NEW AMS 14C DATES OF A MULTICULTURAL ARCHAEOLOGICAL SITE FROM THE PALEO-DELTAIC REGION OF WEST BENGAL, INDIA: CULTURAL AND GEO-ARCHAEOLOGICAL IMPLICATIONS

ABSTRACT This study is on the absolute age dating of a multicultural site of Erenda, East Medinipur district, in coastal West Bengal, India. Charcoal samples were collected and measured using the accelerator mass spectrometry (AMS) facility at the Inter-University Accelerator Centre, New Delhi, India. These samples were collected from secured stratigraphic context of two excavated trenches. A careful collection of samples from two trenches provided us with the first calendar dates, 950 BCE and 1979 BCE, of protohistoric sites in coastal West Bengal. These calibrated calendar dates not only have wider significance in terms of archaeology but also methodological implications to understand the relevance of application of AMS from the dynamic coastal landscape in the humid tropics during the late Holocene period.

Archaeology of rock art at Dalakngalarr 1, centralwestern Arnhem Land

In 2011, we began researching the subsurface archaeology, geomorphology and rock art ofDalakngalarr 1, a moderately sized rock shelter on top of the central-western Arnhem Landplateau in Jawoyn Country. Here, four lines of evidence give relative or absolute ages for rockart:1. Archaeological excavations adjacent to a boulder that contains a painting of a red macropodreveal when that boulder attained its present position, so the red macropod must have beenpainted sometime afterwards.2. Paintings of axe/hoes with metal heads indicate that they were painted during the Europeancontact period. A nearby group of X-ray images are painted in comparable pigments,suggesting that they are contemporaneous with the axe/hoes.3. Geomorphological evidence suggests that parts of the site’s ceiling collapsed at datable timesin the past, indicating that the art on that roof must post-date the roof collapse.4. Direct accelerator mass spectrometry (AMS) radiocarbon dates on beeswax art.

REASSESSMENT OF UNCERTAINTY EXPANSION BY LINEAR ADDITION OF LONG-TERM COMPONENTS FROM TOP-DOWN INFORMATION

ABSTRACT Since radiocarbon accelerator mass spectrometry (14C AMS) is considered a high-precision technique, reassessment of the measurement uncertainty has been a topic of interest. Scientists from analytical and metrological fields have developed the top-down and bottom-up measurement of uncertainty approaches. The 14C quoted error should approximate the uncertainty of long-term repetitions of the top-down approach in order to be realistic. The novelty of this paper is that the uncertainty of both approaches were approximated to each other. Furthermore, we apportioned the graphitization, instrumentation, and bias components in order to additively expand the quoted error. Our results are comparable to error multipliers and to long-term repeatability studies reported by other laboratories. Our laboratory was established in late 2012 with N2 as stripper gas and 7 years later, we changed to helium stripper. Thus, we were able to compare both gases, and demonstrate that helium is a better stripper gas. In absolute F14C units, the ranges of graphitization+bias combined uncertainties were (0.7 to 4.1) × 10–3 for N2 and (0.7–3.0) × 10–3 for He depending on the standard 14C content. The error multiplier for He defined as the expanded uncertainty over quoted error, in average, was 1.7; while without the bias, the multiplier was 1.3.

INTER-UNIVERSITY ACCELERATOR CENTRE, NEW DELHI (IUACD) RADIOCARBON DATE LIST II

ABSTRACT Accelerator mass spectrometry (AMS) activities at the Inter-University Accelerator Centre (IUAC) in New Delhi, India, started with its 15UD Pelletron accelerator and cosmogenic radionuclide (CRN) measurements of 10Be and 26Al. Realizing the demand of a radiocarbon (14C) AMS facility in India, a 500kV Pelletron accelerator based AMS system was installed in 2015. This facility was designated with the lab code IUACD for 14C measurements. 14C dates measured in 2015 and 2016 were published in the first radiocarbon date list (see text for details). The present list is the second 14C date list and consists of dates measured from January to December 2017.

