Paleomagnetic investigation of McMurdo volcanics, Antarctica

Abstract

A total of 212 paleomagnetic samples were collected from the Hut Point Peninsula, the Cape Royds and the Taylor Valley in the McMurdo Sound, Antarctica. These samples have stable natural remanent magnetization. The results of paleomagnetic studies are as follows : (1) The position of Antarctica has been almost the same from the Late Pliocene Age up to the present. The position of the virtual geomagnetic pole (VGP) (11 normals and 3 reverses) from the Pliocene Age to the present is within a polar cap area of about 30°latitude, whose center is located almost exactly at the south geographical pole. (2) The sequence of lava eruption was determined by synthetic evidence from paleomagnetic, geological and geochronological data. The result revealed, from the latest to the earliest, Twin Crater Sequence and Cape Royds Sequence (Brunhes Epoch), Half Moon Crater Sequence (Jaramillo Event), Observation Hill Sequence, Cape Armitage Sequence (Matuyama Epoch), Crater Hill and Castle Rock (Olduvai or Reunion Events) and Taylor Valley Sequence (Kaena Event).