Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

Journal of the Geological Society

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by SIMMS, M. J. Articles by RUFFELL, A. H. Search for Related Content GeoRef GeoRef Citation

Climatic and biotic change in the late Triassic

¹ Department of Geology, Trinity College, Dublin, Eire
² Department of Geology, Royal School of Mines, Imperial College, London SW72BP, UK

Generally arid conditions that pervaded much of Europe and North America during the late Triassic were interrupted by a wet monsoonal climatic phase during Middle and Late Carnian times. Extensive fluviatile sandstones deposited at this time throughout the region, occur within a thick sequence of playa-lake mudstones. The sandstones occasionally contain kaolinite, suggesting a humid climate. An extreme ¹³C depletion in a shallow marine sequence of this age in Israel has been interpreted as evidence for an influx of freshwater. A widespread change from carbonates to clastics in marine sequences at this time may also be climate-related. Water-course cave systems in limestone areas exposed during the late Triassic indicate high levels of runoff during the Middle and Late Carnian.

The marine invertebrate fauna shows a significant turnover at the end of the Early Carnian. The terrestrial fauna and flora were relatively unaffected at this time but subsequently diversified prior to a major biotic turnover at the Carnian-Norian boundary. These periods of biotic change appear to be synchronous with the onset and cessation of a Carnian humid phase.

The change to a monsoonal climate during this interval has been documented over more than 90° of longitude between 5° and 50° north of the Triassic equator. It may have been caused by rising atmospheric CO₂ levels due to volcanism associated with the incipient dispersal of Pangaea.

This article has been cited by other articles:

				C. E. Colombi and J. T. Parrish Late Triassic Environmental Evolution in Southwestern Pangea: Plant Taphonomy of the Ischigualasto Formation Palaios, December 1, 2008; 23(12): 778 - 795. [Abstract] [Full Text] [PDF]

				S. L. PHILIPP Geometry and formation of gypsum veins in mudstones at Watchet, Somerset, SW England Geological Magazine, November 1, 2008; 145(6): 831 - 844. [Abstract] [Full Text] [PDF]

				D. I. WHITESIDE and J. E. A. MARSHALL The age, fauna and palaeoenvironment of the Late Triassic fissure deposits of Tytherington, South Gloucestershire, UK Geological Magazine, January 1, 2008; 145(1): 105 - 147. [Abstract] [Full Text] [PDF]

				W. Kiessling and M. Aberhan Environmental determinants of marine benthic biodiversity dynamics through Triassic Jurassic time Paleobiology, June 1, 2007; 33(3): 414 - 434. [Abstract] [Full Text] [PDF]

				J. Szulc, M. Gradzinski, A. Lewandowska, and C. Heunisch The Upper Triassic crenogenic limestones in Upper Silesia (southern Poland) and their paleoenvironmental context Geological Society of America Special Papers, January 1, 2006; 416(0): 133 - 151. [Abstract] [Full Text] [PDF]

				E. T. Rasbury, E. H. Gierlowski-Kordesch, J. M. Cole, C. Sookdeo, G. Spataro, and J. Nienstedt Calcite cement stratigraphy of a nonpedogenic calcrete in the Triassic New Haven Arkose (Newark Supergroup) Geological Society of America Special Papers, January 1, 2006; 416(0): 203 - 221. [Abstract] [Full Text] [PDF]

				G. R. T. Wall, G. R. T. WALL, and H. C. JENKYNS The age, origin and tectonic significance of Mesozoic sediment-filled fissures in the Mendip Hills (SW England): implications for extension models and Jurassic sea-level curve Geological Magazine, July 1, 2004; 141(4): 471 - 504. [Abstract] [Full Text] [PDF]

				A. RUFFELL and R. SHELTON The control of sedimentary facies by climate during phases of crustal extension: examples from the Triassic of onshore and offshore England and Northern Ireland Journal of the Geological Society, August 1, 1999; 156(4): 779 - 789. [Abstract] [PDF]

				M. J. Benton and M. J. Benton Late Triassic Extinctions and the Origin of the Dinosaurs Science, May 7, 1993; 260(5109): 769 - 770. [PDF]

				A. B. LESLIE, B. SPIRO, and M. E. TUCKER Geochemical and mineralogical variations in the upper Mercia Mudstone Group (Late Triassic), southwest Britain: correlation of outcrop sequences with borehole geophysical logs Journal of the Geological Society, February 1, 1993; 150(1): 67 - 75. [Abstract] [PDF]

				G. Warrington and H. C. Ivimey-Cook Triassic Geological Society, London, Memoirs, January 1, 1992; 13(1): 97 - 106. [Abstract] [PDF]