This article was downloaded by: [Hebrew University] On: 15 June 2013, At: 23:38 Publisher: Routledge Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Journal of the Institute of Conservation Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/rcon20 An elephant task—conservation of elephant remains from Revadim Quarry, Israel Gail Gali Beiner & Rivka Rabinovich Published online: 14 Jun 2013. To cite this article: Gail Gali Beiner & Rivka Rabinovich (2013): An elephant task—conservation of elephant remains from Revadim Quarry, Israel, Journal of the Institute of Conservation, DOI:10.1080/19455224.2013.796887 To link to this article: http://dx.doi.org/10.1080/19455224.2013.796887 PLEASE SCROLL DOWN FOR ARTICLE Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. The publisher does not give any warranty express or implied or make any representation that the contents will be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses should be independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.
Transcript
This article was downloaded by: [Hebrew University]On: 15 June 2013, At: 23:38Publisher: RoutledgeInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: MortimerHouse, 37-41 Mortimer Street, London W1T 3JH, UK
Journal of the Institute of ConservationPublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/rcon20
An elephant task—conservation of elephant remainsfrom Revadim Quarry, IsraelGail Gali Beiner & Rivka RabinovichPublished online: 14 Jun 2013.
To cite this article: Gail Gali Beiner & Rivka Rabinovich (2013): An elephant task—conservation of elephant remains fromRevadim Quarry, Israel, Journal of the Institute of Conservation, DOI:10.1080/19455224.2013.796887
To link to this article: http://dx.doi.org/10.1080/19455224.2013.796887
PLEASE SCROLL DOWN FOR ARTICLE
Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions
This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form toanyone is expressly forbidden.
The publisher does not give any warranty express or implied or make any representation that the contentswill be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug dosesshould be independently verified with primary sources. The publisher shall not be liable for any loss, actions,claims, proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly orindirectly in connection with or arising out of the use of this material.
An elephant task—conservation of elephant remainsfrom Revadim Quarry, Israel
Keywords
elephant bone; taphonomy; fill materials; Paraloid B-72; Japanese tissue; Revadim Quarry;conservation
This article presents examples of conservation of elephant remains fromRevadim Quarry for palaeontological research, with an emphasis on tapho-nomic studies. Taphonomic processes relate to modifications in faunalremains made either by the collectors, modifiers, and/or transporters of theremains (whether hominin or any other predator) both before and after depo-sition, or by other agents of change such as water, wind, and other environ-mental factors. Scientific research usually involves the need to handle theobject as part of a study and may involve particular types of analysis. Com-pared with handling by visitors, handling for research tends to require moreversatility as the object is examined in detail from all angles. In the universityenvironment, research requests are the main reason for moving objects fromstorage. In the examples presented in this article, taphonomic studies of thesurface of the bones as part of an archaeozoological research project requiredspecific treatment approaches. The effects of excavation processes on theobjects, resources and availability of materials, and the intended use of theobjects, are discussed as factors that influenced conservation decisions.
The site: Revadim QuarryRevadim Quarry is located on Israel’s southern coastal plain, 40 km south-east of Tel Aviv (Fig. 1). It is situated on a hillock at an elevation of 71–73 mabove sea level.1 The archaeological finds were within a layer consisting ofquartzitic grey-brown palaeosol (c. 2–2.5 m in depth), a loamy sand tosandy loam palaeosol with abundant carbonate nodules (50% coarsequartz and a fine component of clay and calcite). Most of the elephantbones were concentrated in this area (Area B). Over the years, the centralpart of the site collapsed during the winter. Archaeological finds registeredand studied in situ were retrieved from the collapsed areas.2
Preliminary dates for the site are between 300,000 and 500,000 beforepresent (BP) and possibly older, setting the minimum age estimate forhominin occupation of the site and anthropogenic tools to the Late Acheu-lian techno-complex.3
Finds in context: object excavation historyThe elephant remains from Revadim Quarry included teeth, tusks, scapulae,pelvis, vertebrae, ribs and long bone shafts.4 It is the largest Lower Palaeolithic(c. 1.5 million–300,000 years ago) assemblage of straight-tusk elephants(Palaeoloxodon antiquus) from the southern Levant.5 The Revadim Quarryfauna formed part of a study examining elephant–hominin interaction inthe southern Levant. The purpose of the study was to discern the typical ele-phant bone survival characteristics as opposed to those that were specificallyrelated to a certain type of taphonomical agent, such as fluvial transport, sedi-ment compaction, human butchery, animal feeding, and so forth.6
(Received 27 February 2012; Accepted 15 April 2013)
1 O. Marder et al., ‘Archaeological Hor-izons and Fluvial Processes at the LowerPalaeolithic Open-Air Site of Revadim(Israel)’, Journal Human Evolution 60, no.4 (2011): 508–22, 509; R. Rabinovichet al., ‘Elephants at the Middle Pleisto-cene Acheulian Open-Air Site ofRevadim Quarry, Israel’, Quaternary Inter-national 276–7 (2012): 183–97, 184.
