RADIOCARBON DATES FROM THE OXFORD AMS SYSTEM: ARCHAEOMETRY DATELIST 33
2009; Wiley; Volume: 51; Issue: 2 Linguagem: Inglês
10.1111/j.1475-4754.2008.00457.x
ISSN1475-4754
AutoresChristopher Bronk Ramsey, Thomas Higham, Fiona Brock, David Baker, Peter Ditchfıeld,
Tópico(s)Pleistocene-Era Hominins and Archaeology
ResumoThis is the thirty-third list of dates measured at the Oxford Radiocarbon Accelerator Unit (ORAU). The dates presented here include those measured through the NERC/AHRC-funded Oxford Radiocarbon Accelerator Dating Service (ORADS), those funded by English Heritage, and those submitted to the laboratory on a commercial basis. All dates have been measured using the procedures outlined in Law and Hedges (1989), Hedges et al. (1989, 1992), Bronk Ramsey et al. (Arch.List 30) and Bronk Ramsey et al. (2004a,b,c). AMS determinations with OxA numbers greater than 6293 were measured either as graphite (if sufficiently large) (Dee and Bronk Ramsey 2000), or as CO2 (Bronk Ramsey and Hedges 1997; Bronk Ramsey et al. 2004a). In accordance with international radiocarbon convention all dates are expressed in radiocarbon years before ad 1950 (years bp) using the half-life of 5568 years. Errors are quoted as one standard deviation (1σ) and are based on an assessment of all the contributions to the error in the laboratory isotope ratio measurement. Natural fractionation of carbon isotopes is accounted for by measuring the δ13C values relative to VPDB (with errors of approximately 0.3‰). All combining procedures and significance tests are based on Ward and Wilson (1978). Comments composed by the Laboratory on the basis of information supplied by submitters are given without attribution. All calendrical dates quoted have been calibrated using the OxCal computer program of Bronk Ramsey (2001) using atmospheric data from ‘INTCAL04’ (Reimer et al. 2004), and are quoted to 95.4% probability. Previous Archaeometry datelists are referred to in the form: Arch.List 32. Details of methods applied are described in detail in our in-house documentation. This is regularly updated and archived, so the exact method used for any sample is always fully recorded. The laboratory has used an ultrafiltration method in the purification of gelatin extracted from bones since 2000 (Brown 1998, Arch.List 30). In late 2002 we discovered that without more rigorous precleaning of the filters prior to use traces of a humectant (glycerine) could remain and affect the ages significantly, particularly for low-yielding collagen samples. The effect is relevant for all bone samples with OxA numbers in the range OxA-9361 to -11851 and OxA-12214 to -12236. The initial problem was outlined in Bronk Ramsey et al. (2004b). Rigorous cleaning of the ultrafilters is required in order to effectively remove small amounts of glycerine, which is applied during the manufacturing of the filters to keep them moist prior to use. Subsequent research at ORAU resulted in changes to the methodology, which is fully reported in Bronk Ramsey et al. (2004b). In a recent paper (Brock et al. 2007) we reported on the cleaning procedures in more detail. There are no affected determinations in this Datelist. In the appendix, a list of withdrawn OxAs from Arch.List 31 is provided along with the results of redates and the status of the remainder. Two different methods were applied. First, samples were obtained and redated using the modified protocol outlined by Bronk Ramsey et al. (2004b). Second, spare gelatin was reultrafiltered with ultrafilters cleaned according to the new protocol. OxA-X numbers are given when there is an experimental pre-treatment applied, or where the analytical data associated with the measurement is out of expected range. In these latter cases, the accuracy of the result ought to be viewed with caution. Usually, this is because of low collagen weights, either less than 10 mg or 41 100 Comment (P. N): Šipka Cave is a most important site, located in the hill of Kotouč in northern Moravia. It was excavated by K. J. Maška at the end of the 19th century concurrently with the excavation of Čertova Díra Cave. There are two major problems related to the cave. The first concerns the dating of a hearth