Triassic-Jurassic Moenave Formation revised chronostratigraphy (free pdf)the

[Ben Creisler]

Ben Creisler

bcre...@gmail.com

A new paper:

Free pdf:

Celina A. Suarez, Glenn R. Sharman, Jordan Oefinger, Asher Boudreaux, Dennis Mmasa, James L. Crowley, Michael T. Mohr, Adam D. Marsh, Andrew R.C. Milner & Lisa E. Park Boush (2025)
A revised chronostratigraphy of the Triassic-Jurassic Moenave Formation, western USA: Implications for timing of continental climate change
GSA Bulletin (advance online publication)
doi: https://doi.org/10.1130/B37784.1
https://pubs.geoscienceworld.org/gsa/gsabulletin/article/doi/10.1130/B37784.1/656267/A-revised-chronostratigraphy-of-the-Triassic


The Moenave Formation of the Colorado Plateau region of western USA preserves the Triassic-Jurassic transition, a time period that saw one of the most significant climate disruptions in Earth’s history. During this time, major carbon (C)-cycle perturbations due to carbon release from the emplacement of the Central Atlantic Magmatic Province (CAMP) caused rapid climate change prompting the end-Triassic mass extinction (ETE). Here we present a Bayesian age-model generated from new C-isotope chemostratigraphic records paired with high-precision detrital zircon U-Pb geochronology to constrain the stratigraphic placement of the ETE and Triassic-Jurassic boundary within the Moenave Formation. Maximum depositional ages of detrital zircon from the Moenave Formation range between 203.71 ± 0.09 Ma to 200.20 ± 0.17 Ma. A −6.0‰ C-isotope excursion within the middle Dinosaur Canyon Member (DCM) is correlated to the initial negative C-isotope excursion of the ETE, indicating that the lower to middle DCM is latest Triassic and that climatic and biotic disturbances associated with CAMP should be preserved within this stratigraphic interval. Chemostratigraphic, geochronologic, and biostratigraphic data supports an earliest Jurassic age assignment for the lacustrine Whitmore Point Member, suggesting that it is an example of an earliest Jurassic ecosystem recovering from the ETE that warrants detailed exploration. This study greatly expands our knowledge of the chronostratigraphic framework of the continental Triassic-Jurassic transition and is important for correlating other global records of the ETE event.

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