2 Rabinovich et al., ‘Elephants’, 184.
3 Marder et al., ‘Archaeological Hor-izons’, 511.
4 Marder et al., ‘Archaeological Hor-izons’, 517; Rabinovich et al., ‘Ele-phants’.
5 Marder et al., ‘Archaeological Hor-izons’, 517.
6 Rabinovich et al., ‘Elephants’, 183.
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The elephant remains were excavated over a period of years and underdifferent circumstances, leading to the finds having different excavationhistories. Some were excavated during routine archaeological seasons,others were recovered as part of emergency salvage operations. Somewere found more complete, others were lifted in pieces. These different cir-cumstances led to the remains being treated in different ways as they werelifted, and to the remains being in different states of preservation when theyentered the conservation laboratory. The following three examples demon-strate the range of states of preservation encountered due to their differentexcavation histories.
Scapula I (excavation no. 2107) was found partly exposed in 2006 (Fig. 2),two years after the close of the formal excavations, during a general surveyafter a rainy period. The survey had been undertaken because of the conditionof the site: whole blocks of earth from the once-active quarry had collapsed inlandslides, exposing new finds. A one-day salvage excavation was speciallycommissioned for Scapula I, without the participation of a conservator.During the day of the salvage operation, it began raining, leading to a wetsoil matrix. The bone was very broken and continued fragmenting as it wasexposed. The wet matrix contributed to uneven weight distribution of theobject and made simple lifting too risky. Block lifting was not an optionbecause of the actively eroding state of the collapse area and due to time con-straints, as well as the size and heavy weight of the object. Pre-excavationadvice from the conservator included the use of Paraloid B-72 (an ethyl/methyl methacrylate co-polymer) in acetone and ethanol with gauze on topof the uncleaned bone surface to help hold cracked parts together until theobject could be treated in the laboratory (Fig. 3). Several layers of gauzestrips soaked with Paraloid B-72 were applied to the exposed top side andthen the entire bone was removed quickly, resulting in crumbling of theunconsolidated underside (the lateral side).
Scapula II (excavation no. 2039) was found in separate pieces in a collapseduring the 1998 excavation season. Fresh breaks were evident. The frag-ments were kept together, but initially the body part could not be identified.
Fig. 1 Revadim Quarry, with a view towards excavation area B.
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In the cases of Scapulae I and II, the state of the bones upon excavationresulted in a combination of fragmented bone with weak break edges.
Scapula III (excavation no. 2038) was also found fragmented in a col-lapsed area under Area B, during the excavation season of 2004. Becausenot all parts belonging to Scapula III were identified at the same time,this find was treated in two separate conservation projects. The first, in2010, included only one large bone fragment. A second project took placea year later, in 2011–12, when morphological traits research led to theidentification of further bone parts from the same collapse as belongingto this elephant scapula. In this case, fresh and old breaks were bothevident.
Each scapula, therefore, had a unique excavation history, leading to par-ticular considerations for conservation. All three scapulae were considerablyheavy, but in the cases of Scapulae I and II the situation was complicated bythe presence of large missing areas causing an uneven distribution of weight.In Scapulae I and II break edges also were very weak and friable.
Most of the elephant finds were coated with a quartzitic matrix containingclay and calcite. Post-depositional processes at the site involved authigenicdeposition of manganese oxides, primarily around bones, due to seasonalinundation shortly after deposition, as the site is situated 300m from a conflu-ence of river tributaries. Later percolation via cracks resulted in the formationof calcite nodules, veins and crusts. Chemical analysis of the bones indicatedthe presence of the mineral dahllite and that no collagen was left. The bonecrystallinity ranged between 3.7 and 4.4, values that indicated quite severe dia-genesis of the bone mineral. Manganese oxides covered the surface of the
Fig. 2 Scapula I exposed in situ during survey work.
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bones in varying degrees.7 Interestingly, the old breaks of Scapula III werecovered with a layer of the quartzitic mix, unlike old breaks on other remains.
