New AMS dates on human bone from Mesolithic Oronsay.

New AMS dates on human bone from Mesolithic Oronsay. Introduction Here we report on new AMS AMS - Andrew Message System dates on four human bones from twoMesolithic shell midden middendungheap. sites from the island of Oronsay, InnerHebrides For islands with similar names, see .Oronsay (Scottish Gaelic: Orasaigh), also sometimes spelt and pronounced Oransay by the local community, is a small tidal island south of Colonsay in the Scottish Inner Hebrides with an area of just over two square , Scotland. These new dates were commissioned by the NationalMuseums of Scotland, to provide information for the `Early People'displays in the new Museum of Scotland The Museum of Scotland, Edinburgh, Scotland, is a building which, together with the adjacent Royal Museum, comprises the National Museum of Scotland. It is dedicated to the history, people and cu lture of Scotland. The museum is on Chambers Street, in central Edinburgh. which opened in Edinburgh on 30November 1998. They complement the existing dates on shell and wood fromOronsay, published by Switsur & Mellars (1987), and indicate thatthese human bones date to the last phase of the Mesolithic period Mesolithic period(mĕz'əlĭth`ĭk)or Middle Stone Age,period in human development between the end of the Paleolithic period and the beginning of the Neolithic period. . These four samples had also been used for stable isotope stable isotopen.An isotope of an element that shows no tendency to undergo radioactive breakdown. analysis,and the results were reported in this journal by Richards & Mellars(1998). Because of the obvious marine-based diets of these individualswe had to `correct' the dates for the marine reservoir effectbefore we could calibrate To adjust or bring into balance. Scanners, CRTs and similar peripherals may require periodic adju stment. Unlike digital devices, the electronic components within these analog devices may change from their original specification. See color calibration and tweak. them. This correction is rarely applied tohuman bone, and its application can be controversial, but we argue it iscrucial for correctly dating samples of this type. Calibrating the dates Collagen was extracted from the four samples as reported inRichards & Mellars (1998). The collagen quality was excellent,despite the age of the samples. The uncalibrated radiocarbon ages andassociated [[Delta].sup.13]C values are presented in TABLE 1. TABLE 1. Uncalibrated and calibrated radiocarbon dates from fourhuman bone samples from the island of Oronsay.lab no. sample site context no.OxA-8019 17157 Cnoc Coig Square H13, Unit 4OxA-8014 17203 Cnoc Coig Square I 13, Unit 4OxA-8004 18284 Cnoc Coig Square I 5, unit 4OxA-8005 1281 CNG II Trench P/N, Layer 1/2, Unit 4lab no. [[Delta].sup.13]C(a) uncalibrated [sup.14]C ageOxA-8019 -12.4 5615 [+ or -] 45 BPOxA-8014 -12.0 5495 [+ or -] 55 BPOxA-8004 -12.4 5740 [+ or -] 65 BPOxA-8005 -16.0 5480 [+ or -] 55 BPlab no. calibrated [sup.14]C age(b)OxA-8019 4200-4000 cal BCOxA-8014 4000-3800 cal BCOxA-8004 4300-4000 cal BCOxA-8005 4200-4000 cal BC (a) These [[Delta].sup.13]C values are from a second measurement ofthe collagen before radiocarbon dating. They have an error of [+ or -]0.3% associated with them, and are statistically identical to the valuesreported in Richards & Mellars (1998). (b) At 2[Sigma], rounded to the nearest century. Marine calibrationdata is from Stuiver & Braziunas (1993) and the atmosphericcalibration data is from Stuiver et al. (1998). Calibrations undertakenusing OxCal 3.3 (Bronk Ramsey 1995). Please see text for details of howthe calibration was obtained. Marine organisms have uncalibrated radiocarbon dates that areapproximately 400 radiocarbon years older than contemporary organismsthat derive their carbon from the atmosphere. In order to calibratethese samples to calendar years, it is necessary to use the marinecalibration curve In analytical chemistry, a calibration curve is a general method for determining the concentration of a substance in an unknown sample by comparing the unknown to a set of standard samples of known concentration. outlined