Archive

Article

Geologica Carpathica, 1991, vol. 42, no. 5
TO THE ORIGIN OF VARIEGATED SHALES FROM FLYSCH OF THE POLISH CARPATHIANS
Abstract
Six facies of sediments bearing variegated shales, differing in textures and sedimentary structures, have been distinguished. The variegated shales are interpreted as deposited in bathyal to abyssal depths, below CCD, by the settling of individual particles or particle aggregates from land run-off with some lateral transfer by bottom currents and from highly dispersed turbidity currents. Subordinate to the above process was deposition from dense muddy turbidity currents, slumps and mudflows. Shale colour resulted from (1) sediment composition, (2) seafloor oxygenation, (3) frequency of event sedimentation and associated erosional effects, (4) thickness and shape of event beds, (5) degree and pattern of bioturbation. The beginning of variegated shales sedimentation in the Carpathians, like in the Alps and the Atlantic Ocean, resulted mainly from the Cenomanian sea-level rise. Termination of this sedimentation in the Carpathians was due to the closure of connections with the open ocean.
Pages:
279 - 289
Published online:
0. 0. 1991