Archaeological significance of the Palaeolithic charcoal assemblage from Krems-Wachtberg Otto Cichocki a, * , Bernhard Knibbe a , Isabella Tillich b a VIAS (Vienna Institute for Archaeological Science), Univ. of Vienna, Althanstr.14, A2-224, A-1090 Vienna, Austria b Austrian Academy of Sciences, Fleischmarkt 22, 1010 Vienna, Austria article info Article history: Available online xxx abstract At the Palaeolithic site of Krems-Wachtberg, numerous charcoal remains were excavated since 2005. They were concentrated in the living floor (layer 4.4), especially in fireplaces 1 and 2 and several pits, but also mixed into sediments above the living floor. Since 2008, VIAS dendrolab (Vienna Institute for Archaeological Science, University of Vienna) has been cooperating with the excavators to investigate these charcoal samples for wood species analysis, dendrochronological synchronization, and also to evaluate their palaeoclimatic potential. The dominant wood type is Pine, which includes the species Pinus sylvestris, Pinus mugo, and Pinus cembra/sibirica. Two other gymnospermous wood types were found among the samples. Several charcoal pieces belong to Picea abies/Larix decidua (which cannot be separated by means of wood anatomy) and a single specimen of Abies sp. was found. A single angiosperm wood remain was analysed as Fagus sylvatica. Dendrochronological investigations singled out a number of samples with very similar ring patterns, which obviously had been growing at the same time. As these clusters do not match each other, samples were either not contemporary or grew on climatologically differing places. As a result of these studies, we were able to ascertain the synchronous use of fireplaces 1 and 2 in at least one phase. The advanced methods of charcoal analysis described in this paper can be used for detecting and synchronizing set- tlement phases on many archaeological sites. In particular, it is possible to significantly enhance the temporal resolution achievable with 14 C-ages on wood charcoal. Ó 2013 Elsevier Ltd and INQUA. 1. Introduction On many Palaeolithic sites, large amounts of charcoal are often found together with silica artefacts, bones, and other findings (burials, objects of art), and in many cases the anatomical features of the wood species are still preserved. These charcoal samples therefore contain important information, which can be used in biological and ecological studies (e.g. Grosser,1977; Schweingruber, 1990; Gerisch, 2004) as well as for dendrochronological in- vestigations (e.g. Fermé and Villalba, 2011). This information can be used to enhance the interpretation of other archaeological on-site records, and may also provide independent ecological and clima- tological information (Damblon and Haesaerts, 2011). In the pre- sent paper we further explore all these topics, based on the detailed investigation of more than 2000 individual pieces of charcoal from the site of Krems-Wachtberg. 2. The archaeological site The site of Krems-Wachtberg is situated on a sloping plateau, the edge of which falls from 300 to 200 m above sea level southeast to the rivers Danube and Krems (Simon et al., 2013). Due to loess sedimentation during the glacial maximum, the former surface was about 6e8 m lower than today. This location provided an excellent view across the rivers of the animals migrating on the plain, which were hunted by the people living in this region. The site is located at the eastern end of a narrow valley (Wachau), where the river Danube enters a wide basin (Tullnerfeld). This entrance is a natural obstacle for animals migrating from the Wiener Becken and Hun- garian Plain to the west across the Tullnerfeld basin (Fig. 1). As the Danube was flowing as a braided river or in meanders, the low-lying river bed did not provide adequate resting places for the Palaeolithic hunters, who instead preferred a hillside camp location to avoid the wet and temporarily inundated grounds. On the other hand, a site in close vicinity to the two rivers must have provided large amounts of drift wood, which would have been a valuable resource, in comparison to the otherwise rather sparse tree * Corresponding author. E-mail address: [email protected](O. Cichocki). Contents lists available at SciVerse ScienceDirect Quaternary International journal homepage: www.elsevier.com/locate/quaint 1040-6182/$ e see front matter Ó 2013 Elsevier Ltd and INQUA. http://dx.doi.org/10.1016/j.quaint.2013.07.004 Quaternary International xxx (2013) 1e9 Please cite this article in press as: Cichocki, O., et al., Archaeological significance of the Palaeolithic charcoal assemblage from Krems-Wachtberg, Quaternary International (2013), http://dx.doi.org/10.1016/j.quaint.2013.07.004
Transcript
at SciVerse ScienceDirect
Quaternary International xxx (2013) 1e9
Contents lists available
Quaternary International
journal homepage: www.elsevier .com/locate/quaint
Archaeological significance of the Palaeolithic charcoal assemblagefrom Krems-Wachtberg
Otto Cichocki a,*, Bernhard Knibbe a, Isabella Tillich b
aVIAS (Vienna Institute for Archaeological Science), Univ. of Vienna, Althanstr. 14, A2-224, A-1090 Vienna, AustriabAustrian Academy of Sciences, Fleischmarkt 22, 1010 Vienna, Austria
1040-6182/$ e see front matter � 2013 Elsevier Ltd ahttp://dx.doi.org/10.1016/j.quaint.2013.07.004
Please cite this article in press as: Cichocki, OQuaternary International (2013), http://dx.d
a b s t r a c t
At the Palaeolithic site of Krems-Wachtberg, numerous charcoal remains were excavated since 2005.They were concentrated in the living floor (layer 4.4), especially in fireplaces 1 and 2 and several pits, butalso mixed into sediments above the living floor. Since 2008, VIAS dendrolab (Vienna Institute forArchaeological Science, University of Vienna) has been cooperating with the excavators to investigatethese charcoal samples for wood species analysis, dendrochronological synchronization, and also toevaluate their palaeoclimatic potential. The dominant wood type is Pine, which includes the speciesPinus sylvestris, Pinus mugo, and Pinus cembra/sibirica. Two other gymnospermous wood types werefound among the samples. Several charcoal pieces belong to Picea abies/Larix decidua (which cannot beseparated by means of wood anatomy) and a single specimen of Abies sp. was found. A single angiospermwood remain was analysed as Fagus sylvatica.
