Trzeciorzęd strefy zapadliskowej Rząśnia - Kleszczów – Kamieńsk

Jerzy Derkacz



The foredeep zone Rząśnia-Kleszczów-Kamieńsk, which occurs in the Mesozoic substratum, and is filled in with the continental Tertiary deposits, has been recognized due to the geophysical. and drilling works carried out in the area considered. The zone resembles an elongated channel about 50 km long, and 1,5 - 2 km broad, its depth being 150 - 200 m. Taking into account the facial development of the deposits, the Tertiary formations found in the channel considered may be subdivided into 4 series as follows: 1 - lower series of fluvio-lacustrine deposits, represented by sands with silt intercalations, 2 - series of palustro-lacustrine deposits, consisting of silts, clays and sands with brown coal intercalations, 3 - series of paludal deposits, represented by brown coals, with interbeddings of coal-bearing silts and clays, 4 - upper series of fluvio-Iacustrine deposits, built up of clays and sands. Total thickness of the Tertiary formations amounts here to 400 m. The zone described in the present paper is a foredeep, developed along the margin of some plates, displaced in a step-like manner, the northern one of which was sunk, and the southern one was elevated. The margin of the southern elevated plate makes an abrupt, southern boundary of the basin in which the Tertiary deposits were laid down. An interesting phenomenon, worthy of being stressed here, is a salt plug In the region of Dębina, which pierces the Tertiary deposits found in the foredeep area. The Tertiary deposits are here elevated and •appear in• the form of a brachyanticline.