in Stuiver & Braziunas (1993).Additionally, in some areas of the world there are local variations inthe [sup.14]C contents of marine organisms which have to be taken intoaccount before calibration. Unfortunately, although most researchers areaware of the problem of the marine reservoir effect, a suitablecorrection is not often applied to human bone (but see Arneborg et al.1999), even in cases where the collagen [[Delta].sup.13]C value clearlyindicates the individual has derived the majority of their collagencarbon from marine sources. Below, we apply this correction to the fourOronsay human bone dates. In the UK, we can expect a human that derived all of their proteinfrom marine sources to have a [[Delta].sup.13]C value of approximately-12 [+ or -] 1% (Richards & Hedges 1999), and a human that hadexclusively terrestrial protein to have a [[Delta].sup.13]C value ofapproximately -20 [+ or -] 1% (Richards 1998; Richards & Van Klinken1998). The collagen [[Delta].sup.13]C values of three of the individualsfrom the Cnoc Coig midden are approximately -12%, which is indicative ofan almost 100% marine diet, so these dates can be corrected using themarine calibration curve. The calibrated age range in calendar years isgiven in TABLE 1. However, the Caisteal Nan Gillean II individual, witha [[Delta].sup.13]C value of -16%, derived their collagen carbon from anapproximately 50/50 mixture of atmospheric and marine carbon (us ing a[[Delta].sup.13]C value of-20%, as indicative of a 100% terrestrialdiet). Therefore, calibrating the radiocarbon age of this individual ismore difficult. We have taken the midpoint mid¡¤point?n.1. Mathematics The point of a line segment or curvilinear arc that divides it into two parts of the same length.2. A position midway between two extremes. between the calibrated agesof this sample taken from the atmospheric and marine calibration curve.The range of calibrated ages for this sample if it were 100% terrestrialwould be (at 2[Sigma]) 4460-4220 BC, and 100% marine, 4010-3760 BC.Therefore, the mid-point between these two is 4200-4000 BC (TABLE 1). Harkness (1983) found that for most of the UK, marine organismswere on average about 400 radiocarbon years older than contemporaryterrestrial organisms. Therefore, there is no local effect in theBritish Isles British Isles:see Great Britain; Ireland. which requires a correction factor (The [Delta]R value inStuiver & Bra ziunas 1993) to be applied to the radiocarbon datesbefore calibration using the marine calibration curve. Switsur &Mellars (1987) compared a shell date (Birm-348, inner) with two charcoaldates (Birm-346, Birm-347) from the same stratigraphic stra¡¤tig¡¤ra¡¤phy?n.The study of rock strata, especially the distribution, deposition, and age of sedimentary rocks.strat level at theCaisteal Nan Gillean II midden. They found a difference in radiocarbonages between the shell and charcoal of about 400 radiocarbon years,which confirms Harkness' (1983) findings specifically at this site. Due to the errors on the radiocarbon dates and the[[Delta].sup.13]C values the calibrated age ranges given in TABLE 1 havebeen rounded to the nearest century. Comparison with other dates from Oronsay The calibrated human bone dates are late Mesolithic, and generallyfall in the youngest end of the range of radiocarbon ages obtained fromcharcoal from the middens by Switsur & Mellars (1987). The dates forcharcoal from the Cnoc Coig midden are given in TABLE 2, and theyoungest date (Q-1352) calibrates to 4600-3950 cal BC, within which twoof the calibrated human bone dates fit. The third bone from this midden,17203, could be younger than this youngest midden layer. The dated bonefrom the Caisteal Nan Gillean II midden is from Trench P, layers 3 and 4(Meiklejohn & Denston 1987), where there are three charcoal dates(TABLE 2). The calibrated human bone dates are again in the youngestrange of these charcoal dates (although the errors on the charcoal datesare large). TABLE 2. Conventional radiocarbon dates on charcoal from the CnocCoig and Caisteal Nan Gillean II middens. Data taken from Switsur &Mellars 1987: table 10.1. Calibrated ages are at 2[Sigma], and