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WOS: 000312268800005, The Istanbul Terrane along the Black Sea coast in NW Anatolia, is a Gondwana-derived continental microplate, comprising a well-developed Paleozoic succession. Petrographic and X-ray diffraction studies were performed on rock samples from measured sections throughout Ordovician-Carboniferous sedimentary units. Diagenetic-very low-grade metamorphic clastic (shale/mudstone, siltstone, sandstone) and calcareous rocks (limestone, dolomite) mainly contain phyllosilicates, quartz, feldspar, calcite, dolomite, hematite and goethite minerals. Phyllosilicates are primarily represented by illite, chlorite, mixed-layered chlorite-vermiculite (C-V), chlorite-smectite (C-S) and illite-chlorite (I-C). Feldspar is commonly present in the Ordovician and Carboniferous units, whereas calcite and dolomite are abundant in the Silurian and Devonian sediments. The most important phyllosilicate assemblage is illite + chlorite + I-C + C-V + C-S. Illite and chlorite-bearing mixed layer clays are found in all units. The amounts of illites increase in the upper parts of the Silurian series and the lower parts of the Devonian series, whereas chlorite and chlorite-bearing mixed-layers are dominant in the Ordovician and Carboniferous units. Kubler index values of illites reflect high-grade anchimetamorphism for the Early Ordovician rocks, low-grade metamorphism to high-grade diagenesis for the Middle Ordovician-Early Silurian rocks and high-grade diagenesis for the Late Silurian-Devonian units. The K-white micas b cell dimensions indicate intermediate pressure conditions in the Early Ordovician-Early Silurian units, but lower pressure conditions in the Middle Silurian-Devonian units. Illites are composed of 2M(1) +/- 1M(d) polytypes in all units, except for Upper Ordovician-Lower Silurian units which involve 1M polytype in addition to 2M(1) and 1M(d) polytypes. The 2M(1)/(2M(1) + 1M(d)) ratios rise from Devonian to Ordovician together with the increasing diagenetic-metamorphic grade. Chlorites have IIb polytype. In general, crystal-chemical data of clay minerals in the Istanbul Terrane show a gradual increase in the diagenetic/metamorphic grade together with increasing depth. The new data presented in this work indicate that the diagenetic/metamorphic grade of the Paleozoic of the Istanbul Terrane is higher than that of the neighboring Zonguldak Terrane and generated by a single metamorphic phase developed at the end of Carboniferous. This finding contrasts with the metamorphic history of the neighboring Zonguldak Terrane that displays a distinct Early Devonian unconformity and a thermal event., Cumhuriyet University [M-358], The study is supported by the Scientific Research Project Fund of the Cumhuriyet University under the project number M-358. Dr. Mehmet Cemal Goncuoglu gratefully acknowledges the contribution of the members of MTA-BAS Project Group for some unpublished data on the stratigraphy of NW Anatolian Paleozoic. Michel Faure and the anonymous referee are gratefully acknowledged for their constructive comments on the manuscript. We also appreciate for helpful suggestions and critical comments by Rafael Ferreiro Mahlmann and Sebastien Potel as guest editors. The authors would also like to express thanks to Ibrahim Gedik for valuable assistance during field studies and to Fatma Yalcin and Ufuk Kus, who kindly performed the XRD analysis and thin-section preparations.

WOS: 000301876000001, The Zonguldak terrane is a Gondwana-derived continental microplate along the Black Sea coast in northwest Anatolia. It includes a Cadomian basement, with oceanic-and island-arc sequences, unconformably overlain by siliciclastic rocks of Ordovician to Middle Silurian age. After a period of deformation and erosion, late Lower Devonian (Emsian) quartzites and shallow-marine limestones unconformably cover Middle Silurian (Wenlock) graptolitic shales. Along several cross sections across the unconformity plane, the mineralogical characteristics of the Paleozoic sedimentary rocks in the Zonguldak terrane are studied to check whether this regional unconformity is only of epeirogenic nature or the result of a thermal event. In addition to the appearance of kaolinite in Devonian units, crystal-chemical data of illites show a sudden jump at the unconformity plane. The b cell dimension values of illites of Ordovician-Silurian units are somewhat higher than those of Devonian-Carboniferous units and show a drastic drop between the Silurian and Devonian units. The new mineralogic data indicate that the pre-Emsian rocks in the Zonguldak terrane experienced a thermodynamo event, prior to the Emsian transgression. This Caledonian-time event is also reported in east Moesian terrane but not noticed in the neighboring Istanbul-Zonguldak and in the west Moesian Balkan - Kreishte terranes. By this, it is suggested that Zonguldak and east Moesian terranes behaved independently from the Istanbul-Balkan terranes during the closure of the Rheic Ocean. They very likely docked to Laurussia during Emsian by strike-slip faults and remained thereon at its platform margin, where the Middle-Late Devonian shallow-platform conditions were followed by fluvial (lagoon and delta) conditions and deposition of coal during Late Carboniferous., Cumhuriyet University [M-358], The study is supported by the Scientific Research Project Fund of the Cumhuriyet University under project number M-358. Dr. M.C. Goncuoglu gratefully acknowledges the contribution of the members of the MTA-BAS project group for some unpublished data on the northwest Anatolian Paleozoic stratigraphy. The authors would like to express their thanks to Fatma Yalcin and Ufuk Kus who kindly performed the XRD analysis and thin-section preparations.