Radiocarbon Dating of Charcoal and Bone Collagen Associated With Early Pottery at Yuchanyan Cave, Hunan Province, China Elisabetta Boaretto1,2, *, Xiaohong Wu3,*, Jiarong Yuan4, Ofer Bar-Yosef5, Vikki Chu2, Yan Pan3, Kexin Liu6, David Cohen7, Tianlong Jiao8, Shuicheng Li3, Haibin Gu 4, Paul Goldberg9, Steve Weiner10 1. Department of Land of Israel Studies, Bar Ilan University, 52900 Ramat Gan, Israel. 2. Radiocarbon Dating and Cosmogenic Isotopes Laboratory, Kimmel Center of Archaeological Science, Weizmann Institute of Science, 76100 Rehovot, Israel 3. School of Archaeology and Museology, Peking University, Beijing 100871, China 4. Hunan Institute of Archaeology, China 5. Anthropology Department, Harvard University, Cambridge, MA02138, USA 6. School of Physics, Peking University, Beijing 100871, China 7. International Center for East Asian Archaeology and Cultural History, Boston University, Boston, MA 02215 USA 8. Department of Anthropology, Bishop Museum, Honolulu, Hawaii, USA 9. Department of Archaeology, Boston University, Boston, MA 02215 USA 10. Department of Structural Biology and the Kimmel Center for Archaeological Science, Weizmann Institute of Science, 76100 Rehovot, Israel *Corresponding Authors Dr. Elisabetta Boaretto e-mail Elisabetta.Boaretto@weizmann.ac.il Telephone: 972-8-9343213 Fax: : 972-8-9346062 Dr. Xiaohong Wu e-mail wuxh@pku.edu.cn Telephone: 86-10-62755264 Fax : 86-10-62751667

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Manuscript information: Number of text pages (including references and figure legends): 19 Number of figures: 4 Number of supplementary Figures: 2

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Abstract Yuchanyan Cave in Daoxian County, Hunan Province (PRC), yielded fragmentary remains of two or more ceramic vessels, in addition to large amounts of ash, a rich animal bone assemblage, cobble and flake artifacts, bone tools and shell tools. The artifacts indicate that the cave was a Late Paleolithic foragers’ camp. Here we report on the radiocarbon ages of the sediments based on analyses of charcoal and bone collagen. The best-preserved charcoal and bone samples were identified by prescreening in the field and laboratory. The dates range from around 13,800 years cal BP to 21,000 years cal BP. We show that the age of the ancient pottery ranges between 15,430 and 18,300 years cal BP. Charcoal and bone collagen samples located above and below one of the fragments all produced dates of around 18,000. These ceramic potsherds therefore provide some of the earliest evidence for pottery making in China.

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\bodyIntroduction Numerous caves in the vast karstic landscape of the southern area of the Yangzi River basin of China are known to have been inhabited by hunter-gatherer groups during the Late Pleistocene and early Holocene. The generally good preservation of the cave deposits and the presence of rich archaeological assemblages, including stone, bone, and shell tools, have led to a large number of excavations since the 1980s. While similarly well-preserved Late Pleistocene cave sites are found in other regions of the world, the cave sites in this region of South China (as well as several sites in neighboring Japan and the Russian Far East) are unique due to the presence of ceramic vessels in their otherwise Late Paleolithic assemblages. Among the wellknown sites in China from this period are Xianrendong and Diaotonghuan in Jiangxi Province (1-4), Miaoyan in Guangxi Province (5, 6), and Yuchanyan in Hunan Province (7). Previous studies of these sites have produced dates for this pottery ranging ca. 16,000-10,000 cal BP, (815), indicating that the world’s first pottery was produced in East Asia. Many of these studies do not report a systematic analysis of the ages of the strata within the site, and in particular those containing the potsherds. Here we date the stratigraphic sequence deposited in Yuchanyan Cave, paying particular attention to the strata in close proximity to the potsherds. Chinese Late Paleolithic sites such as Yuchanyan are rich in terrestrial and aquatic fauna, including deer, boar, birds, tortoises, fish, and various small mammals. Rice phytoliths and husks have been identified at Xianrendong, Diaotonghuan, and Yuchanyan, and several studies have attempted to differentiate wild and domestic species or to suggest an incipient stage of cultivation (4, 16, 17). Because of the presence of such plant remains and early pottery, these caves are often seen as the predecessors of the early Holocene open-air Neolithic villages found in the alluvial plain of the Yangzi river and its tributaries, such as the Pengtoushan and Bashidang sites, and other settlement sites of the Pengtoushan Culture (18, 19). Paleoclimatic data for the region suggest similar trends to those reported globally (20). The last glacial maximum (LGM) ca. 23,000-18,000 cal BP led to lower temperatures and increased aridity, with average temperatures in the Yangzi basin ca. 4-5°C cooler than today (21). Deciduous trees were increasingly replaced by grasses (22, 23). The Terminal Pleistocene warming was interrupted by the Younger Dryas ca. 13,000-11,500 cal BP. Although the Younger Dryas is seen in other regions as a generally cold and dry period, in South China the main effect of the Younger Dryas was probably the sudden onset of greater seasonality.

