Relative Importance of Regional Tectonics and Eustasy for the Mesozoic of the Andes

  1. David I. M. Macdonald
  1. A. Hallam

Published Online: 14 APR 2009

DOI: 10.1002/9781444303896.ch11

Sedimentation, Tectonics and Eustasy: Sea-Level Changes at Active Margins

Sedimentation, Tectonics and Eustasy: Sea-Level Changes at Active Margins

How to Cite

Hallam, A. (2009) Relative Importance of Regional Tectonics and Eustasy for the Mesozoic of the Andes, in Sedimentation, Tectonics and Eustasy: Sea-Level Changes at Active Margins (ed D. I. M. Macdonald), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303896.ch11

Editor Information

  1. British Antarctic Survey, Cambridge, UK

Author Information

  1. School of Earth Sciences, University of Birmingham, Birmingham B15 2TT, UK

Publication History

  1. Published Online: 14 APR 2009
  2. Published Print: 13 JUN 1991

ISBN Information

Print ISBN: 9780632030170

Online ISBN: 9781444303896

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Keywords:

  • ancient arc and transform margins;
  • regional tectonics and eustasy for Mesozoic of Andes;
  • Triassic and Jurassic stratigraphy;
  • regressive deposits - gypsum deposit, Oxfordian—Kimmeridgian boundary;
  • cretaceous;
  • five major cycles recognized - Cycle 1 (Tithonian—Valanginian) restricted to NE—SWtrending Grabens;
  • major facies patterns for marine Tithonian-Neocomian of southern part of Andean Basin

Summary

In various parts of the Andes there is a good marine record of Mesozoic deposits from the Norian to the Maastrichtian. These were laid down with associated continental deposits in a series of basins formed by extensional tectonics and thermal subsidence, the best known of which are the back-arc Andean and Magallanes Basins. Of several episodes of regional tectonics and associated igneous activity during this period, causing widespread uplift and regression of the sea, the most important took place in the southern Andes in the Mid-Cretaceous, and the second most important in Late Jurassic times. Both of these events were probably associated with eastward shifts of the subduction zone related to the opening of the South Atlantic. During the much longer intervals of tectonic quiescence, the pattern of marine sedimentation substantially reflected global events, suggesting that eustasy was a significant controlling factor.