Upper Jurassic Calpionellids and calcareous dinoflagellates in the Karpentná section - preliminary results

 

Pavlína Doupovcová, Petr Skupien

Geoscience Research Reports 53, 2020, pages 171–175
Map sheets: Jablůnkov (26-11)

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Published online: 7 December 2020

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Abstract

A new outcrop of the Upper Jurassic sediments of the Silesian Unit of the Outer Western Carpathians was studied. The investigated section is exposed in the outcrop laying on the left bank of the River Olše near the village of Karpentná (Fig. 1, GPS 49.6437475N, 18.6973167E). The section is up to 12 m high (Figs 2, 3), and its lower portion is formed by topmost part of the Vendryně Formation consisting of dark gray to brown-gray claystones and siltstones exhibiting numerous synsedimentary deformations. It is followed by a 5 m thick complex formed by dark grey calcareous claystones with nodules and blocks of limestones. Clasts are ranging in size from several cm to 1 m. The accumulation of limestones may correspond to the Ropice horizon. Claystones provided a relatively poor association of calcareous dinoflagellates with Cadosina sp., Cadosina semiradiata fusca (Wanner), Cadosina semiradiata semiradiata (Wanner), Colomisphaera sp., Colomisphaera pulla (Borza), Colomisphaera minutissima (Colom). The dinoflagellate cyst association is of Upper Tithonian age, representing Semiradiata dinoflagellate Zone (Reháková 2000). In the case of identification of calcareous dinoflagellate Stomiosphaera wanneri Borza, it can be assumed that this species could have been present in the Silesian Unit during the Tithonian. According to Reháková (2000), this species should first appear in the topmost part of the Upper Berriasian.
The upper part of the section is represented by the lowest beds of the Těšín Limestone comprising limestones, claystones and marlstones. Limestones in the basal parts are sandy, whereas the beds in the upper portions are markedly fine-grained to micritic. Representatives of calpionellids Calpionella alpina Lorenz, Calpionella elliptalpina Nagy, Calpionella grandalpina Nagy, Crassicollaria parvula Remane were identified. The association of calpionellids is typical of the uppermost Tithonian Crassicollaria Zone, Intermedia Subzone (Reháková - Michalík 1997). The calcified spores of Globochaete alpina Lombard, and the ostracods are present. Benthic foraminifers of Paleogaudryina sp. occur in the uppermost part of the section.