



12

10 DiscussionAll of the features excavated at this site were associated with iron working and included charcoal pits, furnaces and various extraction and/or disposal pits filled with charcoal and slag. In total, twenty-three cut features were excavated at the site and forty-eight deposits (fills and spreads) were investigated. The stratigraphic matrix from Monganstown 1 was fairly simple, with no difficult sequence of inter-cutting features, implying a relatively short-lived phase of metalworking activity. Metalworking residues excavated across the river at Kinnegad 2 (Murphy 2003 and Murphy 2004, 510) indicate that the general area around Monganstown was a favoured location for metalworking. The location of these sites is dependant on two primary factors; access to fuel and access to ore. Access to bog ore was presumably relatively easy in the midlands as much of this part of the country is covered by raised mires. The bog may also have provided a source of fuel as peat has been identified as a fuel used to fire furnaces in some parts of Scotland in prehistory (Pleiner 2000, 129). However, the primary source of fuel at this site was identified as oak charcoal (Appendix 5 and 6). The fact that charcoal production pits were excavated at the site indicates that the metalworking was carried out near the lo-cation of the fuel source; Pleiner (2000, 118) suggests that it is more economical to locate the site near the fuel source rather than the ore, especially when fuel is in short supply, as ore is smaller in volume and lighter in weight than the charcoal required for smelting and it is therefore less problematic to transport it. The method of making charcoal was probably relatively simple, involving the excavation of a pit, filling it with timber, covering in vegetation to limit the oxygen supply, then lighting the fire and allowing it to smoulder, slowly turning the wood to charcoal. This production process was similar to that identified at Kinnegad 2 (Murphy 2003)It is clear that substantial iron working was carried out at Monganstown 1. In total 61 kg of industrial residues were recovered from a number of pits and furnaces during the archaeological excavation. The industrial residues consisted of material associated with iron working including furnace and amor-phous slag from most contexts. An iron smithing PCB (Plano Convex Bottom), was found in C.62 (from furnace C.60) and pieces of vitrified furnace lining were found in several of the deposits within furnaces (C.60, C.63 and C.40) and in slag-rich waste deposits that backfilled three clay extraction pits (C.2, C.23 and C.45) and in another small pit (C.50), presumably cleared after use of (Appendix 4). Fragments of vitrified clay-lining from Monganstown were very large and they indicate a feature with an internal diameter of c. 0.3 m. In some cases this indicates a feature considerably smaller than the width of the excavated furnaces (generally c. 0.5 – 0.6 m wide) and it may suggest that these furnaces were the bases of shaft furnaces (see Appendix 4). There was also a considerable quantity of material that resembled fluid tapped slag (27.5 kg), the type of slag that is produced in shaft furnaces. However, chemical analysis on a limited number of samples suggested that it was actually slag from a bloomery furnace (see Appendix 7). In this case the vitrified clay linings found among the slag and the fragments of clay walls found within the furnaces may actually be the surviving remains of domes or clay walls temporarily built over small bowl furnaces. Partial remains of the superstructure of several furnaces survived in the form of collapsed clay walls (in C.47, C.63, C.74 and C.40, see an example in Plate 11).



13

In general, simple bowl furnaces are thought to have been utilised at the beginning of the Iron Age and into the Early Historic and medieval period in Ireland (Scott 1991). The identification of shaft furnaces has important technological implications as the procedures used in shaft furnaces were more efficient. There is a possibility that there was a shaft furnace at Monganstown 1, indicating a relatively sophisticated smelting process and suggesting a very early date for use of this technology; the earliest known examples are from a small quantity of tap slag retrieved at Farranstack, Co. Kerry (03E0171) where the furnace was identified as a shaft furnace producing radiocarbon dates of between 1020-1270 AD (Dowd and Fairburn 2005). However, chemical analysis has yet to confirm this issue for certain. What is clear is that the smelting process was relatively efficient, perhaps due to the qualities of the ore used, rather than because of the technology (Appendix 7).The Monganstown 1 radiocarbon results demonstrate a wide period of use at the site, with deposits from the area associated with metalworking producing Iron Age dates and deposits from charcoal production pits indicating Early Medieval activity. This suggests a long period of intermittent activity at the site. Such repeated usage is perhaps down to the ideal location, on a slightly raised island that probably attracted occupation in the past, as the area has been extensively drained since the 1950s. The only artefact from the site, a flint that was disturbed from its original depositional context, indicates that occupation in the general area extends even further back than the radiocarbon dates suggest.

11 ConclusionCharcoal pits and furnaces associated with iron working were excavated at Monganstown 1, with material from the site producing both Iron Age and Early Historic dates. The industrial residues were primarily identified as the remains from iron smelting with a small amount of iron smithing residues. The results from this site will feed into a growing collection of discoveries that is changing our knowl-edge about metalworking technology available in Ireland in the past.



14

12 BibliographyBardan, P. 1913. ‘Fairbill Topography’, Typed manuscript, Westmeath County Council Library

Casey, M. 2002. ‘N6 Kinnegad to Athlone Aerial Survey’, section of the N6 Environmental Impact Statement, 2004.

Conway, M. 1999. ‘Rattin’, in Bennett, I. (ed.) Excavations 1999: Summary account of archaeological excavations in Ireland. Bray, Wordwell.

Dowd, M. and Fairburn, N. 2005 ‘Excavations at Farranstack, Co. Kerry: evidence for the use of shaft furnaces in medieval iron production’ Journal of Irish Archaeology XIV, 115-121.

Gardiner, M.J. and Radford, T. 1980. Soil Associations of Ireland and Their Land Use Potential. Soil Survey Bulletin No.36. An Foras Talúntais, Dublin.

Gwynn, A. and Hadcock, R.N. 1970. Medieval Religious Houses. Ireland. London.

Holland, CH (ed.) 1981. A Geology of Ireland. Scottish Academic Press, Edinburgh.

Irish Archaeological Wetland Unit, UCD, 2001. ‘Cavemount, Esker & Derryhinch Bogs, Cos Meath, Offaly & Westmeath’, in Peatland Survey Report 2001.

Irish Archaeological Wetland Unit, 2002. ‘Fieldwork 2000, Counties Westmeath and Offaly’ in I. Bennett (ed.) Excavations 2000. Bray, Wordwell.

Murphy, D. 2003. ‘Archaeological Excavation Report for site K-E-K M4 Motorway, Contract 1, Kinnegad 2, Co. Westmeath, Licence 02E0926’, Unpublished report by Archaeological Consultancy Services Ltd.

Murphy, D. 2004. ‘Kinnegad 2, Multi-period smelting site 25838 24541 02E0926 Co. Westmeath’ in I. Bennett (ed.) Excavations 2002. Bray Wordwell.

Ordnance Survey field name Books of the County of Westmeath, 1837.

Pleiner, R. 2000. Iron in Archaelogy: The European Bloomery Smelters. Oxford, Oxbow Books.

Riada Consult, 2003. ‘N6 Kinnegad to Athlone Dual Carriageway Environmental Impact Statement’, Unpublished report for Westmeath County Council.

Scott, B. 1991. Early Irish Ironworking. Belfast, Ulster Museum.

Walsh, Rev. Paul, 1957. The Placenames of Westmeath. Dublin

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21

14 Plates

Plate 1: General site photograph

Plate 2: General site photograph



22

Plate 3: C.24 post-excavation

Plate 4: C.63 mid-excavation



23





24





25


Plate 10: Flint A001/01:13:1



26

Plate 11: An example of clay wall remains within furnace C.63



27

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x 0

.45

x 0.

07Fr

iabl

e da

rk b

row

n sil

ty sa

nd w

ith m

oder

ate

char

coal

flec

ks. F

requ

ent f

ine

sub-

angu

lar

pebb

les.

Onl

y fil

l of s

hallo

w d

epre

ssio

n C

10.

Non

eSo

il 3

10Sh

allo

w d

epre

s-sio

n0.

5 E-

W x

0.4

5 x

0.07

Irre

gula

r sha

pe in

pla

n. B

reak

of s

lope

at t

op im

perc

eptib

le, s

ides

smoo

th &

gen

tle. B

reak

of

slop

e at

bas

e gr

adua

l to

impe

rcep

tible

. Bas

e fla

t. Fi

lled

by C

9.N

one

Non

e

11Fi

ll of

C12

Nat

ural

feat

ure.

Top

soil

like

mat

eria

l.N

one

Non

e12

Nat

ural

feat

ure

Irre

gula

r sha

pe in

terp

rete

d as

tree

root

Non

eN

one

13Fi

ll of

pit

C24

2.8

E-W

x 1

.2 x

0.2

max

Firm

bla

ck 9

8% c

harc

oal f

ill w

ith v

ery

occa

siona

l sm

all s

tone

s. Ve

ry o

ccas

iona

l sla

g. In

C

24.

1So

il 17

Cha

rcoa

l 3

14Fi

ll of

pit

C21

2.

85 N

-S x

1.3

x 0

.26

Blac

k 10

0% c

harc

oal f

ill. S

oft.

Und

er C

81, o

ver C

21.

Non

eC

harc

oal 2

15St

akeh

ole

0.33

N-S

x 0

.27

x 0.

14Su

b-ci

rcul

ar st

akeh

ole.

Bre

ak o

f slo

pe a

t top

shar

p. S

ides

stee

p an

d sm

ooth

. Bre

ak o

f slo

pe

at b

ase

grad

ual.

Und

er &

fille

d by

C16

. Ove

r C82

.N

one

Non

e

15

App

endi

ces

15.1

A

ppen

dix

1: C

onte

xt R

egis

ter



28

Con

text

Typ

eD

imen

sion

s (m

)L

x W

x D

Des

crip

tion

Find

sSa

mpl

es

16Fi

ll of

C15

stak

e-ho

le0.

33 E

-W x

0.2

7 x

0.14

Dar

k gr

eyish

bro

wn

silty

sand

with

cha

rcoa

l 10%

. Mod

erat

e fin

e su

b-an

gula

r peb

bles

, oc-

casio

nal m

ediu

m a

nd c

oars

e su

bang

ular

peb

bles

. Ove

r and

fill

of C

15, u

nder

C81

.N

one

Soil

5

17Fi

ll of

nat

ural

fe

atur

e C

18To

psoi

l lik

e m

ater

ial.

Fille

d na

tura

l fea

ture

. Und

er C

81, o

ver C

18.

Non

eSo

il 28

18N

atur

al fe

atur

eIr

regu

lar c

ut. I

nter

pret

ed a

s nat

ural

feat

ure.

Und

er C

17, o

ver C

82.

Non

eN

one

19Fi

ll of

nat

ural

fe

atur

e C

20To

psoi

l lik

e m

ater

ial.

Fille

d na

tura

l fea

ture

. Und

er C

81, o

ver C

20.

Non

eN

one

20N

atur

al fe

atur

eIn

terp

rete

d as

nat

ural

feat

ure.

Und

er a

nd fi

lled

by C

19, o

ver C

82.

Non

eN

one

21C

harc

oal p

ro-

duct

ion

pit

2.85

N-S

x 1

.3 x

0.2

6Su

b re

ctan

gula

r in

plan

. Top

bre

ak o

f slo

pe sh

arp,

side

s nea

r ver

tical

, bot

tom

bre

ak o

f slo

pe g

radu

al, b

ase

flat.

Orie

ntat

ion

N-S

. Und

er a

nd fi

lled

by C

14, o

ver C

82.

Non

eN

one

22Fi

ll of

pit

C23

0.9

E-W

x 0

.85

x 0.

45D

ark

brow

n cl

ayey

silt

with

c. 1

0% sl

ag. F

requ

ent f

ine

sub-

angu

lar p

ebbl

es, o

ccas

iona

l m

ediu

m su

b-an

gula

r peb

bles

. Und

er C

30, o

ver C

32.

Non

eSl

ag 1

23Pi

t1.

57 E

-W x

1.3

5 x

0.55

Pit &

slag

dum

p. F

illed

by

C31

, C30

, C22

& C

32. U

nder

32,

ove

r C82

.N

one

Non

e24

Cha

rcoa

l pro

-du

ctio

n pi

t.2.

8 N

W-S

E x

1.2

x 0.

2 m

axSu

b-re

ctan

gula

r cha

rcoa

l pro

duct

ion

pit i

n pl

an, r

ound

ed c

orne

rs. T

op b

reak

of s

lope

sh

arp,

side

s nea

r ver

tical

, bot

tom

bre

ak o

f slo

pe g

radu

al. O

rient

atio

n N

W-S

E. U

nder

and

fil

led

by C

13, o

ver C

82.

Non

eN

one

25Fi

ll of

pit

C24

2.8

E-W

x 1

.2 x

0.1

4 m

axM

id b

row

nish

bla

ck fi

rm sa

ndy

silt.

Mod

erat

e sla

g (a

ppro

x 5%

) and

cha

rcoa

l fle

cks.

Ap-

pear

s to

be a

mix

ture

of t

opso

il an

d du

mpe

d w

aste

mat

eria

l i.e

. sla

g an

d ch

arco

al. U

nder

C

81, o

ver C

13.

Non

eSo

il 14

26Fi

ll of

nat

ural

fe

atur

e C

270.

68 N

E-SW

x 0

.32

x 0.

14M

id y

ello

wish

bro

wn

fria

ble

silty

sand

. Ver

y oc

casio

nal c

harc

oal f

leck

s. U

nder

81,

ove

r an

d fil

l of C

27.

Non

eSo

il 13

27N

atur

al fe

atur

e0.

68 N

E-SW

x 0

.32

x 0.

14N

atur

al fe

atur

e fo

rmed

by

vege

tatio

n ro

ot a

ctio

n. V

ery

irreg

ular

in sh

ape

and

prof

ile, n

o ob

viou

s cut

. Und

er C

26, o

ver C

82.

Non

eN

one

28Fi

ll of

nat

ural

fe

atur

e C

490.

31 N

-S x

0.2

6 x

0.06

Mid

yel

low

ish b

row

n so

ft sil

ty c

lay.

Occ

asio

nal v

arie

d sto

nes,

very

occ

asio

nal c

harc

oal.

Inte

rpre

ted

as n

on-a

rcha

eolo

gica

l. U

nder

C81

, ove

r and

fill

of C

49.

