163-8 Global Dispersal of Musgrave Sourced Zircons: Unraveling the Planetary Scale Impact of MAPCIS Across Gondwana Terranes

Session: Impact Cratering Processes Across the Solar System: In Memory of Dr. Bevan M. French

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The Massive Australian Precambrian/Cambrian Impact Structure (MAPCIS), centered in the Musgrave Province of central Australia, has been proposed as one of the largest terrestrial impact events in Earth’s history. This study investigates the potential sedimentary and geochemical imprint of MAPCIS ejecta through the detrital zircon record, focusing on globally distributed zircon populations that exhibit characteristic Musgravian isotopic signatures (~1.1–1.2 Ga).

Detrital zircons from proximal formations such as the Mount Currie Conglomerate and Uluru/Mutitjulu Arkose display age spectra and Hf isotopic compositions consistent with derivation from Musgrave basement rocks, suggesting a local source potentially linked to impact-related ejecta dispersal. Remarkably, similar zircon age modes and trace element systematics have been documented in far-flung Gondwanan fragments, including Zealandia (New Zealand and New Caledonia), the Transantarctic Mountains, the Pan-African orogenic belts, and peri-Gondwanan terranes in North Africa and the eastern Mediterranean. The correlation of U–Pb age peaks, εHf(t) values, and REE profiles across these disparate localities suggests a common crustal source and implies the existence of a far-reaching sediment dispersal mechanism, potentially driven by impact-generated atmospheric injection, ballistic transport, or tsunami-mediated redistribution.

These findings challenge conventional models of sediment transport and continental provenance by proposing a syn-impact mechanism for widespread zircon deposition. Furthermore, the temporal coincidence between MAPCIS and early Cambrian tectonic reorganization raises the possibility that this event contributed to lithospheric destabilization during the fragmentation of Gondwana. This study integrates detrital zircon geochronology, isotopic fingerprinting, and stratigraphic correlation to present new evidence for a planetary-scale redistribution of continental material, reinforcing MAPCIS as a candidate for one of Earth’s most consequential impact events.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-7654

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