Dendrochronological investigations singled out a number of samples with very similar ring patterns,which obviously had been growing at the same time. As these clusters do not match each other, sampleswere either not contemporary or grew on climatologically differing places. As a result of these studies,we were able to ascertain the synchronous use of fireplaces 1 and 2 in at least one phase. The advancedmethods of charcoal analysis described in this paper can be used for detecting and synchronizing set-tlement phases on many archaeological sites. In particular, it is possible to significantly enhance thetemporal resolution achievable with 14C-ages on wood charcoal.
� 2013 Elsevier Ltd and INQUA.
1. Introduction
On many Palaeolithic sites, large amounts of charcoal are oftenfound together with silica artefacts, bones, and other findings(burials, objects of art), and in many cases the anatomical featuresof the wood species are still preserved. These charcoal samplestherefore contain important information, which can be used inbiological and ecological studies (e.g. Grosser,1977; Schweingruber,1990; Gerisch, 2004) as well as for dendrochronological in-vestigations (e.g. Fermé and Villalba, 2011). This information can beused to enhance the interpretation of other archaeological on-siterecords, and may also provide independent ecological and clima-tological information (Damblon and Haesaerts, 2011). In the pre-sent paper we further explore all these topics, based on the detailedinvestigation of more than 2000 individual pieces of charcoal fromthe site of Krems-Wachtberg.
ocki).
nd INQUA.
., et al., Archaeological significoi.org/10.1016/j.quaint.2013.0
2. The archaeological site
The site of Krems-Wachtberg is situated on a sloping plateau,the edge of which falls from 300 to 200m above sea level southeastto the rivers Danube and Krems (Simon et al., 2013). Due to loesssedimentation during the glacial maximum, the former surface wasabout 6e8 m lower than today. This location provided an excellentview across the rivers of the animals migrating on the plain, whichwere hunted by the people living in this region. The site is located atthe eastern end of a narrow valley (Wachau), where the riverDanube enters a wide basin (Tullnerfeld). This entrance is a naturalobstacle for animals migrating from the Wiener Becken and Hun-garian Plain to the west across the Tullnerfeld basin (Fig. 1).
As the Danubewas flowing as a braided river or inmeanders, thelow-lying river bed did not provide adequate resting places for thePalaeolithic hunters, who instead preferred a hillside camp locationto avoid the wet and temporarily inundated grounds. On the otherhand, a site in close vicinity to the two rivers must have providedlarge amounts of drift wood, which would have been a valuableresource, in comparison to the otherwise rather sparse tree
ance of the Palaeolithic charcoal assemblage from Krems-Wachtberg,7.004
Fig. 1. Topography of the valley of the Danube east of Krems (Wikipedia, publicdomain).
Fig. 2. Distribution of charcoal samples derived from excavations 2005e2008. Blackcrosses: point-measured (typically larger) pieces of charcoal; bold dots: flotationsamples (typically smaller) with tentative localization (centre of excavation squares).
O. Cichocki et al. / Quaternary International xxx (2013) 1e92
vegetation in the surrounding terrain. The site proximity near to therivers was of further importance, because pebbles from the Danubesediments were an important raw material for local tool production(Händel et al., 2008, 2009). Thearchaeological excavations (13m� 14marea) disclosed amain fireplace 1 (diameterw 1.5m) that was situatedon living floor 4.4, which is recognisable as a large concentric areadefined by a number of small pits. Within a wider concentric zone(w7 m diameter) a second fireplace 2 (to W) and burial 2 (to SE) wereuncovered.Within this zone, the concentration of charcoal decreases inradial direction away from the main fireplace 1. In the direct vicinity ofthis zone, a number of larger pits with 1e1.5 m diameter and burial 1(Einwögerer et al., 2008) are located (Händel et al., 2013).