where a Neanderthal lower jaw was found in layer III in 1880. A sample of burnt bone with the right spatial and stratigraphical position was dated in the Groningen Laboratory. Due to the lack of collagen, the date of 39 940 bp (GrA-29904) must be greater than 40 000 bp. A new sample of a bone with the same position was chosen for comparison, but this one failed due to no yield. The second important question concerns the existence of two Middle Palaeolithic layers, noted by K. J. Maška as layers III and IV. A critical revision of faunal remains did not confirm this division. A bone located in a corridor of Krápníková Chodba was a component of the accumulation of both lithic and faunal remains, noted originally as layer IV. Due to the very low yield of collagen, the date of the Neanderthal occupation is approximate and it is difficult to compare with the Groningen date from layer III. A new sample from layer III is being processed. Kůlna Cave, Moravian Karst, 49:39:59.99N 17:12:59.99E OxA-18567 bone, animal, KULNA2007-1, δ13C =−19.1‰ 52 700 ± 2300 Comment (P. N): the cave of Kůlna is the most important Palaeolithic site in Moravia. The complex of layers contains the remains of Middle Palaeolithic occupation from the end of the penultimate glaciation (OIS 6) to the end of the lower Weichselian glaciation. The most important question is the temporal relationship between layers 7a and 6a. Micoquian layer 7a is dated around 45 kyr uncal bp by 14C and 50 kyr bp by the TL method. Theoretical calibration of 14C therefore fits to the TL data quite well. The uppermost Middle Palaeolithic layer 6a is not dated by radiocarbon. Within the context of the project one bone with intentional cut marks was selected for dating. The position of this sample is well defined in sector E. The supposed age, around 40 kyr BP, was not confirmed. The 52 700 bp age exceeds the age from layer 7a, but from the chronological point of view it must be younger. Both layers were easily controlled because they differed in colour. Now it is difficult to decide which factors affect the dating. It is clear more data from both layers are necessary to solve this problem. Balcarka Cave, 49:37N 17:15E OxA-18494 charcoal, Balcarka 2007-1 S0701U2, δ13C =−23.3‰ 10 810 ± 45 OxA-18495 charcoal, Balcarka 2007-2 Sample 11, δ13C =−23.9‰ 28 360 ± 140 P21385 bone, Balcarka 2007-3 P4 FAILED due to no yield Comment (P. N): the cave of Balcarka (Moravia) was excavated at the end of the 19th century. Magdalenian, Epimagdalenian and probably Middle Palaeolithic occupations were documented. New adjustment of the entrance to the inner cave system resulted in a rescue excavation of Pleistocene sediments in the posterior part of the first cave hall. The main goal was to reconstruct the original stratigraphic sequence and codification of the Magdalenian or Middle Palaeolithic horizons. Unfortunately, only limited stratigraphy was documented. The rest of the cave soil was found on the small wall bank and contained charcoal and teeth of reindeer. We supposed that this level indicated the original position of the Magdalenian/Epimagdalenian horizon (Valoch and Neruda 2005). OxA-18495 (charcoal) was submitted to date this layer. The result (28 360 ± 140 bp) is surprising and opens the question of possible human occupation in this time. Unfortunately, we cannot correlate the date with any archaeological records. However, it must be stressed that this part of the cave was destroyed by modification of the entrance to the cave system in the first half of the 20th century. The lower layers uncovered during the rescue excavation have not been dated because sample P21385 (bone) failed due to no yield. According to the layer mentioned above we can just estimate the age of the lower Weichselian glacial. One probe was situated on the left side from the entrance to describe the stratigraphy in front of the cave. Sample OxA-18494 (charcoal) fits to the stratigraphy quite well. It was situated on the base of the Holocene soil complex and there is only limited residual volume of the Pleistocene sediments on the slope from the entrance to the valley. Lostice, 50:12N 17:32E OxA-18493 charcoal, Alnus glutinosa/Carpinus, 2007-1, δ13C =−25.6‰ 4317 ± 30 Comment (P. N): Loštice (Moravia) is an open-air site and has been excavated by the staff of the Anthropos Institute since 2006 (Neruda and Nerudová in press). The majority of the site has been destroyed by a quarry. There are remains of a Magdalenian layer with burins of Lacan situated only 40–60 cm under the recent surface that was changed during prehistoric and/or recent times. Sample OxA-18493 was obtained from macroscopically intact sediment but a botanic analysis of charcoals indicated probable contamination by material from a younger layer. The result confirms Eneolithic occupation demonstrated by ceramic rests fragments. Dating of the Magdalenian occupation must be determined by different methods (e.g. TL) or by the opening of concentration 2 where a Magdalenian horizon looks less disturbed. Pestera Cioclovina, 45:35N 23:07E, Romania Samples submitted by E. Trinkaus, Dept. Anthropol., Campus Box 1114, Washington Univ., St. Louis, MO 63130-4899, USA. OxA-16328 bone, Ursus spelaeus, Cio05-3, δ13C =−20.3‰ 40 550 ± 600 Comment (E. T.): the date helps to secure the age of the one remaining stratigraphic column in the Pestera Cioclovina. Pestera Muierii, 45:12N 23:46E, Romania OxA-16380 bone, Panthera spelaea, Mui05-8, δ13C =−19.1‰ 47 500 ± 900 OxA-16381 bone, Ursus spelaeus, Mui05-9, δ13C =−20.3‰ 40 950 ± 450 OxA-16382 bone, Ursus spelaeus, Mui05-10, δ13C =−20.2‰ 42 700 ± 550 OxA-16383 bone, Ursus spelaeus, Mui05-11, δ13C =−20.7‰ > 52 400 Comment (E. T.): this series of dates relate to a Middle to Upper Palaeolithic stratigraphic sequence in the Galeria Principala of the Pestera Muierii, Baia de Fier, Romania, one of the more important Palaeolithic sites in southern Romania. Dog Hole Cave, Haverbrack Dog Hole Cave, Haverbrack in southern Cumbria (NGR SD 486803) was first excavated by J.W. Jackson in 1912. Further excavations were carried out in the 1950s (Benson and Bland 1963) and by ourselves in 2003. Since our 2003 excavations, renewed caving activity has exposed more bones. Samples submitted by D. M. Wilkinson, Dept. of Biological & Earth Sciences, Liverpool John Moores Univ., Byrom St, Liverpool, L3 3AF. OxA-15994 bone, Homo sapiens, Dog Hole 3, δ13C =−19.9‰ 1734 ± 30 OxA-15995 bone, Canis familiaris, Dog Hole 3, δ13C =−20.2‰ 1890 ± 30 Comment (D. M. W.): OxA-15994 on a human bone from excavations in the 1950s has a date statistically indistinguishable from our previous date on a bone from a different human from the site (OxA-14173). This shows that at least two of the humans excavated during the 1950s died around the third century ad. The dog bone (OxA-15995) was collected from material disturbed by recent caving activity. It had clearly come from sediments underlying the position of those excavated in the 1950s. The date suggests that (while still Romano-British) it is probably somewhat earlier than the two dated humans. An Corran, Skye Samples of human and pig bone found within bioturbated deposits in the shell midden at An Corran (NG4912 6850), excavated in 1993 by Roger Miket and others (Saville 2004). ACO627 human bone (navicular, left), ACO632 human bone (lumbar vertebrae), ACO458 human bone (cervical vertebrae), ACO143 pig bone (rib), ACO132, ACO178 and ACO713 cattle bone. Samples obtained by kind permission of Alan Saville at the National Museum of Scotland. Dates funded by AHRB grant (B/RG/AN1717/APN14658). Submitted by N. Milner, Dept. of Archaeol., Univ. of York. OxA-13549 human bone, ACO627, δ13C =−19.4‰ 4650 ± 55 OxA-13550 human bone, ACO632, δ13C =−20.5‰ 4360 ± 55 OxA-13551 pig bone, ACO143, δ13C =−21.5‰ 7485 ± 55 OxA-13552 human bone, ACO458, δ13C =−19.9‰ 4535 ± 50 OxA-14751 bone, Bos taurus, ACO132,C36, δ13C =−22.3‰ 7555 ± 45 OxA-14752 bone, Bos taurus, ACO178,C36, δ13C =−22.0‰ 7595 ± 50 OxA-14753 bone, Bos Taurus, ACO713, C34, δ13C =−21.6‰ 7525 ± 45 Comment (N. M.): isotopic studies were performed on a selection of human bones from the site. The first four bones listed above were originally all thought to be human. The date of ACO143 is much older than the others (i.e., Mesolithic) and the bone was examined again by László Bartosiewicz, Terry O’Connor and Don Brothwell, all of whom confirmed