Article
Geosciences, Multidisciplinary
Herve Rezeau, Marc Hassig, Emin Sadikhov, Massimo Chiaradia, Robert Moritz
Summary: The present-day configuration of the Lesser Caucasus and Eastern Pontides regions has been shaped by multiple episodes of arc magmatism and tectonic events. These regions are also rich in mineral deposits, such as polymetallic deposits and porphyry Cu-Mo deposits. New zircon Hf isotopic data has provided insights into the geological evolution of these areas, highlighting three distinct cycles of arc magmatism and revealing the presence of a composite basement. This study offers new constraints for understanding the geodynamic evolution of the region and provides valuable information for mineral exploration.
EARTH-SCIENCE REVIEWS
(2023)
Article
Geosciences, Multidisciplinary
Jinglian Yuan, Yongjiang Liu, Weimin Li, Liwei Jiang, Sihua Yuan, Sanzhong Li
Summary: This study used 745 detrital zircon LA-ICP-MS U-Pb ages from the Heishuigou and Mangya sections in the western Qaidam Basin to trace the provenances of Jurassic sediments and to further constrain the tectonic evolution of the Qaidam Basin. The results indicate that the South Altyn Tagh Range and the South Qilian Range were the main sources of sediment during the early to middle Jurassic in the western Qaidam Basin.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Geology
Ezgi Saglam, Turgut Duzman, Cemre Ay, Aral I. Okay, Gultekin Topuz, Gursel Sunal, Ercan Ozcan, Demir Altiner, Aynur Hakyemez, Jia-Min Wang, Andrew R. C. Kylander-Clark
Summary: During the Late Cretaceous, a 2700 km-long magmatic arc extended from the Lesser Caucasus through the northern margin of the Pontides into ABTS in the Balkans. The arc magmatism started in the Turonian, peaked in the middle Campanian, and became rare after the late Campanian. The magmatism showed calc-alkaline to high-K calc-alkaline composition and subduction geochemical signatures.
INTERNATIONAL GEOLOGY REVIEW
(2023)
Article
Geosciences, Multidisciplinary
Hidetoshi Hara, Tetsuya Tokiwa, Toshiyuki Kurihara, Thasinee Charoentitirat, Apsorn Sardsud
Summary: Detrital zircon U-Pb ages from sediments in northern Thailand provide constraints for tectonic interpretations of the Indochina Block, Sibumasu Block, Inthanon Zone accretionary complex, and Nan Back-arc Basin during the Triassic. These ages also reveal the changing tectonic settings in the Palaeo-Tethys convergence zone.
GEOLOGICAL MAGAZINE
(2021)
Article
Geosciences, Multidisciplinary
Tatyana Svetlitskaya, Thi Huong Ngo, Peter A. Nevolko, Tuan Anh Tran, Andrey E. Izokh, Roman A. Shelepaev, Trong Hoa Tran, Thi Phuong Ngo, Pavel A. Fominykh, Ngoc Can Pham
Summary: The study reveals a peak of magmatic activity at 247-248 Ma in the Song Hien structure, generating both mafic and felsic units, with two similar peaks at 250 Ma and 241-243 Ma in zircon ages. These results further confirm that the igneous activities in the region were 12 Myr younger than the Emeishan mantle plume, and may be associated with the Indosinian orogeny.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Chang-Hao Xiao, Zheng-Le Chen, Feng-Bin Han, Liang-Xi Wei, Liang-Tao Ma
Summary: This study presents U-Pb ages and Hf isotopic compositions of detrital zircons from a pebbly slate of clastic sedimentary rock in the West Qinling Orogenic Belt, providing insights into the Triassic tectonic setting in the region. Provenance analysis suggests multiple sources for the pebble-bearing slate, and the presence of an Early Triassic continental arc is implied by detrital zircon data. The integrated results indicate that the Longwuhe Formation was likely deposited in a forearc setting around 250 Ma, followed by arc magma intrusion in the Early Triassic, possibly associated with the northward subduction of the Qinling Paleo-Tethys Ocean lithosphere.
JOURNAL OF ASIAN EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Gaoyuan Sun, Jianuo Chen
Summary: A large number of high-quality detrital zircon data from the Middle East have been compiled and analyzed, revealing different age populations and Hf isotopes. This database allows for further research on provenance analysis and the timing of major tectonic events in the Middle East, as well as exploration of plate affinities for future paleogeographic research.
GEOSCIENCE DATA JOURNAL
(2023)
Article
Geosciences, Multidisciplinary
Hanyu Huang, Dengfa He, Yingqiang Li, Chen Zhang, Di Li
Summary: By comparing the detrital zircon U-Pb-Hf isotopic data from sedimentary rocks on the northern margin of the Yangtze Block with adjacent blocks, valuable information about the evolution of the Shangdan Ocean, a branch of the Proto-Tethys, was discovered. The detrital zircon ages indicate that the clastic material in the basin during the Cambrian came from the uplifted regions of the Yangtze Block, while in the Silurian, material from the North Qinling Block was transported to the basin due to the closure of the Shangdan Ocean. These findings provide new insights on the tectonic evolution of the Proto-Tethys Ocean.
