Facies

, Volume 53, Issue 3, pp 409–425

Earliest Triassic microbialites in the South China block and other areas: controls on their growth and distribution

  • Steve Kershaw
  • Yue Li
  • Sylvie Crasquin-Soleau
  • Qinglai Feng
  • Xinan Mu
  • Pierre-Yves Collin
  • Alan Reynolds
  • Li Guo
Original Article

DOI: 10.1007/s10347-007-0105-5

Cite this article as:
Kershaw, S., Li, Y., Crasquin-Soleau, S. et al. Facies (2007) 53: 409. doi:10.1007/s10347-007-0105-5

Abstract

Earliest Triassic microbialites (ETMs) and inorganic carbonate crystal fans formed after the end-Permian mass extinction (ca. 251.4 Ma) within the basal Triassic Hindeodus parvus conodont zone. ETMs are distinguished from rarer, and more regional, subsequent Triassic microbialites. Large differences in ETMs between northern and southern areas of the South China block suggest geographic provinces, and ETMs are most abundant throughout the equatorial Tethys Ocean with further geographic variation. ETMs occur in shallow-marine shelves in a superanoxic stratified ocean and form the only widespread Phanerozoic microbialites with structures similar to those of the Cambro-Ordovician, and briefly after the latest Ordovician, Late Silurian and Late Devonian extinctions. ETMs disappeared long before the mid-Triassic biotic recovery, but it is not clear why, if they are interpreted as disaster taxa. In general, ETM occurrence suggests that microbially mediated calcification occurred where upwelled carbonate-rich anoxic waters mixed with warm aerated surface waters, forming regional dysoxia, so that extreme carbonate supersaturation and dysoxic conditions were both required for their growth. Long-term oceanic and atmospheric changes may have contributed to a trigger for ETM formation. In equatorial western Pangea, the earliest microbialites are late Early Triassic, but it is possible that ETMs could exist in western Pangea, if well-preserved earliest Triassic facies are discovered in future work.

Keywords

Microbialite Dendrolite Thrombolite Permian–Triassic boundary Anoxia Mass extinction 

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • Steve Kershaw
    • 1
  • Yue Li
    • 2
  • Sylvie Crasquin-Soleau
    • 3
  • Qinglai Feng
    • 4
  • Xinan Mu
    • 2
  • Pierre-Yves Collin
    • 3
  • Alan Reynolds
    • 5
  • Li Guo
    • 6
  1. 1.Department of Geography and Earth SciencesBrunel UniversityUxbridgeUK
  2. 2.Nanjing Institute of Geology and PalaeontologyNanjingChina
  3. 3.CNRS, UMR 5143 “Paléobiodiversité et paléoenvironnements”Université Pierre et Marie CurieParis Cedex 05France
  4. 4.Geosciences UniversityWuhanPeople’s Republic of China
  5. 5.Experimental Techniques CentreBrunel UniversityUxbridgeUK
  6. 6.CASP, Department of Earth SciencesUniversity of CambridgeCambridgeUK