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Understanding the local impact of the Younger Dryas on the basin of the Yangzi River and in particular in the limestone region south of the main river channel is still not possible (20). While there have been previous excavations of Late Pleistocene cave sites in the Yangzi Basin, the dating of these sites has been problematic. First, the complex deposition of interdigitating lenses of ashes, clays, and sometimes fine gravel requires systematic dating based on a series of radiocarbon determinations, and this has been lacking. Secondly, accurate and precise radiocarbon dating of these sites in the past has proven to be difficult. While excavators of the cave sites have cited the cause as contamination from calcium carbonate in the karstic environment of the cave (2), this problem actually may be related to the presence of large amounts of calcite in the archaeological matrix of the caves. This can indirectly result in poor charcoal preservation (24). Here we apply a pre-screening strategy for identifying the best-preserved bone collagen and charcoal samples. We then analyze 29 prescreened samples for radiocarbon contents. This results in a much clearer understanding of the chronology of Yuchanyan Cave and the age of the pottery found in this site, as compared to other Late Pleistocene caves in East Asia. Excavations in Yuchanyan Cave Yuchanyan Cave (N 25°30’, E 111°30’) is located in Daoxian County, ca. 450 km south of the main course of the Yangzi River (Fig. 1 inset). The cave is 12-15 m wide along its east-west axis and about 6-8 meters wide from north to south. The uppermost deposits were removed in historical time. The cave was first excavated in 1993 and 1995 by one of the authors (J.Y.), who uncovered two clusters of potsherds indicating the presence of two vessels. A piece of charcoal closely associated with the potsherds was dated to 16,700 – 15,850 cal BP and organic residue from the ceramic to 17,750 – 16,900 cal BP ((7, 16, 17, 25) see Table 1). The pottery was coarsely made, with thick, uneven walls up to 2 cm thick, and was fired at low temperatures. Infrared spectra indicate that the firing temperature was between 400 and 500ºC, with kaolinite being a major clay component (unpublished observation). Due to the crumbly state of the sherds, only one pot could be reconstructed. Its form features a round rim 31 cm in diameter and a pointed base—a type known in the Chinese literature as a fu cauldron. The vessel has a height of 29 cm. Both the interior and exterior surfaces were impressed, possibly with cordage (7). The 1993 and 1995 excavations at Yuchanyan opened an area of 46 square meters, with an excavation grid subdivided into squares (Fig. 1). During the excavations in 2004-2005, we subdivided the large rectangular square T1 into 1 x1 m squares and added, along the baulk 4