Conservation aims and objectivesTreating the elephant remains from Revadim Quarry was an exercise in bring-ing together conservation and palaeontology. The bone finds from the sitewere intended for use in the study of surface modification in particular.Archaeological elephant remains have been shown to contain evidence ofhominin activity, including indications of butchery patterns and the use ofspecific elephant bone tools. Cut marks found on the elephant remains fromthe quarry are of special importance because early evidence of hominin exploi-tation of animals heavier than 3000 kg is uncommon and the issue of huntingversus scavenging before the European Upper Palaeolithic is still underdebate.8 The combination of ongoing damage due to post-depositional pro-cesses and the need to extend research beyond the fragmentary state intothe study of morphological traits and surface modifications led to preliminarystudy of the fragments and then to varying levels of cleaning, consolidationand repair, depending on the state of preservation of each specimen.
Practical considerations for conservation derived mainly from the exca-vation history of each specimen. Excavation techniques were affected bytime and budget restrictions, in situ location (collapse zones versus exca-vation areas), level of bone part identification, working in a mostly dryenvironment and by the fact that no conservator was present on site. Forexample, Scapula I arrived in the laboratory with one face very fragmenteddue to excavation time constrictions, while another find from the same site,an elephant pelvis (excavation no. 2040) treated similarly with Paraloid B-72 and gauze strips, was gradually consolidated on all sides and lifted morecarefully because it was exposed during the formal excavation season andthere was much more time available. The latter object arrived in the conser-vation laboratory in a nearly complete condition.
Fig. 3 Scapula I: coating the exposed parts in situ with gauze strips impregnated with ParaloidB-72 in acetone.
7 Rabinovich et al., ‘Elephants’, 187, 189.
8 Rabinovich et al., ‘Elephants’.
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Although a conservator was not on site during excavations, conservationadvice was provided. Thus, conservation-grade materials were used duringthe lifting processes. It can be tempting when conservation-grade materialsare not readily available to choose adhesives that are easy to obtain andapply on site. However, ethical considerations determine that productsshould be chosen on the basis of reversibility, consolidation properties, andlong-term stability. Readily available commercial products do not necessarilymeet these standards.9 Paraloid B-72 has been used on bone in other cases, isknown to work well with dry bone material10 and is increasingly in use inthe field of palaeontology.11 Bone material still holds a high level of organiccontent and, therefore, may react with conservation materials more readilythan fully fossilized bone,12 making the choice of appropriate materials allthe more important. The disadvantages of B72 include higher costs comparedwith the purchase of ready-made commercial adhesives and the need to under-stand how to apply different concentrations of the consolidant. The latter can bean issue when no conservator is present on site during fieldwork. Cost-relatedissues required creative thinking, mainly where gap-filling was concerned.
Decisions on the amount of conservation and reconstruction undertakenwere determined according to the type and quality of information thatcould be gained from the objects. Ideally, keeping the specimens in theirbroken state could be useful for future study. However some information,such as butchery marks, can become more evident on a repaired bone.Other information, such as zoological comparative data, may also requireassembly of broken parts. Therefore, before conservation, the bone frag-ments retrieved from excavation first underwent assessment by archaeolo-gists and palaeontologists, who determined whether re-assembly would beuseful for further study. For the bones discussed in this article it wasdecided that more data could be obtained from reconstruction of the frag-ments. In addition, Scapula II could not be readily identified before re-assembly. Assembly was undertaken with the use of unpainted fills, andthe fills were to be applied only as necessary to hold the constructiontogether and enable safer handling for study. This also led to two furtherdecisions. The first was to remove the soil matrix layers from old breakson the bone. The second was to keep fills slightly sunken below the levelof the actual surface to facilitate easy study of the bone itself.
Conservation materials and methodsOnce exposed in situ during excavation most of the bones started to crack.Paraloid B-72 diluted in acetone (3–5% w/v) had been repeatedly appliedto their surfaces with the aim of consolidating the fragments before exca-vation, and strips of fine medical gauze soaked in Paraloid B-72 in acetonewere adhered over the bone surfaces when they proved too fragmentary to lift.
Thorough cleaning in the laboratory was necessary in order to enablemicroscopic observation of bone surfaces, since many of the bones wereencrusted in sediment. In some cases, cleaning necessitated the use ofdiluted ethanoic acid (3% v/v in water), as the crust was often too hard toremove by mechanical means without risking damage to the bone surface.
In the case of Scapula I, the bone, still covered with earth, had been partlyconsolidated in situ with Paraloid B-72 in acetone and ethanol. The bonewas coated with a layer of gauze strips consolidated with Paraloid B-72in order to keep fragments in the same relationship to each other, andthen packed for transport to the laboratory. The gauze strips wereremoved in the laboratory using acetone applied with a soft brush.
