A new Early Jurassic brachiopod fauna from the Eastern Pontides (Turkey)

Abstract

A newly collected Early Jurassic brachiopod fauna from the Kocamantasi section (Gumushane region, Eastern Pontides, Turkey) yielded 160 specimens and 13 species (4 rhynchonellids, 3 spiriferinids, 6 terebratulids). Apart from some long-ranging forms, five species prove the Late Pliensbachian age of the fauna. The paleoenvironmental setting of the Kocamantasi fauna shows analogies to the Alpine Hierlatz limestones. On the basis of common lithological characters, bedding features and sedimentary associations, this lithofacies is interpreted as a complex of submarine, biodetrital talus associated with fault-related submarine rocky slopes. The numerical comparison of the Kocamantasi brachiopod fauna to Pliensbachian brachiopod faunas of Europe revealed that the faunal similarity was the highest to Kotel (Balkans) and the Crimea. Very strong affinity was recorded to further NW-European faunas, whereas very low, or no similarity was recognized to the Mediterranean faunas. This paleobiogeographical result supports the hypothesis that in the Late Pliensbachian the Eastern Pontide segment of the Cimmerian microcontinent was far from the Gondwana and close to the Eurasian margin of the Tethys.