that it was not human but pig. This Mesolithic date is comparable with other dates from the midden: a red deer bevel-ended tool 7590 ± 90 bp (OxA-4994); a ruminant long bone 6420 ± 75 bp (AA-27746) and a broken bevel-ended bone tool made from a ruminant long bone fragment 6215 ± 60 bp (AA-29316) (Ashmore 2004). The human bones date to the Neolithic period and are comparable with another disarticulated human bone previously dated from this midden 4405 ± 65 bp (AA-27744). The occurrence of Neolithic human bone in Mesolithic shell middens has been found at other sites along the west coast of Scotland. Isotopes of cattle bone collagen were analysed to compare with the human bones. It had been thought that the cattle were domesticated, because of their small size, and were most probably Neolithic in date. However, they were also dated and were found to be of Mesolithic age, comparable to the pig bone, and thus more likely to be small auroch. This work is part of a project investigating palaeodiet at the Mesolithic–Neolithic transition. Broomend of Critchie, Scotland Samples of charcoal from the site of Broomend of Crichie, Aberdeen (NGR NJ 778 196), submitted by Prof. R. J Bradley, Dept. Archaeol., Univ. of Reading. OxA-18251 charcoal, Corylus, BRO 07 2017, S.185, δ13C =−27.0‰ 3327 ± 27 OxA-18252 charcoal, Betula, BRO 07 2033, S.186, δ13C =−26.9‰ 3432 ± 30 Comment: (R. J. B.): taken together, the two dates suggest that a substantial timber circle was built immediately outside the entrance to the well-known henge monument at Broomend of Crichie a century or more after that earthwork had been constructed. The wooden structure may have been in use during the later phases of the cremation cemetery established inside the henge. Wetzlar-Dalheim Samples of bone and charcoal from the sites Wetzlar-Dalheim, B49 (50:33N 8:27E), Laubach-Freienseen (50:33:29N 9:04:42E) and Mosbach-Quarry, Wiesbaden (50:02:18N 8:15:47E), Germany. Submitted by Dr Sabine Schade-Lindig, Landesamt fur Denkmalpflege Hessen, Abt. Archaologishche Denkmalpflege, Schloss Biebrich – Ostflugel, D-65203 Wiesbaden, Germany. Laubach-Freienseen, 50:33:29N 9:04:42E, Germany OxA-16545 human bone, 053231, δ13C =−19.2‰ 975 ± 26 OxA-16586 wood, 053234, δ13C =−29.1‰ 948 ± 26 Wetzlar-Dalheim, B49, 50:33N 8:27E, Germany OxA-16556 charcoal, leafwood, C3053, δ13C =−25.4‰ 1073 ± 32 OxA-16557 charcoal, leafwood, C3054, δ13C =−26.9‰ 1260 ± 50 OxA-16558 charcoal, leafwood, C3059, δ13C =−26.9 ‰ 1093 ± 28 OxA-16587 charcoal, leafwood, C235, δ13C =−24.6‰ 1273 ± 28 OxA-16588 charcoal, leafwood, C3051, δ13C =−24.3‰ 972 ± 26 OxA-16589 charcoal, leafwood, C3052, δ13C =−26.1‰ 971 ± 26 OxA-16590 charcoal, leafwood, C3055, δ13C =−25.3‰ 1296 ± 27 OxA-16591 charcoal, Quercus sp., C3056, δ13C =−24.8‰ 1332 ± 26 OxA-16592 charcoal, leafwood, C3057, δ13C =−25.6‰ 1758 ± 30 OxA-16593 charcoal, leafwood, C3058, δ13C =−24.6 1278 ± 27 OxA-16594 charcoal, ashes, C4051, δ13C =−24.4‰ 921 ± 29 OxA-16595 charcoal, C4049, δ13C =−23.4‰ 1258 ± 27 OxA-16596 charcoal, C4047, δ13C =−24.3‰ 6203 ± 34 OxA-16615 bone, C234, δ13C =−19.3‰ 1367 ± 29 OxA-16616 bone, C4050, δ13C =−21.0‰ 1503 ± 27 OxA-16646 charcoal, C4048, δ13C =−26.5‰ 6135 ± 45 Mosbach-Quarry, Wiesbaden, 50:02:18N 8:15:47E, Germany OxA-16648 bone, Marmota bobak, 150/93, δ13C =−20.1‰ 38 850 ± 600 OxA-16649 bone, Marmota bobak, 55/03, δ13C =−19.7‰ 41 900 ± 900 Comment (S. S.-L. & N. B.): the AMS results from Wetzlar-Dalheim were mostly very helpful. They confirm generally that it is possible to identify areas used during different times and that certain types of deposits belong to certain time periods. Also, it is now possible to show that regular Carolingian activities took place alongside the high medieval period of iron smelting. In comparison to archaeological data of chronological relevance in the surrounding features, most of the charcoal results appear to be slightly older (50 to 100 years), but that is not entirely unexpected, since the wood used for fuel of course grew some time prior to its felling date. The Neolithic AMS data support the archaeological data as well. Only two samples caused some problems (OxA-16557/Sample C3054/feature 3016 and OxA-16592/Sample C3057/feature 