between T1 and T3, four 1 x1 m squares, T10-T13. These were subdivided into four quadrants of 50 x 50 cm (Fig.1). We also excavated a one meter square in T4 and cleaned all the sections in order to clarify the exposed stratigraphy. In addition to the radiocarbon dating reported here, we studied site formation processes using micromorphology and mineralogy. A taxonomic and taphonomic study of the fauna was also carried out ((26) submitted). The small collection of lithic artifacts recovered was recently recorded and found to reflect the same tool categories known from the first excavations, dominated by core-choppers and retouched flakes. A few bone and shell tools were reported previously (16). Results Cave Sediments The bedrock of Yuchanyan cave slopes steeply from the east, where it is about 2.0 m below datum, to the west, where it is 3.2 m below datum. The cave can be roughly sub-divided into 3 main areas differentiated mainly by major rockfalls. The western area (mainly square T1) is composed of two major lithostratigraphic units: the uppermost intact unit is composed of ~ 80 cm of calcareous anthropogenic deposits resulting from numerous burning events. Specifically, they are stringers composed of white and light gray calcitic ash lenses, that in cases overlie discontinuous bands of red clay which are ~ 1 – 3 cm thick by ~ 30 – 50 cm long. The many ashes and red bands are compact and massive, with mm size aggregates of red clay (Figs. 2 and S1). Well bedded lenses with varying white and red colored fine-grained sediments are separated by brown colored sediments. The major mineral components of these sediments are calcite, quartz, and clay. The central area (squares T3 and T4) contains brown colored sediments, with fewer lenses. The sediments here are also composed mainly of calcite, quartz, and clay. The eastern part of the cave (square T5) contains massive brown sediments with almost no color differences, and stratification is not clearly visible. These sediments are also dominated by calcite, quartz, and clay. Micromorphological analyses of the sediments clearly show that the calcite is mainly composed of wood ash that has been weakly cemented. The ash is remarkably well preserved, and in many samples rectangular pseudomorphs of wood-derived calcium oxalate crystals can be observed. Furthermore, much of the red clay (Fig. S2) was purposefully brought into the cave, as there are no possible geological means for clay to accumulate as lenses within the cave. In fact, the massive lenses (e.g., the one shown in Fig.S1) are constructed surfaces and are virtually identical to similar features from the Paleoindian site of Dust Cave in Alabama (27). Infrared spectra of the red lenses shows that some of them were exposed to temperatures between 400 and 500ºC based on the absence of 5

absorption peaks around 3600cm-1. For kaolinite, one of the major clay components in these sediments, these peaks disappear when the clay is exposed to temperatures above 400ºC (28). Note, too, that the clay component extracted from white lenses also often showed these characteristics. Thus, the exposure to elevated temperatures was probably part of the normal use of fires and was not associated with the production of ceramics. Prescreening of Bone and Charcoal Samples for Radiocarbon Analysis The distribution of bones was more or less uniform in all areas of the cave. In contrast, the charcoal was much less abundant in the western T5 square, especially in the deeper part of the section. Of the samples collected from throughout the cave, about 35% of the bones and about 45% of the charcoal were suitable for dating. For both bone and charcoal, the proportions of dateable samples in squares T4 and T5 were much less than for the squares in the eastern parts of the cave. The preservation conditions are clearly much better in the western part of the cave. The results of the pre-screening procedure are presented in Table 2. Seventy-five charcoal samples were selected, pre-screened, and pretreated. After the pre-treatment, 21 samples were found to contain clay based on their infrared spectra (strong absorptions at 1033cm-1 together with absorptions at 535 and 472cm-1). As clay is a potential carbon carrier and therefore a possible contaminant, these samples were excluded. Furthermore, an additional 8 samples dissolved completely during the procedure. The infrared spectra of the remaining samples showed only charcoal (peaks from 1718 to 1595 cm-1) and thus could potentially be used for 14C analysis. Twenty of these samples that contained relatively large amounts of material were also analyzed by Raman spectroscopy. The average fluorescence intensity after the first and last HCl steps decreased in all the samples except for 4 samples (YAS 237d, 540, 559 and T1E 6), indicating that most of the humic acid was removed during the acid-alkali-acid (AAA) treatment. These 4 were also rejected. Sixty-seven bones were analyzed from the different areas in the cave. All were treated with 1N HCl, and an acid insoluble fraction was identified in 43 samples. This fraction was then isolated, and 25 samples were shown to produce a pure collagen infrared spectrum. The weight percentage of insoluble collagen ranged from 0.02% to 1.6%. The infrared splitting factor (IRSF) values of 4 samples were within 2.6-2.9, i.e., the IRSF values of fresh bones (29), while most of the samples had an IRSF value between 2.9 and 3.3. In some of the collagen spectra the presence of humic acid was detected; therefore, after whole pretreatment, the collagen was again characterized by infrared spectroscopy before target preparation for AMS dating (30). 6

