40Ar/39Ar Dating of Detrital White Mica as a Complementary Tool for Provenance Analysis: A Case Study from the Cenozoic Qaidam Basin (China)

  1. Gary Nichols,
  2. Ed Williams and
  3. Chris Paola
  1. Andrea B. Rieser1,†,
  2. Franz Neubauer1,
  3. Yongjiang Liu2,
  4. Johann Genser1,
  5. Robert Handler1,
  6. Xiao-Hong Ge2 and
  7. Gertrude Friedl1

Published Online: 30 MAR 2009

DOI: 10.1002/9781444304411.ch14

Sedimentary Processes, Environments and Basins: A Tribute to Peter Friend

Sedimentary Processes, Environments and Basins: A Tribute to Peter Friend

How to Cite

Rieser, A. B., Neubauer, F., Liu, Y., Genser, J., Handler, R., Ge, X.-H. and Friedl, G. (2007) 40Ar/39Ar Dating of Detrital White Mica as a Complementary Tool for Provenance Analysis: A Case Study from the Cenozoic Qaidam Basin (China), in Sedimentary Processes, Environments and Basins: A Tribute to Peter Friend (eds G. Nichols, E. Williams and C. Paola), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304411.ch14

Author Information

  1. 1

    Department of Geography and Geology, Division General Geology and Geodynamics, University of Salzburg, Hellbrunnerstr. 34, 5020 Salzburg, Austria

  2. 2

    College of Earth Sciences, Jilin University, Jianshe Str. 2199, 130061 Changchun, China

  1. Nagra, Hardstrasse 73, 5430 Wettingen, Switzerland

Publication History

  1. Published Online: 30 MAR 2009
  2. Published Print: 7 DEC 2007

Book Series:

  1. Special Publication Number 38 of the International Association of Sedimentologists

Book Series Editors:

  1. Ian Jarvis

Series Editor Information

  1. School of Earth Sciences & Geography, Centre for Earth & Environmental Science Research, Kingston University, Penrhyn Road, Kingston upon Thames KT1 2EE, UK

ISBN Information

Print ISBN: 9781405179225

Online ISBN: 9781444304411

SEARCH

Keywords:

  • 40Ar/39Ar dating of detrital white mica - vital information on age of source area in hinterland;
  • Qaidam basin of western China;
  • Wacke classification after Pettijohn;
  • detrital white mica 40Ar/39Ar total-fusion ages from Ganchaigou;
  • source-area signature

Summary

When classic petrographic analysis of the modal composition of sandstones yields no distinction between different source regions, 40Ar/39Ar dating of detrital white mica can provide vital information on the age of a source area and thus link the sediments to a specific provenance in the hinterland. This approach is exemplified by a case study of the intramontane Qaidam Basin (western China). While the geology of the surrounding mountains of the Qaidam Basin shows considerable lithological variation and the basin's palaeoclimate changed from semi-arid to arid, modal analysis of sandstones from two sections in the northwestern basin, as well as a section on the eastern margin, yielded no significant spatial or temporal differences. All sandstones, most of them classified as lithic wackes with matrix/cement contents between 14 and 39%, plot mainly in the recycled orogenic field of Dickinson's ternary discrimination diagrams for a tectonic environment. The sandstones are quartz dominated, with quartz contents of 33–65% and relative high contents of feldspar and lithic grains. On the other hand, 40Ar/39Ar total-fusion age data obtained from detrital white mica of between 123 and 546 Ma yielded three age clusters (120–180, 220–280, 350–450 Ma) that could be assigned to certain provenance areas within the early Palaeozoic and Permian basement in the Altyn and Qimantagh mountains. This contrasts with the Lulehe section in the east of the basin, where exclusively Permian ages between 250 and 279 Ma were found. This significant difference in age distribution, and thus provenance, could not be deduced from sandstone composition. The results of this study show how 40Ar/39Ar thermochronology can complement classic point-count analysis.