The lateral aspect of Scapula I was in a very broken state (Fig. 4a), withthe medial aspect coated with gauze. After gauze removal, the looseearth matrix was first cleaned by manually picking out the larger blocksof earth and placing them in a polyethylene bag for future research and
9 J.S. Johnson, ‘Consolidation ofArchaeological Bone: A ConservationPerspective’, Journal of Field Archaeology
21 (1994): 221–33, 222; on cellulosenitrate adhesives, see Division of Ver-tebrate Paleontology, University ofFlorida, http://www.flmnh.ufl.edu/vertpaleo/prep.htm#Adhesives(accessed April 28, 2013).
10 Johnson, ‘Consolidation of Archaeo-logical Bone’, 222; S. Stollman et al.,‘The Conservation Treatment of Canter-bury Museum’s Blue Whale Skeleton’,Records of the Canterbury Museum 19(2005): 35–60, 43; N.R. Larkin, ‘Literallya “Mammoth Task”: The Conservation,Preparation and Curation of the WestRunton Mammoth Skeleton’, Quaternary
International 228 (2012): 233–40, 236.
11 A. Davidson and G.W. Brown, ‘Para-loidTM B-72: Practical Tips for the Ver-tebrate Fossil Preparator’, CollectionForum 26, no. 1 (2012): 99–119, 99.
12 N.R. Larkin and E. Makridou, ‘Com-paring Gap-Fillers Used in ConservingSub-Fossil Material’, The Geological
Curator 7, no. 2 (1999): 81–90, 82.
An elephant task—conservation of elephant remains from Revadim Quarry, Israel 5
reference. The surface was gently cleaned with a soft brush whetted withacetone, alternating with a dry brush and a bamboo pick. This gentlemode of cleaning successfully revealed ancient cut marks on the bonesurface (Fig. 4b). Bone surfaces were consolidated with the same consoli-dant used on the excavation site, Paraloid B-72 in acetone, at concentrationsvarying from 5% to 10% (w/v). Loose fragments were re-adhered with 30%(w/v) Paraloid B-72 in acetone, after cleaning the join areas with a brushwhetted with acetone and with picks (porcupine needles and dental tools).
Since elephant scapulae are naturally large and heavy, but the archaeolo-gical finds were internally weak, it was necessary to fortify gaps and losses.To this end, crumpled acid-free Japanese tissue impregnated with ParaloidB-72 was pushed into the gaps with a bamboo stick (Fig. 4c, see also Discus-sion). The increased surface area of a crumpled sheet turns fine tissue into avery strong filling that is easy to remove if required. In addition to its poten-tial strength and reversibility, Japanese tissue is also relatively cheap andeasy to obtain. Alternatives, such as glass microballoons mixed with Para-loid B-72, are not only more expensive, but also far more difficult to applyand would take much more work to remove. A major consideration was theease with which crumpled tissue could be discerned from the original bone.Scapula II was treated using a similar methodology.
At this stage, there were still many gaps in the bone structure of Scapula I(Fig. 5a), and the entire glenoid cavity could not be reconstructed because ofthe gap lying in between the ventral and dorsal edges. Scapula II also suf-fered from large losses of bone in a manner that made future handling dif-ficult without the object breaking.
Small, stable gaps were filled with crumpled Japanese tissue impregnatedwith Paraloid B-72. Larger gaps were bridged with additional layers of longstrips of Japanese tissue impregnated with consolidant and laid perpendicu-lar to each other. Structural gaps that needed to support considerable weight,such as for Scapula I, were treated differently. These had a scaffolding struc-ture made of wooden bamboo sticks adhered in place with 30% (w/v) Para-loid B-72 in acetone (Fig. 5b). Strips of Japanese tissue impregnated withconsolidant were interwoven into the scaffolding, left to set and thencovered with layers of similar strips perpendicular to each other (Fig. 5c).The same solution was applied to Scapula II in the largest bone losses justto the degree of stabilizing the bone without completely reconstructing it.
Fig. 4 Scapula I. (a) Before treatment, with the lateral aspect in very fragmented condition. (b)Cut marks across fragments (highlighted by arrows) became evident after cleaning and recon-struction of the bone surface. (c) Local fortification with crumpled Japanese tissue impregnatedwith Paraloid B-72 in acetone.
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All types of gaps with Japanese tissue fills were coated with a final layer ofMicrocrystalline wax (Cosmolloid 80 H) (Fig. 5d).
