T04_P27

Status of the AMS-dating at Radiocarbon laboratory of the Institute of geography RAS

Zazovskaya E¹, Shishkov V¹, Turchinskaya S, Cherkinsky A²

¹Institute of geography RAS, Moscow, Russian Federation, ²University of Georgia, CAIS, Athens, USA

The Radiocarbon Dating Laboratory (Lab code IGAN) was founded at the Institute of Geography of the Russian Academy of Sciences in the 1970s and has since continuously dated different carbon-containing materials using the liquid scintillation counting method. In 2015, our Laboratory has acquired the Ionplus automated graphitization system – AGE 3, together with a Vario Isotope Cube CHNS elemental analyzer. In early 2018 (with the help of Ionplus specialists), an isotope ratio mass spectrometer was coupled to the AGE 3 and our Laboratory staff members attended a brief training. Graphite ¹⁴C/¹³C ratios were measured using the CAIS 0.5 MeV Accelerator Mass Spectrometer at the Center for Applied Isotope Studies (CAIS), University of Georgia. Anthracite and phthalic anhydride were used as BG for graphitization. The BG results consistently give ages between 44,000 and 49,000 BP for anthracite and 46,000 and 52,000 BP for phthalic anhydride. OXII and OX1 are used as the modern standard for graphitization. An inter-laboratory comparison between IGAN and CAIS was conducted in respect to graphitization and dating of materials of known ages, with the results obtained being highly comparable. During the work of AGE-3 system more than 5000 graphites of high quality were obtained from such carbon-bearing materials as coal, wood (cellulose), human and animal bones, soils, sediments of different genesis, peats, fouling from ceramic material, fabric. Samples for graphitization are prepared according to accepted protocols. The  methods modified in the IGRAN laboratory are also used when dating the organic matter of soils.