Article
Geosciences, Multidisciplinary
Fuwei Xie, Juxing Tang
Summary: The study reveals that the Late Triassic-Jurassic igneous rocks in the southern Lhasa subterrane can be divided into two groups with different geochemical characteristics. These magmatic activities were controlled by double subduction, with Group 1 forming in an intraoceanic arc setting and Group 2 forming in a continental margin arc setting.
Article
Geosciences, Multidisciplinary
Yuhui Feng, Tao Yang, Fei Liang, Ge Sun
Summary: The new U-Pb dating results of rhyolite samples collected in the Late Triassic Tianqiaoling flora-bearing beds provide important chronological evidence for the development of the flora, which is consistent with paleobiological evidence. This contributes to a better understanding of the geology and phytogeography in East Asia during the Late Triassic period.
SCIENCE CHINA-EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Nan Su, Guang Zhu, Xiaodong Wu, Hao Yin, Yuanchao Lu, Shuai Zhang
Summary: Research in the western Liaoning region of eastern China has revealed four extensional stages and three compressional events during the Jurassic-Cretaceous period. Each extensional stage lasted 20-40 million years with associated volcanism, while each compressional event lasted around 1 million years on a 30-40 million year cycle. The back-arc tectonic evolution shows a frequent alternation between long-lived extensional phases and short-lived compressional events.
Article
Geosciences, Multidisciplinary
Abdullah Sar, Sevcan Kurum, Ahmet Feyzi Bingol
Summary: This study investigates the magmatic evolution of the Eastern Pontides orogenic belt in northeastern Turkey using new zircon U-Pb ages, Lu-Hf isotopes, and whole-rock geochemical and Sr-Nd isotopic analyses. The results suggest a heterogeneous magma source, possibly derived from a juvenile lower crust. Additionally, the magmatism in the area is associated with the collision of the Anatolide Taurid Platform with the Pontides.
JOURNAL OF EARTH SCIENCE
(2023)
Article
Geosciences, Multidisciplinary
Masahiro Ohkawa, Makoto Takeuchi, Yuaxiao Li, Shimon Saitoh, Koshi Yamamoto
Summary: The Shingai Unit in the Kurosegawa Belt is subdivided into sedimentary zone and melange zone, with sandstones of varying compositions. Detrital zircon ages suggest an Early Triassic depositional age and a change in provenance from basement rocks to volcanic arc. This provenance change supports progressive denudation of the volcanic arc, with similarities in provenance found in upper Permian-Lower Triassic strata in neighboring belts. The sedimentary environment is inferred to have been a trench and shelf adjacent to an isolated island arc.
JOURNAL OF ASIAN EARTH SCIENCES
(2021)
Article
Geosciences, Multidisciplinary
Aaron J. Martin, Mireia Domenech, Daniel F. Stockli, David Gomez-Gras
Summary: The Upper Triassic to lowest Upper Jurassic strata in north-eastern Mexico record surface processes during the early rifting that led to the opening of the Gulf of Mexico. This study uses detrital zircon U-Pb ages and clast compositions to constrain depositional ages and reconstruct tectonic setting and provenance, indicating deposition in partitioned rift basins receiving sediment from local sources within a distance of approximately 100 km. These data contribute to understanding surface processes during the initial rifting that eventually led to the opening of the Gulf of Mexico.
Article
Geosciences, Multidisciplinary
Ruihong Chang, Franz Neubauer, Yongjiang Liu, Sihua Yuan, Johann Genser, Qianwen Huang, Qingbin Guan, Shengyao Yu
Summary: The pre-Alpine basement of the Austroalpine mega-unit in the Alps is composed of a heterogeneous series of continental units, island arcs, ophiolites, subduction meacute accent langes, accretionary wedges, and seamounts affected by different metamorphic grades. The complex tectonic evolutionary histories and remolten sources of different ages in the pre-Alpine complexes likely assembled not earlier than the Late Permian or Early Triassic, representing multiple locations before final accretion.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geology
Remziye Akdogan, Istvan Dunkl, Aral I. Okay, Xiumian Hu, Gultekin Topuz
Summary: Apatite fission-track and (U-Th)/He ages from Carboniferous to Eocene siliciclastic rocks in the Istanbul Zone of NW Turkey suggest three major deformation and uplift/exhumation phases. These phases are attributed to orogeny, accretion of oceanic plateaus, and closure of oceanic domains in the region.