3. Material
For the purposes of the present studies, we sampled more than2000 pieces of charcoal from the 2005 to 2008 excavations. The sizeof individual pieces varied between 5 and 30 mm. In an initialscreening step, pieces too small for further preparation were takenout of the sample, as well as those containing an insufficientnumber of rings. According to the excavation procedures, we thendistinguished between two categories of samples: (1) larger pieceswhich have an individual sample number and for which exact sitecoordinates (point-measurements) were available, and (2) smallerpieces which were extracted by water-flotation (the majority ofsamples), and for which site coordinates were available as cornersof a quarter of a squaremeter. Formapping purposes, these sampleswere given a tentative position in the centres of these squares. Inconsequence, the plots of all charcoal samples that were success-fully screened for dendrochronological studies show an artificialbias at the centres of the squares (Fig. 2, lines and crosses), as do theflotation samples, which are alsowithout exact individual locations.In comparison, the individually point-measured charcoal samples(Fig. 2, dots) are plotted with precise locations. Significantly, thesesamples provide a distinct outline for fireplace 1 and burial 1.
Having been picked from the layer, or from following flotation,all charcoal samples were packed in small plastic bags, which werenot completely sealed to allow slow drying. This is important, asotherwise the samples may become mouldy or crumble away.Wood anatomical studies require that all samples must becompletely dry. To avoid mechanical pressure or blows, whichwould further fracture the single pieces and thus complicate theinvestigation, the plastic bags were packed into boxes.
Please cite this article in press as: Cichocki, O., et al., Archaeological significQuaternary International (2013), http://dx.doi.org/10.1016/j.quaint.2013.0
4. Methods
For investigation, the content of a single bag is first inspectedunder a binocular microscope. Larger pieces and all irregularshapes are extracted, placed into a separate container, weightedand labelled. A selected square surface of each charcoal sample isthen ground to produce an even surface that allows visible in-spection and photography. On this square surface, a first diagnosisof the wood species is performed (gymnosperm or angiosperm,rays, resin ducts, estimation of ring number). All conspicuoussamples are then further separated for detailed microscopicinvestigation. For dendrochronological measurements, samples areglued to electron microscope stubs in a properly oriented positionand ground. After coating with gold, one or more series of over-lapping microphotographs are shot and linked together to onepicture of one radius of the sample. The mosaic picture is processedwith the software OSM4 (On-ScreenMeasurement, developed by B.Knibbe) and ring widths are measured to an accuracy of 0.01 mm.The resulting growth data are then transferred to the programPAST5 (Personal Analysis System for Tree-ring research, developedby B. Knibbe) and further processed and synchronized. As manyrings are rather tiny and even ground surfaces are never completelyplain (i.e. coplanar with the mounting stub), we used an electronmicroscope (JEOL JSM-6300) to combine high magnification withsufficient focal depth to produce sharp photographs. A disadvan-tage of this method is that, due to the high magnification (100e200fold), it was necessary to process a large number of overlappingphotographs. Altogether, for the 2578 investigated radii, a total of16,261 photographs were made. After mounting the single photosin correct overlapping positions, we then measured the ring widthsby determining and marking the ring borders on screen. Eachradius produced a set of ring-width data. If two or more radii of thesame specimen were measured, the mean of the series was calcu-lated and used for synchronization.
ance of the Palaeolithic charcoal assemblage fromKrems-Wachtberg,7.004
Fig. 5. Cone of P. cembra with nutlets.
Fig. 3. Ring pattern typical for P. cembra (Wa37606).
O. Cichocki et al. / Quaternary International xxx (2013) 1e9 3
5. Results
5.1. Wood species analysis
The majority of samples from the Wachtberg site are membersof the genus Pinus. The species Pinus sylvestris and Pinus mugo arenot distinguishable by anatomic features (Schweingruber, 1990).Although Pinus cembra has different ray features, these are rarelypreserved in charcoal and are difficult to distinguish under theelectron microscope. The latewood zones of these species areconstructed in different ways: P. cembra has thin-walled latewoodtracheids with smooth transition (Fig. 3), and P. sylvestris/mugo bothhave distinct latewoodwith thick tracheid walls (Fig. 4). As sampleswith all intermediate stages of these features as well as with bothfeatures in one sample do exist, species determination is difficult.One direct hint towards the presence of P. cembra is the existence ofa small carbonized cone (Fig. 5). The surface of this cone is notcompletely preserved (the tips of the scabs are missing), but insidenutlets are visible, typical for P. cembra. Utilizing these properties, itwas possible to determine all samples fromWachtberg on the levelof species Pinus sp. (cf. sylvestris, mugo, cembra). This knowledge isuseful for further ecological and climatological conclusions, as allthree species of Pinus are known to be more or less equally droughtand frost resistant, and have similar frugal nutrition demands.
