AMS-dating of Late Pleistocene and Holocene syngenetic ice-wedges

We discuss the C-14 dating (both conventional and AMS) of Siberian permafrost sediments and ice-wedge ice. Direct dating of Late Pleistocene and Holocene syngenetic ice-wedges was done on organic material included in the ice. The time of ice formation (in C-14 years) is 21,000-14,000 BP for Seyaha, and 7100 BP for Shchuch'ya. The AMS dates show that the ice-wedges stratification is normal, i.e., the older ice is located below the younger. The C-14 dates yield for the first time a timescale (in C-14 years) for paleoclimatic indicators (oxygen and hydrogen isotope ratios from the ice). (C) 2000 Elsevier Science B.V. All rights reserved