This study investigates the origin of the Choiyoi Magmatic Province's silicic magmatism in southwestern Pangea during the mid-Permian-Triassic. By integrating plate-kinematic reconstructions, lower mantle slab records, geochronological information, and geochemical data analysis, the authors demonstrate that this magmatic event was caused by a large-scale slab loss. A paleogeographic coincidence between a reconstructed slab gap and the Choiyoi Magmatic Province, along with geochemical data indicating a slab break-off fingerprint, support this conclusion. The findings establish the Choiyoi Magmatic Province as the oldest example of a geophysically constrained slab loss event and offer new insights into the geodynamic setting of silicic large igneous provinces in the late Paleozoic.

Guido M. Gianni, César R. Navarrete