The base of the Lystrosaurus Assemblage Zone, Karoo Basin, predates the end-Permian marine extinction.
| Autor: | Gastaldo RA; Department of Geology, Colby College, Waterville, ME, 04901, USA. robert.gastaldo@colby.edu., Kamo SL; Department of Earth Sciences, Jack Satterly Geochronology Laboratory, University of Toronto, Toronto, Ontario, M5S 3B1, Canada., Neveling J; Council for Geosciences, Private Bag x112, Silverton, Pretoria, 0001, South Africa., Geissman JW; Department of Geosciences, The University of Texas at Dallas, Richardson, TX, 75080-3021, USA.; Department of Earth and Planetary Sciences, The University of New Mexico, Albuquerque, NM, 87131-0001, USA., Looy CV; Department of Integrative Biology, Museum of Paleontology, University and Jepson Herbaria, University of California-Berkeley, 3060 Valley Life Sciences Building #3140, Berkeley, CA, 94720-3140, USA., Martini AM; Department of Geology, Amherst College, Amherst, MA, 01002, USA. |
|---|---|
| Jazyk: | angličtina |
| Zdroj: | Nature communications [Nat Commun] 2020 Mar 18; Vol. 11 (1), pp. 1428. Date of Electronic Publication: 2020 Mar 18. |
| DOI: | 10.1038/s41467-020-15243-7 |
| Abstrakt: | The current model for the end-Permian terrestrial ecosystem crisis holds that systematic loss exhibited by an abrupt turnover from the Daptocephalus to the Lystrosaurus Assemblage Zone (AZ; Karoo Basin, South Africa) is time equivalent with the marine Permian-Triassic boundary (PTB). The marine event began at 251.941 ± 0.037 Ma, with the PTB placed at 251.902 ± 0.024 Ma (2σ). Radio-isotopic dates over this interval in the Karoo Basin were limited to one high resolution ash-fall deposit in the upper Daptocephalus AZ (253.48 ± 0.15 (2σ) Ma) with no similar age constraints for the overlying biozone. Here, we present the first U-Pb CA-ID-TIMS zircon age (252.24 ± 0.11 (2σ) Ma) from a pristine ash-fall deposit in the Karoo Lystrosaurus AZ. This date confirms that the lower exposures of the Lystrosaurus AZ are of latest Permian age and that the purported turnover in the basin preceded the end-Permian marine event by over 300 ka, thus refuting the previously used stratigraphic marker for terrestrial end-Permian extinction. |
| Databáze: | MEDLINE |
| Externí odkaz: |
|