Radiocarbon dates of snow petrel (Pagodroma nivea) nest sites in central Dronning Maud Land, Antarctica

Abstract

AbstractThis paper presents the results of a radiocarbon dating study of snow petrel (Pagodroma nivea) nest sites in central Dronning Maud Land, Antarctica. Mumiyo (a sub-fossilized accumulation of regurgitated proventricular oil) samples were collected from 15 snow petrel nest sites at nunataks in the northern Ahlmannryggen, Gjelsvikfjella, and Mühlig-Hofmannfjella.Radiocarbon dating revealed Holocene ages of ca 8500 years and less for all but one of these mumiyo samples. A sample collected at S varthamaren in the Muhlig-Hofmannfjella was dated as old as ca 34,000 a BP, indicating that at least some areas of that mountain escaped the scouring action of glaciers during the last glacial period. Similar pre-Holocene ages have been determined for a small number of mumiyo samples in previous studies. Mumiyo accumulations from some nests indicate periods of occupation as long as 6000 years, whereas the radiocarbon age and volume of other mumiyo samples suggest short periods of frequent nesting activity. As expected, sub-samples extracted from the lower layers of mumiyo pieces generally displayed greater ages than sub-samples from upper layers of the same piece. However, there was no clear-cut correlation between the age of a mumiyo sample and its height above the present ice level. It is suspected that this lack of correlation is due to some of the mumiyo samples being displaced previously through rockfalls.