Środowisko sedymentacji cechsztyńskiego łupku miedzionośnego w południowo-zachodniej Polsce
Abstract
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.
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.