Radiocarbon Analysis A total of 27 samples were analyzed for their 14C contents. They were selected based on the quality of context and material preservation. Of these, ten pretreated samples were separated into two parts and were prepared separately as duplicate analyses. Three samples (BA 95098, 95057a, 95057b) (12) were analyzed during the 1990s excavations when prescreening procedures were not used (Table 1). Table 3 lists the 40 radiocarbon dates according to excavation square, and within each square the samples are arranged according to increasing stratigraphic depth. The duplicate analyses are also listed. The uncalibrated and calibrated ages are shown. All the radiocarbon dates were calibrated with OxCal 3.10 by Bronk-Ramsey 2005 (31, 32). The reproducibility of the duplicate measurement analyses (Fig.3) shows that the data distribution based on the analytical uncertainty follows a normal distribution. This shows there is no bias between the measurements. There is no consistent difference between charcoal and bone samples from the same depth or level. In square T9, near the western cave wall, the ages are similar and show no trend with depth. Figure 4 shows a plot of the calibrated ages obtained in each excavation square, and within each square the samples are arranged according to increasing depth. This shows that the upper part of each section contains sediments from around 13,800-14,600 cal BP. Older sediments were found close to the base of the sections in squares T1 D and E, as well as in squares T10-12. Most of these sediments are from around 16,400-18,000 cal BP. A major exception is a bone sample which was just above bedrock in T1 that gave an age of 21,000 cal BP. Discussion In each stratigraphic section from which samples were analyzed, the ages increase with increasing stratigraphic depth, with two exceptions. The dates show that the cave was occupied from around 18,000 to 14,000 cal BP (Table 3). There were some periods from which no dates were obtained. This may be due to the sample distribution or because during these periods very little sediment may have accumulated. The mineralogical and micromorphological analyses of the sediments both indicate that ash calcite was a major component of almost all samples, implying that they were produced mainly during periods of human occupations. Another unusual anthropogenic activity is evidenced by the clay-rich sediment formed into lenticular bands that must have been brought 7

into the cave by humans and functioned as prepared surfaces (Fig. S2). The clay may have been red colored initially or became red due to heating. Infrared analysis shows that some of these sediments were heated to temperatures between 400 and 500ºC (28). Snail shells found in the cave sediments were analyzed and almost all were found to be composed entirely of aragonite. As aragonite is less stable than calcite, its presence indicates that the preservation conditions were generally good for ash and bones (33). Calcite however buffers the ground water to above pH 8, and this is often not conducive to the preservation of charred materials. In fact, the pre-screening showed that the charcoal was generally poorly preserved, especially in the eastern part of the cave, which today, at least, is much wetter than the western part (24). We also note that less than half the bones contained acid insoluble collagen. This, too, points to relatively poor preservation conditions for organic matter. Bearing this in mind, we assume that the consistent dates obtained can be attributed to the rigorous pre-screening procedures. We did not analyze the radiocarbon contents of any of the samples that were rejected during the pre-screening. The distribution of the dates in the 70-80 cm of the upper part of the ash and red clay deposits reflect a more or less undisturbed accumulation as the series of radiocarbon dates demonstrate an increasingly older age with depth (Fig. 4). This is less clear in the area where most of the potsherds were found in Square T1. During the 2004 excavation a sherd was found in sub-layer 3E at 255 cm below datum and close (some 40-50 cm) to where the original cluster of reconstructable potsherds were uncovered during the previous excavations. The location is shown in Fig. 1. The deposits in T1 between the large boulder and the northern section slope toward the northern wall of the cave and in addition were somewhat disturbed. We note that the two samples (RTT 5110 and RTT 5108) that are clearly out of the overall stratigraphic order are from this location. The calibrated ages for sediments associated with the cluster of the pottery in T1 are from 13,580 to 16,950 cal BP with two standard deviations (SD) (RTB 5110, 5107, 5108, 5109 and 5114) (Table3). The sherd that was found in Square T11 is underlain and overlain by sediments that date between 17,150 and 18,600 cal BP with 2 SD (RTB 5465, 5463, 5466, 5464 and 5470). We note that a charcoal fragment from sub-layer 3E that was located just above the cluster of sherds during the previous excavation was dated to 13,680±70, or 15,85016,700 cal BP (7) (BA95058, see Table 1). A fragment of the pot that was dated earlier produced a date of 14,390±230 calibrated as 15,450-18,050 with 2 SD (BA95057b, Table 1.). Bearing in mind that all the samples dated were from a ten centimeter thick sediment sequence that was rather disturbed, we conclude that the lower limit for the age of the ceramics is around 8