The first identified part of Scapula III was received in the laboratory in 2010nearly completely covered with a very hard layer of the quartz, clay and calcitecomponents of the excavation matrix (Fig. 6a). This bone part was immersed in3% (v/v) ethanoic acid in water for no more than 20 minutes at a time, alternat-ing with immersions in fresh water to rinse out the acid and enable evaluationof the cleaning progress. Since encrustation still remained, ethanoic acid wasapplied locally with cotton wool poultices (Fig. 6b) rather than via baths toavoid over-treatment. Washing at the end of the process needed to be repeatedseveral times and for longer than the recommended ‘washing for two to fourtimes as long as the bone was in acid’13 to rinse all the acid out. Once damp,the bone was kept damp throughout the various stages of acid treatment in
Fig. 5 Scapula I. (a) Large open structural gaps remained after reconstruction of fragments. (b)Gap-filling with a scaffolding of bamboo sticks. (c) Strips of Japanese tissue impregnated withParaloid B-72 in acetone, woven through the scaffolding sticks. (d) After treatment.
13 http://preparation.paleo.amnh.org/42/chemical (accessed April 28, 2013).
An elephant task—conservation of elephant remains from Revadim Quarry, Israel 7
a relatively cold room to minimize mechanical damage due to differential con-traction of the bone. The end result is shown in Fig. 6c.
Towards the end of 2011, during the study of the fauna from the site, severalmore fragments from the collapses under the excavation areas were identifiedas parts of Scapula III, on the basis of morphological traits. On these additionalfragments, the pre-excavation soil matrix covered the areas that joined with thealready treated part of the scapula (Fig. 7a). Following study of the matrix andobserving the potential of conjoining, it was decided to remove the matrix fromthe join areas using air pressure and a microjack. Acid treatments (see Discus-sion) were rejected on the grounds that the matrix covering the joins was thick,but the accumulations on the other parts of the fragments were often muchthinner, so acid baths would possibly damage the external bone surface.
Fragments were then adhered with 30% (w/v) Paraloid B-72 in acetone.All join areas had good contact points, although the edges of the joins wereoften badly damaged and required fortification with small pieces of Japa-nese tissue impregnated with Paraloid B-72. The tissue was then coatedwith Cosmolloid 80H microcrystalline wax (see Discussion). One gap inthe centre of the thickest part of the bone area required initially fillingcorners with Japanese tissue, then creating a wall from Japanese tissueimpregnated with Paraloid B-72 on one side. A fill of glass microballoonsmixed with 30% (w/v) Paraloid B-72 in acetone was applied (Fig. 7b) andcoated with a second layer of Japanese tissue impregnated with ParaloidB-72. Both layers were coated with a final layer of Cosmolloid 80H micro-crystalline wax (Fig. 7c). The final reconstructed scapula could be safelylaid down on a study table and studied from different angles (Fig. 7d).
Discussion: gap-filling bone materialHistorically, many different materials have been used for filling gaps inbone material, for example waxes, plaster of Paris and commercialputties. Not many of these treatments have been published. Shelton andChaney reviewed adhesives and consolidants, with the conclusion thatpolyvinyl acetate, Paraloid B-72 and Paraloid B-67 (polybutyl methacrylate)were the most acceptable to use from a conservation perspective.14 In theirreview of published bone fillers, Larkin et al. mention plaster of Paris, AJKdough (containing jute and kaolin mixed with polyvinyl acetal), micro-glass beads in polymethyl-methacrylate mixtures and even horse hair,newspaper, wood, sand, pebbles, iron nails, car body filler, asbestos andepoxies.15 Many of these materials were selected for their short-term prop-erties, with little regard for their long-term deterioration, including cross-linking, shrinkage or colour-change. Most recently, Paraloid B-72 hasbeen used for gap-filling, mixed with inert fillers, such as calcium
Fig. 6 Scapula III. (a) Before first treatment, coated with hard matrix. (b) Local acid treatment with poultices. (c) After first treatment, withsome matrix still left.
14 S.Y. Shelton and D. S. Chaney, ‘AnEvaluation of Adhesives and Consoli-dants Recommended for Fossil Ver-tebrates’, in Vertebrate PaleontologicalTechniques vol. 1, ed. Patrick Leiggi andPeter May (New York: Cambridge Uni-versity Press, 1994), 35–44.
