The Smithian-Spathian boundary: a critical juncture in the Early Triassic recovery of marine ecosystems.

Thomas J. Algeo (1, 2) , Arnaud Brayard (3) , Sylvain Richoz (4, 5)

1 Department of Geology
2 GPMR - State Key Laboratory of Geological Processes and Mineral Resources [Wuhan]
3 BGS - Biogéosciences [UMR 6282]
4 Department of Geology [Lund]
5 Institute of Earth Sciences

The Smithian-Spathian boundary (SSB), i.e., the transition between the Smithian and Spathian substages of the Olenekian Stage (late Early Triassic), was a key interval associated with major climatic, oceanic and biotic changes at a global scale (Fig. 1). It coincided with the first sustained amelioration of marine conditions and recovery of marine ecosystems following the end-Permian crisis. Specifically, the SSB marked a shift away from the widely fluctuating and frequently extreme global environmental conditions that characterized the first ~2 million years of the Early Triassic (i.e., the Griesbachian, Dienerian, and Smithian substages) to less severe conditions during the latter part of the Early Triassic (i.e., the Spathian substage). At the SSB, a major cooling event was accompanied by re-invigorated global-ocean circulation and turnovers in a number of marine invertebrate clades. The present thematic issue explores these developments in a series of 11 studies covering aspects of the biostratigraphy, paleoecology, paleoceanography, and volcanic history of the late Early Triassic, with special emphasis on the SSB (Fig. 1, Fig. 2). These studies represent the current state of knowledge regarding the SSB event and lay the groundwork for future studies on this topic

Domaines: Paléontologie; Milieux et Changements globaux; Géochimie; Océanographie

Thomas J. Algeo, Arnaud Brayard, Sylvain Richoz. The Smithian-Spathian boundary: a critical juncture in the Early Triassic recovery of marine ecosystems.. Earth-Science Reviews, 2019, 195, pp.1-6. ⟨10.1016/j.earscirev.2019.102877⟩. ⟨hal-02270741⟩