A centennial reappraisal of the Vredefort pseudotachylytes: shaken, not stirred by meteorite impact

A centennial reappraisal of the Vredefort pseudotachylytes reveals that these enigmatic features, long attributed to meteorite impact, were not formed by faulting but rather through intense seismic shaking initiated by the impact itself. The study demonstrates that pseudotachylyte zones in the 2.023-billion-year-old Vredefort Dome, South Africa, resulted from cataclasis and frictional heating of temporarily loosened rock blocks within dendritic fracture systems, caused by high-frequency oscillations during cratering. This process, well-documented in lunar impacts, terrestrial earthquakes, and nuclear tests, was overlooked in terrestrial cratering studies until now. The findings challenge traditional interpretations and highlight the role of acoustic fluidization in pseudotachylyte formation.

Garde, A. A., & Klausen, M. B. (2016). A centennial reappraisal of the Vredefort pseudotachylytes: shaken, not stirred by meteorite impact. Journal of the Geological Society, 173(6), 954–965. https://doi.org/10.1144/jgs2015-147