Some charcoal specimens belong to Picea abies/Larix decidua.The two genera are not distinguishable by anatomic features. Onthe square section they are appear somewhat similar to Pinuswood,but show different resin duct cells (which are rarely preserved) aswell as different crossfield pittings on the radial section (Pinus has
Fig. 4. Ring pattern typical for P. sylvestris/mugo (Wa27479).
Please cite this article in press as: Cichocki, O., et al., Archaeological significQuaternary International (2013), http://dx.doi.org/10.1016/j.quaint.2013.0
fenestroid (¼window-like) pits) (Fig. 6). In comparison, Picea/Larixhave small slits (Fig. 7). Larix is very frost resistant and forms highalpine forests up to the timber line together with Pinus cembra,sometimes with Picea abies (Aas, 2012). In contrast to previousresults of charcoal investigations from the “old” Wachtberg exca-vation conducted by J. Bayer in 1930 (Cichocki, 2000), we havefound no clear evidence for the occurrence of Abies sp. (Abies albaand sibirica cannot be distinguished by means of wood anatomy).One sample showed crossfield pits similar to Abies sp. (Fig. 8) and
Fig. 6. Cross field pits of P. sylvestris/mugo (Wa96867_1).
ance of the Palaeolithic charcoal assemblage from Krems-Wachtberg,7.004
Table 1Internal synchronization results of subset 9
TBP THO GL % Significancetest GL
Sub 9 Average Sync results 8.79 8.89 76.1Wa87019_Mean Value 5.96 6.03 68 ##Wa71154_21 6.65 8.45 67.1 #Wa74231_Mean Value 5.69 6.05 69 ###Wa85923_Mean Value 6.21 6 71.5 ###Wa71968_4_1 6.5 8 83 ###Wa70484_Mean Value 8.03 8.05 75 ###Wa85350 Mean Value 7.54 7.2 70.5 ###Wa70260-Mean Value 12 13.6 83.2 ###Wa71968_5_Mean Value 10.4 10.5 78.5 ###Wa19771_Mean Value 11.4 12.4 88.4 ###Wa23775 9.82 9.13 75 ###Wa19771 mean value 11.4 12.4 88.4 ###
Fig. 7. Cross field pits of Picea/Larix (Wa96868_1).
O. Cichocki et al. / Quaternary International xxx (2013) 1e94
the tiny square surface did not show any resin ducts. These featureswould indeed be typical for Abies sp. Wood, but the single samplewas too small for further conclusions.
The only angiosperm charcoal found at this site is a semi-ringporous wood with broad and narrow rays and thick-walledlatewood cells (Fig. 9). The tiny piece is likely to represent Fagussylvatica wood. In temperate climate this species today formsmixed forests together with Pinus sylvatica. In East Europeanmountains with heavy snowfall, F. sylvatica occurs at the timber line(Fanta, 1981).
5.2. Dendrochronology
Most samples comprise small pieces with up to 50 rings. Aroundone third of the selected samples contained between 50 and 100rings and only 10% have more than 100 rings. The sample with thelongest sequence has 328 rings. Approximately 15% of the samplescontain the pith, which is the centre of the stem/branch. Accordingto the degree of bending of the ring borders, most samples are frombranches (Fig. 10) or small stems. The proportion of material fromouter portions of stems or bigger branches is much higher than ofthe inner portions, which makes it difficult to estimate the
Fig. 8. Cross field pits of Abies sp. (Wa107527_2).
Please cite this article in press as: Cichocki, O., et al., Archaeological significQuaternary International (2013), http://dx.doi.org/10.1016/j.quaint.2013.0
percentage of thin and thick pieces of wood originally used forfiring. Reconstruction of the original stem diameter in dendro-chronology is usually done with the core length (Bakker, 2005),which is not available in charcoals. Additionally, the charcoalsamples were too small to give an exact estimation of the bendingradius. Hence it was not possible to apply the ring curvaturemethod to reconstruct the stem diameter (Müller, 2007). Inbranches/stemswith eccentric growth (reactionwood) this methodfails because of the changing width of a single ring along itscircumference. In consequence, we characterized our samples inqualitative terms (recorded pith, narrow bending, flat bending,almost no bending).
Unfortunately only very seldom was the “waney edge” (¼thelast ring underneath the bark, lain down in the year before the treedies) preserved (Fig. 10). This complicates the interpretation of datafor growth synchronization purposes. Hence, a large number ofsamples are necessary to provide statistically significant results.
