Środowisko sedymentacji cechsztyńskiego łupku miedzionośnego w południowo-zachodniej Polsce

Sławomir Oszczepalski

Abstrakt


DEPOSITIONAL ENVIRONMENT OF THE KUPFERSCHIEFER IN SOUTH-WESTERN POLAND

Summary
The Kupferschiefer in SW Poland consists of clayshales and shaly laminated marlstones with occasional massive interbeds. Q-mode cluster analysis of 11 variables for 250 thin sections generated 9 microlithofacies (A- I). A quantified microlithofacies analysis of the Kupferschiefer sediments enabled sedimentary environments to be reconstructed.
The spatial distribution of the microlithofacies indicates that the Kupferschiefer was deposited in a relatively shallow, mud-dominated stratified shelf sea. Two main paleogeographical zones of the Kupferschiefer can be distinguished: l) deep shelf, which comprises the center of sedimentary basin, characterized by clayshales interbedded with laminated marlstones of low and fairly consistent thickness (30-60 cm), and 2) shallow shelf, which comprises basin margins, characterized by laminated ( or bioturbated) marlstones of variable thickness (0-170 cm) and occurrence of terrigenous and carbonate tempestites.
Deposition of the Kupferschiefer generally took place below fairweather wave base, in low-energy environments; the deep shelflithofacies was formed in anaerobic-dysaerobic waters mainly below storm wave base, whilst the shallow shelf lithofacies was deposited within storm wave base in dysaerobic-aerobic waters. Conditions of oxygenated and agitated waters predominated around shoreline and on intrabasinal elevations, where the Kupferschiefer is lacking.

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