Results of Radiocarbon Dating of Early Burials in the Firsovo Archaeological Area, Barnaul Stretch of the Ob

An especially noteworthy part of the Firsovo archaeological area is a group of early burials at the fl at-grave cemeteries Novoaltaisk-Razvilka, Firsovo XI, and Firsovo XIV. Nine radiocarbon dates have been generated for those cemeteries at various laboratories: two by the liquid-scintillation (LSC) method and seven using the accelerator mass spectrometry (AMS) method. The dates were calibrated using OxCal version 3.10 software. Dates for the Chalcolithic Bolshoy Mys culture burials at Novoaltaisk-Razvilka and Tuzovskiye Bugry-1 burial 7 match the previously suggested ones (around 3000 BC). Certain Neolithic burials in the Altai differ from others in the position of the bodies (fl exed on the side). They were dated to the late 5th to the early 4th millennia BC by the AMS method. Burials belonging to the “cultural core” of Firsovo XI, then, fall within the Early Neolithic (68 % interval, 5710–5460 BC; 95 % interval, 5740–5360 BC). The date 9106 ± 80 BP (GV-02889), obtained for Firsovo XI burial 18, may be somewhat accurate, pointing to the Final Mesolithic or Early Neolithic. Both the date and the cultural characteristics of this burial (sitting position, abundant ocher) are accompanied by the craniometric distinctness of the male cranium (huge total size).

LIQUID SCINTILLATION COUNTING (LSC)—PAST, PRESENT, AND FUTURE

ABSTRACT Radiocarbon (14C) dating by liquid scintillation (LS) spectroscopy (also known as LS counting or LSC) provides an alternate method of 14C analysis where accelerator mass spectrometry (AMS) analysis is less desirable. The past, present, and future applications of the method are discussed.

LIST OF 14C DATES OBTAINED UNDER THE PROJECT “THE DOBUŻEK SCARP MICROREGION AS A PART OF A PHYSIOLOGICAL AND BIOCULTURAL FRONTIER BETWEEN THE BALTIC AND THE PONTIC ZONE (FROM THE 6TH TO THE 2ND MILLENNIUM BC)”

ABSTRACT This paper presents results of accelerator mass spectrometry radiocarbon (AMS 14C) dating of prehistoric samples (human and animal bones, cremated human bones, charcoals, and other charred plant macroremains) from archaeological sites located in the area of Dobużek Scarp, on the Sokal Ridge in central-eastern Poland (E Poland). The date list reports 46 14C age measurements performed within the project “The Dobużek Scarp Microregion as a part of a physiological and biocultural frontier between the Baltic and the Pontic zone (from the 6th to the 2nd millennium BC)” conducted in 2016–2021. The resulting 14C dates fall into quite a long interval, which in terms of the regional archaeological periodization lasts from the Middle Eneolithic to the Early Iron Age, and in terms of the climatological one corresponds with the Subboreal.

RADIOCARBON IN MEXICO: FROM PROPORTIONAL COUNTERS TO AMS

ABSTRACT Augusto Moreno is credited with establishing the first radiocarbon (14C) laboratory in Mexico in the 1950s, however, 14C measurement with the accelerator mass spectrometry (AMS) technique was not achieved in our country until 2003. Douglas Donahue from the University of Arizona, a pioneer in using AMS for 14C dating, participated in that experiment; then, the idea of establishing a 14C AMS laboratory evolved into a feasible project. This was finally reached in 2013, thanks to the technological developments in AMS and sample preparation with automated equipment, and the backing and support of the National Autonomous University of Mexico and the National Council for Science and Technology. The Mexican AMS Laboratory, LEMA, with a compact 1 MV system from High Voltage Engineering Europa, and its sample preparation laboratories with IonPlus automated graphitization equipment, is now a reality.