As the similarity of ring patterns (change of wide and narrowrings) is the basic tool of dendrochronology, we compared thelonger data sets with each other to find the fitting ones. Several setsof matching data emerged, three of these are presented and dis-cussed in this paper.
5.2.1. Data set Sub9This is composed only from charcoals from fireplace1 and few
flotation samples This data set contains 19 subsets of data of singlepieces of charcoal, two of which yielded 14C data (Einwögerer et al.,2009; Tables 1 and 2).
Wa69890_1 11.7 9.97 73.9 ###Wa85379_2_Mean Value 7.01 7.04 69.5 ###Wa69890_10_Mean Value 6.25 6.93 76.2 ###Wa71968_1 12.1 10.5 72.9 ###Wa24879 Mean Value 9.76 8.81 80.1 ###Wa74344_Mean Value 8.9 8.57 76.5 ###Wa84935_3_Mean Value 9.51 9.32 78.8 ###
Table 214C data of SUB9.
Lab nr. Find nr. Quad. Strat. Record C14 date uncalib.
VERA 3935 ID 19771 GH 26 AH 4.4 G2 Hearth 27.220 þ 230/�220VERA 3941 ID 23775 GH 26 AH 4.4 H3 Living
floor26.870 � 220
It is not possible to decide howmany phases (¼fires in temporaldistance) are included in this subset. As many of the subsets endat �49, this might provide a hint towards the existence of a com-mon cutting year, but this conclusion requires much more similarlyfitting data for confirmation.
ance of the Palaeolithic charcoal assemblage fromKrems-Wachtberg,7.004
O. Cichocki et al. / Quaternary International xxx (2013) 1e9 5
5.2.2. Data set Sub11This set (35 samples) consists of two subsets connected by a
very long single sample (Wa87801, 190 rings, Fig. 11). Both subsetsare internally and with each other well-fitting (Tables 3 and 4). Theright set contains a sample providing a 14C date (Einwögerer et al.,2009; Table 5).
Table 3Internal synchronization results of subset 11
Point-measured samples from fireplace 1 are mixed withflotation samples, both found within the concentration of charcoalsfrom this hearth. The two data subsets are 144 years apart. Thismight be indicative of a two-phase usage of the same fireplace.
Please cite this article in press as: Cichocki, O., et al., Archaeological significQuaternary International (2013), http://dx.doi.org/10.1016/j.quaint.2013.0
In its middle part, Sub11 has a very high similarity to Sub9, butsimilarity fades away on both sides. Although the samples were re-measured, no error was identified. An explanation might bemissing rings. As quite a number of rings are only two or three cellswide (Fig. 12), these trees were clearly at their survival limits. Insuch cases, some rings did not grow around all the circumference ofthe stem/branch. Hence, should this side of the ring be missing, thiscan only be detected by synchronization with a tree having thatring. This problem requires further research on larger data sets.
5.2.3. Data set Sub12This subset again has good statistical values for its coherency
(Table 6). Subset 12 has no similarity to other existing subsets. Itcontains samples from fireplace 1 and fireplace 2 (Fig. 13). There isevidence for the synchronous use of both fireplaces in a certainphase, which presently remains chronologically floating. Theindentation of end years might denote two different phases, butthis needs more fitting samples to verify the hypothesis (Fig. 14).
6. Discussion
The massive agglomeration of charcoal, particularly in fireplace1, hints towards a long-term use of this site location. The existenceof different use-phases is already indicated by the observedcompaction of several thin sediment layers into one combinedlayer. Nevertheless, it is archaeologically inherently difficult toclearly record as well as to correctly interpret such microstructures,since isochronous and nonsynchronous samples are mixedtogether into the same layer. This also provides a viable explanationfor the occurrence of clearly different subsets of internally well-fitting data from the same location. Another reason may be in themixture of locally grown wood along with isochronous driftwood
ance of the Palaeolithic charcoal assemblage from Krems-Wachtberg,7.004
O. Cichocki et al. / Quaternary International xxx (2013) 1e96
from distant places (with different micro-climatic influence), andwhich could therefore differ in their ring patterns, although growncontemporaneously.
