Provenance of Upper Jurassic-Lower Cretaceous strata in the Mentelle Basin, southwestern Australia, reveals a trans-Gondwanan fluvial pathway

Australia, and East Gondwana more broadly, host extensive PaleozoicMesozoic sedimentary basins with thick siliciclastic sequences. These sediments were for the greater part transported by large-scale fluvial systems; however, the spatial and temporal patterns of sediment dispersal remain poorly understood. We investigate the provenance of rift strata in the Mentelle Basin, Western Australia, which were deposited during the Late Jurassic-Early Cretaceous breakup of India from Australia-Antarctica. Monazite U-Pb and zircon U-Pb-Hf isotopic signatures suggest that the Upper Jurassic-Lower Cretaceous syn-rift sediments were supplied predominately by a transcontinental river system draining sediments from interior regions of East Antarctica to the northern Gondwanan passive margin. This fluvial system was focused within the developing rift between India and Australia-Antarctica. Provenance of the transgressive marine post-breakup strata reflects a transition to a proximal sediment source and marks the end of the transcontinental fluvial system after the final breakup of India from Australia-Antarctica in the Valanginian (similar to 136 Ma). Statistical comparison of detrital zircon spectra of Mentelle Basin syn-rift strata with other Australian Paleozoic-Mesozoic rift strata located along our proposed transport route suggests that the transcontinental fluvial pathway was active since the Late Paleozoic. We infer that this fluvial system was one of the principal modes of siliciclastic sediment delivery to rift and passive margin basins of western Australia. (C) 2021 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

Automated summary

This study investigates the provenance of rift strata in the Mentelle Basin of Western Australia, revealing that the syn-rift sediments were primarily supplied by a transcontinental river system draining sediments from interior regions of East Antarctica to the northern Gondwanan passive margin. The study suggests that this fluvial system played a significant role in delivering siliciclastic sediment to rift and passive margin basins of western Australia.