15,000 cal BP. The upper limit is based on the fragment found in square T11 that is more firmly dated to 18,300 cal BP. Dates as early as 16,000 to 17,000 cal BP have been conjectured for the earliest pottery in East Asia, such as at the Xianrendong and Diaotonghuan sites in Jiangxi Province, but these could not be confirmed due to ambiguities in the stratigraphic sequences of these sites (8, 20). Our work in dating Yuchanyan Cave differs from previously dated early pottery sites in China in that it is based on high-precision dating the entire sequence of the deposits, and by doing this with small sampling intervals of only a few centimeters in the areas close to where potsherds were excavated. The results obtained allow us to securely date the pottery in Yuchanyan Cave to as early as 17,500 to 18,300cal BP (one standard deviation). These dates precede by thousand 14C years the earliest date of the Incipient Jomon (NUTA-6510 13780±170 14C year BP) (34) 16700-16100 ±1SD, and 17050-15850 cal BP 2SD) pottery in the Japanese archipelago (8, 35, 36). This supports the proposal made in the past that pottery making by foragers began in south China. Materials and Methods Pre-screening in the field In the field, samples from well defined contexts (for example ash lenses) were collected with the associated sediments. All charcoal pieces were collected separately, placed in aluminum foil, and dried before closing. For the bones, preliminary tests were conducted onsite by dissolving a small bone fragment in 1N HCl and then determining if a light insoluble fraction was preserved. The light insoluble fraction indicates, but does not prove, that insoluble collagen is preserved. As only about half the bones did have an insoluble fraction, we collected many more samples for an extensive pre-screening in the laboratory. Prescreening in the laboratory All the samples that were selected in the field based on context and size for radiocarbon dating were subjected to further pre-screening procedures in order to determine the state of preservation and finally their suitability for dating based on the quality parameters defined in (30). Sixty four bones from squares T1, T4, T5, T9, T11, T12, T14 and T15 were initially checked in the laboratory for mineral crystallinity based on their splitting factor (37). The splitting factors ranged from 2.6 to 3.0, which is close to the value of 2.7±0.2 for modern bone (29). Only one sample had a splitting factor as high as 4. The HCl insoluble fraction was then quantitatively extracted and used to determine if any collagen was present based on infrared 9

spectroscopy. The FTIR spectra of the 1N HCl insoluble fractions indicated that 23 samples showed good preservation of collagen as indicated by the 1645, 1545 and 1450 cm-1 Amide I and II and proline peaks respectively. In some of the collagen spectra the presence of collagen and/or humic acid was detected. Therefore after the entire pretreatment procedure, the collagen was again characterized by infrared spectroscopy to ensure that it was pure (30) before target preparation for AMS dating. Many charcoal samples were collected and pre-screened in the laboratory before and after acid and alkali treatment using Raman micro-spectroscopy to assess humic acid contamination (30, 38) removal, infrared spectroscopy to assess clay contamination (30) and loss of weight. The latter proves to be a good indicator of charcoal preservation (24) and in practice determines the yield of clean charcoal and hence whether or not the sample can be dated. Only samples that were well preserved and free of detectable contaminants were dated. Bone and charcoal pretreatment for radiocarbon Sample pretreatment for bone and charcoal was performed at the Weizmann Institute according to the procedure presented in (30). The cleaning procedure for the collagen samples chosen for dating was based on the acid- alkali- acid (AAA) technique (39). The bone (2 to 4 g) was ground to powder and homogenized. Ten to 20 ml of 1N HCl were added and after 30 minutes the sample was centrifuged for 3 min at 3000 rpm. The supernatant was removed and the pellet was washed with distilled water (DW) to pH 7. The pellet was re-suspended in 7ml of 0.1 % NaOH for 15 minutes and centrifuged again for 7 minutes at 3000 rpm. The supernatant was removed and the pellet was washed with DW to pH 7. The atmospheric CO2 adsorbed during the alkali treatment was removed by adding 7 ml of 1N HCl for 30 min. and washing the pellet until the supernatant reached pH 3. A few milliliters of solution were left over the pellet. Gelatinization was achieved by heating the pellet in acid solution pH 3 to 70ºC for 20 hours (40). The solution was then filtered through a polyethylene filter (Eezi-filterTM) and then by superfiltration (Vivaspin 20). The filtrate was lyophilized (Heto LyoLab 3000) to produce pure dry collagen(41). The quality of the collagen was checked again using infrared spectroscopy. Charcoal Purification The cleaning procedure was based on the AAA procedure (39), except that after each step the pellets were dried at 60ºC, weighed, and a few milligrams were taken for infrared and Raman analyses. The alkaline step was repeated between two to three times depending on the 10

