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

A Lower Devonian silicified ostracod fauna has been recovered from limestone interbeds in the Büyükdere section of the Kozyata?ı 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. © 2014 Cambridge University Press

Silurian Graptolite, Conodont and Cryptospore Biostratigraphy of the Guluc Section in Eregli, Zonguldak Terrane, NW Anatolia, Turkey

The studied Guluc section of the Silurian Findikli Formation is situated on the western bank of Guluc Creek in Eregli, NW Anatolia, Turkey, in the eastern part of the Zonguldak Terrane. The Guluc section consists of 3 sedimentary packages: greenish grey limy siltstones, 5-7 m thick (1), overlain by an irregular alternation of black shales and clayey limestones, about 15 m thick (2), and a 6-7 m thick succession of mainly siltstones and sandy limestones (3). A combined biostratigraphy based upon graptolites, cryptospores and conodonts indicates that Package 1 is of Llandovery (Rhuddanian, Aeronian and/or early Telychian) age, Package 2 and Package 3 are of late Wenlock-early Ludlow (Homerian and Ludfordian) age. Graptolites in packages 2 and 3 indicate the presence of the Cyrtograptus lundgreni, Neodiversograptus nilssoni and Lobograptus scanicus graptolite biozones. The Ozarkodina crassa Biozone occurs in the lower Gorstian (Ludlow). The specific features of the Guluc section (lithological changes, condensation, stratigraphic gap, change in graptolite diversity) are related to the global model of Silurian T-R cycles. The Silurian Findikli Formation in the Guluc section, about 20 m thick, represents a condensed lithological succession which differs significantly from the coeval thick, stratigraphically widespread black shales and siltstones of the same formation in the Zonguldak and Istanbul terranes. Sixteen cryptospore species are described and their stratigraphic and geographic distributions are summarised

Foraminifera, Radiolaria and Conodont assemblages from the Early Mississipian (late Tournaisian)/Early Pennsylvanian (early Bashkirian) blocks within the Mersin Melange, southern Turkey: Biochronological and paleogeographical implications

The Mersin Melange, a sedimentary complex in southern Turkey, includes blocks of various origins within a Late Cretaceous matrix. Two blocks in the Mersin Melange are herein recognized to be of Carboniferous age. One block (the Kozan Block) is composed of alternating chert and mudstone, and includes radiolarian and conodont assemblages revealing a late Tournaisian (Early Mississippian) age. The other (Keven-West Block) consists of platform carbonate containing abundant foraminifera indicating Bashkirian (Early Pennsylvanian) age. These dates are so far the oldest obtained from the blocks within the Mersin Melange. A correlation of the lithostratigraphies of blocks in the Mersin Melange with the coeval Tauride sequences indicates that they correspond to the successions in the Beysehir-Hoyran Nappes. In these nappes, the late Tournaisian is characterized by radiolarian rich chert and mudstone of an open marine environment, whereas the Bashkirian succession represents a shallow water environment with Foraminifera-bearing limestone. The Tournaisian deepening can be ascribed to the opening of a deep marginal basin to the north of the Tauride Platform and uplifting of the northern Tauride-Anatolide Platform margin during the Late Mississippian and Early Pennsylvanian