Non

eN

one



29

Con

text

Typ

eD

imen

sion

s (m

)L

x W

x D

Des

crip

tion

Find

sSa

mpl

es

29La

yer

3.2

N-S

x 1

.3 x

0.1

Dar

k gr

eyish

bro

wn

sand

y sil

t with

circ

a 20

% sl

ag. V

ery

freq

uent

cha

rcoa

l (10

%).

Und

er

C33

& C

66. O

ver C

68.

Non

eN

one

30Fi

ll of

pit

C23

1.1

E-W

x 0

.9 x

0.15

Ligh

t bro

wni

sh g

rey

firm

sand

y cl

ay, m

oder

ate

fine

pebb

les.

Mod

erat

e sm

all p

iece

s of s

lag.

U

nder

C22

, ove

r C23

.N

one

Soil

7

31Fi

ll of

pit

C23

1.

5 E-

W x

1.3

x 0

.08

Ligh

t gre

yish

bro

wn

soft

sand

y cl

ay. D

elib

erat

e ba

ckfil

l of p

it. U

nder

C81

, ove

r C30

.N

one

Soil

6

32Fi

ll of

pit

C23

0.

9 E-

W x

0.7

x 0

.1Li

ght g

rey

sand

y cl

ay, o

ccas

iona

l fin

e pe

bble

s. D

elib

erat

e ba

ckfil

l of p

it. U

nder

31,

ove

r C

22. P

rimar

y fil

l of C

23.

Non

eSo

il 8

33Sp

read

of m

id-

den

mat

eria

l1.

0 N

-S x

0.4

x 0

.1D

ark

yello

wish

bla

ck sa

ndy

silt s

oft c

harc

oal-r

ich

spre

ad. U

nder

C36

, ove

r C29

. N

one

Soil

15

34Fi

ll of

pit

C36

1.5

E-W

x 1

.1 x

0.1

7D

ark

yello

wish

bro

wn

firm

sand

y sil

t with

freq

uent

slag

, mod

erat

e ch

arco

al. C

ut b

y C

37,

only

fill

of C

36.

Non

eSo

il 16

35Fi

ll of

mid

den

cut C

370.

8 N

-S x

0.5

x 0

.1M

id g

reyi

sh b

row

n so

ft gr

avel

ly si

lt. O

ccas

iona

l sla

g. O

nly

fill o

f C37

.N

one

36C

ut o

f mid

den

dum

p C

361.

5 E-

W x

1.4

5 x

0.16

Sub-

circ

ular

mid

den

pit.

Side

s con

cave

. Bre

ak o

f slo

pe b

ase:

gra

dual

. Fill

ed b

y C

34.

Non

e

37C

ut o

f disp

osal

pi

t C37

0.8

N-S

x 0

.5 x

0.1

Poss

ible

pit

for d

ispos

al o

f sla

g, o

val b

ut ir

regu

lar.

Top

brea

k of

slop

e gr

adua

l, ex

cept

at

NE

impe

rcep

tible

. Sid

es c

onve

x an

d sm

ooth

. Orie

ntat

ed N

-S. F

illed

by

C35

N

one

38Fi

ll of

C40

(C

38)

1.74

N-S

x 0

.54

x 0.

32M

id b

luei

sh b

row

n fr

iabl

e sa

ndy

silt.

Mod

erat

e an

gula

r, su

b-ro

unde

d fin

e pe

bble

s, oc

-ca

siona

l sub

-rou

nded

med

ium

& c

oars

e pe

bble

s, oc

casio

nal s

ub-r

ound

ed, r

ound

ed sm

all

stone

s, m

oder

ate

fleck

s & sm

all c

harc

oal.

Und

er C

81, o

ver C

39.

Non

eSo

il 18

, 31

Slag

3

39Fi

ll of

C40

(C

39)

1.6

N-S

x 0

.49

x 0.

15Br

owni

sh b

lack

cha

rcoa

l-ric

h fir

m c

laye

y sil

t. M

oder

ate

roun

ded

fine

pebb

les,

occa

siona

l su

b-ro

unde

d m

ediu

m p

ebbl

es, o

ccas

iona

l sub

-ang

ular

, sub

-rou

nded

coa

rse

pebb

les,

oc-

casio

nal f

leck

s cha

rcoa

l, m

oder

ate

smal

l cha

rcoa

l, oc

casio

nal f

leck

s, m

ediu

m, l

arge

, bur

nt

clay

, mod

erat

e sm

all b

urnt

cla

y. U

nder

C38

, ove

r C40

.

Non

eSo

il 19

Sl

ag 4

, 11

Cha

rcoa

l 8

40Fu

rnac

e (sh

aft

smel

ting)

1.74

N-S

x 0

.54

x 0.

32Su

b-re

ctan

gula

r rou

nded

cor

ners

. Top

bre

ak o

f slo

pe sh

arp

exce

pt a

t S &

NE

grad

ual.

Side

s N &

S c

onve

x, W

& E

con

cave

. Bas

e br

eak

of sl

ope

shar

p ex

cept

at N

E gr

adua

l. Fi

lled

by C

38, C

39.

Non

e

44Fi

ll of

C45

3.8

E-W

x 0

.7 x

0.3

Dar

k br

owni

sh b

lack

soft

sand

y sil

t. M

oder

ate

sub-

angu

lar f

ine

pebb

les,

mod

erat

e sm

all

& la

rge

slag,

freq

uent

med

ium

slag

, fre

quen

t fle

cks c

harc

oal,

mod

erat

e sm

all c

harc

oal.

Und

er C

55, o

ver C

45.

Non

eSo

il 11



30

Con

text

Typ

eD

imen

sion

s (m

)L

x W

x D

Des

crip

tion

Find

sSa

mpl

es

45C

ut C

453.

8 E-

W x

0.8

x 0

.4Li

near

pit

roun

ded

corn

ers.

Top

brea

k of

slop

e N

shar

p-gr

adua

l, S

grad

ual,

N W

gra

dual

, sid

es N

E ir

regu

lar,

S co

ncav

e, W

smoo

th, b

ase

brea

k of

slop

e N

S sh

arp,

E g

radu

al, W

im

perc

eptib

le. O

rient

ated

E-W

. Fill

ed b

y C

44 C

55 C

56.

Non

e

46Fi

ll of

C47

Bl

ack

char

coal

-ric

h bo

ttom

laye

r. U

nder

C48

ove

r C47

.N

one

Soil

20 C

harc

oal

5 Sl

ag 8

47

Furn

ace

0.5

4 x

0.5

Furn

ace.

Und

er C

46, o

ver C

82.

Non

e

48Fi

ll of

C47

M

id y

ello

wish

bro

wn

fria

ble

clay

ey si

lt. O

ccas

iona

l rou

nded

fine

, med

ium

& c

oars

e pe

bble

s, ra

re su

b-ro

unde

d sm

all s

tone

s, oc

casio

nal s

mal

l sla

g, o

ccas

iona

l fle

cks c

harc

oal.

Und

er to

psoi

l, ov

er C

46

Non

eSo

il 21

49C

ut C

490.

31 N

-S x

0.2

6 x

0.06

Very

irre

gula

r in

plan

and

pro

file.

Bre

aks o

f slo

pe a

nd si

des v

ary

from

impe

rcep

tible

to

vert

ical

. Int

erpr

eted

as c

ause

d by

veg

etat

ion.

Fill

ed b

y C

28.

Non

e

50Pi

t0.

54 E

-W x

0.5

x 0

.15C

ircul

ar p

it. T

op b

reak

of s

lope

shar

p. O

rient

ated

E-W

. Fill

ed b

y C

51N

one

51Fi

ll of

pit

C50

0.54

E-W

x 0

.5 x

0.15

Mid

ora

nge

brow

n fir

m sa

ndy

silt.

Freq

uent

sub-

roun

ded

sub-

angu

lar f

ine

pebb

les,

mod

-er

ate

med

ium

peb

bles

, mod

erat

e an

gula

r, su

b-ro

unde

d co

arse

peb

bles

, fre

quen

t sub

-ang

u-la

r, su

b-ro

unde

d sm

all s

tone

s. O

ver C

50.

Non

eC

harc

oal 7

52Pi

t3.

5 E-

W x

1.1

x 0

.3Pi

t & sl

ag d

ump.

Cur

ving

line

ar ro

unde

d co

rner

s top

bre

ak o

f slo

pe N

S g

radu

al, E

W

impe

rcep

tible

, sid

es N

con

vex,

S sm

ooth

, W ir

regu

lar,

E co

ncav

e, b

ase

brea

k of

slop

e N

S

shar

p, E

W g

radu

al. F

illed

by

C53

, C54

.

Non

e

53Fi

ll of

C52

3.12

SE-

NW

x 0

.7 x

0.2

Mid

gre

yish

bla

ck fi

rm sa

ndy

silt.

Occ

asio

nal s

ub-a

ngul

ar sm

all s

tone

s, m

oder

ate

smal

l sla

g, fr

eque

nt fl

ecks

cha

rcoa

l. U

nder

C54

, ove

r C52

.N

one

54Fi

ll of

C52

2.08

SE-

NW

x 0

.56

x 0.

17M

id g

reyi

sh b

row

n fir

m sa

ndy

silt.

Occ

asio

nal s

ub-a

ngul

ar sm

all s

tone

s, m

ediu

m, l

arge

sla

g. O

ver C

53N

one

55Fi

ll of

C45

2.8

E-W

x 0

.7 x

0.1

4M

id g

reyi

sh b

row

n co

mpa

ct si

lty sa

nd. F

requ

ent s

ub-a

ngul

ar fi

ne p

ebbl

es, m

oder

ate

sub-

angu

lar m

ediu

m p

ebbl

es, o

ccas

iona

l fle

cks c

harc

oal.

Und

er to

psoi

l, ov

er C

45.

Non

eSo

il 10

56Fi

ll of

C45

0.27

SW

-NE

x 0.

2 x

0.1

Red

bur

nt c

lay

linin

g po

ssib

le b

owl f

urna

ce. M

id re

ddish

ora

nge

soft

clay

. Und

er C

55 o

ver

C44

.N

one

Soil

12

57C

ut C

57

Poss

ible

furn

ace

circ

ular

. Fill

ed b

y C

58, C

59N

one

58Fi

ll of

C57

M

id re

ddish

bro

wn

firm

silty

sand

. Occ

asio

nal s

ub-r

ooun

ded

fine

pebb

les,

occa

siona

l fle

cks c

harc

oal,

mod

erat

e sm

all c

harc

oal,

occa

siona

l fle

cks s

lag,

mod

erat

e sm

all s

lag.

U

nder

tops

oil,

over

C59

Non

eSo

il 24

59Fi

ll of

C57

D

ark

brow

n/bl

ack

sand

y sil

t. U

nder

C58

, ove

r C57

.N

one

Soil

25



31

Con

text

Typ

eD

imen

sion

s (m

)L

x W

x D

Des

crip

tion

Find

sSa

mpl

es

60Fu

rnac

e0.

8 N

-S x

0.6

x 0

.35

Som

e bu

rnin

g in

situ

. Sub

-circ

ular

pos

sible

furn

ace.

Top

bre

ak o

f slo

pe sh

arp,

side

s N S

st

eppe

d, E

irre

gula

r, ba

se b

reak

of s

lope

gra

dual

. Orie

ntat

ed N

-s. F

illed

by

C61

, C62

.N

one

Soil

26

61Fi

ll of

C60

0.8

N-S

x 0

.56

x 0.

2M

id b

row

nish

ora

nge

firm

& c

ompa

ct sa

ndy

clay

. Mod

erat

e su

b-ro

unde

d fin

e pe

bble

s, oc

casio

nal s

ub-r

ound

ed sm

all s

tone

s. U

nder

tops

oil,

over

C62

.N

one

Slag

12

62Fi

ll of

C60

0.78

N-S

x 0

.6 x

0.1

8D

ark

blac

k so

ft sa

ndy

silt.

Cha

rcoa

l ric

h. U

nder

C61

, ove

r C60

.N

one

Soil

9 C

harc

oal 6

Sl

ag 9

63

Cut

0.76

E-W

x 0

.62

x 0.

5Su

b-ci

rcul

ar P

ossib

le fu

rnac

e w

ith ro

unde

d co

rner

s. Br

eak

of sl

ope

top

shar

p, si

des c

on-

cave

, bas

e br

eak

of sl

ope

grad

ual t

o im

perc

eptib

le. F

illed

by

C64

, C65

and

C75

.N

one

64Fi

ll of

C63

0.52

E-W

x 0

.4 x

0.2

2M

id re

ddish

bro

wn

firm

cla

yey

silt.

Occ

asio

nal r

ound

ed fi

ne &

coa

rse

pebb

les,

occa

siona

l ro

unde

d &

sub-

roun

ded

med

ium

peb

bles

, occ

asio

nal s

ub-r

ound

ed sm

all s

tone

s, m

oder

-at

e fle

cks b

urnt

cla

y, oc

casio

nal s

mal

l & m

ediu

m b

urnt

cla

y, m

oder

ate

fleck

s, sm

all &

m

ediu

m sl

ag &

cha

rcoa

l. U

nder

tops

oil,

over

C65

.

Non

eSo

il 30

Cha

rcoa

l 9

65Fi

ll of

C63

0.55

E-W

x 0

.4 x

0.15

Yello

wish

ora

nge

burn

t cla

y? M

id p

inki

sh b

row

n co

mpa

ct/fi

rm si

lty c

lay.

Occ

asio

nal

roun

ded

fine,

med

ium

& c

oars

e pe

bble

s, fr

eque

nt fl

ecks

cha

rcoa

l, m

oder

ate

smal

l cha

r-co

al, o

ccas

iona

l med

ium

cha

rcoa

l, oc

casio

nal f

leck

s & m

ediu

m b

urnt

cla

y &

cha

rcoa

l, m

oder

ate

smal

l bur

nt c

lay

& c

harc

oal.

Und

er C

64, o

ver C

75, C

63.

Non

eSl

ag 1

5

66C

ut2.

5 N

-S x

0.8

5 x

0.23

Poss

ible

ext

ract

ion

pit &

slag

dum

p. Ir

regu

lar p

it w

ith ro

unde

d co

rner

s. Ba

se b

reak

of

slope

gra

dual

. Fill

ed b

y C

67.

Non

e

67Fi

ll of

C66

2.5

N-S

x 0

.85

x 0.

23D

ark

oran

ge sa

ndy

clay

with

mod

. Sla

g?? D

ark

brow

nish

bla

ck c

ompa

ct si

lty sa

nd. U

nder

C

81, o

ver C

66N

one

68Fi

ll of

C66

1.4

N-S

x 0

.45

x 0.

