Origins and Sedimentary Features of Supersurfaces in the Northwestern Gran Desierto Sand Sea

  1. K. Pye2 and
  2. N. Lancaster3
  1. N. Lancaster

Published Online: 8 APR 2009

DOI: 10.1002/9781444303971.ch6

Aeolian Sediments: Ancient and Modern

Aeolian Sediments: Ancient and Modern

How to Cite

Lancaster, N. (1993) Origins and Sedimentary Features of Supersurfaces in the Northwestern Gran Desierto Sand Sea, in Aeolian Sediments: Ancient and Modern (eds K. Pye and N. Lancaster), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303971.ch6

Editor Information

  1. 2

    Reading, UK

  2. 3

    Reno, Nevada, USA

Author Information

  1. Quaternary Sciences Center, Desert Research Institute, University of Nevada System, PO Box 60220, Reno, NV 89506, USA

Publication History

  1. Published Online: 8 APR 2009
  2. Published Print: 27 MAY 1993

ISBN Information

Print ISBN: 9780632035441

Online ISBN: 9781444303971

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Keywords:

  • origin and sedimentary features of supersurfaces in northwestern Gran Desierto Sand Sea;
  • Gran Desierto Sand Sea - regional-scale or super bounding surfaces in aeolian sequences;
  • Gran Desierto - studying effects of climatic, tectonic and eustatic changes on sand supply;
  • northwestern Gran Desierto dunes;
  • sand sheets - component of many sand seas;
  • Units II and III in sand sheets - lacking wind-ripple laminations;
  • wind ripple deposition in areas of sparse desert vegetation

Summary

Studies of sand sheets and dunes in the northwestern margins of the Gran Desierto Sand Sea provide criteria for the recognition of regional-scale or super bounding surfaces in aeolian sequences. Genetic units in the sand sheets and dunes are separated by supersurfaces. The sand sheets were formed in conditions of limited sand supply, sediment bypassing and a sparse vegetation cover. Termination of sand supply to the area from the Colorado River valley resulted in deflation of sand sheet deposits until a protective lag had formed on supersurface A. Renewed sand sheet and dune accumulation was ended by climatic changes resulting in an increase in the vegetation cover, stabilization of the surface and pedogenic alteration of underlying deposits to form supersurface B. In this area, it appears that super-surfaces resulting from termination of sand supply are characterized by deflation and development of surface lags, whereas those resulting from regional climatic changes are marked by pedogenic alteration.