Rb-Sr Dating of the Gneissic Rocks from the East Coast of Lützow-Holm Bay, Antarctica

Abstract

Rb-Sr age determinations have been carried out on rock samples collected in the area along the east coast of Lützow-Holm Bay, East Antarctica. Two different age groups of 458±10 my. and 1, 110 ± 100 my. have been obtained from the biotites and K-feldspars, respectively. The present Rb-Sr age of biotites is in close agreement with the determinations in previous works, indicating that the last metamorphic acitvity occurred in the early Paleozoic age. The age of 383 my. of the K-feldspar on the rock from the Yamato Mountains differs widely from those of other samples from the east coast of Lützow-Holm Bay.