Structural and geochemical analyses of fragment-rich pseudotachylite bodies and the Vredefort Granophyre of the Vredefort Impact Structure, South Africa

A groundbreaking analysis of the Vredefort Dome, the eroded core of South Africa's 2.023±4 billion-year-old Vredefort Impact Structure, reveals that pseudotachylite bodies and structural fabrics exhibit centro-symmetric patterns consistent with numerical models of impact-induced vertical stretching and uplift. Geochemical data indicate significant compositional deviations between pseudotachylite matrices and their wall rocks, suggesting assimilation of wall rock material and the presence of a primary granitoid melt component akin to the Vredefort Granophyre. This study provides evidence for the allochthonous nature of the melt, emplaced during the late-stage collapse of the central uplift, and identifies two distinct impact melt pulses in the Granophyre, likely formed by injection from an overlying differentiated impact melt pool.

Lieger, D. (2011). Structural and geochemical analyses of fragment-rich pseudotachylite bodies and the Vredefort Granophyre of the Vredefort Impact Structure, South Africa [Freie Universität Berlin]. https://doi.org/10.17169/REFUBIUM-10326