wherethere is more than one possibility, only the highest probability (givenin brackets) age range is shown.lab no. site context uncalibrated [sup.14]C age radiocarbon years BPQ-1352 Cnoc Coig Trench A, Unit 3 5430 [+ or -] 130Q-1351 Cnoc Coig Trench E, Unit 2 5495 [+ or -] 75Q-1354 Cnoc Coig Trench E, Unit 6 5535 [+ or -] 140Q-1353 Cnoc Coig Trench E, Unit 8 5645 [+ or -] 80Q-3005 Cnoc Coig Pre-midden 5650 [+ or -] 60Q-3006 Cnoc Coig Pre-midden 5675 [+ or -] 60Birm-346 CNG II Trench P, Layer 3 5150 [+ or -] 380Birm-347 CNG II Trench P, Layer 4 5450 [+ or -] 140Q-1355 CNG II Trench P, Layer 4 5460 [+ or -] 65lab no. calibrated [sup.14]C age(*) calendar years BCQ-1352 4550-3950Q-1351 4500-4220 (89-5%)Q-1354 4700-4000Q-1353 4690-4340Q-3005 4620-4350 (94.4%)Q-3006 4690-4360Birm-346 4800-2900Birm-347 4600-3950Q-1355 4460-4210 (84%) (*) Calibrated using data from Stuiver et al. (1998) using OxCal3.3. Implications of the dates The Mesolithic dates for the human bones make these two Oronsaymiddens unique in the Scottish Mesolithic, as other dated bones fromostensibly os¡¤ten¡¤si¡¤ble?adj.Represented or appearing as such; ostensive: His ostensible purpose was charity, but his real goal was popularity. `Mesolithic' contexts have turned out to be considerablylater (Saville & Hallen 1994). The late Oronsay dates themselveshave implications for the Scottish Mesolithic, and indeed the BritishMesolithic. They coincide with the earliest Neolithic activity inBritain at c. 5300-5200 BP (approximately 4000 cal BC, Zvelebil &Rowley-Conwy 1986; Williams 1989). This suggests that these two middenson Oronsay were still in use while the use of domesticated animals This article or section may contain original research or unverified claims.Please help Wikipedia by adding references. See the for details.This article has been tagged since September 2007.This is a list of animals which have been domesticated by humans. andcrops was beginning elsewhere in Britain. Un til there are more datesfrom Neolithic sites on the west coast of Scotland it is impossible tosay more about the relationship between the Mesolithic and Neolithic inthis region (but see Sheridan (in press) on the earliest Neolithic ofwestern Scotland). The new dates also help to provide a better context to understandthe stable isotope values. It appears that people with two differentsubsistence strategies are using the island, or at least are ending upon or in the middens, at about the same time. The individuals from CnocCoig have a marine-based diet, while the one individual from Casteal NanGillean II has a mixed marine/terrestrial diet. Possible explanationsfor the differing Casteal Nan Gillean II [[Delta].sup.13]C value arediscussed in Richards & Mellars (1998). These new bone dates demonstrate that the human bones wereincorporated into these two middens at the very end of the use of thesites. The nature of the human bone material is significant, as onlyfragmentary bones were recovered, usually hand and foot bones(Meiklejohn &Denston 1987). Did the deposition of human bones in themidden signify the end of the use of the midden? Conclusion We have presented here four new human bone dates from the twoMesolithic midden sites of Cnoc Coig and Caisteal Nan Gillean II on theisland of Oronsay. Due to the marine-based diets of these individuals itwas necessary to calibrate the dates using the marine calibration curve.The calibrated ages date the very last period of use of the two middens,and the late dates for these Mesolithic humans overlap with some of theearliest dates for the appearance of the Neolithic in Britain. Acknowledgements. MPR (MultiProtocol Router) Software from Novell that provides router capabilities for its NetWare servers. It supports IPX, IP, AppleTalk and OSI protocols as well as all the major LANs and WANs. would like to thank D. Erle Nelson and C.Bronk-Ramsey for useful discussions and advice on marine calibration . References ARNEBORG, J., J. HEINEMEIR, N. LYNNERUP, H.I. NIELSEN, N. RUD,& A.E. SVEINBJORNSDOTTIR. 