05M

id-d

ark

grey

wea

kly

cem

ente

d sil

ty sa

nd. S

ub-r

ound

ed fi

ne p

ebbl

es, s

ub-a

ngul

ar m

e-di

um &

coa

rse

pebb

les,

sub-

roun

ded

smal

l & m

ediu

m st

ones

, mod

erat

e m

ediu

m S

lag.

U

nder

C29

, ove

r C36

.

Non

eSl

ag 1

0

69Pi

t3.

3 SE

-NW

x 0

.8 x

0.4

Pit &

slag

dum

p. L

inea

r with

roun

ded

corn

ers.

Top

brea

l of s

lope

shar

p, si

des N

& S

ir-

regu

lar,

NW

con

cave

, bas

e br

eak

of sl

ope

N im

perc

eptib

le S

shar

p. F

illed

by

C71

.N

one

70Fi

ll of

C69

2.9

SE-N

W x

0.4

8 x

0.15

Mid

bro

wn

soft

sand

y sil

t. O

ccas

iona

l aub

-ang

ular

smal

l sto

nes,

mod

erat

e fle

cks s

lag.

U

nder

tops

oil,

over

C71

.N

one

Soil

22

71Fi

ll of

C69

3.3

SE-N

W x

0.4

5 x

0.4

Blac

k cl

ayey

silt

with

freq

slag

& c

harc

oal?

Dar

k br

owni

sh g

rey

soft

sand

y sil

t. O

ccas

iona

l su

b-an

gula

r sm

all s

tone

s, m

oder

ate

fleck

s sla

g &

cha

rcoa

l. O

ver C

69, u

nder

C70

.N

one

Soil

23

72Fi

ll of

C74

Col

laps

ed m

ater

ial.

Ligh

t pin

kish

ora

nge

com

pact

sand

y cl

ay. M

oder

ate

sub-

roun

ded

&

sub-

angu

lar f

ine

pebb

les,

occa

siona

l sub

-rou

nded

& ro

unde

d m

ediu

m p

ebbl

es. O

ver C

73,

unde

r top

soil.

Non

e

73Fi

ll of

C74

Ora

nge

burn

t cla

y fu

rnac

e w

alls.

Lig

ht re

ddish

gre

y sil

ty sa

nd. L

ess t

han

5% b

urnt

cla

y &

ch

arco

al. U

nder

C72

, ove

r C74

.N

one

Slag

13

74Fu

rnac

e

Sub-

circ

ular

con

stru

ctio

n cu

t. Fi

lled

by C

72, C

73.

Non

e



32

Con

text

Typ

eD

imen

sion

s (m

)L

x W

x D

Des

crip

tion

Find

sSa

mpl

es

75Fi

ll of

C63

Bl

ack

char

coal

laye

r. D

ark

blui

sh b

lack

fria

ble

silt.

100%

cha

rcoa

l. U

nder

C65

, ove

r C63

.N

one

Soil

27 S

lag

1476

Fill

of C

780.

42 E

-W x

0.3

8 x

0.03

Blac

k ch

arco

al la

yer,

dark

bla

ck, f

requ

ent f

leck

s, sm

all &

med

ium

cha

rcoa

l. U

nder

C77

, ov

er C

78N

one

77Fi

ll of

C78

1.34

N-S

x 1

.26

x 0.

24C

olla

psed

mat

eria

l. Li

ght b

row

nish

gre

y w

eakl

y ce

men

ted

silty

sand

/peb

bles

. Fre

quen

t su

b-an

gula

r & su

b-ro

unde

d fin

e &

med

ium

peb

bles

, occ

asio

nal s

ub-r

ound

ed sm

all s

tone

s, m

oder

ate

fleck

s silt

. Und

er to

psoi

l, ov

er C

76.

Non

e

78Pi

t2.

05 S

W-N

E x

1.1

x 0.

21Su

b-re

ctan

gula

r in

plan

, rou

nded

cor

ners

. Top

bre

ak o

f slo

pe N

E im

perc

eptib

le, S

E gr

ad-

ual t

o sh

arp,

SW

& N

W g

radu

al, s

ides

NE

smoo

th, S

E irr

egul

ar, S

W &

NW

con

cave

, ba

se b

reak

of s

lope

NE

& S

W im

perc

eptib

le, S

E sh

arp,

NW

gra

dual

. Orie

ntat

ed N

E-SW

. Fi

lled

by C

76, C

77.

Non

e

79Pi

t2.

9 N

W-S

E x

1.78

x 0

.67

Ova

l/irr

egul

ar. B

reak

of s

lope

top

W S

E SW

gra

dual

, NE

NW

shar

p, si

des N

W S

W

irreg

ular

, NE

SE c

onca

ve, b

reak

of s

lope

bas

e N

E SW

gra

dual

, SE

impe

rcep

tible

, NW

sh

arp.

Orie

ntat

ed N

W-S

E. F

illed

by

C29

, C68

Non

e

80Fi

ll

Mid

bro

wni

sh g

reen

cla

yey

sand

Non

eSo

il 29

81To

psoi

l E

xten

sive

82Su

bsoi

lEx

tens

ive

Surf

ace

Find

Po

ssib

le w

orke

d sto

ne fo

und

clos

e to

C14

N/A



33

Topso

il C.8

1

15

914

16

25

31

35

54

38

48

51

55

58

61

70

77

36

10

21

15

13

30

37

53

39

46

50

56

59

62

71

76

424

22

34

52

40

47

44

57

60

69

78

232

36

67

72

45

23

33

66

73

74

29

68

79

Nat

ura

l C.8

2

15.2

A

ppen

dix

2: S

trat

igra

phic

Mat

rix



34

15.3 Appendix 3: Radiocarbon dates from Monganstown 1

Analysis by 14Chrono Centre, Queen’s University Belfast

Context Sample Charcoal Lab no. δ13C 14 C Date 2 Sigma calibration Period14 2 Oak UB6937 -26.0 1050+/-29 cal AD

898-920AND946-1026

Early Medieval

13 3 Oak UB6938 -27.0 1056+/-30 cal AD 897-921AND942-1024

Early Medieval

1 4 Oak UB6939 -24.0 2110+/-31 cal BC338-330AND203-46

Iron Age

39 8 Diffuse-porous

UB6940 -26.0 2168+/-31 cal BC361-270AND264-151AND138-113

Iron Age



35

15.4 Appendix 4: Assessment of Industrial Residues from Excavations at Monganstown 1

By Neil FairburnOctober 2006

Summary

The excavations at Monganstown, Co. Westmeath have produced a small, but exciting, collection of industrial residues. The slag that was recovered from the excavation has come from shaft furnaces and includes tap slags and fluid furnace slags. Radiocarbon dates that have been obtained from iron work-ing features have provided an Early Iron Age date and demonstrates at long last that the technology of producing iron in a shaft furnace was in Ireland from the beginning of the Iron Age. As slag finds in Ireland have not been reported very often from a shaft furnace and are at the moment considered to be very rare, their presence at Monganstown in an archaeological context is extremely noteworthy. They should now be recognised as coming from an iron smelting site that was using a shaft furnace and not a bowl furnace. Slag that was recovered from pit feature C.2 and chemically analysed is likely to be from the remains of a slag pit shaft furnace. It is possible that the pit is in fact the slag pit base of the shaft furnace. Simi-larly, the slag recovered from the later furnace feature C.47, which has also been chemically analysed, is also likely to be from the remains of a slag pit shaft furnace. The presence of the slag pit furnaces may explain why furnace C.40 has cut into the earlier furnace C.74.Monganstown can now be added to the limited but growing evidence for the use of the shaft furnace in the iron smelting process in Ireland, and also now demonstrates at long last that the technology of producing iron in a shaft furnace was in Ireland. Monganstown is also the first reported use of the slag pit shaft furnace in Ireland. A type that was in regular use on the European continent, but of which there is a lack reported evidence of use in Ireland and Britain. In total 61kg of industrial residues were recovered from a number of pits and furnace bases during the archaeological excavation. The industrial residues consisted of material associated with iron working: Bloomery/Furnace Slag, 27.5kg of a fluid slag, an iron smithing PCB, amorphous slag and pieces of vitrified furnace lining. The furnace lining fragments were of size that it was possible to determine the internal diameter of one shaft furnace located on the site, which was 0.3m. It is suggested the recovered material is primarily the residues of iron smelting with a small amount of associated iron smithing. Chemical analysis undertaken by Dr Marcos Martinón-Torres from University College London con-firmed that the slag from C.4 and C.47 had slowly cooled, indicated by the shape of the fayalite crys-tals and small quantities of wűstite dendrites, which are consistent with slag that solidified relatively slowly within or below the furnace. Thus suggesting that this slag is the by-product of a slag pit shaft furnace. The analysis of the slag has shown that the slag is largely fayalitic, with high manganese oxide concentrations and the near absence of free iron oxide or metal, altogether point to an efficient iron smelting technology, which is contrary to the use of the bowl furnace that has been demonstrated to be highly inefficient and thought to be in continuous use in the Westmeath area.The presence of the slags from shaft furnaces and a slag pit shaft furnace along with slags from other



36

contexts associated with furnace structures will now challenge Scott’s 1991 (p.159) statement of no shaft furnaces in Early Ireland into question and this will now need to be revised.

Introduction

Excavations on the N6 at Monganstown was undertaken by John Lehane for Eachtra Archaeological Services Ltd and recovered a quantity material that was associated with metalworking and this was submitted for assessment and analysis.The majority of the material was recovered from features that have been identified as possible shaft fur-naces as well as a possible base of a slag pit shaft furnace. Other material was recovered from a number of other contexts from pits within an area around these furnaces. It is not known if any structures were present surrounding any of the possible furnaces, but stakeholes recorded during the excavation may indicate that this was the case.

Iron Working Background

When an archaeologist excavates a site that has the remains of iron production, the assemblage of finds will mainly consist of burnt ore, charcoal, slag and fired clay. The charcoal, slag and clay form integral and inseparable parts of the metallurgical process. This inevitably means that to understand the site; first it is necessary to identify and interpret the slag and burnt clay remains; and second one has to understand the basic technology of iron production that has produced the assemblage.The manufacture of an iron artefact from iron ore can be separated into three distinct processes. The smelting of the ore in a furnace, which will produce a bloom of iron as well as fayaltic slag residues; the primary smithing consolidation of the iron bloom into a billet; and finally secondary smithing - the shaping of the billet into an object. Each of these processes will produce a range of residues. Work by Brian Scott (1991) has indicated the range of material that might be found on early ironwork-ing sites in Ireland, and recent work by Peter Crew and Thilo Rehren on material from the excavations at Ráith Na Ríg, Tara, Co. Meath has highlighted the types of industrial residues that are diagnostic of both iron smithing and non-ferrous metalworking (Crew and Rehren 2002). However, aside from this recently published work, very little analytical work has been carried out on early Irish ironworking sites. Edwards (1996) notes that in past excavations in Ireland the slag was often not recorded system-atically or rarely analysed to provide additional information about the activity that produced it.Experimental and analytical work on iron production and iron working residues in Britain, particu-larly work by Peter Crew, Snowdonia National Park, at Bryn y Castell, Crawcwellt and Llwyn Du, Wales, (Crew 1986, 1989, 1990, 1991, 1998, Crew and Crew 1995) and Gerry McDonnell, Bradford University (1988), along with work in Europe by Radomír Pleiner (Pleiner 2000), has clearly shown the nature of the archaeological evidence for iron production and for secondary smithing, and ar-chaeologists can now identify the range of metalworking activity on sites in Ireland and Britain more confidently.



37

The Ironworking Process

The base material for making iron is ore. Any iron ore needs to have a sufficient concentration of iron minerals for conversion to metallic iron, but the reducibility and availability of ore will influence the willingness to use lower-grade ores. Therefore it is reasonable to accept that mineral composition, both of the iron mineral, the location and availability of ores had the most influence over the production of iron.The commonest iron ores in a geological sense are hematites, limonates and carbonates. The largest concentration of these iron ores in Ireland is in County Wicklow (Scott 1991, 153-154). However, one of the major sources of iron ore and the most likely to have been used for iron smelting in Ireland, was bog ore. A relatively easy ore to extract once it had been located. In theory there are plenty of sources of bog ore around Ireland, but this aspect has not been studied but is often cited. An analysis of the iron working slags recovered from the rath at Mullaghbane, Co Tyrone (Harper 1972) and the ringfort at Cush, Co Limerick (O’Riordain 1940) showed that bog ore was used on these sites for the manufacture of iron. Before it was smelted, it was necessary for the mineral ore to be broken into smaller fragments and roasted to drive off excess water and also to change the ore to an iron oxide. On most sites, the roast-ing of the ore would have taken place in a simple bonfire on to which was heaped the iron ore and a bonfire erected around it. This may have taken place close to the furnace, but equally may have taken place near to the ore source.Ore and fuel, usually charcoal, are fired in a furnace in a reducing atmosphere to remove unwanted material (the slag) and produce raw iron. The furnaces were either a shaft furnace or a bowl furnace. The air-supply for the burning fuel is provided by forcing the air through blowing holes in the sides of the furnace with use of bellows, or by natural draught as has been proposed for the Medieval furnaces at Stanley Grange, Derbyshire (Challis 2002). Shaft furnaces could have been up to 1.5m tall and some 0.30m in diameter and were built with clay. Considerable quantities of clay would have been used in the construction of furnaces and it could have been an important aspect in the location of a site. It is the large quantity of the vitrified remains of the furnace superstructure that helps to identify the remains of a shaft furnace. At the base of the majority of the shaft furnaces was a small arch that enabled the slag to be removed. The efficiency of the shaft furnace improved in Britain with the arrival of the Romans, who went on to industrialise iron producing areas like the Weald (Cleere and Crossley 1986), using efficient large furnaces similar to the one found at Laxton (Jackson and Tylecote 1988 and Crew 1998a). For exam-ple, the known Roman sites in the Weald produced tens of thousands cubic metres of slag and tonnes of iron (Cleere and Crossley 1986).The Post Roman period in Britain has produced no evidence to suggest great centres of smelting com-parable with the Roman occupation (Cleere and Crossley 1986, 87). The evidence that can be gathered suggests that the Roman metallurgical techniques for smelting iron were not passed onto the native population of Britain (Tylecote 1986, 179). Instead the evidence suggests that the native population returned to a pre-Roman Iron Age tradition of producing iron probably with smaller shaft furnaces. The two possible explanations Tylecote (1986) give for this are that the old techniques were reintro-



