Os Isotopic Investigations of Earth's Evolution

点击翻译按钮获取中文摘要

Awards resulting from earlier versions of this proposal dating back to July, '88, were in large part for the development of a SRIMS technique for the isotopic analysis of Os, using Lamont's new Isolab 54 mass spectrometer. But after 1990 when the NTIMS was shown to be better, this is what has been used in the PI's lab. Efforts during the proposed funding period will involve Re-Os investigations of ancient crustal rocks, mantle-derived peridotites, and modern mantle-derived volcanics. The goals are to: 1) investigate the extent to which old cratonic rocks represent intracrustal "recycling" of even older continental materials; 2) establish the present state of Os isotopic heterogeneity in the modern mantle; and 3) characterize Re and Os distributions on mineralogical scales in both crustal and mantle rocks.