1999. Change of diet of the GreenlandVikings determined from stable carbon isotope analysis Isotope analysis is the identification of isotopic signature, the distribution of certain stable isotopes and chemical elements within chemical compounds. This can be applied to a food web to make it possible to draw direct inferences regarding diet, trophic level, and subsistence. and [sup.14]Cdating of their bones, Radiocarbon 41: 157-68. BRONK RAMSEY, C. 1995. Radiocarbon calibration and analysis ofstratigraphy stratigraphy,branch of geology specifically concerned with the arrangement of layered rocks (see stratification). Stratigraphy is based on the law of superposition, which states that in a normal sequence of rock layers the youngest is on top and the oldest on the : The OxCal Program, Radiocarbon 37(2): 425-30. HARKNESS, D.D. 1983. The extent of natural [sup.14]C defic iency inthe coastal environment of the United Kingdom, PACT 8: 351-64. MEIKLEJOHN, C. & C. DENSTON. 1987. The human skeletal material,in P.A. Mellars (ed.), Excavations on Oronsay: 290300. Edinburgh:Edinburgh University Press Edinburgh University Press is a university publisher that is part of the University of Edinburgh in Edinburgh, Scotland. External linksEdinburgh University Press . RICHARDS, M.P. 1998. Palaeodietary studies of European humanpopulations using bone stable isotopes. Unpublished D.Phil. thesis,University of Oxford. RICHARDS, M.P. & R.E.M. HEDGES. 1999. Stable isotope evidencefor similarities in the types of marine foods used by Late Mesolithichumans at sites along the Atlantic coast of Europe, Journal ofArchaeological Science 26: 717-22. RICHARDS, M.P. & P, MELLARS, 1998, Stable isotopes and theseasonality of the Oronsay middens, Antiquity 72: 178-84. RICHARDS, M.P. & G.J. VAN KLINKEN. 1997. A survey of Europeanhuman bone stable carbon and nitrogen isotope values, in A.G.M.Sinclair, E.A. Slater & J.A.J. Gowlett (ed.), Archaeologicalsciences 1995: 363-8. Oxford: Oxbow. Monograph 64. SAVlLLE, A. & Y. HALLEN. 1994. The `Obanian Iron Age':Human remains from the Oban Cave sites, Argyll, Scotland, Antiquity 68:715-23. SHERIDAN, J.A. In press. Achnacreebeag and its French connections:vive the `auld alliance', in J. Hendersen (ed.), The prehistory prehistory,period of human evolution before writing was invented and records kept. The term was coined by Daniel Wilson in 1851. It is followed by protohistory, the period for which we have some records but must still rely largely on archaeological evidence to andearly history of Atlantic Europe, Oxford: Archaeopress. STUIVER, M. & T. BRAZIUNAS. 1993. Modelling atmospheric[sup.14]C influences and [sup.14]C ages of marine samples to 10,000 BC,Radiocarbon 35(1), 137-90. STUIVER, M., P.J. REIMER, E. BARD, J.W. BECK, G.S. BURR, K.A.HUGHEN, B. KROMER, G. MCCO RMAC, J. VAN DER DER - Distinguished Encoding Rules PLICHT & M. SPURK. 1998.INTCAL98 radiocarbon age calibration, 24,000-0 cal BP, Radiocarbon40(3): 1041-83. SWITSUR, V. & P. MELLARS. 1987. Radiocarbon dating of the shellmidden sites, in Mellars (ed.), Excavations on Oronsay: 139-49.Edinburgh: Edinburgh University Press. WILLIAMS, E. 1989. Dating the introduction of food production intoBritain and Ireland, Antiquity 63: 510-21. ZVELEBIL, M. & P.A. ROWLEY-CONWY. ]986. Foragers and farmers inAtlantic Europe, in M. Zvelebil (ed.), Hunters in transition: Mesolithicsocieties of temperate Eurasia and their transition to farming: 67-94.Cambridge: Cambridge University Press Cambridge University Press (known colloquially as CUP) is a publisher given a Royal Charter by Henry VIII in 1534, and one of the two privileged presses (the other being Oxford University Press). . M.P. RICHARDS & J.A. SHERIDAN(*) (*) Richards, Research Laboratory for Archaeology and the Hist oryof Art The Research Laboratory for Archaeology and the History of Art is a laboratory at the University of Oxford which develops and applies scientific methods to the study of the past.As of 2005, the Laboratory is directed by Prof. Mark Pollard. , University of Oxford, 6 Keble Road, Oxford OX1 303, England.michael.richards@rlaha.oc.ac.uk Sheridan, National Museums of Scotland,Chambers Street, Edinburgh EH1 1JF, Scotland. Received 18 August 1999, accepted 29 October 1999, revised 2 March2000.