Bentonitized tuffites in the Lower Eocene deposits of the Subsilesian Unit (Western Outer Carpathians, Poland): lithology, stratigraphic position and mineral composition

Marek Cieszkowski, Jan Środoń, Anna Waśkowska-Oliwa, Tadeusz Leśniak


Zbentonityzowane tufity w dolnoeoceńskich osadach jednostki podśląskiej (Polskie Zachodnie Karpaty zewnętrzne)

New occurrences of bentonitized tuffites were described from numerous outcrops of the Lower Eocene flysch rocks of the Subsilesian Unit. These deposits crop out in the Żywiec tectonic window and in the tectonic windows of the Lanckorona - Żegocina Structural Zone. The bentonitized tuffites, composed of almost pure dioctahedral motmorillonite, form numerous thin layers and laminae, only occasionally exceeding 5 cm. The age of the tuffites is estimated as the Early Eocene (Glomospira div. sp. and Saccamminoides carpathicus zones) on the basis of foraminiferal assemblages. They occur in the upper part of green shales and in the lower part of the Lipowa beds that consist mainly of muddy turbidites represented by green or green-brownish shales with rare intercalations of sandstones. The sedimentary sequences with the tuffite intercalations form a lithostratigraphic level in the Subsilesian Unit called in the present paper "the Glichów Tuffite Horizon". This tuffite horizon could probably be correlated with deposits of similar age containing tuffites which are known from the Magura, Silesian and Skole nappes.

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