38

duced by the migration of peoples from north east Europe and more likely- the economic conditions did not warrant the same large scale production as the Roman period did. The main notable develop-ment, however, in the Medieval period in terms of iron production, comes later with the introduction of waterpower in the fourteenth century (Cleere and Crossley 1986,106).The shaft furnace was loaded from the top with alternate layers of iron ore and charcoal. Molten slag was drawn off through an arched opening at the bottom and ran away in channels in which it solidi-fied as a tapped slag. The arched opening allowed air to be drawn into the shaft but bellows could also be used. Shaft furnaces achieved a higher temperature, so increasing the carbon content of the iron and also could produce larger amounts of iron. In Europe, particularly in Poland and Sweden, the shaft furnace was often not tapped and a pit was dug beneath the shaft to collect the fluid slag as it became molten and dropped down the shaft. These furnaces are known as slag pit furnaces. The pit was usually lined with wood and brush to support the charge of the furnace, as the slag became molten, it flowed down and burnt away the material and dropped into the pit. As the slag flowed and dropped it created flow like slags, similar to the flowed tapped slags. When the pit beneath shaft had filled up the, the furnace was moved to a new location and a new pit dug and the process started again.During smelting the iron minerals are reduced and broken up by reaction with the burning charcoal. The unwanted minerals and elements, of which silicon is the most important, react with part of the iron oxides from the ore and with the clay and fuel ash form a liquid slag that falls to the bottom of the furnace. The clay used in construction of the furnace and possible air-pipes is subjected to the high furnace temperatures as well. If sufficiently heated it may melt, resulting in vitrified clay, or is even dissolved into the slag.The final product of smelting, besides the residues of ash and slag, is called a bloom. This is a rough, often spongy mass, containing metallic iron flakes and nodules that have sintered together, mixed with bits of slag, partially reduced ore, charcoal and parts of the furnace clay. The bloom gives the early production technology its name of “the bloomery process”.The bloom has then to be refined. This is done by hammering the bloom into a smaller piece, consoli-dating the iron particles and this is part of the primary smithing process.Primary smithing requires that the iron bloom is heated again until red-hot and soft, and subsequently hammered to squeeze out remaining slag and consolidate the fragment into a workable shape. This piece of iron, called a billet, can then be worked on again and made into an artefact. The slag that is squeezed out during the primary smithing of the bloom will end up in the bottom of the hearth, and it differs from smelting slag in that it is more or less magnetic and less fluid. These slags forming just above the bottom of the hearth are very characteristic and are often described as smithing hearth cakes or more frequently as Plano Convex Bottoms (PCB’s). These slags are sub-circular convex-con-vex shaped and usually magnetic. The smithing process hardly changed from the Prehistoric period through to the Medieval period, leaving similar residues. The smithing of the bloom can be done anywhere. Quite often this primary smithing was carried out on the smelting site. The bloom is heated in a hearth or forge. The hearth doesn’t need a purpose built structure but would require a shelter from the elements for the smith and also so as to provide low



39

light for the smith to be able to judge the temperature of iron. Early ironworking hearths were situated at ground level, while some Roman, and later, Medieval, hearths were positioned at waist height. The anvils, positioned close to the hearth, to strike the red hot bloom quite often utilised a large flat-topped stone or a large wooden block. The hammering of the metal bloom produces further waste products; slag spheres, solid balls or ve-sicular balls of slag that can fly for a considerable distance; hammer scale, small flat and thin pieces of magnetic metal. Hammer scale is usually a prime indicator of smithing and can be used to locate where the process was taking place. However hammer scale can also be produced during the consoli-dation of the bloom,If a large amount of smithing has taken place, the residues from this process can become trampled in to the floor around smithing area and form a cemented smithing pan. The pan is a conglomerate of highly magnetic material, dust, hammer scale, slag spheres and some other non-related material.Secondary smithing is the process that turns a refined billet into an artefact or implement and is carried out in the same way as the primary smithing and leaves the same sort of residues described above. This is the sort of small-scale smithing work is the sort of work that would be expected to be undertaken within the small nucleated farmsteads and enclosures. It has been suggested that many people were using basic iron technology to make and repair simple artefacts (secondary smithing), but the actual production of iron and manufacture of complex iron artefacts were still being produced by specialised smiths (Mytum 1992). Documentary evidence from the Irish Annals suggests that the blacksmith was held in high esteem and that the forge was a central part of the community (Scott 1987, Edwards 1996, 86).

Assessment

All of the material was washed and cleaned by the author and visually examined by eye in 2005 (Fair-burn 2005d). The slags were weighed and were assessed on a typological appearance, which has been outlined by the work of Bachmann (1982), Crew (2002) and English Heritage (2001). Where surfaces had been fractured and a clean break could be observed, these were examined by using an x30 hand lense and then additionally examined under a microscope with x70 and x400 objective lense. The slags could not be cut open for examination, as there was not a licence to alter issued by the National Museum of Ireland.The material was considered to be very interesting, as it appeared to have come from a shaft furnace with an Early Iron Age date. Further analysis was needed to obtain an understanding of the composi-tion and construction of the slags as very little analysis of these early slags has been undertaken within Ireland. It was also needed to provide a useful comparison with other material that has been excavated in the area and analysed. It is understood, that some analysis of excavated material recovered along the route of the nearby N4 at Kinnegad, has been undertaken, with results as yet un-published. The results of this analysis from Kinnegad suggested that the material was all the result of smelting in a bowl furnace (Photos-Jones 2003).



40

Results

Quantification of the industrial residues from the excavations at Monganstown.

Context Sample Type Qty Total No WeightF47 21 Furnace slag 7 1960F39 21 Furnace lining 5 705F39 11 Tap slag 33 1808F39 11 Slag unreduced 3 204F39 11 Amorphous 17 1334F39 4 Furnace slag 3 660F39 4 Amorphous 9 424F51 1 Furnace lining 1 108F51 1 Tap slag 5 106F51 1 Amorphous 13 112F13 17 Furnace slag 1 505F13 17 Amorphous 2 24F13 17 Tap slag 1 20F39 19 Furnace slag 2 130F39 19 Amorphous 22 116C71 23 Amorphous 25 176F68 10 Furnace slag 3 565F68 10 Amorphous 7 250F68 10 Tap slag 3 140C56 12 Amorphous 3 46F38 18 Tap slag 16 394C55 10 Tap slag 4 320C55 10 Amorphous 16 70F58 24 Amorphous 3 30F42 7 Tap slag 13 154F42 7 Amorphous 2 22F1 1 Fluid slag 6 104F1 1 Amorphous 21 302F46 8 Furnace slag 3 1210F46 8 Amorphous 12 174F46 8 Fluid slag 8 418F59 25 Amorphous 32 118F59 25 Tap slag 4 46C53 Furnace slag 2 60C53 Amorphous 6 58C53 Tap slag 2 148F38 3 Furnace Lining 1 68F38 3 Tap slag 13 1880F61 12 Amorphous 4 106F61 12 Tap slag 9 2402F61 12 Furnace Lining 7 3136F38 31 Furnace Lining 4 3355F41 6 Furnace Lining 1 3500F41 6 Furnace Lining 6 560F41 6 Tap slag 10 414Loose Tap slag 24 4705Loose Ore 1 30C44 11 Tap slag 20 1030C44 11 Furnace Lining 1 100C44 11 Furnace slag 1 1885



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Context Sample Type Qty Total No WeightF4 5 Amorphous 9 1175F62 9 Tap slag 44 2352F62 9 Slag cake pcb 1 464Loose Tap slag 55 2950Loose Furnace Lining 1 50Loose Amorphous 2 72Loose Amorphous 1 28F65 15 Tap slag 2 116F65 15 Furnace Lining 33 3290F4 Furnace Lining 4 696F4 Amorphous 3 154A002 17 Furnace Lining 1 274F75 14 Tap slag 58 1742F75 14 Furnace Lining 1 102F75 14 Amorphous 3 236F22 1 Tap slag 18 2865F22 1 Furnace Lining 4 118F22 1 Amorphous 33 1330F1 2 Fluid slag 35 3345F1 2 Furnace Lining 2 585F1 2 Amorphous 18 545F1 2 Furnace slag 4 2650Total 416 61331

Amorphous slag

As with most assemblages there is a quantity of material that is difficult to classify and is termed ‘amor-phous’. Amorphous slags do not have any distinguishing characteristics and are amorphous in shape and are often small. They could be from either the smelting or the smithing process. In this case all of the material was recovered from a furnace and therefore can be considered to be part of the smelting process. A small number of these slags had calcite in their matrix suggesting that a limestone flux or gypsum flux had either been used when the iron was smelted. This is similar to the material that was recovered from the excavations at Castledermot by Eachtra - Licence 04E0750 (Fairburn 2005c). The flux will make the slags more fluid and allow the separation of the metal from the waste to be more efficient, hence the low ratio of iron oxide (FeO) in the slags and a raised silica content (SiO2).

Fluid slag

This slag was recovered from a furnace feature C.47 and pit C.2 and probably represents the last use of a slag pit shaft furnace. This type of slag is typical of a slag that would be found in the base of furnace that is using a pit beneath it to drain of this waste material. A number of the pieces of the Monganstown slag had wood impressions, suggesting that the slag had formed around pieces of wood. This would be similar to examples from Sweden and Iron Age examples from the Weald in Britain. It is thought that the wood was criss crossed at the base of the furnace, over a pit, and stopped the slag from forming a large lump in the furnace. The wood, while it was intact, provided a riddling affect and allowed the slag to run through. Some larger pieces of the slag show how the slag has run down the inside of the furnace and down



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into the slag pit and then it has flowed flat, creating an L shaped pieces of slag, which are sometimes referred to as “elephants feet”. This clearly demonstrates that the slag was very viscous and flowed eas-ily, perhaps facilitated by the criss crossed wood.

Tap slag

Characteristic finds from iron smelting sites dating from late prehistoric times up until the 15th Cen-tury are pieces of slag with flat rounded or distorted bottoms and contorted upper surfaces with flow patterns. These are known as tap slags. The molten slag was drawn off through an arched opening at the bottom of a shaft furnace and ran away in channels in which it solidified. Tap slag has a character-istic ropey shape resembling a flow of lava. This type of slag represented the largest quantity of material recovered from the Monganstown exca-vations. This slag was recovered from the furnace features possibly represents the last use of a furnace as the material was not removed from it. The slag is normally removed and discarded and the furnace repaired ready for the next smelt.

Furnace Slag or Bloomery Slag

The bloomery slag is usually represented by the largest amount of material recovered by weight, which is not surprising as these slags are usually large and heavy. The quantity of these slags produced from the furnace is dependant on the quality of the ore (Crew 1991). The bloomery slag from the furnace was typical of material described by Tylecote (1986) containing partially reduced ore and charcoal. Some of the slag exhibited could be considered as viscous with very small runs, suggesting that the slag may have been raked out during the tapping process.

Smithing Hearth PCB

Smithing PCB’s or Plano Convex Bottoms (PCB’s) are diagnostic of the smithing process. The smith-ing process produces as well as hammer scale and small slag spheres, residues that consolidate in the bottom of the hearth as PCB’s as fayaltic slag lumps. These fayalitic slags are similar in composition to furnace slags but are distinguishable by their shape, a curved base and a level contorted surface. Their production is still poorly understood but the process that produces them is well documented. The Monganstown PCB is a small thin plate of slag and represents material that has accumulated in a very very short time period within the smithing hearth.

Vitrified Clay Lining

This material consists of clay that has been vitrified on one side in the high temperature area of the furnace or the smithing hearth. Vitrified lining is produced by a high temperature reaction between the clay lining and the alkaline fuel ashes or slag.It can be difficult to identify if pieces of vitrified clay come from a furnace or a hearth structure. Smelt-ing sites usually produce significantly larger quantities than smithing sites, because of the difference in the size of the structures.



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The lining has probably been made from the local clay and has oxidised to an orangey red colour. Where one face of this lining has been exposed to high temperatures, it has started to vitrify to a slightly vesicular vitreous material with a black colour. Vitrified surfaces on furnace lining can vary in colour from black through to olive green, which in turn reflects the temperature conditions and the make up of the silica content in the clay.A number of the Monganstown furnace lining pieces were very large weighing over 3kg and are part of a shaft furnace superstructure. The curve of the shaft furnace can be seen in three of the pieces and the internal diameter of the shaft can be ascertained – 0.3m. One piece of furnace lining has clearing come from the base as it has a large amount slag adhering to it.

Hammer Scale

Magnetic bluish-grey flakes of iron oxides formed on the surface of iron when heated for smithing. Primary and secondary smithing produces hammer scale when a hot iron object is struck. It is usually found in the area where the smithing was carried out. Hammer scale was noticed amongst the debris and dust accompanying the collection of slags.

Spheroidal Hammer Scale

Spheroidal hammer scales consist of round droplets, which can be hollow to varying degrees and are mainly formed during the primary smithing of an iron bloom. The small droplets, some of which, but not all, are magnetic are expelled from the bloom when the hot bloom is struck during the consolida-tion process. They can also be formed by the welding process of two iron objects.The Spheroids recovered from the excavation vary in size from 2mm to 9mm and there are also some fragments of expunged slag, which have not formed spheroids. The location of the material would be indicative of the area in which the smithing of the bloom took place. Spheroiadal hammer scale was noticed amongst the debris and dust accompanying the collection of slags.

Analysis

Three samples of the slag were sent to Dr Marcos Martinón-Torres from University College London for bulk chemical analysis. Two samples were taken from Context C.4 and one from C.46 The aim of this analysis was to obtain a chemical breakdown of the slag to understand the process by which it had been formed. It was also hoped to use the analysis to compare with the work undertaken on mate-rial recovered from Kinnegad in 2003. The detailed report of the analysis is presented as Appendix 7 (excavation report appendix).The analysis of the slag showed that the slags were fayalitic, had cooled slowly and had a high Iron Oxide (FeO) content with moderate amounts of manganese and alumina. This would suggest that slag was from a fairly efficient furnace, as the iron content was not high, and that a non-slag tapping shaft furnace must have been used to account for the slow cooling of these slags. The analysis also showed that the slags had high Strontium (Sr) and Bromine (Br) and this provides a useful geological indicator of the ore used, which was a source of bog ore. The manganese content has probably come from the ore, (bog ore) and has assisted the ore separation process.