15 Larkin and Makridou, ‘ComparingGap-Fillers’, 87.
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carbonate, airbrasive powders, glass microballoons or phenolic microbal-loons. The use of Milliput epoxy putty has also been described.16 Theselatter fillers were often chosen with regard for long-term properties, butmay require the use of large quantities of expensive polymer and can becostly, and sometimes irreversible.
Fig. 7 Scapula III. (a) Matrix on join areas of old breaks before second treatment. (b) Experimentalfilling of the central hole with glass microballoons. (c) With wax coating on the gap fillers. (d) Aftertreatment.
16 Larkin, ‘Literally a “MammothTask”’, 233.
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In some cases, it is possible to use an inert solid block to fill the bulk of agap, covering it with a layer nearer the surface of the bone that is easier toshape. Blocks of Ethafoam have been used to fill voids in parts of amodern blue whale skeleton to just below the surface, then a putty ofhollow, unicellular soda lime borosilicate glass microspheres mixed withParaloid B-72 was applied to bone surface level.17 In the case of the scapulaefrom Revadim, the edges and break areas of the bone matrix itself were weakand friable, requiring caution when considering the addition of any solidblocks. Any alternative fill needed to be reasonably lightweight, chemicallystable, aesthetically unobtrusive and as cost-effective as possible. Mostimportantly, the chosen fill needed to be able to support the weight of theobject and make it possible for the bone to be handled from differentangles. Reversibility was another important factor, since with so many uni-dentified fragments it was possible that additional pieces may be found and,therefore, added to the specimen, as indeed happened with Scapula III.
Japanese tissue is cheap, readily available, long-fibred and soft. It has beenused as a gap-filler in other fields of conservation.18 Crumpled Japanese tissueimpregnated with consolidant can result in strong fills, and Japanese tissue cutinto strips can be manipulated to bridge gaps varying in shape and size. If agap area can be sufficiently fortified without completely filling it, the remain-ing void can be bridged, thus avoiding excessive pressure on the bone. The useof scaffolding made of materials, such as carbon fibre tubes,19 stainless steelpins or wooden bamboo sticks, can form a supportive structure capable ofsupporting heavier bone parts. In this case, availability and ease of usedecided the choice of scaffolding material. Bamboo sticks could be easily cutinto the varying lengths required for each stage of the work. If the scaffoldingstructure is appropriately fortified, it can carry considerable weight. Thread-ing strips of Japanese tissue impregnated with consolidant through the scaf-folding structure and coating this with strips laid perpendicular to eachother served the purpose of creating a fill able to withstand the tensionscreated from the weight of the bone. Japanese tissue can also be used tocreate gap-fills that conform to particular shapes.
The extra layer of microcrystalline wax applied to the Revadim scapulaegap-fills served both to add strength to the fill and create an aestheticallyacceptable finish. This was also considered an appropriately easy-to-replenish sacrificial layer to protect the underlying fills from dust and theelements, and proved easy to mould exactly to the required shape. Theneutral white colour of the wax is easily distinguishable from the bonebut relatively unobtrusive to the eye.
Gap-filling materials and methods are not the only aspects of bone treatmentstrongly affected by the twin banes of funding and materials availability. In ourcase, fine pneumatic tools, such as an air abrasive (microjack) facility of the typeoccasionally used for removing hard matrix layers, were not available initially,therefore alternative methods needed to be considered for removing hardmatrix from the first part of Scapula III. Hard sediment layers can be extremelydifficult to work with, at times leading to the use of hammers and chisels. Sincethe sediment layer coating Scapula III was hard but not very thick, acid prep-aration was selected for use in this case. Several acids have been in generaluse in the field of bone preparation, most notably ethanoic and methanoicacids, and others have been proposed for use, for example sulfamic acid.20 Etha-noic acid is commonly used for removing diagenetic carbonate from bone andenamel.21 The use of ethanoic acid in the preparation of vertebrate remains isnot new, although recommended concentrations have varied over time.22
The theory is that the ethanoic acid dissolves the carbonates in the earthmatrix covering the bone before it significantly affects the apatite within thebone structure. However, acid treatment is a problematic choice for taphonomicstudy because acid environments produce etching of bone and enamel.
17 Stollman et al., ‘Canterbury Museum’sBlue Whale Skeleton’, 43.
18 C. Rozeik, ‘Thinking Outside theBox: The Re-conservation of a CeramicClazomenian Sarcophagus in the Fitz-william Museum, Cambridge’, Journalof the Institute of Conservation 34, no. 1(2011): 80–9, 84.
