Formation of central uplift structures in large, complex impact craters: Mechanical importance of pseudotachylitic breccia zones and prominent dislocations in the development of the Vredefort Dome, South Africa

尽管大型陨石撞击属于行星地质学中最不了解的过程，但对陆地撞击结构的详细结构研究仍处于起步阶段，更不用说大型复杂结构了。相当大的不确定性围绕着中央隆起的形成，更具体地说，（1）突出位错的几何学和运动学意义，（2）连续和不连续变形之间的时间和力学关系，以及（3）在这个过程中大量假玄武质角砾岩体的力学作用。这些问题是解决在一个综合的现场结构，实验室和三维几何恢复分析使用的Vredefort圆顶，一个深受侵蚀的遗迹的中央隆起和保存最完好的天然实验室在地球上进行这种研究。这项研究还将测试冲击引起的熔化，即，假玄武玻璃质角砾岩，是在中央隆起的形成过程中从高压向低压迁移的，因此直接涉及到解决假玄武玻璃的争议。本文提出的构造分析与U。雷默德

Despite the fact that large meteorite impact belongs to the least understood processes in planetary geology, detailed structural studies of terrestrial impact structures, let alone of large complex ones, are still in their infancy. Considerable uncertainty centres around the formation of central uplifts, more specifically, the (1) geometric and kinematic significance of prominent dislocations, (2) the temporal and mechanical relationships between continuous and discontinuous deformation and (3) the mechanical role of voluminous pseudotachylitic breccia bodies in this process. These issues are addressed in a combined field-structural, laboratory and 3D geometric restoration analysis using the Vredefort Dome, a deeply eroded relic of a central uplift and best preserved natural laboratory on Earth for such study. The study will also test whether shock-induced melt, i.e., pseudotachylitic breccia, was transported from highpressure to low-pressure sites during formation of the central uplift, und thus pertains directly to solving the pseudotachylite controversy . Structural analyses proposed herein are intimately linked with the petrographic and geochemical and analyses of pseudotachylitic breccia delineated in the companion proposal by Prof. U. Reimold.