Reevaluation of dating results for some 14C - AMS applications on the basis of the new calibration curves available

Abstract

In this paper we describe briefly some characteristics of the Accelerator Mass Spectrometry (AMS) technique and the need of corrections in the radiocarbon ages by specific calibration curves. Then we discuss previous results of some Brazilian projects where radiocarbon AMS had been applied in order to reevaluate the dates obtained on the basis of the new calibration curves available.

Late Pleistocene and Holocene environmental and climatic conditions in the eastern Andean piedmont of Mendoza (33°–34°S, Argentina)

“…Radiocarbon dates were calibrated with the Calib Radiocarbon Calibration Program 6.1.0 (Stuiver, Reimer and Reimer Copyright 1986e2011, http://calib.qub.ac.uk/calib/); McCormac et al (2004) calibration data set was used (Table 2). Ages invalid for the Southern Hemisphere calibration curve -older than 11 cal kyr BP-were reported as radiocarbon dates; in accordance with McCormac et al (2004) and Macario et al (2008), these ages should not be calibrated using the Northern Hemisphere calibration curve as an alternative because large-scale carbon reservoirs changes may have altered the interhemispheric offset before the Holocene. For interpretation purpose, calibrated ages consider a 95.4% confidence interval (2 Sigma).…”

Towards a complete 14C AMS facility at the Universidade Federal Fluminense (Niterói, Brazil): Sample preparation laboratory tests

“…Researchers from the Physics Institute of Universidade Federal Fluminense (UFF), Archaeology, Marine Geology, Geochemistry, Oceanography areas have, for about 20 years, run collaborative projects with external AMS facilities such as PRIME Lab at Purdue University and the ones at Australian National University and UC-Irvine [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. In 2009 the radiocarbon sample preparation laboratory was set up at the Physics Institute of UFF, in Niterói, Rio de Janeiro State, with the aim to improve existing and foster new collaborations with Brazilian archaeologists and geoscientists.…”