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Discussion

The only certain indications for an iron smelting site are primarily the presence of ores and tap slags and also the presence of pieces of the furnace superstructure. Without either of the two reliable indi-cators, a site should be considered to be an iron smithing site. Slag is not datable in itself, but it is an important indicator of the site activities. At Monganstown only a relatively small amount of slag was recovered from the features on the site as well as the truncated remains of furnaces. The majority of the slag was a mixture of tap slag furnace slag and fluid slag and can only have come from slag tapping shaft furnaces and also from at least one non slag tapping shaft furnace with slag pit beneath it and not from bowl furnaces as is so often erro-neously described. A small number of significant parts of the furnace superstructure and one piece of ore were recovered at Monganstown, and indicates that iron smelting was taking place and that shaft furnaces were being used for this.We do know that at least a small amount of iron smithing has taken place as a small PCB was recov-ered from close to the furnace. The smithing was probably connected with the primary smithing of the bloom from the furnace.The small quantity of material found at Monganstown would not be indicative of large scale produc-tion associated with trading, as there are insufficient quantities of slag. However it is possible that further deposits of slag and iron working features lie in the area beyond the excavation. The slag was recovered from the now truncated bases of the furnaces and this may suggest that the furnaces were not used again, which is typical of a slag pit furnace, but not of slag tapping shaft fur-nace. The truncated base is usually all that remains of the shaft furnace and is in effect just a bowl or hole in the ground. The remains of this feature demonstrate how the erroneous bowl furnace myth still persists, as the feature with its distinctive slag potentially is not recognised for what it is or as-sessed. It is therefore perceived as a bowl in the ground with slag and therefore must be a bowl furnace. However, in this case, a large quantity of the furnace superstructure was also recovered along with a reasonable quantity of fluid tap slag from the features and this clearly shows that shaft furnaces were being used.Experimental work by Crew and others has shown how difficult it actually is, even today, to produce iron using the same techniques utilising our own modern knowledge and technology. In fact, so far, no experiment in iron production has actually reproduced material from the slags to a bloom that is comparable to any material recovered from a prehistoric iron smelting site. Peter Crew took 27 experi-mental smelts before he produced something that could be considered to be the bloom of iron. To get to that stage a lot of manpower, a lot of charcoal and a lot of ore was used. Therefore it can be deduced that if modern technology and knowledge cannot easily produce the iron it must have been very hard in the prehistoric period.Analysis of iron working slags recovered from excavations of a number of sites by ACS Ltd on the N4 at Kinnegad, showed that the ore was not being smelted properly and that these smelts would have probably produced poor quality, if any, iron at all. The excavations and the subsequent analysis of the slags from Kinnegad II reported that the iron smelting on these sites had been undertaken in bowl fur-



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naces Photos-Jones 2003). These so-called bowl furnaces are now known from experimental work to be highly inefficient and produce very limited quantities of workable iron. Radiocarbon dates from the Kinnegad II site gave dates of around 810-420 Cal BC. However, two later dates were also obtained of 420-360 and 370-50 Cal BC (Photos-Jones 2003 and Murphy 2004), which are broadly similar in date to the Monganstown site. It should also be noted that Photos-Jones reported that slags from later Medieval sites from excavations on the N4 were also considered to have been smelted in bowl furnaces, and on this basis it was sug-gested that bowl furnace had not been replaced by shaft furnace by iron workers in Ireland, therefore it was still in use the Medieval period. This view is discussed further later in the report. The material from the Kinnegad II excavations supported by the radio carbon dates suggests that iron working, possibly in bowl furnaces, was being undertaken in Ireland during the transitional period between the Bronze Age and the Iron Age - the early beginnings of the Iron Age. This was also thought to be the case in Britain, but there are now no documented sites for the bowl furnace iron smelting work, as the two examples Kes Tor and Chelmes Combe, which are often quoted as early bowl furnace sites, have been recently re-examined and are not iron smelting sites nor are they Iron Age (Pers Comm Peter Crew). Scott quotes numerous examples in Ireland (1991, 159), but these should perhaps all now be reassessed in a similar way to the British examples. Scott in 1991 suggested that only the sites at Dressogagh, Co Amargh (Collins 1966) Ballyvourney and Garryduff, Co.Cork (O’Kelly 1952 and 1962), excavated prior to 1970 could be considered to be iron smelting sites. However, none of these early excavated site or sites excavated afterwards between 1970 and 1988 have been dated to the Iron Age and all were considered to be using the bowl furnace, hence Scott’s quote “All of the archaeologi-cal evidence to date indicates that during the period under review, iron was smelted in Ireland only in what has been called the bowl furnace.”It is not clear how the iron smelting technology evolved. As the technology of iron smelting was ad-vancing in the Bronze Age/Iron Age transitional period, it is possible that the use of the bowl hearth/bowl furnace was employed, perhaps on the Kinnegad sites, but was found very early on to be inef-ficient (as we now know) and was gradually replaced with the shaft furnace. This advance can now, at long last, be clearly seen in Ireland within the excavation of the site at Monganstown and also at Lisnagar Demesne 1 (Fairburn 2006).Lisnagar Demesne 1, Co. Cork (licence 03E01510) was excavated by Deirdre Murphy of ACS Ltd dur-ing the construction of the Fermoy Bypass. Excavation uncovered a metalworking area with evidence for a slag tapping shaft furnace. A radiocarbon date of 390-50 Cal BC was obtained from suitable material that was mixed in with the slag, which had been recovered from the furnace feature, which also provides an Early Iron Age date for the use of the shaft furnace in Ireland (Ibid). To summarise at this point of the report, the material recovered from the furnace at Monganstown, indicates that iron smelting was taking place, using slag tapping shaft furnaces and non-slag tapping slag pit furnaces. In addition a small iron smithing PCB was also recovered and this would suggest that the iron bloom from the smelting process was probably consolidated on site.



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Kinnegad II and Monganstown

The N4 Kinnegad II excavations and the nearby N6 Monganstown excavations suggest a clear line of technological change. The reason for this is not clear and this is not reflected in the radiocarbon dates, as the activities at both sites are broadly similar in time. However the chemical analysis from both sites shows indicates two different activities. Monganstown is efficient with a low iron content within the slags and Kinnegad II with an inefficient high iron content within the slags. It has been suggested that Kinnegad II was using a bowl furnace, a known and highly inefficient process to produce iron while the excavation evidence and analysis shows that the efficient shaft furnace was being used a short distance away at Monganstown.The excavations on the N4 and now on the N6 also suggest that a large amount of iron working was being undertaken in the Irish Midlands of West Meath. This may be due to the presence of suitable bog ores in the area, perhaps from the Bog of Cullen. Analysis from Kinnegad II and now from Mon-ganstown supports the use of bog ore as the ore source for the smelting of the iron. The ore is rich in manganese and should therefore be relatively easy to smelt. The source of charcoal for the furnaces may additionally indicate that there was abundance of wood, shown to be oak and this may have been managed and coppiced. Oak has been shown from numerous excavations in Ireland and Britain to be the usual main choice of charcoal for smelting.

Monganstown and Ironworking in Ireland

The ironworking debris material recovered from Monganstown was not large and it is impossible to say on how many occasions iron smelting has taken place. Experimental work has shown that the iron smelting process, to produce a bloom, followed by its smithing, would be expected to produce a lot more slag waste, with at least 7kg of slag waste per episode from a small shaft furnace (Crew 1991). As only 3.5kg of material was recovered from the excavation it probably is only representative of a small number of smelts.The low quantity of material from Monganstown could suggest that the other material is still wait-ing to be found outside of the excavation area, possibly in the area outside of the road take. However, the low quantity of slags and lack of other furnaces and hearths, might suggest that there is no more material to be found. The size of the small PCB recovered from a nearby pit is the only indication of primary smithing and is probably only from one episode of smithing work. This may suggest that the blooms were smithed elsewhere and support the view that other material is outside of the excavation area.However, early shaft furnaces and even later Roman furnaces from Britain are now known to have been inherently inefficient, as also was the material produced in bowl furnaces in Ireland. The slag from these early iron working sites still remained rich in iron and this was often plundered for re-smelt-ing during the 18th and 19th centuries. It was also used in road building and sometimes in agriculture even for manuring to aid soil drainage.The amount of slag on a site can provide information about the metal working processes that took place. The 7th –8th century ringfort at Lisleagh, Co. Cork produced over 800 kg of slag (Scott 1991, 158). Later Roman and Medieval sites in Britain can have upwards from one tonne to hundreds of



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tonnes of slag. Many of these later slag heaps were huge and may once have been larger still. Therefore as stated above, 61kg from Monganstown is not a large quantity of slagSmelting sites are usually located close to the resources that are required to produce the metal. Any ironworking site should be close to the ore source, wood for the charcoal and clay for the furnace lining, as transporting the raw materials from one place to another would have been a waste of time and effort. Peter Crew has made an approximate calculation that to produce 1kg of iron with a shaft furnace; ancient smelters would have needed some 15kg of ore, 100kg of charcoal and this would have taken 25 man days work (Crew 1991). In comparison, Tylecote’s experiments with a bowl furnace, undertaken in laboratory conditions, which bear no relation to actual field conditions, estimated that it would require 5-7kg or ore and 60kg of charcoal, but did not quantify the required man-days work (Tylecote 1986, 133). These experiments are discussed further later in the next section of the report.

Bowl Furnace or Shaft Furnace

A large number of smelting furnaces have been identified in Ireland and Britain, mostly in Britain, and are of the shaft type with provision for slag tapping. In Ireland the only smelting furnace identified has until recently, according to excavation reports and the Excavation Bulletins, been the bowl furnace. As Scott wrote in 1991, “the principle difficulty in interpreting ironworking structures on Irish sites is the probability that hemispherical holes in the ground showing evidence of intense heat is as likely to have resulted from smithing as from smelting or even a combination of both”. Unfortunately this is still the case twelve years on, with very few ironworking sites in Ireland studied in any depth and disseminated through publication. Therefore, it is difficult to find comparable sites from published sources on work in Ireland with the exception of the influential work by Scott (1991). Ironworking residues seem to be dismissed by field archaeologists as assuming Scott’s conclusion ‘its iron working slag and must be from a bowl furnace’ as definitive. A bowl furnace has been described by Scott and Tylecote (Scott 1991 and Tylecote 1986) as a furnace consisting of an open or possibly covered bowl-shaped depression in the ground, which may or may not be lined with a clay ceramic or a layer of refractory stones. Bowl furnaces are currently, through the work of Scott, thought to be the only type of furnace that was used in Ireland from the Iron Age through to the Medieval period (Scott 1991, Pleiner 2000). There is some debate as to whether or not the bowl furnace could function properly to produce a large quantity of iron for a sizable iron bloom. The iron blooms, which have been found so far in Ireland, such as at Carrigmurrish Cave and Broth-ers’ Cave in Co. Waterford (Scott 1991, 162), are too big to have come from a bowl furnace, probably indicating that larger furnaces of the shaft type were used. Tylecote’s experiments have shown that bowl furnaces had similar charges of ore and charcoal like the shaft furnace, but these were placed vertically on the side of the furnace, opposite the tuyère-blowing hole. The slag then ran downwards and consolidated into a disc like lump of slag (furnace bottom) or even formed on the side of the hearth below the tuyère. The iron bloom then formed on top of the slag. The conglomerate of slag and iron was removed by lifting it from the top. Tylecote showed that it would then have been necessary to break this conglomerate up to separate the iron from the slag and



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then it was reheated to form a small bloom.Characteristic finds from shaft-furnace sites are large pieces of furnace lining and pieces of slag that have solidified in the channels with rounded bottoms and a contorted upper surface with flow patterns. These are known as tap slags. It is the absence of these tap slags and large quantities of clay furnace structural evidence from sites in Ireland, which has led to Scott (1991) and Pleiner (2000) to suggest that the shaft furnace was not used in Ireland during the Irish Iron Age and the Medieval period. Scott suggests that the lack of innovative technology was blocked by socio-political developments and subsequently poor communication between craftsmen in Ireland and with Britain (1991, 213-214). Excavations on Irish sites have turned up a number of the so-called curved furnace bottoms, which are believed to have come from the bases of bowl furnaces. It is more likely that these furnace bottoms are in fact smithing hearth plano-convex bottoms (PCB’s) that the sites were actually iron smithing rather than smelting sites and the ‘bowl furnaces’ were in fact smithing hearths. This would at least explain the lack of tap slag and furnace lining material. However, the material from these sites needs to be re-examined with the benefit of the recent work by Crew and McDonnell before this can be confirmed.The bowl furnaces from Early and later Irish sites where smelting has been confirmed, are probably but not exclusively the remains of low shaft furnaces. This can now be demonstrated from the Mon-ganstown and Lisnagar Demesne 1 excavations. Tylecote’s experiments with bowl furnaces found that they were much more successful if the bowl was actually enclosed with a dome or a low shaft. This type of furnace would have allowed the bowl to have a large diameter and the shaft or dome would have produced the necessary reducing conditions to smelt a reasonable quantity of iron. The slag from this furnace is unlikely to have been tapped, and the bloom would have had to be brought out through the top of the structure or the structure was broken open to obtain the bloom. If the structure had been broken it might explain the lack of lining structure around the feature, as this material would have been more widely dispersed rather than concentrated in one area after the furnace had been aban-doned. However, the bowl furnace would not produce a tapped slag or a significant fluid slag.Bowl furnaces associated with iron smelting were identified by O’Kelly at the ringfort of Garryduff 1 and at Ballyvourney Co, Cork, The furnaces on these two sites were reported as small pits, lined with clay into which the charcoal and iron ore would be placed. The slag it was also reported was not tapped but had formed in the bottom of the furnace, while the iron had been left to form a bloom (O’Kelly 1952 and 1962). Evidence of iron smelting during the Early Medieval period is known from other sites besides Bally-vourney and Garryduff 1. These include Garranes, Co. Cork (O’Riordain and Hartnett 1943), Laith-more, Co.Tipperary (Tylecote 1986, 188), Lagore Crannog, (Hencken 1950) Clogher (Scott 1983), the ecclesiastical centre on Church Island, Co Kerry (O’Kelly 1958). None of the material from any of the sites above has been re-examined in the light of the recent work and new discoveries in the past 15 years.Examination of iron working material from recent excavations along the route of the M4 motorway between Kilcock, Co Meath and Kinnegad, Co. West Meath by ACS Ltd has suggested that the ma-jority of the recovered material was from the smelting of iron in bowl furnaces, with the excavated sites and material dating between the Iron Age and the Medieval period (Photos Jones 2003).