3030). They are are exactly the reverse of the dates that were expected. Finds from the deposit containing sample C3054 can be dated quite precisely from end of the second century ad to the third century ad. On the other hand the context C3057 should be medieval, since none of the deposits in this area are older than Early Medieval. Therefore, material from the two features was redated (OxA-17095/ Sample A305/ feature 3016 and OxA-17096/ Sample A3020/ feature 3030). The radiocarbon accelerator dates are: Wetzlar-Dalheim, B49, 50:33N 8:27E, Germany OxA-17095 charcoal, A305, δ13C =−24.3‰ 1712 ± 27 OxA-17096 charcoal, A3020, δ13C =−23.7‰ 1307 ± 26 This confirms that an exchange has taken place and that there must have been a mix-up somewhere along the line. The new data are completely within the expected period. Coma del Poll Samples of bone from Coma del Poll, Spain (41:54:42N 0:55:30E) submitted by Prof. J. M. Fullola i Pericot, Dept. Prehist. Historia Antiga i Arqueol., S.E.R.P., Universitat de Barcelona, E-08028 Barcelona, Spain. OxA-16422 bone, Bos Taurus, CP.N.II/UBOX 35, δ13C =−20.1‰ 3245 ± 31 OxA-16423 bone, Bos Taurus, CP.N.III/UBOX 36, δ13C =−20.7‰ 3282 ± 30 OxA-16613 bone, Ovis or Capra?, CP.N.VI/UBOX 37, δ13C =−19.6‰ 3140 ± 31 Comment (J. M. F-P.): these dates obtained from the site of Coma del Poll (Alòs de Balaguer, Lleida) coincide well with the chronostratigraphical records, that is, with the cultural horizon of the later stages of the Early Bronze Age. The site is particularly interesting from the geoarchaeological point of view since it allows the dating of sedimentary and pedologic processes. The information obtained will help us to complete the palaeoenvironmental sequence of the recent Holocene in the north-east of the Iberian Peninsula. Colomera Cave Comment (J. M. F-P.): Sample 1 is a little more recent that expected, dating to the Late Middle Neolithic or Late Neolithic, when we expected epicardial Early Neolithic. Because the selected seed came from the top of the archaeological level, we think that the problem comes from this selection, and it could derive from the uppermost level. In our excavation, however, we related this sample to epicardial pottery. Comment (J. M. F-P.): Sample 2, coming from stockpit EE, has provided a date in accordance with what was expected, Early Bronze Age with epicampaniform pottery, in a transitional period between the IIIrd and IInd millenium cal bc. Parco Cave OxA-17730 charcoal, UBOX 39-Parco 10, δ13C =−23.1‰ 13 095 ± 55 Comment (J. M. F-P.): this result confirms what we had expected, that we are in the same area of the excavation where we obtained previously a result of 13 070 ± 140 bp. It confirms that activities in this part of the site are synchronous with activities in the shelter part of the site. Montlleó OxA-X-2234-52 tooth, horse, UBOX 40-Montlleo 3, δ13C =−19.9‰ 16 900 ± 110 Comment (J. M. F-P.): the date coming from the Montlleó site confirms that we are in the Early Magdalenian, as we had observed from technological studies. Up to now we had two dates (15 550 and 15 450 bp respectively) and we presumed that we were in an older period. The only problem is that the sample comes from the same level as these old dates, so we are examining the geomorphology of the site to be sure of the taphonomic influences in the level concerned. Lab comment: this sample produced a low yield of collagen (1120 mg bone yielded 5.6 mg of gelatin), which is less than our minimum threshold of 10 mg (or 1wt% collagen). The CN atomic ratio, however, was 3.3, which is acceptable. The sample was OxA-X’ed for these reasons. Cova Foradada Cave OxA-17818 human bone, UBOX 46-Foradada 1, δ13C =−19.9‰ 304 ± 23 Comment (J. M. F-P.): this date is not consistent with what we expected (2200 to 1500 years bc), and we cannot consider it as correct. Maybe the bone chosen was badly selected. Cuina Turcului Sample of tooth from the site of Cuina Turcului, Romania, submitted by Alexandru Dinu, 2107 Waunona Way, Madison, WI 53713, USA. OxA-18354 tooth, Cervus elaphus, CT 1, δ13C =−21.3‰ 6990 ± 40 Comment (A. D.): it has been suggested (Boric and Dimitrijevic 2007
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