Stratygrafia kredy górnej w wierceniu Jedlanka Nowa w okolicy Radomia

Abstract

STRATIGRAPHY OF THE UPPER CRETACEOUS IN BORE HOLE JEDLANKA NOWA NEAR RADOMThe Jedlanka Nowa bore hole has been drilled in 1953 in the vicinity of Radom (northern periphery of the Święty Krzyż Mountains). This bore hole pierced the Quaternary, and subsequently the Santonian, the Coniacian and, partly, the Upper Turonian. A section of this bore hole in shown in Fig. 1.Santonian (depth from 7.20 to 156.0 m.) is developed in the form of arenaceous glauconitic marls. Both glauconite and sandiness is connected with Sub-Hercynian movements which have caused a shallowing of the sea and emergence of the Święty Krzyż massif. The fauna appearing in this bore hole indicates the Middle and Lower Santonian. The Upper Santonian exists here probably too, but fails to be documented palaeontologically (Fig. 1, Table 1).In contrast with the Santonian, the Coniacian (depth from 155.0 to 210.0 m.) is developed in the form of marls without glauconites; in the Lower Coniacian, however, there already appears siliceous marls ("opoka") with cherts. FaunaIly; ,the boundary between the Turonian and Coniacian is very distinct (Fig. 1, Table 1). On the other hand, the upper boundary between the Coniacian and the Santonian is partly based on their lithological difference. The Inoceramus forms appearing in this bore hole indicate the Lower Coniacian; the author failed, however, to find here Upper Coniacian Inoceramus forms, whereas they are known in the northern ,periphery, in neighboring bore holes.The Turonian (depth from 210.0 to 264.8 m.) is developed in the form of "opoka" rock with cherts. The bore hole has merely pierced the Upper Turonian, horizon IV, and, partly, horizon III. The thickness of the entire Turonian in this area is known to exceed 200 m. The Turonian fauna is fairly numerous, and typical (Fig. 1, Table 1).