Turonian through Santonian deposits of the Central Polish Uplands; their facies development, inoceramid paleontology and stratigraphy

Abstract

Stratigraphy, inoceramid paleontology and facies characteristics of the Turonian through Santonian deposits of the Central Polish Uplands are presented, on the basis of which 17 inoceramid zones are recognized and their position against the ammonite standard division is discussed. Apart from the Middle/Upper Santonian and Santonian/Campanian boundary all other stage and substage boundaries are well recognizable with the inoceramid fauna. Most of the inoceramids, comprising about 40 species, assigned to six genera, are monographed. Two species from the Turonian-Coniacian boundary interval are described as new: Mytiloides turonicus sp. n. and Inoceramus vistulensis sp. n. The Mytiloides labiatus group is thoroughly treated and particular members are discussed, to show that M. suhmytiloides (SEITZ) and M. subhercynicus (SEITZ), the widely cited species of this group, are invalid and thus should be rejected. The names Mytiloides opalensis sensu SEITZ (non BSE) and M. duplicostatus sensu KAUFFMAN (non ANDERSON) are younger synonyms of M. kossmati (HElNZ). A revision of the whole genus Cremnoceramus is also presented.The stratigraphic scheme applied to the Turonian through Santonian deposits of the Central Polish Uplands allows to solve some regional problems, and to construct a unified chronostratigraphic facies scheme for the southern part of the epicontinental areas in Poland. The facies characteristics combined with the paleotectonic setting of the studied area is the base of the distinguishing of the four geotectonic-facies regions: the Circum-Sudetic Trap Basins, the Cracow Swell, the Danish Polish Trough, and the Russian Chalk Sea. The evolution of the studied areas during Turonian through Santonian time is assembled to indicate the primary role of tectonic movements of the Subhercynian phase of the Alpine orogeny.