19 Stollman et al., ‘CanterburyMuseum’s Blue Whale Skeleton’, 48.
20 C.B. Padilla and M.L. Parra, ‘AcidPreparation of Fossils using SulfamicAcid, a Weak Organic Acid, and itsAdvantages over Acetic and FormicAcid Preparation’ (oral presentation,Society of Vertebrate Palaeontology, Pre-parators’ Session, 2009), http://www.docstoc.com/docs/47981803/Acid-
Therefore, for the objects from Revadim, the weakest acid available was chosen,applied in highly dilute form, and acid treatment was stopped before all of thesediment was dissolved due to concerns regarding the effects on the bone.
ConclusionsWork on all three scapulae required an ongoing dialogue betweenpalaeontologist and conservator and consideration of external restrictions,such as budget and facilities. Issues such as how much earth matrix toremove, what methods to apply when cleaning surfaces, correct alignmentand joining of bone fragments and how much gap-filling was necessary toachieve handling for research, were discussed constantly throughoutthe conservation process. The main considerations were the preservationof surface markings, the creation of supportive fills, the stability ofconservation materials and their reversibility. The end result was abalanced mixture of palaeontology and conservation.
Acknowledgements
We would like to thank the participants of the Revadim Quarryexcavation directed by Ofer Marder in collaboration with Ianir Mile-vski and Hamoudi Khalaily, from the Israel Antiquities Authority.The conservation was partially funded by the Israel AntiquitiesAuthority and by the Irene-Levi Sala CARE Foundation.
Abstract
Large bones present their own conservation problems. Three fossilelephant scapulae, received in different states of preservation,demonstrated the difficulties faced by a conservator on a lowbudget. Considerations included the state of preservation and theneed to prepare the objects for research rather than display. Sincethe elephant finds were part of a taphonomic research project, pre-serving the bone surfaces was of supreme importance. Fill materialshad to be light because of the need for researchers to handle theobjects post-conservation. Following studies of other cases of gap-filling, both in modern and ancient bones, and considering therestrictions and particular requirements of the materials available,a system was devised consisting of Japanese tissue impregnatedwith Paraloid B-72 in acetone applied in layers over a scaffoldingof rods, with a final layer of microcrystalline wax then beingapplied. The resultant fill was lightweight, reversible, relativelycheap, and unobtrusive to the researching scientists.
Resume
«Une tache d’elephant—la conservation de restes d’elephants pro-venant de Revadim Quarry, Israel»
Les grands os presentent des problemes de conservation specifi-ques. Trois omoplates d’elephants fossilises, recueillies dans desetats de conservation differents, ont mis en evidence les difficultesrencontrees par un restaurateur dote d’un petit budget. Les reflex-ions ont porte sur l’etat de conservation et la necessite de preparerles objets en vue de la recherche plutot que pour etre exposes.Comme les decouvertes d’elephants faisaient partie d’un projet derecherche en taphonomie, la preservation de la surface des os etaitd’une extreme importance. Les materiaux de comblement devaientetre legers en raison de la necessite pour les chercheurs de manipu-ler les objets apres conservation. Apres avoir etudie d’autres cas decomblements de lacunes, tant dans les os anciens que modernes, ettenu compte des restrictions et des contraintes particulieres concer-nant les materiaux disponibles, un systeme a ete mis au point,compose de papier japonais impregne de Paraloid B-72 dans del’acetone applique en couches sur un echafaudage de tiges, avecune couche finale de cire microcristalline. Le comblement obtenuetait leger, reversible, relativement peu cher et, du point de vuedes chercheurs scientifiques, discret.
Zusammenfassung
,,Eine Elephantenaufgabe - Die Konservierung von Elefantenuber-resten aus dem Revadim Steinbruch, Israel”
Grosse Knochen stellen spezifische Konservierungsproblemedar. Drei fossile Elefanten scapulae, die in unterschiedlichenErhaltungszustanden geliefert wurden zeigen die unterschiedli-chen Schwierigkeiten auf, mit denen ein Restaurator mit einemkleinen Budget konfrontiert werden kann. Berucksichtigtwurden unter anderem der Erhaltungszustand und dieNotwendigkeit, die Objekte fur die Forschung und nicht fureine dauerhafte Ausstellung zu praparieren. Da die Elefanten-funde Teil eines taphonomischen Forschungsprojekts waren,war es von uberragender Wichtigkeit, die Oberflachencharakter-istika der Knochen zu erhalten. Fullmaterialien mussten leichtsein, damit die Forscher die Objekte nach der Restaurierunggut handhaben konnen. Fallstudien anderer Fehlstellenerganzun-gen in modernen und in historischen Knochen folgend und unterder Berucksichtigung der spezifischen Materialvorgaben undBedingungen wurde ein System auf der Basis von Japanpapierentworfen. Das Japanpapier wurde mit Paraloid b-72 in Acetongetrankt und uber einem Gerust von Stabchen aufgebracht undanschließend mit einer Lage von mikrokristallinem Wachsbedeckt. Die so konstruierte Erganzung war leicht, reversibel,relativ kostengunstig und stellte fur die Forscher keinerleiBehinderung dar.
