Beach skirt

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Beach skirt on the coast of Reunion
Components of Beachrock

So-called Beach skirt (engl., Dt. Mutatis mutandis beach rock ) forms at the sea shores in tropical to subtropical climate of beach deposits by a kind of fast rock formation.

overview

The rock can comprise a wide variety of materials, including coral debris; The main binders are magnesium-rich carbonates such as dolomite , calcite or aragonite . The formation, especially in the coastal and beach area, is indicated by an oversaturation of CaCO 3 due to strong evaporation (Scoffin, 1970), inflow of carbonate-rich groundwater in the beach area (Hanor, 1978) and in the brackish water zone as well as precipitation of carbonate rock due to microbiological activities (Neumeier, 1999). Beach rock only needs a few decades to form under good conditions.

The possible interpretation as a sea level indicator is not easy. There is very little fossil beach rock, which can be explained, among other things, by a possible multiple reshaping. Beach rock, submerged by lowering the beach or rising sea levels, is a good reason for coral reefs to form .

Trivia

Regular, pillow-like formations of beach rock on the Biminiroad gave rise to speculation about a human production similar to megaliths .

The inclusion of coarse civilization garbage ( plastic garbage as well as tin cans) turns individual, very peculiar beach rock variants into collectibles.

See also

literature

  • Neumeier U .: The role of microbial activity in early cementation of beach rocks (intertidal sediments). PhD Thesis, University of Geneva . In: Terre et Environment . No. 12, 1998.
  • Hanor JS: Precipitation of beachrock cements: mixing of marine and meteoric waters vs. CO2 degassing . In: Journal of Sedimentary Petrology . No. 48, 1978.
  • Scoffin TP & Stoddart DR: Beachrock and intertidal sediments, Chemical Sediments and Geomorphology . Academic Press, Inc., 1983.
  • Schmalz RF: Formation of beachrock at Eniwetok Atoll . Johns Hopkins Press, Baltimore 1971.

Individual evidence

  1. ↑ Collective of authors: Lexicon of Geosciences , Volume I, Spektrum Akademischer Verlag, Heidelberg, Berlin 2000, ISBN 3-8274-0299-9 , p. 205
  2. ↑ Beachrock as Sea-Level Indicator? Remarks from a Geomorphological Point of View Dieter Kelletat, in Journal of Coastal Research 22 (6): 1558-1564. 2006 doi : 10.2112 / 04-0328.1
  3. ↑ See E. Shinn: A Geologist's Adventures with Bimini Beachrock and Atlantis True Believers , in: The Secptical Inquirer 28 , 2004.