Calcrete Profiles in the Eyam Limestone (Carboniferous) of Derbyshire: Petrology and Regional Significance

  1. V. Paul Wright2 and
  2. Maurice E. Tucker3
  1. A. E. Adams

Published Online: 8 APR 2009

DOI: 10.1002/9781444304497.ch7

Calcretes

Calcretes

How to Cite

Adams, A. E. (1991) Calcrete Profiles in the Eyam Limestone (Carboniferous) of Derbyshire: Petrology and Regional Significance, in Calcretes (eds V. P. Wright and M. E. Tucker), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304497.ch7

Editor Information

  1. 2

    Postgraduate Research Institute of Sedimentology (PRIS), University of Reading, UK

  2. 3

    Department of Geological Sciences, University of Durham, UK

Author Information

  1. Department of Geology, University of Manchester, Manchester M13 9PL, UK

Publication History

  1. Published Online: 8 APR 2009
  2. Published Print: 13 JUN 1991

ISBN Information

Print ISBN: 9780632031870

Online ISBN: 9781444304497

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Keywords:

  • calcrete profiles in Eyam Limestone of Derbyshire - petrology and regional significance;
  • Eyam Limestone, occurring in Carboniferous Limestone;
  • calcretes, indicating subaerial exposure;
  • second unit of the calcrete profile containing higher proportion of fine-grained matrix;
  • pelleted calcrete, having transitional contact with underlying units

Summary

Calcrete profiles (caliche) have been recognized in the Eyam Limestone from the Lower Carboniferous in the area around Monyash, Derbyshire. They occur at the top of the flank facies surrounding carbonate-mud buildups (‘knoll reefs’). Four units make up the complete profile. These are from base to top: (1) grain-supported sediment with rhizocretions, (2) matrix-supported sediment with alveolar texture, (3) pelleted calcrete, (4) laminar calcrete. Commonly one or more units are missing from the profile. Calcretes indicate subaerial exposure. The carbonate buildups of the Eyam Limestone were completely exposed soon after deposition, requiring a fall in sea-level probably in excess of 10 m. This discovery demands a review of previous regional palaeoenvironmental studies.