Cooling induced fracturing in impact melt dikes derived from drone photogrammetry and Python simulation: Example from the Lesutoskraal Granophyre Dike in South Africa

Cooling-induced fracturing in impact melt dikes can facilitate the multi-phase emplacement of later melt phases, as demonstrated by a study at the Vredefort Dome. High-resolution drone photogrammetry and Python simulations revealed that fractures parallel to dike margins form due to tensional cooling stress, reaching up to -75 MPa, sufficient to overcome lithostatic stresses. This process allows subsequent impact melt to intrude into earlier phases within 150 days of emplacement, supporting the concept of prolonged, multi-phase dike formation. The study provides a mechanism for understanding complex dike structures in large meteorite impact events.

Clark, M. D., Kovaleva, E., Huber, M. S., Riekert, S., & Fourie, F. D. (2025). Cooling induced fracturing in impact melt dikes derived from drone photogrammetry and Python simulation: Example from the Lesutoskraal Granophyre Dike in South Africa. Journal of Structural Geology, 197, 105428. https://doi.org/10.1016/j.jsg.2025.105428