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More recently, excavation work in County Kerry by Eachtra has uncovered definite evidence of the use of a shaft furnace for the production of iron in Ireland at Ballydowney and Farrananstack (Fairburn 2003a and Fairburn 2003b). Work by ACS Ltd at Cappakeel during work on the Monasterevin Bypass and at Newtown 1 on the Mullingar Bypass also has undated evidence for slag tapping shaft furnaces (Fairburn 2004 and 2005). Excavation work by ACS ltd at Corrin 1 and Lisnagar Demesne 1 on the N8 Fermoy Bypass (Fairburn 2005a and 2005b) has also recovered slag that can only have come from a slag tapping shaft furnace. The evidence from these sites and also now from Monganstown combined with the large blooms from Carrigmurrish Cave and Brothers’ Cave in Co. Waterford appears to con-tradict Scott’s 1991 statement of that there were no shaft furnaces in Early Ireland into question and therefore this statement will now need to be revised.It does seem bizarre that the innovative technology of the shaft furnace was being employed a short distance away across the Irish Sea in West Wales, and yet with clear evidence of trade and raiding between Ireland and Britain, particularly Wales, during the Iron Age through to the Early Medieval period, that this efficient method of iron production was not brought to the Irish Blacksmith and utilised. The later arrival of the Hiberno Norse with their metallurgical traditions should also have brought this technological advance on the bowl furnace to the Irish shores, likewise with the Anglo – Normans. Yet the myth persists that only the bowl furnace was employed in Ireland and this is seen in nearly all of the reports that appear in the Irish Excavation Bulletins. Radio carbon dates from excavations on the N4 Kinnegad and analysis of the recovered material has appeared to support the view of Scott (Photos Jones 2003). However, the evidence of the use of the shaft furnace from the analysis of material from other excavated sites and also now from Mongan-stown, combined with the obvious trade and technology links with Britain and the Hiberno Norse, shows that Scott’s statement can no longer be fully supported and needs to be revised. As more sites are excavated and more material analysed, this view should eventually change to one where it is accepted that the shaft furnace was used for the production of iron from the Iron Age through to the Medieval period. Monganstown joins the small but growing list of sites in Ireland where it can be shown that the shaft furnace was in use in Early Iron Age Ireland. Additional sites will eventually be recognised as more excavated industrial residues are studied and excavators become more familiar with the products of iron working technology.

Conclusion

The excavations at Monganstown have produced a small amount of industrial residues from the iron working smelting and iron smithing process. The largest amount material recovered from the excava-tion was tap slag. This type of fluid slag can only have been produced in a shaft furnace and not a bowl furnace. This material has provided further evidence, to substantiate the use of the shaft furnace in the production of iron in Ireland in the Early Iron Age. The material from the excavated furnace has shown that early iron working in Ireland made use of the same technology to produce iron, namely the shaft furnace, to that used in Britain and Europe and that the country was not solely reliant on the inefficient bowl furnace as previously thought.



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It is clear that this site will eventually make a major contribution to our understanding of the cultural sequence of the metalworking in the region and in the country. The well stratified nature of the de-posits and, indeed, the presence of directly datable residues with the ironworking slag will allow this assemblage to be used by researchers in the future in a much more meaningful way than has previously been possible.

Recommendations

Further follow up work at Monganstown would be useful in attempting to pinpoint the extent of the metalworking site, if there is one, and to look for the characteristic dump of waste slag. This ideally should be done with a combination of non-invasive geophysics augmented with trial trenching. Work by Peter Crew et al has shown the benefits of using geophysics to pinpoint metalworking sites and also to obtain archaeomagnetic dates from them (Crew 2002 and Crew, Smekalova and Bevan 2002).

Acknowledgements

Thanks to Peter Crew for discussions on Irish iron working and metalworking in general.Thanks to Dr Marcos Martinon-Torres from UCL for undertaking the chemical analysis.Thanks to all the staff at Eachtra Ltd for their help in dealing with my numerous questions, particu-larly Jacinta Kiely. A special thanks is also due to Jacinta Kiely and John Tierney at Eachtra Ltd for their patience and continued support for the assessment and analysis of metalworking residues. Slag really is interesting and it can tell you so much about a site.



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Edwards, N. 1996, The Archaeology of Early Medieval Ireland, London.

English Heritage, 2001, Guidelines for Archaeo-Mettalurgy.

Fairburn, N. 2003a, Assessment of the Metalurgical Residues from the archaeological investigations at Ballydowney, County Kerry, Unpublished report for Eachtra Archaeological Services.

Fairburn, N. 2003b, The Evidence is Out There: Metallurgical Residues from Farrananstack, Co. Kerry, Unpublished report for Eachtra Archaeological Services.

Fairburn, N. 2004, Assessment of Industrial Residues from Excavations at Cappakeel 3, Unpublished report for Archaeological Consultancy Services Ltd.

Fairburn, N. 2005 Assessment of Industrial Residues from Excavations at Newtown 1, Unpublished report for Archaeological Consultancy Services Ltd.

Fairburn, N. 2005a Assessment of Industrial Residues from Excavations at Corrin 1, Unpublished report for Archaeological Consultancy Services Ltd.

Fairburn, N. 2005b Assessment of Industrial Residues from Excavations at Lisnagar Demesne 1, Unpublished report for Archaeological Consultancy Services Ltd.

Fairburn, N. 2005c Assessment of Industrial Residues from Excavations at Castle Dermot, Unpublished report for Eachtra Archaeological Services Ltd.

Fairburn, N. 2005d Assessment of Industrial Residues from Excavations at Monganstwon, Unpublished report for Eachtra Archaeological Services Ltd.

Fairburn, N. 2006, Analysis of Industrial Residue from Excavations at Lisnagar Demesne 1 Final Report, Unpublished report for Archaeological Consultancy Services Ltd.

Harper, A.E.T., 1972, The excavation of a Rath in Mullaghbane Townland, Co. Tyrone, Ulster Journal of Archaeology 35, pp.37-45.

Hencken, H.O’N. 1950, Lagore crannog: an Irish royal residence of the seventh to tenth centuries AD, Proceedings of the Royal Irish Academy 53C, pp.1-247.

Jackson, D.J. and Tylecote, R.F. 1988, two new Romano-British ironworking sites in Northamptonshire – A new type of furnace, Britannia 19, pp.275-298.

McDonnald, J.G. 1988, Ore to artefact – a study of early ironworking technology in Slater. In: E.A. and Tate, J.O. (eds) Science and Archaeology, 283-93. British Archaeological Reports, British



53

Series 196.

Murphy, D. 2003 ‘Archaeological Excavation Report for site K-E-K M4 Motorway, Contract 1, Kinnegad 2, Co. Westmeath, Licence 02E0926’. Unpublished report by Archaeological Consultancy Services Ltd.

Mytum, H. 1992, The Origins of Early Christian Ireland, Routledge, London.

O’Kelly, M.J. 1952, St Gobnet’s house, Ballyvourney, Co. Cork, Journal of the Cork Historical and Archaeological Society 57, 18-40.

O’Kelly, M.J. 1958, Church Island, near Valencia, County Kerry, Proceedings of the Royal Irish Academy 59C, pp.57-136.

O’Kelly, M.J. 1962, Two ring forts at Garryduff, Co. Cork, Proceedings of the Royal Irish Academy 63C, 17-25.

O’Riordain, S.P. 1940, Excavations at Cush, Co. Limerick, Proceedings of the Royal Irish Academy 45C, pp.83-181.

O’Riordain, S.P. and Hartnett, P.J., 1943, the excavation of Ballycatteen Fort, Co. Cork, Proceedings of the Royal Irish Academy 49C, pp. 1-43.

Photos-Jones, E. 2003, “If it works, do not fix it”: Early (and later) Iron working in Ireland along the KEK-M4 Motorway, unpublished report for ACS Ltd, Drogeheda.

Pleiner, R. 2000, Iron in Archaeology: The European Bloomery Smelters, Prague.

Roche, H. 2002, Excavations at Raith Na Rig, Tara, Co. Meath 1997, Discovery Programme Reports: 6, Royal Irish Academy/Discovery Programme, Dublin.

Scott, B.G. 1987, The Status of the Blacksmith in Early Ireland, in Scott, B.G. and Cleere, H. (Eds) The Crafts of the Ancient Blacksmith, Proceedings of the 1984 Symposium of the UISPP Comite pour la Siderurgie Ancienne, Belfast.

Scott, B.G. 1991, Early Irish ironworking, Belfast.

Tylecote, R.F. 1986, The Prehistory of Metallurgy in the British Isles, The Institute of Metals, London.



54

15.5 Appendix 5: Charred plant remains and charcoal from Monganstown 1

By Penny Johnston and Abigail Brewer

Introduction

This report describes the plant remains retrieved from a site excavated at Monganstown (A001/001). The samples were taken from features such as charcoal production pits and metalworking pits associ-ated with smelting and/or smithing. While charcoal was frequent in all the sampled deposits, other plant remains such as charred seeds were not common and only a small assemblage of remains was retrieved.

Methodology

The samples were collected on site as bulk soil and were processed using a simple flotation method. Each sample was saturated in water to allow carbonised plant material to float; this “flot” (the float-ing material) was then poured into a stack of geological sieves and trapped in the sieve meshes (the smallest measured 250µm). When all the carbonised material was collected the flot was air-dried prior to storage in airtight plastic bags. The samples were scanned under low-powered magnification and the results are presented in Tables 1 at the end of this report. Sorting and identification of the flots was carried out using a low-powered binocular microscope (magnification x10 to x40) and identified seeds were separated and stored in sealed glass phials. Nomenclature and taxonomic order follow Stace (1997), although in order to facilitate easy reading of this text the scientific names are included only in the table of identified seeds presented at the end of this report (Table 2). Separate samples were taken for charcoal analysis; these were air-dried and each charcoal piece was snapped by hand to reveal the anatomical features necessary for identification, which was carried out using a binocular microscope (magnification range up to x50). The low-level of magnification available meant that while it was pos-sible to separate different wood types from each other, it was not possible to identify non-oak species. The magnification range was, however, sufficient for the identification of oak, which made up the bulk of this assemblage. Identification was carried out with reference to the online wood identification key “Wood Anatomy”.

Results: Charred seeds

In total, twenty-one samples from the site were scanned for charred plant material and environmental remains (results are in Table 1 at the end of this report). Only six samples contained the remains of charred seeds; C.1 (S.1), C.7 (S.4), C.33 (S.16), C.44 (S.11), C.56 (S.12) and C.71 (S.23). In each of these the plant remains were present in only very small amounts; four samples contained hazel nut shell fragments, one had the remains of an indeterminate fruit stone and an indeterminate seed was also found. One fragment of hazelnut shell, a fragment of straw/stem and two indeterminate, broken seed frag-ments were recorded in C.56 and C.44, fills of a charcoal making pit. Samples from C.33 a spread of



55

midden material, C.7 the fill of a natural feature and C.71 the fill of a pit also contained fragments of hazel nut shell. Waste hazel nut shells would occasionally have been burnt with fuel as a disposal mechanism (Monk 2000, 75) and their presence at this metalworking site is probably a result of this. Similar conclusions may perhaps be drawn to explain the presence of other small pieces of charred plant material such as the fruit stone fragment. Two indeterminate seeds were recovered from C.33 and C.44. The seeds could not be identified due to damage caused by heating. A fragment of straw or stem was found in a sample from C.44. Fragments of straw and other plant stems are often found together with other by-products of crop processing such as chaff and weed seeds in archaeobotanical assemblages. Metalworking sites excavated by Eachtra Archaeological Projects at Ballydowney, Co. Kerry (02E0055), Farranstack, Co. Kerry (03E0171) and Tracy’s Hill, Co. Waterford (00E0059) have also produced few macro-plant remains, despite extensive sampling. One reason for this is probably the high tempera-tures in the furnaces which would have burnt to ash, rather than charred, any plant remains that may have been present. The infrequent plant remains that occurred at these sites include cereal grains, chaff, weed seeds and hazelnut shells. These are likely to be the result of crop processing waste and hazelnut shells being used as tinder or fuel.

Results: Charcoal identification

The charcoal from eight specially selected charcoal samples were examined, taken from charcoal pro-duction pits, furnaces and slag dumps. Two samples were taken from charcoal production pits; C.4 (Charcoal S#2) and C.13 (Charcoal S#3). The only fuel type identified from these pits was oak. Charcoal forms when it is burned in an inad-equate supply of oxygen, and oak produces good charcoal as it tends to burn more slowly than woods that are less dense such as, for example, willow. These factors ensure that oak charcoal is an ideal fuel for activities such as metalworking, where temperature control is necessary. Four samples of charcoal were taken from the lower fills of four furnace bowls; C.59 (Charcoal S#5), C.62 (Charcoal S#6), C.39 (Charcoal S#8) and C.64 (Charcoal S#9). The fuel types in three of these were also identified as oak, but in the fourth (from C.39) a diffuse porous type of wood was found. This could not be identified to species with low-powered magnification. The recovery of mostly oak charcoal fuel from the smelting/smithing pits complements the recovery of prepared oak charcoal found in the charcoal production pits nearby.Two samples were taken from slag dumps; C.4 (Charcoal S#1) and C.1 (Charcoal S#4). All of the charcoal from these samples was also identified as oak.

Conclusions

The plant remains assemblages from this site were all small in quantity and poorly preserved. Hazel nut shells and fruit stone fragments from furnaces probably represent waste used as fuel or tinder. The results of charcoal identification suggest that oak was the main raw material for fuel, in the form of charcoal, at the site. Analysis of charcoal residues in slag from Johnstown 1, Co. Meath also identi-fied oak as the predominant fuel type in use (Miller and Ramsay 2003). Some hazel was also found



56

at Johnstown 1 and it is possible that the diffuse–porous wood type identified at Monganstown was also hazel. Although this is an unusual type of wood to use as fuel in a smelting furnace it may have bee used as kindling or as wattle superstructure in the furnace; this coincides with the evidence from analysis of the Monganstown plant remains, which suggests that some domestic or agricultural resi-dues (such as waste plant remains) may have been used as fuel, including hazel nut shell and fruit stone fragments as well as some straw. This material was probably used as tinder to get the fire in the furnace going initially before the larger charcoal fragments caught fire.

