Permian Saar-Nahe Basin and Recent Lake Constance (Germany): Two Environments of Lacustrine Algal Carbonates

  1. Albert Matter and
  2. Maurice E. Tucker
  1. Andreas Schäfer1 and
  2. Karl R. G. Stapf2

Published Online: 29 JUN 2009

DOI: 10.1002/9781444303698.ch5

Modern and Ancient Lake Sediments

Modern and Ancient Lake Sediments

How to Cite

Schäfer, A. and Stapf, K. R. G. (1978) Permian Saar-Nahe Basin and Recent Lake Constance (Germany): Two Environments of Lacustrine Algal Carbonates, in Modern and Ancient Lake Sediments (eds A. Matter and M. E. Tucker), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303698.ch5

Author Information

  1. 1

    Geologisches Institut der Universität, Nussallee 8, D-5300 Bonn, West Germany

  2. 2

    Institut für Geowissenschaften der Universität, Saarstrasse 21, D-6500 Mainz, West Germany

Publication History

  1. Published Online: 29 JUN 2009
  2. Published Print: 24 NOV 1978

ISBN Information

Print ISBN: 9780632002344

Online ISBN: 9781444303698

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Keywords:

  • lacustrine stromatolites and oncolites;
  • Petrography of the algal carbonates;
  • large elongate oncolites occur in sandstones;
  • Ermatingen Embayment;
  • zonation of algal communities

Summary

Algal carbonates of a Permian and Recent lacustrine environment are described and their occurrence discussed. The stromatolites of the Permian Saar-Nahe Basin are diverse in shape, forming small domes, mats and oncolites. Their scale ranges from millimetres to metres. Embedded in limestone, mudstone and muddy sandstone, the algal carbonates are locally restricted to distinct horizons. The algal origin is demonstrated by the gross fabrics since there is no evidence for algal filaments within the stromatolite microstructures. In Recent Lake Constance algal carbonates exhibit fabrics which can be related to different blue-green algae. These carbonates mainly occur in the Untersee of Lake Constance and are restricted to its shallow-water areas. The algal nodules, 0.5–30 cm in size, possess both smooth and spongy surfaces. The smooth surfaces are formed by Schizothrix, the spongy surfaces by Phormidium, Calothrix and/or Dichothrix; occasionally colonies of Rivularia are intercalated. The smooth nodules are found close to the shoreline of the lake. The spongy nodules occur in loose carbonate sands which are influenced by the Rhine river current. Both types are covered by water for most of the year.