Osmium isotopes as petrogenetic and geological tracers |
| |
Authors: | Claude J Allègre Jean-Marc Luck |
| |
Institution: | 1. Laboratoire de Géochimie et Cosmochimie (LA 196), Institut de Physique du Globe de Paris, Universitéde Paris VI, 4, Place Jussieu, 75230 Paris Cedex 05 France;2. Département des Sciences de la Terre, VII, 4, Place Jussieu, 75230 Paris Cedex 05 France |
| |
Abstract: | Using terrestrial osmium-enriched samples of known ages, we have shown that187Os/186Os varies with time in result of the187Re β? radioactivity. Such a variation in the earth's mantle can be fitted by a straight line corresponding to187Re/186Os = 3.15 for the mantle, comparable to C1 carbonaceous chondrites. Using this result and the Re and Os contents of various rocks, several theoretical considerations and predictions can be deduced for the chemical evolution of the earth, such as a method for distinguishing between different processes of development of the continental crust. The special result of187Os/186Os from Bushveld is discussed with respect to the possible existence of an “enriched” subcontinental mantle. |
| |
Keywords: | |
本文献已被 ScienceDirect 等数据库收录! |
|