Browsing by Author "Bedi, Yavuz"

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Citation - WoS: 6
Citation - Scopus: 7
Biostratigraphy of Lower Permian Foraminiferal Assemblages From Platform-Slope Carbonate Blocks Within the Mersin Melange, Southern Turkey: Paleogeographical Implications
(ELSEVIER FRANCE-EDITIONS SCIENTIFIQUES MEDICALES ELSEVIER, 2020) Okuyucu, Cengiz; Tekin, U. Kağan; Bedi, Yavuz; Sayit, Kaan
The Mersin Melange (MM) as a part of the Mersin Ophiolitic Complex in southern Turkey is a sedimentary complex including blocks and tectonic slices within a Late Cretaceous matrix. Two blocks (Keven and Cingeypinari) within the MM originated from the northern branch of Neotethys (Izmir-Ankara-Erzincan Ocean) and have been studied in detail using foraminiferal assemblages to correlate them with coeval successions in the Taurides and to approach the Early Permian evolution of the northern branch of the Neotethys. The Keven block includes mainly slope deposits (poorly-sorted carbonate breccia and fossiliferous calcarenite) and dated as late Asselian-Sakmarian, whereas the Cingeypinari block consists of platform deposits (fossiliferous platform carbonate and quartz sandstone alternation) assigned to the Sakmarian-early Artinskian. These Early Permian Cingeypinari and Keven blocks from the Beysehir-Hoyran Nappes are biostratigraphically well correlated to the northerly originated Hadim nappe and its equivalents in the Tauride Belt. Considering recent studies on the Mersin Melange, a possible mantle plume existed during the Late Carboniferous-Early Permian time interval along the northern Gondwanan margin. This event led to the opening of the northern Neotethys and deposition of the pelagic Karincali sequence with volcanic material in the basinal conditions. The data presented suggest that the Keven block relates to the slope and the Cingeypinari block to platform conditions deposited as a lateral equivalent of the Karincali sequences during the Early Permian. (C) 2020 Elsevier Masson SAS. All rights reserved.
Citation - WoS: 12
Citation - Scopus: 11
Carnian (upper Triassic) Lavas and Tuffites From the Mersin Melange: Evidence for Intraoceanic Arc Rifting in the Northern Neotethys
(UNIV CHICAGO PRESS, 2020) Sayit, Kaan; Bedi, Yavuz; Tekin, U. Kağan; Okuyucu, Cengiz
In Anatolia, the northern branch of Neotethys is represented by Izmir-Ankara-Erzincan (IAE) Ocean, whose fragments and associated continental entities are preserved in the IAE Suture. However, the traces of this northerly located ocean are not solely bound to the IAE Suture, but can also be found further to the south. The Mersin Melange, situated in southern Turkey, is such a place that preserves the southerly transported remnants of the northern Neotethys. The Mersin Melange essentially displays block-in-matrix features, with blocks/slices of different age and lithological characteristics embedded in a clastic matrix. Within the melange, the Degirmenocagi region consists of a volcano-sedimentary sequence of middle Carnian age, which is characterized by lavas and tuffites interbedded with pelagic sedimentary lithologies. The lavas are chemically of basaltic/basaltic-andesitic composition, whereas the tuffites are of rhyolitic composition. Both lavas and tuffites display negative Nb anomalies, suggesting the involvement of subduction-related components. The high Zr/Nb and low Nb/Yb ratios (compared with normal mid-ocean ridge basalt [N-MORB]) imply a variably depleted mantle source, which has experienced previous melt extraction. The ratio-based melting systematics reflects melt generation largely dominated by spinel-facies melts. The overall geological and geochemical characteristics of the Degirmenocagi sequence suggest an oceanic backarc setting during the Carnian, which may have developed by the rifting of the Sorgun Arc. Although this new finding shows that the Triassic intraoceanic subduction is not uncommon in the Neotethys, it also strengthens a pre-Liassic opening of the northern domain (i.e., the IAE Ocean) and may further explain the longevity of the Middle-Late Triassic intraoceanic subduction in the northern Neotethys.
Citation - WoS: 12
Citation - Scopus: 13
Late Triassic To Early Jurassic Radiolarian, Conodont and Ammonite Assemblages From the Tavuscayiri Block, Mersin Melange, Southern Turkey: Time Constraints for the T/J Boundary and Sedimentary Evolution of the Southern Margin of the Northern Neotethys
(MUSEUM NATL HISTOIRE NATURELLE, 2020) Tekin, U. Kağan; Krystyn, Leopold; Okuyucu, Cengiz; Bedi, Yavuz; Sayit, Kaan
The Mersin Melange (northwest of Mersin city) includes a variety of large sedimentary blocks/tectonic slices of Palaeozoic and Mesozoic origins. Of these, the latter represents facial and tectonostratigraphic counterparts of the Beysehir-Hoyran Nappes (remnants of the northern Neotethys). The Tavuscayiri Block, located at the center of the melange and dose to the Orbuklukeli hill, is one of such Mesozoic occurrences, with a continuous pelagic sequence from the Upper Triassic to Lower Jurassic. At the Orbuklukeli hill, a succession of middle Norian to Toarcian age has been precisely dated, which starts with conodont assemblages for the Norian and Rhaetian and includes radiolarians for the upper Rhaetian. An acidic tuff layer corresponds to the T-J boundary, which passes above to an increasingly dominating chert-bearing limestone series, marking a gradually deepening-upward of the sequence. The early Hettangian radiolarians are poorly represented, but diverse and well-preserved radiolarians have been retrieved from the middle Hettangian to the Pliensbachian. A total of eighty-five taxa, including fourteen new species, have been determined. In addition to these, one new genus (Praeudalia Tekin, n. gen.) has been described from the Rhaetian part of the section. The top of the section is represented by nodular limestones in Ammonitico rosso facies, including a diverse Toarcian ammonite fauna. All lithologies of the Orbuklukeli section along the Tavuscayiri Block can be correlated with the previously described lithologies of the Kayabasi Group/Formation in the Bozkir Unit, and Gulbahar/Gumuslu units in the Lycian Nappes.