Resumen
“Una tarea de elefante-la conservacion de los restos de elefante de lamina de Revadim, Israel”
La conservacion de huesos grandes presenta sus propios pro-blemas. Tres fosiles escapula de elefante fueron recibidos en dis-tintos estados de preservacion, demostrando las dificultades a lasque se enfrentan los conservadores con un bajo presupuesto eco-nomico. Se incluyeron consideraciones sobre el estado de preser-vacion y la necesidad de preparar los objetos para suinvestigacion mas que para su exposicion. Como estos hallazgosformaban parte de un proyecto de estudio taxonomico era funda-mental preservar la superficie de los huesos. Los materiales derelleno tenıan que ser ligeros ya que los investigadores necesita-ban usar los objetos despues de su conservacion. Se estudiaronotros casos de rellenos de huecos, para huesos tanto antiguoscomo modernos, y finalmente se ideo un sistema usando papelJapones impregnado en Paraloid-72 en acetona, el cual fue apli-cado en capas sobre un andamiaje de varas con una capa finalde cera microcristalina. El resultado final fue ligero, reversible,relativamente barato y discreto para poder facilitar la investiga-cion cientıfica.
Preparation-of-fossils-using-Sulfamic-acid-a-weak (accessed April 28, 2013).
21 C.M. Nielsen-Marsh and R.E.M.Hedges, ‘Patterns of Diagenesis inBone II: Effects of Acetic Acid Treatmentand the Removal of Diagenetic CO3
22’,Journal of Archaeological Science 27, no.12 (2000): 1151–9, 1151.
22 See, for example, the changes in con-centrations suggested in 1948 (H.A.Toombs, ‘The Use of Acetic Acid in theDevelopment of Vertebrate Fossils’,Museum Journal 48 (1948): 54–5) and1976 (A.E. Rixon, Fossil Animal Remains:
their Preparation and Conservation (Univer-sity of London: The Athlone Press, 1976)).
An elephant task—conservation of elephant remains from Revadim Quarry, Israel 11
Gali Beiner started working with the archaeozoological collections atthe Hebrew University of Jerusalem, Israel when an undergraduatestudent of Archaeology. In 2001 she obtained an MA in Conservationfrom Durham University, UK. She has worked as a conservator at theIsrael Museum, the National Conservation Centre at NationalMuseums Liverpool and the Pitt Rivers Museum, Oxford. Gali hadalso acted as on-site conservator for excavations in Israel. She is cur-rently collections conservator of the National Natural History Collec-tions (NNHC) at the Hebrew University of Jerusalem.
Rivka Rabinovich’s interest in animal bones and their taph-onomy started as an Archaeology undergraduate. Her Masterswas on the faunal taphonomy of a Mousterian open air siteand her PhD focused on faunal exploitation in UpperPleistocene sites. She is currently the curator and director incharge of the palaeontological, archaeozoological and compara-tive osteological collections at the Hebrew University of Jerusa-lem. Her interest in elephants increased with the study ofRevadim Quarry site and has become a major topic of herresearch.
Paraloid B72:Rohm & Haas (Dow Chemical Company)Dow Chemical Customer InformationGroupHerbert H Dowweg 5Haven 461Ground Floor4542 NM HoekTerneuzenNetherlands
Cosmolloid 80H wax:Picreator Enterprises Ltd44 Park View GardensLondon NW4 2PNUK
Microjack:PaleoTools (formerly Murray Engineering)1006 West Hwy.13Suite 4Brigham CityUT 84302USA
Contact addresses
Gail Gali BeinerConservatorHebrew University of JerusalemPalaeontology LabNational Natural History CollectionsBerman BuildingEdmond J. Safra Campus, Givat RamJerusalem 91904IsraelEmail: [email protected]
Rivka RabinovichCurator and Scientific DirectorNational Natural History CollectionsLecturer, Institute of Archaeology and Insti-tute of Earth SciencesHebrew University of JerusalemPalaeontology LabBerman BuildingEdmond J. Safra Campus, Givat RamJerusalem 91904IsraelEmail: [email protected]