solution color, and in the last step after adding the 1N HCl, the solution was placed on a hot plate and heated slowly to 80ºC for an hour, centrifuged, and the pellet was washed with DW to pH 7 and dried at 60ºC. Monitoring the removal of humic acids from the charcoal samples by Raman spectroscopy is based on the fact that humic acids tend to fluoresce strongly (42). Measurements were made using a Raman Imaging Microscope (Renishaw) through a 50× lens. The excitation at 632 nm was produced by a 25 mw He/Ne laser. Each homogenized sample was measured 10 times at different places, and the spectra were averaged. The spectral resolution was 4 cm-1 and the range analyzed was1200-2000 cm-1. For details of the method see (38). Bone and charcoal samples indicated the highest preservation and provided enough material for the accelerator mass spectrometry measurement. Target preparation and 14C measurement The carbon content of the samples was analyzed by Elemental Analyzer – ELEMENTAR, vario EL, made in Germany. Samples were weighed according to their carbon contents and sealed with copper oxide and silver in quartz tubes under vacuum system. The combustion temperature was 850 . The CO2 from the tubes was purified and transferred into the
°

gas container separately. The reduction from CO2 to graphite was performed with H2/Fe in a new vacuum line. The new system has two graphitization lines, each line has 10 reactors. Fe catalyst is cleaned and activated under 450 C with O2 and H2 separately before reduction (43).
°

The graphite was formed at 540 C. Magnesium perchlorate is used to trap water (44), and it
°

was replaced for every new sample. The AMS radiocarbon measurements were carried out on a NEC 1.5SDH-1 0.5MV Pelletron with 40-sample MC-SNICS ion source. The accuracy of this system is better than 0.4% and the machine background is lower than 0.03pMC. Acknowledgements Prof. Yan Wenming serves as the director of the project and we are grateful for his advice and encouragement during the entire research period. We thank Tongli Qu and He Zan, both members of the excavation team in the field. S.W. is the incumbent Dr. Trude Burchardt Professorial Chair of Structural Biology. We thank the American School for Prehistoric Research (Peabody Museum, Harvard University) and the Hunan Provincial Institute of Archaeology and Cultural Relics, Changsha, Hunan (PRC), who funded the field project and 11

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39. 40. 41. 42. 43. 44.

de Vries HL, Barendsen, GW (1954) Measurements of age by the carbon 14 technique. Nature 174:1138-1141. Law IA, Hedges, REM (1989) A semi-automated bone pretreatment of older and contaminated samples. Radiocarbon 31:247-253. Brown TA, Nelson, DE, Vogel, JS, Southon, JR (1988) Improved collagen extraction by modified Longin method. Radiocarbon 30:1-7. Yang Y, Wang, T (1997) Fourier transform Raman spectroscopy characterization of humic substances. Vibrational spectroscopy 14:105-112. Nadeau MI, Schleicher, M, Grootes, PM, Erlenkeuser, H, et al. (1997) The LeibnizLabor AMS facility at the Christian-Albrechts University, Kiel, Germany. Nuclear Instruments and Methods in Physics Research B 123:22-30. Santos GM, Southon, JR, Druffel-Rodriguez, KC, Griffin, S, et al. (2004) Magnesium perchlorate as an alternative water trap in AMS graphite sample preparation: A report on sample preparation at the KCCAMS Facility at the University of California, Irvine. Radiocarbon 46:165-173.

Figure Legends Figure 1. Location of Yuchanyan Cave in China (inset) and excavation grid showing locations of ceramics. Figure 2. Photograph of the section in square T11 showing the calcitic ash lenses and reddish clay-rich lenses. One of the ceramic sherds was found embedded in this sequence. Its location is marked with O. Scale bar: 20cms. Figure 3: Plot of the duplicate measurements showing the distribution of the data and the analytical reproducibility. The linear interpolation line with the intercept =0 and the correlation coefficient are shown in the plot. The data are reported in table 2. Figure 4: Age distribution of the samples analysed from Yuchanyan Cave. The samples are ordered according to stratigraphic depth following Table 3.

