Magmatism of the Baikal Rift, Russia: Asthenospheric Upwelling Along a Lithospheric Boundary

该项目将整合同位素，全岩主要和痕量 玄武岩和包体的元素和矿物化学数据 它们是沿着贝加尔湖南部500公里长的样带采集的 裂谷 样带从元古宙-古生代岩石圈延伸 穿过缝合线到达太古代克拉通 西北 贝加尔裂谷提供了一个绝佳的机会来测试 两个主要假设：1）是否空间和时间 玄武岩的地球化学演化可能与 软流圈源熔体和对比岩石圈柱 穿过裂缝的走向 2)非放射成因的铅同位素 与非放射成因的亚亚洲OIB有关的玄武岩特征 地幔源（Allegre等人，1987年）或广泛的地壳 污染. 该项目是美国的产物-中苏 格兰德河和贝加尔裂谷比较裂谷讲习班 由美国国家科学院和 它将涉及实地工作， 以及在麻省理工学院进行的广泛的化学分析。

This project will integrate isotopic, whole-rock major and trace element, and mineral chemistry data from basalts and xenoliths collected along a 500-km-long transect across the southern Baikal Rift. The transect extends from Proterozoic-Paleozoic lithosphere in the southeast across the suture onto the Archean craton in the northwest. The Baikal Rift offers an excellent opportunity to test two major hypotheses: 1) whether the spatial and temporal evolution of basalt geochemistry can be related to interaction of asthenospheric derived melts and contrasting lithospheric columns across the strike of the rift. 2) Is the unradiogenic Pb isotopic character of the basalts related to an unradiogenic sub-Asian OIB mantle source (Allegre et al., 1987) or to widespread crustal contamination. The project is an outgrowth of the U.S.-U.S.S.R comparative rift workshop on the Rio Grande and Baikal rifts sponsored jointly by the U.S. National Academy of Sciences and the Academy of Sciences of the U.S.S.R. It will involve field work as well as extensive chemical analyses to be done at MIT.