References

Miller, J. and Ramsay, S. 2003 ‘Fuel analysis from metalworking slag from Johnstown 1’ in Photo-Jones, E. ‘Analysis of metallurgical waste from the M4 Kinnegad-Enfiled-Kilcock Motorway Scheme, the Johnstown 1 site’ Report by Scottish Services for Art and Archaeology for Archaeological Consultancy Services Ltd.

Monk, M. 2000 ‘Seeds and Soils of Discontent: an environmental archaeolgical contribution to the nature of the early Neolithic’, in: A. Desmond, G. Johnson, M. McCarthy, J. Sheehan and E. Shee Twohig (eds) New Agendas in Irish Prehistory, 67-87. Wordwell. Wicklow.

Stace, C. A. 1997 New Flora of the British Isles (2nd edition) Cambridge, Cambridge University Press.

“Wood Anatomy” accessed 25th January 2005 at http//:www.woodanatomy.ch



57

Table 1: Scanning record from Monganstown, Co. Westmeath (A001/001)

Context no. Sample no. Seeds Charcoal Invertebrates Modern1 1 Spore * **** Roots *5 2 **** Roots *

7 4 Corylus avellana * Spores*

**** * (modern) Roots *

9 31 *** Roots **13 17 **** Roots *16 5 ****17 28 Spores * **** Roots *25 4 Roots ****30 19 ****33 16 Spores* and indet. seed ****38 18 Corylus avellana * ** Roots **44 11 Spore*

Fruit stone fragment* Stem/straw *

****

46 20 ****53 ? Spore* **** Roots **55 10 ** Roots **56 12 Corylus avellana * **** Roots *59 25 ****62 9 **** Stem *71 23 Corylus avellana * **** Roots *75 27 ****76 28 ****

Table 2: Identified remains

Cut 8 45 45 69Context 1 7 33 44 56 71Sample 1 4 16 11 12 23Hazel nut shell frag-ments (Corylus avellana)

2 1 1 1

Indeterminate fruit stone fragment (cf Prunus spp.)

1

Stem/Straw fragment 1

Indeterminate seed 1 1



58

Table 3: Identified Charcoal from Monganstown 1, Co. Westmeath (A001/001)

Context No Charcoal Sample No.

Feature Type Identifications Comment

4 1 Slag dump in extraction pit

Oak (Quercus spp.) 2 fragments Very large pieces with growth rings close together

14 2 Charcoal produc-tion pit

Oak (Quercus spp.) 14 fragments

13 3 Charcoal produc-tion pit


1 4 Slag dump in extraction pit


59 5 Lower fill in fur-nace bowl





Diffuse porous wood charcoal; 11 fragments examined

64 9 Charcoal layer at base of furnace bowl

Oak (Quercus spp.) 6 fragments Possible oak (cf Quercus spp.) 2 fragments

Bark frequent



59

15.6 Appendix 6: Analysis of charcoal assemblages from Monganstown 1

By Mary Dillon

Introduction

This report details the results of charcoal analysis from archaeological excavations carried out at Mon-ganstown 1, approximately 2 km west of Kinnegad in Westmeath in the townland of Monganstown. The excavation was located 150 m north of, and in the flood plain of, the Kinnegad River, which forms the county boundary between Westmeath and Meath. It is on a slightly raised ridge in a level boggy field at the eastern end of the new section of road.Six furnaces and two charcoal production pits indicate that the site had an industrial/metallurgical role. Several other pits were excavated, and had been used for the disposal of slag, although they may have originally had a different function. Two of the furnaces were dated to the early to mid Iron Age, while the two charcoal production pits dated to between the late 9th to 11th century

Methodology

Bulk soil samples were collected on site and were processed post-excavation using a simple flotation method. Each sample was saturated in water to allow the carbonised plant material to float, which was then poured off into a series of sieves (1 mm and 250 µm), trapping the ‘flot’ (floating material). This was air-dried and stored in air-tight plastic bags. The flots were sorted and scanned for plant material and charcoal using a low-powered binocular microscope (magnification x 10 to x 40). All charcoal fragments of 2 mm or greater were identified. Each fragment was prepared for microscopic examina-tion by fracturing it by hand and thereby exposing a clean surface along transverse, radial and tangen-tial planes. All three planes were examined at a range of magnifications (x 5 to x 100) under a Nikon stereo microscope. For reference literature the website “wood anatomy” was consulted. The number and weight of fragments were recorded for each charcoal type. The following details were also noted: Ring curvature. The analysis of ring curvature can be regarded as broadly indicative of age, and this was noted during charcoal analysis. On the basis of the degree of ring curvature the charcoal fragments were classified according to age categories as follows: strong curvature, <5 y (years); medium curvature, 6-10 y; weak curvature, 11-15 y; curvature negligible, 15+ y, i.e. mature wood. Where the pith was present, the age of the fragment was noted (equal to the number of rings present). Insect and fungi infestation. Holes, round and larger than vessels, are usually regarded as caused by bur-rowing insects; their frequency was noted.

Results

In all, 437 charcoal fragments were identified in the thirteen samples. In Figs. 1 and 2 percentage frequencies of the various charcoal types based on fragment count and dry weight, respectively, are shown. Bar charts (Figs. 3-5) illustrate the frequencies of the various wood



60

types in different feature types.

The most frequent charcoal type overall is oak at 88.6%, or 85.3.5% by weight (Fig. 2). This is followed in descending frequency by ash (8%), willow/popular (1.4%), yew (0.9%), elm (0.5%), hazel (0.5%) and hazel/alder (0.2%). When considered on a weight basis, the overall picture remains broadly similar apart from yew, which makes up 7% of the percentage weight (the fragments were very large).

As regards the individual features, there is some variation between feature and feature type (see bar charts Figs. 3-5). C1 from Pit 2, which contained slag waste, contained a majority of ash. Similarly C62 from Furnace 60 contained only ash. This contrasts with the other features which were domi-nated by oak. C46 from Furnace 47 is distinctive in that, in addition to oak, it contained large branch pieces of yew wood (see below).

There are two time periods represented on the site - the early to mid Iron Age (two of the furnaces) and the later Early Historic Period (the two charcoal making pits). There are no notable differences in the charcoal assemblages from these periods. Only one structural feature -a posthole- was found. Like the other features it contained a majority of oak wood. Given that this sample was purely composed of oak, it may be the remains of a burnt-out post. This feature is not represented in bar charts 3-5.

Oak88.6%

Ash8.0%

Willow /Popular1.4%

Yew0.9%

Hazel/Alder0.2%

Elm0.5%

Hazel0.5%

Fig. 1 Pie chart showing percentage frequencies of wood types



61

Ash 7.3%

Yew 7.0%

Willow/Popular 0.1%

Elm 0.2%

Hazel/Alder 0.004%

Hazel 0.02%

Oak 85.3%

Fig. 2 Pie chart showing percentage weight of wood types

0

20

40

60

80

100

120

Oak Ash Willow /Popular

Fig. 3 Bar chart showing wood type counts from charcoal pits



62

0

20

40

60

80

100

120

140

Oak Ash Elm Hazel / Alder

Fig. 4 Bar chart showing wood type counts from waste pits

0

20

40

60

80

100

120

Oak Ash Hazel Yew

Fig. 5 Bar chart showing wood type counts from furnaces



63

Ages and forms of wood present

While ring curvature does not give a strict qualitative indicator of age, the results nevertheless are useful in that they give insights into the age of the wood that was burned. Mature wood (c. >15 y) is presumed to be derived mainly from large branches and trunks, while young wood (<15 y) is presumed to derive from young branches and twigs. The vast majority of the fragments analysed derive from mature wood, i.e. the rings have low curvature and furthermore they are, by and large, narrow (<2 mm) which is typical of mature wood. The main exceptions are as follows: (i) The ash fragments from C14 (Charcoal pit 2) were whole branch pieces, c. 10 y old. (ii) The yew fragments from C46 (Furnace 47) were also whole branch pieces c. 15 y old. Most of the wood contained no insect burrowing holes, a feature that is common in dead wood. As the wood would have to have been seasoned prior to charcoal making, it must have been stored care-fully to avoid burrowing insects. The exception to this is the yew wood from C46 (Furnace 47). This indicates that this wood was possibly gathered off the forest floor, where it was subject to insect attack. It may also indicate that it was structural wood, (perhaps a pole given its size) and was burrowed by insects at this stage.

Discussion

Comments on charcoal taxa

Quercus (oak) The charcoal data as a whole show that oak was the main tree burnt on the site (Figs. 1 - 5). It accounts for 88.6% of all charcoal fragments identified. The charcoal from Monganstown 1 likely represents the remains of charcoal burning rather than wood burning (given that the samples originate from charcoal making pits, furnaces for smelting and pits used to dump furnace waste). High temperatures of between 1100-1250˚ are needed to smelt iron (Waddell 2000, 286). Oak is slow burn-ing and gives out substantial heat as it burns which would have made it a natural choice. Historically, oak was one of the preferred woods for making charcoal along with alder and strawberry tree (Arbutus unedo) (Feehan 2003, 299-355). There are two native species of oak in Ireland, namely the Sesile oak (Q. petraea) and the pedunculate oak (Q. robur). The former tolerates poor, acidic edaphic conditions (e.g. it is the main canopy tree of Atlantic oak woodlands, e.g. Killarney National Park; Kelly 1981) and the latter is characteristic of the more fertile parts of Ireland such as the site area. Unfortunately, it is difficult to distinguish these species on the basis of wood anatomy (Grosser 1977). On the basis of present-day distribution pat-tern and ecological preferences, it is probable that the charcoal derives mainly, if not exclusively, the pedunculate oak The ring patterns of the charcoal indicated that oak was from mature wood i.e. trunks and large branches were utilized. The narrow ring widths of the oak wood suggest the trees grew in dense wood-land. In the Iron Age the main canopy trees were oak, ash and elm (see Molloys pollen diagram in Dillon, forthcoming). Oak would have been deliberately selected to fuel the iron smelting process. As the Early Historic period progressed, oak would have become less widespread but still would have been common. It is likely that the centres for smelting were situated in areas where mature oak wood was abundant. In medieval England we know that oak was coppiced to provide a self-renewing supply of



64

timber, without the need to clearfell woodlands. There is no evidence of coppiced oak being used at Monganstown, possibly because there was a plentiful supply of oak woodland.

Fraxinus (ash; F. excelsior). Ash makes up 8% of the assemblage. It makes great fuel, burned green or dead, and this may have influenced its selection. Ash is only prominent in two samples, and one sample consisted of branch wood c. 8cm in diameter. This may have been structural rather than fuel wood.

The hazel (Corylus Avellana), willow/popular (Salix/Populus) and hazel/alder (Corylus /Alnus) may have been used as kindling wood, as it is much less dense than oak and (apart from alder) does not make good charcoal. It may also have been use to provide a wattle frame for the furnaces.

Land-use history based on pollen analytical data

As part of an integrated study into the history of land use in the Blackwater Valley, Co. Meath, a core was taken 7 km to the north-east of Kells, about 20 miles north-east of Monganstown 1 (Dillon et. al. forthcoming). This pollen core shows that trees decline and farming indicators rise in the period 300 BC-AD 20. Tall canopy trees, especially elm and ash, were cleared but most striking is the clearance of hazel which emphasises the intensity of farming during this period. In the period AD 20-500 oak, ash, elm and hazel increase alongside the decline in pastoral and arable indicators. Oak is well represented in the Iron Age pollen profile but would have shared the canopy with elm and ash trees. Hazel woods would have been plentiful. The unbroken curve for Taxus suggests that yew was present but was not frequent (Taxus is generally regarded as over-represented in pollen records). There is an intensification of farming activity, at the expense of woodland cover, during the period from the 9th to 11th centuries.

Comparative studies

The remains of iron smelting (slag and charcoal) were found in a kiln the Early Historic period site at Randalstown, near Navan in Co. Meath. The charcoal analysis results from Randalstown were very similar to those from Monganstown 1. The charcoal from the Randalstown contexts was exclusively oak, and was very clean, suggesting that it was the remains of charcoal used to fuel the smelting proc-ess (Dillon 2006). At Johnstown 1, a nearby site in Co. Meath where evidence of metalworking was found, oak and hazel charcoal were recovered, suggesting that these two wood types were predominantly used to fuel the metallurgical activities. It is concluded that the hazel wood was probably not used in the smelting process itself, but in some activity relating to it (Miller and Ramsey, 2003). The two comparative studies above had similar findings to those from Monganstown 1 i.e. oak was predominately used to make charcoal for smelting iron.

Summary

The charcoal assemblages from Monganstown 1 were dominated by oak wood, which was collected as charcoal-making fuel for iron smelting. Oak is well documented as a reliable wood for charcoal mak-



65

ing and was traditionally used as such. It would have been deliberately selected from woodlands, which we know from a semi-local pollen profile, were not dominated by oak, but by a combination of oak, ash, elm and hazel. The curvature of the rings and the rings widths of the oak charcoal indicate that mature oak was sourced from closed woodlands to fuel the iron works at Monganstown.

Acknowledgments

Pollen analysis at Emlagh Bog was carried out by Dr. Karen Molloy of the Paleo-environmental Unit, NUI, Galway, published in Dillon et. al. forthcoming

References

Dillon M. 2006. People and the Environment. Towards an Anthropology of Woodlands in Prehistoric and Early Historic Ireland. Unpublished thesis, NUI, Galway.

Dillon M., Newman C., Molloy K, M. and O’Connell M. (forthcoming).

Environment and ritual in a late Iron Age context: an example from Raffin Fort, Co. Meath, Ireland in BAR I.S. Charcoals From the past. Cultural and Palaeoenvironmental implications.

Feehan J. 2003. Farming in Ireland. History, Heritage and Environment. UCD, Dublin.

Grosser, D., 1977. Die Holzer Mitteleuropas. Berlin: Springer-Verlag.

Kelly, D.L., 1981. The native forest vegetation of Killarney, south-west Ireland: an ecological account. Journal of Ecology, 69, 437-472.

