Biostratigrafie a litologie slinovcu a silicitu cenomanskeho stari na bazi basskeho souvrstvi potoka Kasice

Attention has recently been paid to Albian-Turonian sediments of the Baška Development in the frame of the long-term study of Cretaceous formations of the Silesian Unit, Outer Western Carpathians. The Baška Development represents in particular a continental slope facies (Eliáš 1979). The studied stratigraphic interval corresponds to the Chlebovice Member of the Hradiště and Baška formations. According to Boorová et al. (2003), conglomerate sediments belonging to the Chlebovice Member extend as far as the Middle Cenomanian on the Ondřejnice brook section near Hukvaldy. Layers overlying conglomerates of the Chlebovice Member consist of bedded silicified sandstones to biodetritic silicites that are in places disturbed by beds of grey to light grey limestones, and calcareous claystones. This sequence of strata can be regarded as the base of the Baška Formation.
Very similar sediments belonging to the lower part of the Baška Formation were studied in the Palkovické hůrky area in foothills of the Beskydy Mts. Some outcrops occur on the right bank of the Kašice brook, and in an abandoned quarry on the west slope of Kabátice Hill, about 1.5 km west of Krnalovice.
The lower part of the section consists of dark grey fine-grained laminated limestones which are composed of micrite and sparite and abundant radiolarians, sponge spicules, and rare foraminifera. A few millimetres thick laminae containing fish scales and fish remnants can occasionally be found in the uppermost parts of the layers. The rock contains up to 55 vol.% of calcite and 40 vol.% of SiO₂. The higher part of the outcrop consists of grey-green claystones and siltstones, often silicified and non-calcareous.
The strata can be correlated, according to presence of Florentinia radiculata and Epelidosphaeridia spinosa, with the Middle to Upper Cenomanian. The Cenomanian age is also confirmed by representatives of Achomosphaera sagena, Impletosphaeridium clavulum, Litosphaeridium siphoniphorum, Pervosphaeridium truncatum, and Surculosphaeridium longifurcatum.
Sedimentation in a distal deep-water marine environment can be assumed, judging from the abundance of mostly deep-water genera of dinoflagellates, such as Achomosphaera, Epelidosphaeridia, Florentinia, Hystrichodinium, Impletosphaeridium, Ovoidinium, Spiniferites and other species.

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