Synchroneity of climatic change and extinctions in the Late Triassic

Abstract

Research Article| March 01, 1989 Synchroneity of climatic change and extinctions in the Late Triassic Michael J. Simms; Michael J. Simms 1Department of Earth Sciences, University of Liverpool, P.O. Box 147, Liverpool L69 3BX, England Search for other works by this author on: GSW Google Scholar Alastair H. Ruffell Alastair H. Ruffell 2School of Earth Sciences, University of Birmingham, P.O. Box 363, Birmingham B15 2TT, England Search for other works by this author on: GSW Google Scholar Geology (1989) 17 (3): 265–268. https://doi.org/10.1130/0091-7613(1989)017<0265:SOCCAE>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Michael J. Simms, Alastair H. Ruffell; Synchroneity of climatic change and extinctions in the Late Triassic. Geology 1989;; 17 (3): 265–268. doi: https://doi.org/10.1130/0091-7613(1989)017<0265:SOCCAE>2.3.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract Although the Late Triassic was a time of widespread aridity, evidence exists for a significant increase in rainfall during the middle to late Carnian. Upper Triassic playa-lake sediments were interrupted by late Carnian fluviatile sandstones with erosive bases and high kao-linite/illite ratios. There was also an increase in the clastic component of marine sequences during this interval. Middle and upper Carnian marine carbonates show an extreme depletion in δ13C values, consistent with increased fresh-water influx. Large-scale karstic phenomena in limestone areas subaerially exposed during the Late Triassic are a further indication of increased rainfall. Important faunal and floral changes occurred during the Carnian-Norian interval; marine invertebrate turnover was greatest at the lower/middle Carnian boundary, and terrestrial extinctions were concentrated at the Carnian/Norian boundary. The cause of this Carnian pluvial episode may have been related to the rifting of Pangea, through disruption of atmospheric and oceanic circulation patterns, eustatic changes, or the effects of volcanism associated with rifting. A change in surface ocean temperature, salinity or pH, or habitat loss may have caused the decline of many shallow-marine invertebrates at the start of the middle Carnian; a return to arid conditions at the Carnian/Norian boundary would account for the turnover among terrestrial vertebrates and plants. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.