Miller J. Ramsay S. 2003 Fuel Analysis from Metalworking Slag from Johnstown I. In: Photos-Jones E. Analysis Metallurgical Waste from the M4. Kinnegad-Enfield-Kilcock. Motorway Scheme, the Johnstown I site. Report produced by Scottish Analytical Services for Art & Archaeology for ACS, Drogheda

Waddell J. 1998. The Prehistoric Archaeology of Ireland. Galway University Press, Galway

“Wood Anatomy” at http//:www.woodanatomy.ch



66

Tabl

e of

raw

dat

a fro

m c

harc

oal i

dent

ifica

tion

Dep

osit

C.1

C.4

C.1

3C

.13

C.1

4C

.16

C.3

3C

.38

C.4

6C

.59

C.6

2C

.64

C.6

9C

utC

.2C

.2C

.24

C.2

4C

.21

C.1

5

C

.40

C.4

7C

.57

C.6

0C

.63

C.6

9Sa

mpl

eS.

4S.

1S.

3S.

17S.

2S.

5S.

16S.

18S.

20S.

5?

S.9

S.5

Wei

ght (

g)O

ak (Q

uerc

us sp

p.)

725

.830

10.3

141

27.2

1.9

27

73.5

55

.561

.5A

sh (F

raxi

nus e

xcels

ior)

6.8

15

.5

0.

06

17

.3

El

m (U

lmus

glab

ra)

1.2

Haz

el (C

orylu

s ave

llena

)

0.02

H

azel

(Cor

ylus)

/ Ald

er (A

lnus

)

0.1

W

illow

/Pop

ular

(S

alix

/Pop

u-lu

s)

0.

8

Ye

w (T

axus

bac

cata

)

0.02

37.7

Frag

men

t cou

nt

Oak

(Que

rcus

spp.

)10

4944

2050

5010

4

50

5050

Ash

(Fra

xinu

s exc

elsio

r)12

2

2

19

Elm

(Ulm

us gl

abra

)2

Haz

el (C

orylu

s ave

llena

)

2

Haz

el (C

orylu

s) / A

lder

(Aln

us)

1

W

illow

/Pop

ular

(S

alix

/Pop

u-lu

s)

6

Yew

(Tax

us b

acca

ta)

1

3



67

Analytical report on iron slag samples from Monganstown,

Ireland Marcos Martinón-Torres <[email protected]>

Institute of Archaeology, UCL. July 2006

Analytical method

Bulk chemical compositions were obtained by polarising energy dispersive X-ray

fluorescence analysis (ED-XRF) of pressed powder pellets. The analysis was carried out with

a Spectro X-Lab Pro 2000 instrument, using an evaluation method with standards optimised

for iron-rich materials. In order to assess precision and accuracy, each specimen was

analysed three times, and alongside standard reference materials. All the resulting data are

given in Table 1.

Pellets were prepared by milling 10 g from the core of the slag in a tungsten carbide swing

mill with counterweight, down to a particle size of approximately 50 μm. This powder was

dried and thoroughly mixed with a small fraction of industrial wax, and subsequently

subjected to 15 T of pressure in a 32 mm diameter mould.

A cross-section of approximately 1 cm3 section of the same slag lump was mounted in epoxy

resin and polished down to a grain size of 0.25 μm. These sections were examined under

plane polarised (PPL) and cross-polarised (XPL) reflected light in a Leica DM LM

metallographic microscope.

Analysis and interpretation

Three slag samples were received, sized approximately 8 to 10 cm in the longest axis.

Macroscopically, they show a dark orange to brown colour, indicative of some external rust.

1

15.7 Appendix 7: Chemical analysis of industrial residues



68

Sample F4/F2 A has the typical bulbous appearance of bloomery iron smelting furnace slag.

On the other hand, both F4/F2 B and F46/F47 have plano- to concavo-convex profiles,

which at first could be suggestive of smithing slags. The analytical study, however, confirms

all three as derived from bloomery iron smelting, without any indication of tapping or

smithing.

The chemical composition of the three samples falls within a consistent compositional

range, although with some variation in the silica to iron oxide ratios. Most remarkable are

the high manganese oxide concentrations, around 8 wt%, which are accounted for by the

generally low iron oxide levels (43-60 wt%). The use of manganese-rich iron ores can

facilitate the production of slag – and, consequently, of iron – as manganese replaces iron

oxide in the slag, resulting in slag that is poorer in iron, i.e. a more efficient smelting

process. Other noteworthy aspects in the chemical data are the relatively high levels of

strontium and barium. Considering the low contribution of ceramic materials to the slag

formation – as reflected in the low alumina levels – it can be assumed that Sr and Br

constitute a geological signature of the ore used. This, in addition to the high Mn, could be

used as indicators to try to identify potential sources of iron ores in the vicinity.

In cross section, all three slag samples show a layered structure and significant accretions

of clay and small stones on one side at least. This could indicate that all of them solidified

whilst in direct contact with either the surrounding soil – if the slag was tapped –, a smithing

hearth bottom, or the bottom/walls of a bloomery furnace. On the basis of the

microstructural examination, however, the first two hypotheses can be rejected.

Sample F4/F2 A shows a very homogeneous structure. This consists of relatively large,

mostly euhedral, fayalitic blocks, some with skeletal development but none showing the

elongated shapes of fast-cooled systems. The interstitial glassy matrix shows some acicular

crystals, possibly enriched in calcium oxide (bulk CaO is >3 wt%), whose development is also

indicative of a slow cooling rate. Small wüstite dendrites are only found in very localised

areas. This is consistent with slag that solidified slowly inside a furnace, and where little free

iron oxide is present. In fact, this is the sample showing the lowest bulk iron oxide

concentration. Only towards the area in direct contact with clay or soil can some

heterogeneity be noticed, namely the presence of some leucitic phases and small crystals of

magnetite. Both of these may be explained as a result of the localised chemical

environment, which would be richer in oxygen and clay oxides such as alumina and potash.

Sample F4/F2 B is richer in iron oxide (although still within relatively low ranges), and this is

reflected in the higher abundance of dendritic formations of wüstite noticed under the

microscope. The specimen mounted for cross section shows the interface between two slag

2



69

layers. Whilst both of them show developed fayalitic structures, the main difference between

the two is the different abundance of wüstite dendrites. This is probably a reflection of two

subsequent episodes of slag deposition within the furnace during the same smelt, one of

them being slightly richer in iron oxide. The absence of external flow textures or an oxidation

skin of magnetite between the two layers – wich would form upon solidification in air –, and

the fact that the interface between the two is not clear-cut – some crystals clearly develop

across the two layers – allow to rule out the possibility of this constituting tap slag.

Furthermore, the internal homogeneity and the lack of sand or charcoal inclusions within

the slag are against the interpretation of this as smithing debris, in spite of the plano-convex

profile. In fact, the clay- and stone-rich layer is addhering to the flat side of the slag lump,

which probably constitutes the bottom of a non-tapping bloomery furnace.

Finally, sample F46/F47 is also comparable to the above samples, with a developed

fayalitic structure and little free iron oxide present. Again, in spite of the layering, this slag

clearly cooled slowly and inside a smelting furnace. The only noteworthy feature is the

presence of a few small sulphide inclusions within a devitrified matrix. As in F4/F2 A, an

area richer in magnetite can be noticed near the furnace wall area.

In sum, the samples analysed are indicative of bloomery iron smelting, most likely in a non-

tapping furnace. The ores smelted where rich in manganese and, to a lesser extent,

strontium and barium, which is reflected in the composition of the slag. The slag samples

contain relatively low iron oxide concentrations, therefore it can be inferred that the

technology was efficient for a bloomery furnace.

3



70

Figs. 1 (left) and 2 (right). Monganstown F4/F2 A. Left, microstructure of the slag, showing quite developed, euhedral fayalite blocks (light grey) in a glassy matrix (PPL, x50, width 2 mm). Right, view of the same area under cross-polarised light, where the internal reflections reveal the bright acicular crystals within the glassy matrix.

Figs. 3 (left) and 4 (right). Monganstown F4/F2 A. Left, area of the slag showing the development of small wüstite dendrites in the interstitial glass within a fayalite-dominated system (PPL, x50, width 2 mm). Right, detail of the same area under higher magnification (PPL, x200, width 0.5 mm).

4



71

5

Figs. 5 (left) and 6 (right). Monganstown F4/F2 B. Left, interface between two layers of slag deposited within the furnace. Note that the bottom layer is richer in free iron oxide, with more abundant wüstite (white), but also that some fayalite crystals (light grey) cut across the two layers (PPL, x50, width 2 mm). Right, detail of the bottom layer, showing eutectic intergrowths of fayalite and wüstite (PPL, x100, width 1 mm).

Figs. 7 (left) and 8 (right). Monganstown F46/F47. Left, microstructure of the slag, showing developed euhedral fayalite crystals resulting from slow cooling (light grey), and bright magnetite in some areas of the glassy matrix (PPL, x100, width 1 mm). Right, detail of the microstructure showing some bright sulphide inclusions within a devitrified matrix (PPL, x200, width 0.5 mm).



72

Na2

OM

gOA

l2O

3S

iO2

P2O

5S

O3

K2O

CaO

Cr2

O3

MnO

FeO

NiO

CuO

ZnO

Se

SrO

YZr

O2

Ba

Sum

%%

%%

%%

%%

%%

%pp

mpp

mpp

mpp

mpp

mpp

mpp

mpp

m%

Mon

gans

tow

n F4

F2

0.41

0.43

1.84

40.0

60.

300.

320.

193.

650.

028.

0043

.32

489

4920

235

1895

3271

98

.87

Mon

gans

tow

n F4

F2

0.39

0.42

1.84

40.5

90.

290.

340.

203.

680.

028.

1443

.83

4110

4821

238

1677

3299

10

0.07

M

onga

nsto

wn

F4F2

0.

420.

401.

8740

.79

0.44

0.33

0.21

3.74

0.02

8.12

44.1

564

1047

1923

718

8633

28

100.

82

Mon

gans

tow

n F4

F2B

0.

270.

181.

8625

.65

1.09

0.29

0.34

2.85

0.02

8.30

59.3

513

639

3937

919

7760

87

100.

81

Mon

gans

tow

n F4

F2B

0.

250.

171.

9325

.44

1.09

0.29

0.34

2.83

0.02

8.31

59.0

119

936

3237

918

6160

20

100.

28

Mon

gans

tow

n F4

F2B

0.

370.

171.

9225

.64

1.11

0.29

0.34

2.83

0.02

8.18

59.1

528

741

4338

720

8361

08

100.

62

Mon

gans

tow

n

F46F

47

0.47

0.25

2.72

31.6

61.

010.

280.

583.

980.

028.

1950

.02

507

7142

703

2584

7457

99

.92

Mon

gans

tow

n F4

6F47

0.

720.

222.

6931

.59

0.99

0.28

0.58

3.99

0.02

8.20

50.0

036

966

4270

525

111

7410

10

0.03

M

onga

nsto

wn

F46F

47

0.69

0.20

2.68

31.8

31.

030.

290.

573.

990.

028.

1750

.06

26bd

l65

3470

822

109

7450

10

0.29

BCS3

01-1

ce

rtifie

d0.

071.

734.

267.

400.

801.

000.

3222

.60

1.

2527

.55

67.1

4BC

S301

-1

anal

ysed

bd

l1.

504.

296.

970.

690.

560.

3321

.01

0.02

1.14

32.3

870

1517

7bd

l29

856

108

5368

.90

BCS3

01-1

an

alys

ed

bdl

1.49

4.36

7.02

0.71

0.58

0.34

21.1

70.

021.

1332

.57

7714

177

bdl

301

5696

5869

.39

BCS3

01-1

an

alys

ed

bdl

1.43

4.22

6.85

0.69

0.57

0.32

20.6

30.

021.

1231

.84

7312

177

bdl

292

5510

949

67.6

8

ECR

M68

1-1

certi

fied

0.09

1.48

10.6

217

.81

2.02

0.26

0.59

3.92

0.06

0.28

38.4

420

4

76.2

0EC

RM

681-

1 an

alys

ed

0.18

1.28

12.6

416

.26

2.06

0.30

0.55

3.74

0.07

0.28

43.0

593

1040

8bd

l11

91

108

287

136

80.4

0EC

RM

681-

1 an

alys

ed

0.23

1.26

12.6

116

.39

2.07

0.31

0.55

3.75

0.07

0.28

43.0

071

1239

1bd

l11

93

105

299

145

80.5

2EC

RM

681-

1 an

alys

ed

0.25

1.22

12.5

416

.36

2.05

0.31

0.55

3.76

0.07

0.28

43.0

994

1639

7bd

l11

83

105

299

142

80.4

8

Tabl

e 1.

Che

mic

al c

ompo

sitio

n of

the

slag

sam

ples

from

Mon

gans

tow

n as

obt

aine

d by

ED

-XRF

in th

ree

diffe

rent

runs

, with

all

dete

cted

ele

men

ts

from

the

slag

. The

bot

tom

row

s pr

esen

t a c

ompa

rison

of t

he c

ertif

ied

valu

es a

nd th

e an

alyt

ical

resu

lts fo

r sta

ndar

d re

fere

nce

mat

eria

ls, s

how

n he

re to

illu

stra

te th

e in

stru

men

t’s a

ccur

acy.

6



73

15.8 Appendix 8: Lithics Finds Report for A001/01 – Monganstown 1, Co. Westmeath

Farina SternkeDepartment of Archaeology, University College Cork

One lithic find (A001/01:13:1) from Monganstown 1, Co. Westmeath was presented for analysis.

Condition:

The lithic which is a flint survives in burnt and incomplete condition.

Context:

This find was recovered from context 13.

Technology/Morphology:

The find A001/01:13:1 is an unretouched cortical flake produced on a beach pebble with a soft stone hammer.

Dating:

The find is morphologically undiagnostic. Based on its technological characteristics, it is possible that it belongs to a residual Early Mesolithic phase on the site. Alternatively, it could represent evidence for Neolithic activity in the area. An association with the Iron Age and Early Medieval occupation of the site cannot be established.

Interpretation:

The single lithic find from the excavation at Monganstown 1, Co. Westmeath is simple cortical flake which is either associated with an Early Mesolithic or Neolithic occupation. Given the site location on slightly raised ground on an island surrounded by marshland, the possibility of it being evidence for residual Early Mesolithic activity in the area certainly has to be considered. However, it is difficult to support this argument with a single isolated find.

Date post:	21-Jan-2015
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Ex., A001 01, N6 K2 K, Monganstown1, Co. Westmeath Eap Journal

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