To complete our studies, three samples were submitted to theVERA-14C-AMS laboratory for radiocarbon dating, with resultsshown in Table 7. Two of these samples (VERA 3935 and VERA3941) were measured on different pieces of charcoal, but thedendrochronological sequence indicates they derive from thesame calendar year (relative end year: �155) and for which the14C-ages should therefore be identical. This is assessed by a sta-tistical test (based on Chi-square) which gives a probability of
Fig. 9. Fagus sylvatic
Table 714C data and relative position from dendrochronological synchronization
Lab nr. Find nr. Quad. Record
VERA 3938 ID 22056 G2 Pit 3VERA 3935 ID 19771 G2 HearthVERA 3941 ID 23775 H3 Living
floor
Please cite this article in press as: Cichocki, O., et al., Archaeological significQuaternary International (2013), http://dx.doi.org/10.1016/j.quaint.2013.0
26% that the two 14C-ages may be combined. Furthermore, theweighted 14C-age of 27,041 � 157 BP of these two samples isclearly also statistically identical with the 14C-age of the thirdsample (VERA-3939: 27,000 � 220 BP). However, an averaging ofall three 14C-ages would not be truly meaningful, due to theknown (dendrochronologically derived) calendrical age differ-ence � 117 yrs (Table 7). Calibration used the presently recom-mended Hulu-based INTCAL09 data set (Reimer et al., 2009). Allthree ages point clearly to the beginning of the Würm Stadialphase that follows Interstadial 5 as documented in Greenland icecores.
ance of the Palaeolithic charcoal assemblage fromKrems-Wachtberg,7.004
Fig. 10. Twig with pith and waney edge (Wa98528_13).
Fig. 12. One tiny ring (two cells wide, Wa68150).
O. Cichocki et al. / Quaternary International xxx (2013) 1e9 7
Wood species analysis produced a monotonous spectrum ofPinus sp. (cf. P. cembra/sibirica, possibly P. sylvestris, P. mugo), P.abies/L. decidua, A. alba/sibirica (a single dubious sample) and F.sylvatica (a tiny single sample). All species (Abies to a lesserdegree) can endure drought and low temperatures, as todaythey grow well in such habitats and also form forests up to thetimber line (or even tree line). The extremely narrow rings,traumatic resin ducts and other growth abnormalities arefurther indicators of harsh and unfavourable conditions at leastfor short periods in this (probably pre-stadial) section of thePalaeolithic.
On the one hand, within given error limits the calibrated 14C-ages confirm the close temporal proximity of the fireplaces 1 and 2,as deduced from the tree ring sequence. On the other hand, theoverall resolution of the 14C-method is presently still insufficient toallow a clear differentiation of the age of the study samples on thecalendric time scale, as is only possible by dendrochronological
Fig. 11. Subset Sub11, inte
Please cite this article in press as: Cichocki, O., et al., Archaeological significQuaternary International (2013), http://dx.doi.org/10.1016/j.quaint.2013.0
procedures. Another obstacle to provide better resolution by 14C isthe necessity to combine many of the tiny rings to a mixed sample,which prevents wiggle-matching. Nevertheless, the combination ofboth dating methods does at least demonstrate the plausibility ofusing the method of matching tree-ring patterns to provide a site-internal (relative) chronology for the Gravettian occupation atKrems-Wachtberg.
Some of the samples show degradation (cell walls and theiranatomical features as pits, Fig. 15). This might give a hint towardswood being exposed to weathering for some time, which had beencollected for fire wood as dead wood or drift wood. Artefacts incharcoal are also produced at high heat during the carbonizationprocess. Such cracks or decomposition of cell wall structure can beused to reconstruct temperatures at this process (Ascough et al.,2010). Finally some pieces of charcoal show a relief on their sur-face, which is caused by mechanical impact on the single charcoalpieces after carbonization. Archaeological experiments have pro-duced similar effects, when charcoal is driven around by wind afterthe fire is extinguished (Einwögerer et al., 2003; Einwögerer andSimon, 2004). Depending on the surrounding material and micro-relief (stones around the fireplace, pit) and time of exposure thethin early wood cells are more degraded than thick late wood andproduce this distinct relief.
rnal synchronization.
ance of the Palaeolithic charcoal assemblage from Krems-Wachtberg,7.004
Fig. 13. Subset Sub12, internal synchronization.
O. Cichocki et al. / Quaternary International xxx (2013) 1e98
7. Conclusions and prospects
The study of tree rings of Palaeolithic charcoal samples allowsrelative dating of chronological phases on archaeological sites,which otherwise cannot be resolved. Although the samples arerelatively small, the number of preserved rings is impressive,indeed unexpected. As larger pieces of wood will have fallen apartduring the fire, and as the charcoal remains are further fractured bychanges in temperature, moisture and mechanical impacts duringtheir stay in the sediment and also due to the excavation process, itwas necessary to reconstruct the original wood pieces by complexprocedures. Simple mechanical refitting of the small charcoalpieces, similar to pottery refitting, would not have helped, as thefitting areas are far too small. Instead, we have used wood-anatomical methods in combination with dendrochronologicalprocedures to identify which charcoal pieces derive from the sameor from different stems/branches. We first created a number of data
Fig. 14. Subset Sub12 e spatial distribution of included samples.
