The early Devonian continental/marine succession at Chęciny in the Holy Cross Mts, and its paleogeographic and tectonic significance

Abstract

The early Devonian transgressive deposits at Chęciny in the Holy Cross Mts, which rest on a weathered surface of Lower Cambrian claystones, are represented by diverse terrigenous looks containing scarce marine fossils in their higher part. The lower part represents a laical waste, redeposited under continental conditions. The thin development of the transgressive terrigenous sequence (8 m) points to slow subsidence and a rapid advance of marine conditions. These deposits are overlain by carbonate-terrigenous (chiefly dolomitic) rocks containing a diversified open-marine fauna. The paleogeography of the early Devonian is discussed. Evidence is presented for a swell, trending E-W, in the southern part of the Holy Cross area; also for the presence of an epicontinental basin filled with Lower Devonian deposits over 1 km thick in the northern periphery of that area. It is concluded that there is little evidence for the concept of Caledonian geosyncline in southern Central Poland.