Table Legends Table 1. Uncalibrated and calibrated radiocarbon dates of the samples analyzed after the excavations in 1993 and 1995 (Yuan 2002).

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Table 2: Pre-screening results for bones and charcoal from different excavation squares in the cave. Table 3. Uncalibrated and calibrated radiocarbon dates of all the samples analyzed. The samples are ordered by stratigraphic depth. The results from the western section (T9, T1, T10T12) are followed by those from the eastern section (T5). Note that there is a distance of about 5m between the two areas in the cave.

Reproducibility
13000
14C year BP second measurement

12800 12600 12400 12200 12000 11800 11600 11400

y = 0.9994x R2 = 0.8561

11400 11600 11800 12000 12200 12400 12600 12800 13000 14C year BP first measurement

Figure 3: Age distribution of the samples analysed from Yuchanyan Cave. The samples are ordered according to stratigraphic depth following Table 3.

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Atm pher d f Rei e etal ( 0 4 os i ata rom m r c 2 0 );OxCal v .1 Br Ram y ( 0 5 c r:5 s 2 p us hro 3 0 onk se 2 0 ); ub d:1 rob p[c n]

RTT 3 967-8 12 089± 62BP RTT 3 966 119 75±8 5BP RTT 3 969 122 30±8 5BP RTB 51 1218 17 8±12 4BP RTT 3 970 118 65±8 5BP RTB 52 1239 08 5±28 BP RTB 51 1226 13 0±35 BP RTB 51 1234 12 8±33 BP RTB 52 1163 05 5±28 BP RTB 52 1186 06 5±28 BP RTB 52 1202 07 0±28 BP RTB 52 1240 09 0±40 BP RTB 52 1231 04 5±16 3BP RTB 51 1389 10 0±50 BP RTB 51 1282 07 9±33 BP RTB 51 1185 08 5±50 BP RTB 51 1273 09 5±70 BP RTB 51 1342 14 5±60 BP RTB 54 1469 65 5±55 BP RTB 54 1461 63 0±55 BP RTB 54 1483 66 5±60 BP RTB 54 1480 64 0±55 BP RTB 54 1497 70 5±60 BP RTB 51 1772 15 0±90 BP RTB 51 1224 11 5±38 BP RTB 51 1231 16 5±60 BP RTB 54 1282 71 5±50 BP BA 058 136 95 80±2 70BP BA 057a 11 95 970± 120BP BA 057b 14 95 390± 230BP 250 00CalBP

T9

T1, T10 – T12

ceramic T 11 ceramic

T5

200 00CalBP Calibrat dat ed e

150 00CalBP

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Table 1. Uncalibrated and calibrated radiocarbon dates of the samples analyzed after the excavations in 1993 and 1995 (Yuan 2002). PKU lab Number BA95058 Charcoal Humic substances from Potsherds Potsherds residue T1, layer: 3E

C age±1σ year BP 13680 ± 270

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Calibrated age ±1σ year BP 16700 - 15850

Calibrated age ±2σ year BP 17150 - 15450

BA95057a BA95057b

T1, layer: 3H T1, layer: 3H

11970 ± 120 14390 ± 230

13970 - 13720 17750 - 16900

14150 - 13550 18050 - 16450

Table 2: Pre-screening results for bones and charcoal from different excavation squares in the cave. Bones Excavation square No. of samples analyzed No. samples with pure collagen suitable for dating 2 6 1 2 Charcoal No. of samples analyzed No. of well preserved samples suitable for dating (2) 10

T9 T1 Sub-squares D and E T10 T11 T12 T4 T5 Totals

(4) 12

21 11 12 12 64

10 8 3 2 26

18 8 21 12 75

5 6 4 6 33

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Table 3. Uncalibrated and calibrated radiocarbon dates of all the samples analyzed. The samples are ordered by stratigraphic depth. The results from the western section (T9, T1, T10-T12) are followed by those from the eastern section (T5). Note that there is a distance of about 5m between the two areas in the cave. Weizmann Institute Number RTT 3967 RTT 3968 RTT 3966 RTT 3969 RTB 5117 RTB 5117 RTT 3970 RTB 5208 RTB 5208 RTB 5113 RTB 5113 RTB 5112 RTB 5112 RTB 5205 RTB 5205 RTB 5206 RTB 5206 RTB 5207 RTB 5207 RTB 5209 RTB 5204 RTB 5204 RTB 5110 RTB 5107 RTB 5107 BA05429a BA05429b Average BA05898-1 BA05898-2 Average BA05425a BA05425b Average BA05424a BA05424b Average BA05895-1 BA05895-2 Average BA05896-1 BA05896-2 Average BA05897-1 BA05897-2 Average BA05899 BA05894-1 BA05894-2 Average BA05422 BA05419a BA05419b PKU lab Number

