U-Pb Dating the Mechanical Fusion of Archean Crust to its Mantle Keel in a Cross-Section through the African Continent

[805210]莫泽：太古宙早期地壳形成的问题是一个关系到行星演化和被称为“构造圈”的地壳-地幔关系的关键问题。由于缺乏下地壳的暴露，很少有地方可以研究这一点。然而，Kaapvaal地区是一个主要的地壳部分在弗雷德堡撞击构造周围倾斜的地方。正是在这里，这项研究将关注下地壳和上地幔之间的关系，特别是关注下地壳是如何与上地幔焊接在一起的，而上地幔现在形成了一个强大的地幔“龙骨”。如果成功的话，这项研究将阐明南非地壳的早期演化，但对地球和其他类似行星岩石圈的起源也有普遍的应用。

9805210 Moser The problem of early crust formation in the Archean is a critical one bearing on planetary evolution and on crust-mantle relationships in what has become known as the 'tectosphere.' Because of the lack of exposure of the lower crust, there are very few places where this can be studied. However, the Kaapvaal area is one place where a major section of the crust has been tilted in the region surrounding the Vredefort impact structure. It is here that this study will focus on the relationship between the lower crust and upper mantle, focusing in particularly on the how the lower crust came to be welded to the upper mantle that now forms a strong mantle 'keel.' If successful, this study will shed light on the early evolution of the crust in South Africa, but with general applications to the origin of the lithosphere on earth and on other similar planets.