Please cite this article in press as: Cichocki, O., et al., Archaeological significQuaternary International (2013), http://dx.doi.org/10.1016/j.quaint.2013.0
sets, in which each individual piece of wood is described, and thesedata sets are then used as basic units for further synchronization.Due to the time consuming character of these studies, they requiredfurther input of archaeological data e.g. the exact site-location (andin particular the packaging) of the charcoal pieces (which hadpartly fallen apart) in order to reconstruct the different stems/branches. With this data combination it was, in many cases,possible to reconstruct the temporal depth of the site with previ-ously unachievable dating resolution. In consequence, it is nowpossible to trace the exact contemporaneity or staggered use ofneighbouring sites, which will help in reconstructing e.g. huntinghabits and short term migrations. In addition, since tree ringgrowth is controlled by climatic factors, it is possible to reconstructsome of the major driving climatic factors directly from the ringdata. Both ring width as well as density are useful parameters inthis respect, but deriving such data from charcoal samples isespecially challenging. In this paper we focussed our efforts on thestudy of ring width, which is highly dynamic (as can be seen fromthe samples from Krems-Wachtberg), and therefore provides the
Fig. 15. Decomposition of cell wall layers (Wa107832_2).
ance of the Palaeolithic charcoal assemblage fromKrems-Wachtberg,7.004
O. Cichocki et al. / Quaternary International xxx (2013) 1e9 9
most promising study variable. Tree growth is not only under cli-matic control, but is also affected by many other factors, includinginsect attack and geological processes (e.g. soil movement, aerialsoil transport and sedimentation). Although it is generally difficultto differentiate between these different active factors, and inparticular to quantify the degree of their influence, the dedicatedstudy of the climatological archive as preserved in tree rings isnevertheless capable of providing a detailed image of climatic shortterm oscillations in terms of temperature and precipitation, whichin turn can be matched (and thus help to explain) the phases ofrecovery and/or abandonment of the archaeological site, and inparticular its duration. We conclude that the synopsis of resultsfrom an interdisciplinary site investigation is indeed capable ofproviding a detailed reconstruction of the environmental historyduring the Gravettien, as postulated e.g. by Simon and Händel(2010), Neugebauer-Maresch (2010), and Haesaerts et al. (2010).
Acknowledgments
This research, which is still in progress, was conducted withfinancial support by FWF (Austrian Science Fund P-17258-G02, P-19347, P-21660-G19, P-23612-G19, excavation of charcoal samples,employment of I. Tillich), and with logistic support by VIAS (ViennaInst. for Archaeological Science). We were encouraged by manyhelpful discussions with the excavators (Chr. Neugebauer-Maresch,T. Einwögerer, M. Händel and U. Simon, Academy of Science,Vienna), with G. Trnka (Institute of Prehistory and HistoricalArchaeology, University of Vienna) and by the valuable and helpfulinput of the reviewer of this paper.
References
Aas, G., 2012. Die Europäische Lärche e Taxonomie, Verbreitung, Morphologie. In:Bayerische Landesanstalt für Wald und Forstwirtschaft, LWF-Wissen 69, pp. 7e12.
Ascough, P.L., Bird, M.I., Scott, A.C., Collinson, M.E., Cohen-Ofri, I., Snape, C.E., LeManquais, K., 2010. Charcoal reflectance measurements: implications forstructural characterization and assessment of diagenetic alteration. Journal ofArchaeological Science 37, 1590e1599.
Bakker, J.D., 2005. A new, proportional method for reconstructing historical treediameters. Canadian Journal of Forest Research 35, 2515e2520.
Cichocki, O., 2000. Xylotomische Untersuchungen an paläolothischen Holzkohle-funden. In: Einwögerer, Th (Ed.), Die jungpaläolothische Station auf demWachtberg in Krems, NÖ. Eine Rekonstruktion und wissenschaftliche Darle-gung der Grabung von J. Bayer aus dem Jahre 1930. 204 S. Verlag der Österr.Akademie der Wissenschaften, Wien.
Damblon, F., Haesaerts, P., 2011. Charcoal as tracer of local tree taxa in the Pleis-tocene loess field of Central Europe. Which relationship with flora, vegetation,landscape or climate? Saguntum 11, 27e29. Valencia.
Please cite this article in press as: Cichocki, O., et al., Archaeological significQuaternary International (2013), http://dx.doi.org/10.1016/j.quaint.2013.0
Einwögerer, T., Händel, M., Neugebauer-Maresch, Chr., Simon, U., Teschler-Nicola, M., 2008. The Gravettian Infant Burials from Krems-Wachtberg. In:British Archaeological Reports International Series 1832, vol. 24, pp. 15e19.
Einwögerer, T., Händel, M., Neugebauer-Maresch, C., Simon, U., Steier, P., Teschler-Nicola, M., Wild, E.M., 2009. 14C dating of the Upper Palaeolithic Site at Krems-Wachtberg, Austria. Radiocarbon 51 (2), 847e855.
