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Timing and causes of the mid-Cretaceous global plate reorganization event
journal contributionposted on 2023-05-20, 10:18 authored by Olierook, HKH, Jourdan, F, Joanne WhittakerJoanne Whittaker, Merle, RE, Jiang, Q, Pourteau, A, Doucet, LS
Global plate reorganization events (GPREs) can have profound impact on plate velocities, climate and the biotic cycle but the timing and triggers for GPREs remain debated. The timing and causes of the mid-Cretaceous GPRE, one of only two GPREs since the breakup of Pangea, remains poorly constrained because it occurred during the Cretaceous Normal Superchron. Here, we provide a new plagioclase 40Ar/39Ar age of Ma (2σ) at DSDP site 256 along the world's clearest curved fracture zones in the Wharton Basin, off NW Australia. Using Monte Carlo simulations, we compute that the mid-Cretaceous GPRE commenced at Ma (95% confidence). The mid-Cretaceous GPRE was associated with a significant plate deceleration (minimum ∼26%), similar to the Eocene GPRE, implying that this process is fundamental to plate reconfigurations. We propose that the mid-Cretaceous GPRE was caused by slab-breakoff and cessation of the south-dipping subduction zone in the Mesotethys Ocean at ca. 111 Ma. Ultimately, we posit that subduction zone initiations and cessations are the primary triggers for both post-Pangean GPREs and that top-down processes may be the fundamental drivers for GPREs.
Publication titleEarth and Planetary Science Letters
Department/SchoolInstitute for Marine and Antarctic Studies
PublisherElsevier Science Bv
Place of publicationPo Box 211, Amsterdam, Netherlands, 1000 Ae
Rights statement©2020 Elsevier B.V. All rights reserved.