14C Ages of a Varved Last Glacial Maximum Section Off Pakistan

Abstract

In a core off Pakistan, we obtained 38 14C analyses by accelerator mass spectrometry (AMS) from a 4.4-m-thick, expanded, annually-laminated Last Glacial Maximum (LGM) section, bracketed by bioturbated intervals ascribed to the Heinrich-1 (H1) and Heinrich-2 (H2) equivalent events (52 14C analyses between 24-15 kyr BP). A floating varve age scale, anchored to the oxygen isotope record of the layer-counted GISP2 ice core at the H2/LGM boundary, results in an annually dated record for the LGM from 23,450-17,900 cal BP. The floating varve scale of the LGM provides us with a tentative calibration of local marine AMS 14C age dates to calendar years.