Einwögerer, Th., Simon, U., 2004. Experimentelle Feuerstellen auf Lösssediment.Experimentelle Archäologie in Europa. Bilanz 2004, Heft 3, 79e84. Oldenburg.
Einwögerer, Th, Simon, U., Einwögerer, Chr, 2003. Experimente zur Genese paläoli-thischer Feuerstellen auf Lösssedimenten. Archäologie Österreichs 14 (2), 22e26.
Fanta, J., 1981. Fagus sylvatica L. und das aceri-fagetum an der alpinen Waldgrenzein Mitteleuropäischen Gebirgen. Plant Ecology 44, 13e24.
Fermé, L.C., Villalba, R., 2011. Dendrochronological study of charred wood at theCerro Pintado archaeological site (Patagonia, Argentina). Saguntum 11, 37e39.Valencia.
Gerisch, R., 2004. Holzkohleuntersuchungen an pharaonischem und byzantini-schem Material aus Amarna und Umgebung. In: Münchner ÄgyptologischeStudien, vol. 53. Mainz, von Zabern.
Grosser, D., 1977. Die Hölzer Mitteleuropas. Springer, 208 S., Berlin.Haesaerts, P., Bachner, M., Borziak, I., Chirica, V., Damblon, F., Drozdov, N.,
Koulakovska, L., Pirson, S., 2010. New insight on the environmental backgroundand the chronology of the Early Upper Palaeolithic in Central Europe. In:Neugebauer-Maresch, C., Owen, L. (Eds.), New Aspects of the Central andEastern European Upper Palaeolithic e Methods, Chronology, Technology andSubsistence. MPK 72, Vienna 2010.
Händel, M., Einwögerer, T., Simon, U., 2008. Krems-Wachtberg e a Gravettian Set-tlement Site in the Middle Danube Region. In: Wiss. Mitt. NiederösterreichLandesmuseum, vol. 19, pp. 91e108.
Händel, M., Simon, U., Einwögerer, T., Neugebauer-Maresch, C., 2009. New excava-tions at Krems-Wachtberg e approaching a well-preserved Gravettian settle-ment site in the middle Danube region. Neue Ausgrabungen am KremserWachtberg e Annäherung an einen gut erhaltenen Siedlungsplatz des Grave-ttien im mittleren Donauraum. Quartär 56, 187e196.
Händel, M., Einwögerer, T., Simon, U., Neugebauer-Maresch, C., 2013. Krems-Wachtberg Excavations 2005e12: Main Profiles, Sampling, Stratigraphy and SiteFormation (in this volume).
Müller, A., 2007. Jahrringanalytische Untersuchungen zum Informationsgehalt vonHolzkohle-Rückständen der historischen Meilerköhlerei. Albert-Ludwigs-Uni-versität Freiburg, Diss.
Neugebauer-Maresch, C., 2010. Archaeological and palaeoecological studies ofpalaeolithic industries before the Last Glacial Maximum between 32,000 and20,000 BP. Investigations, results and new questions. In: Neugebauer-Maresch, C., Owen, L. (Eds.), New Aspects of the Central and Eastern EuropeanUpper Palaeolithic e Methods, Chronology, Technology and Subsistence. MPK72, Vienna 2010.
Reimer, P.J., Baillie, M.G.L., Bard, E., Bayliss, A., Beck, J.W., Blackwell, P.G., BronkRamsey, C., Buck, C.E., Burr, G.S., Edwards, R.L., Friedrich, M., Grootes, P.M.,Guilderson, T.P., Hajdas, I., Heaton, T.J., Hogg, A.G., Hughen, K.A., Kaiser, K.F.,Kromer, B., McCormac, F.G., Manning, S.W., Reimer, R.W., Richards, D.A.,Southon, J.R., Talamo, S., Turney, C.S.M., van der Plicht, J., Weyhenmeyer, C.E.,2009. IntCal09 and Marine09 radiocarbon age calibration curves, 0-50,000years cal BP. Radiocarbon 51 (4), 1111e1150.
Schweingruber, F., 1990. Anatomie europäischer Hölzer, 800 S., Haupt, Bern.Simon, U., Händel, M., 2010. Interdisziplinäre Forschungsansätze und Geländeun-
tersuchungen an der jungpaläolithischen Fundstelle Krems-Wachtberg, Öster-reich. Pangeo Austria 2010, Abstract Volume. Journal of Alpine Geology 52,229e230.
Simon, U., Händel, M., Einwögerer, T., Neugebauer-Maresch, C., 2013. The Archae-ological Record of the Gravettian Open Air Site Krems-Wachtberg (in thisvolume).
ance of the Palaeolithic charcoal assemblage from Krems-Wachtberg,7.004
