Stratigraphic record of continental breakup, offshore NW Australia—Discussion

Abstract

AbstractReeve et al. (2022) address the stratigraphic record of continental breakup by focusing on a set of stratigraphic unconformities from a proximal sector of the NW Australian continental margin, inboard from the Exmouth Plateau. They suggest that such unconformities can potentially document a well‐defined three‐stage process: end of the syn‐rift phase, formation of a wide continent‐ocean transition zone (COTZ) and generation of ‘true’ Penrose‐type oceanic crust. We counterargue that continental breakup is a protracted event that can only be understood via seismic‐ and chronostratigraphic correlations of strata, and their composing sequences, across and along rifted margins. Tying proximal stratigraphic unconformities to magnetic anomalies outboard from the study area in Reeve et al. (2022) is open to question. In parallel, we suggest that age resolutions of ca. 1 Ma are not achievable using the micropaleontological data presented in Reeve et al. (2022), with an important reworking of microfossil assemblages potentially occurring during the erosional process forming local and regional unconformities. Our discussion addresses these points in more detail.