Lower Devonian ostracods from the Istanbul area, Western Pontides (NW Turkey): Gondwanan and peri-Gondwanan affinities


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OLEMPSKA E., NAZİK A., ÇAPKINOĞLU Ş. , SAYDAM-DEMIRAY D. G.

GEOLOGICAL MAGAZINE, cilt.152, ss.298-315, 2015 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 152 Konu: 2
  • Basım Tarihi: 2015
  • Doi Numarası: 10.1017/s0016756814000296
  • Dergi Adı: GEOLOGICAL MAGAZINE
  • Sayfa Sayıları: ss.298-315

Özet

A Lower Devonian silicified ostracod fauna has been recovered from limestone interbeds in the Buyukdere section of the Kozyatagi Member of the Pendik Formation. Forty-one species belonging to 33 genera have been recognized. Twenty-three are already known, and 15 are described in open nomenclature. One genus and three species (Omerliella rectangulata gen. et sp. nov., Microcheilinella istanbulensis sp. nov. and Roundyella goekchenae sp. nov.) are described. Silicified larval stages of trilobites, agglutinated foraminifers and conodonts co-occur with the ostracods. The ostracod assemblages are `mixed faunas', between the epineritic Eifelian Mega-Assemblage, representative of high-energy environments, and the basinal Thuringian Mega-Assemblage, representative of lowenergy environments. The conodont faunas of the Pendik Formation represent the serotinus, patulus and partitus biozones of the late Emsian -earliest Eifelian. The Emsian ostracods of NW Turkey show numerous species-level links between the Western Pontides (Istanbul Terrane) and assemblages of contemporaneous faunas of the Cantabrian Mountains (Spain), Morocco and Thuringia (Germany), and of similar biofacies. This supports the notion that the Istanbul Terrane, Armorican terrane-collage and northern margins of Gondwana were in geographical proximity in late Early Devonian time.

Abstract – A Lower Devonian silicified ostracod fauna has been recovered from limestone interbeds in the Büyükdere section of the Kozyata^gı Member of the Pendik Formation. Forty-one species belonging to 33 genera have been recognized. Twenty-three are already known, and 15 are described in open nomenclature. One genus and three species (Omerliella rectangulata gen. et sp. nov., Microcheilinella istanbulensis sp. nov. and Roundyella goekchenae sp. nov.) are described. Silicified larval stages of trilobites, agglutinated foraminifers and conodonts co-occur with the ostracods. The ostracod assemblages are ‘mixed faunas’, between the epineritic Eifelian Mega-Assemblage, representative of high-energy environments, and the basinal Thuringian Mega-Assemblage, representative of low energy environments. The conodont faunas of the Pendik Formation represent the serotinus, patulus and partitus biozones of the late Emsian – earliest Eifelian. The Emsian ostracods of NW Turkey show numerous species-level links between the Western Pontides (Istanbul Terrane) and assemblages of contemporaneous faunas of the Cantabrian Mountains (Spain), Morocco and Thuringia (Germany), and of similar biofacies. This supports the notion that the Istanbul Terrane, Armorican terrane-collage and northern margins of Gondwana were in geographical proximity in late Early Devonian time.