Average

charcoal charcoal charcoal bone charcoal bone charcoal charcoal charcoal charcoal charcoal bone charcoal charcoal charcoal

T9, west section, 129cm T9, west section, 135cm T9, west section, 190cm T9, west section, 191m T9, west section, 194cm T10a, 3A, 195cm T1, south, 198cm T1, south, 204cm T11a, 3A IV, 217cm T10a, 3A, 219cm T1c, 3BIII, 228cm T10c, 3B III, 230cm T11a, 3C, 236cm T1D-c, layer: 3E, 251cm T1E, layer: 3E, 251cm

C age±1σ year BP 12190 ± 85 11970 ± 90 12089 ± 62 11975 ± 85 12230 ± 85 12100 ± 70 12275 ± 50 12188 ± 124 11865 ± 85 12440 ± 40 12350 ± 40 12395 ± 28 12290 ± 50 12230 ± 50 12260 ± 35 12360 ± 50 12345 ± 60 12348 ± 33 11670 ± 40 11600 ± 40 11635 ± 28 11860 ± 40 11870 ± 40 11865 ± 28 12020 ± 40 12020 ± 40 12020 ± 28 12400 ± 40 12200 ± 40 12430 ± 40 12315 ± 163 13890 ± 50 12835 ± 40 12815 ± 60

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Calibrated age ±1σ year BP 14020 - 13850 13940-13750 14210-13960 14210 - 13850 13820 - 13630 14490 - 14190 14180 - 14050 14380 - 14130 13540 - 13410 13780 - 13700 13930 - 13810 14580(6.7%)14530 14500(61.5%)14200 14650 - 14000 16760 - 16340 15250 - 15020

Calibrated age ±2σ year BP 14090 - 13790 14030-13670 14600-13800 14650 - 13750 13920 – 13480 14750 – 14100 14250 – 13990 14650 – 14050 13620 – 13370 13820 – 13650 13980 – 13780 14800 -14100 14950 – 13850 16950 – 16150 15400 – 14940

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Average RTB 5108 RTB 5109 RTB 5114 RTB 5465 RTB 5463 RTB 5466 RTB 5464 RTB 5470 RTB 5115 RTB 5111 RTB 5111 RTB 5116 RTB 5471 BA05420 BA05421 BA05426 BA06865 BA06863 BA06866 BA06864 BA06867 BA05427 BA05423a BA05423b Average BA05428 BA06868 charcoal charcoal bone bone charcoal bone charcoal Charcoal Bone charcoal bone charcoal T1E, layer: 3E 254cm T1A, layer: 3E, 255cm T1E, layer: 3E 253258cm T11a, layer: 3FH, 252cm T11c, layer: 3H, 255cm T11c, layer: 3H, 257cm T11c, layer: 3H, 260cm T12a, layer: 3H, 260 cm T1E, layer: 3I, 260264cm T5, east, 222cm T5, east, 229cm T5, 305-314cm

12829 ± 33 11855 ± 50 12735 ± 70 13425 ± 70 14695 ± 55 14610 ± 55 14835 ± 60 14800 ± 55 14795 ± 60 17720 ± 90 12260 ± 60 12235 ± 50 12245 ± 38 12315 ± 60 12825 ± 50 13790 - 13670 15170 - 14910 16140 - 15740 17990 - 17700 17900 - 17510 18500(14.1%)18350 18200(54.1%)17850 18080 - 17800 18500(13.3%)18420 18390(54.9%)18100 21110 - 20700 14160 - 14040 14370 - 14070 15250 -15010 13840 – 13580 15350 -14700 16400 – 15550 18050 – 17350 18000 – 17150 18550-17750 18500 – 17650 18600 – 18000 21300 – 20550 14230 – 13980 14650 – 14000 15420 – 14920

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