Radiocarbon chronology of the mammoth site at Niederweningen, Switzerland:: Results from dating bones, teeth, wood, and peat

The peat section at Niederweningen is a site of spectacular excavations of numerous bones of mammoth and other animals that was first recognized in the late 19th century. In 1987/1990, new excavations provided more peat material, which was radiocarbon dated to 33,000 C-14 years BP and 42,000 C-14 years BP. The first AMS radiocarbon ages of mammoth bones from 1890/1891 excavations placed the age between 33,000 C-14 years BP and 35,000 C-14 years BP. In this study, new results were obtained on bones, teeth, wood and peat from the layer that buried the mammoths. The ages confirm that the mammoths as well as the peat section, in which they were found, are older than 40,000 C-14 years BP. In order to explain the discrepancy between the previous chronology and the new results, two preparation techniques were applied for the dating of bones. An organic fraction called collagen used to obtain the first radiocarbon ages was dated as well as gelatine prepared using the modified Longin method. The differences of up to 7000 years between ages obtained on collagen and gelatine fractions show contamination of the collagen fraction with modern carbon. The oldest age of 45,870 +/- 1080 C-14 years BP was obtained on base cleaned gelatine from mammoth bone. This age is close to an age of 45,430 +/- 1020 C-14 years BP obtained for the peat layer that buried the mammoths. (C) 2006 Elsevier Ltd and INQUA. All rights reserved.