INTERNATIONAL GEOLOGY REVIEW
(2022)
Article
Geosciences, Multidisciplinary
Umitcan Erbil, Aral Okay, Aynur Hakyemez
Summary: Late Cenozoic in the Aegean region was characterized by large-scale extension, except for the Thrace Basin which showed continuous marine sedimentation from Middle Eocene to Oligocene. The Korudag anticline in the Thrace Basin, formed by north-northwest shortening, is an asymmetric fold with a subhorizontal axis and is unconformably overlain by Middle Miocene sandstones. This shortening event in the Late Oligocene-Early Miocene might be related to changes in subduction dynamics along the Hellenic trench.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2021)
Article
Geochemistry & Geophysics
Seungsoon Choi, Olivier Fabbri, Gultekin Topuz, Aral Okay, Haemyeong Jung
Summary: This study examined the impact of twinning on crystal preferred orientation, CPO strength, and seismic anisotropy in lawsonite blueschists, finding that the presence of twins can significantly reduce seismic anisotropy.
Article
Paleontology
Ercan Ozcan, Ali Osman Yucel, Rita Catanzariti, Sibel Kaygili, Aral I. Okay, Michael D. Simmons, Johannes Pignatti, Iftikhar Ahmed Abbasi, Umitcan Erbil
Summary: The study reveals the existence of multiple lineages of Orbitoides during the Maastrichtian, including Orbitoides 'medius' and Orbitoides pamiri, which display retrograde evolutionary features. This suggests a more complex evolutionary history for Orbitoides during this time period.
SWISS JOURNAL OF PALAEONTOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Mesut Aygul, Aral Okay, Bradley R. Hacker, Andrew R. C. Kylander-Clark
Summary: In situ laser probing of minerals in lawsonite-bearing eclogites and a metabasite provides insights into the redistribution and mobility of REEs controlled by metamorphic reactions. The study reveals significant HREE depletion in garnets due to the nucleation of lawsonite, and enrichment of MREE caused by the breakdown of lawsonite in epidote-bearing eclogites. These findings suggest that the behavior of REEs are influenced by different factors in warm and cold subduction zones.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2022)
Article
Geosciences, Multidisciplinary
Aral Okay, Demir Altiner, Taniel Danelian, Gultekin Topuz, Ercan Ozcan, Andrew R. C. Kylander-Clark
Summary: Ophiolitic melanges in Anatolia are Mesozoic subduction-accretion complexes with a scarcity of land-derived coarse-clastic rocks. Through the study of a segment in the Beynam region, it was found that the ophiolitic melange consists of three accretionary units, formed in two stages. The first stage, in the Late Jurassic - Early Cretaceous, involved intra-oceanic subduction and the generation of supra-subduction type oceanic crust. The second stage, in the Late Cretaceous, led to the incorporation of Jurassic oceanic crust into the subduction-accretion complex and the formation of an Andean-type convergent margin.
GEOLOGICAL MAGAZINE
(2022)
Editorial Material
Geochemistry & Geophysics
Aral I. Okay
Article
Geosciences, Multidisciplinary
Aral I. Okay, Andrew R. C. Kylander-Clark
Summary: Detrital zircon ages from Upper Cretaceous sandstones in the Pontides and Anatolide-Tauride Block reveal differences in zircon compositions between the two regions. The absence of sediment transport between the two blocks during the latest Cretaceous suggests an earlier deformation event in the Bornova Flysch Zone related to ophiolite obduction. The predominance of Carboniferous detrital zircons highlights the significance of Carboniferous magmatic activity in the Anatolide-Tauride Block.
INTERNATIONAL JOURNAL OF EARTH SCIENCES
(2023)
Article
Geology
Donna L. Whitney, Jonathan R. Delph, Stuart N. Thomson, Susan L. Beck, Gilles Y. Brocard, Michael A. Cosca, Michael H. Darin, Nuretdin Kaymakci, Maud J. M. Meijers, Aral I. Okay, Bora Rojay, Christian Teyssier, Paul J. Umhoefer
Summary: Escape tectonics is a mechanism for the formation of new plates, in which lithospheric fragments move laterally along strike-slip faults in response to collision. Analysis of thermochronology data and seismic images near the East Anatolian fault zone provides insights into the development of the Anatolian plate and escape system. The younger ages of rocks in and near the EAFZ, as well as the presence of strong Arabian lithospheric mantle beneath the Anatolian crust, suggest that thermal activity and underthrusting of Arabian lithosphere played a fundamental role in the formation of the Anatolian plate and escape system.
Article
Geology
Cumhur Babaoglu, Gultekin Topuz, Aral I. Okay, Serhat Koksal, Jia-Min Wang, Fatma Toksoy-Koksal
Summary: This paper investigates the petrology and age of the volcanism in the Istanbul Zone, NW Turkey. It discovers minor alkaline basalt and acidic volcanic rocks that date back to approximately 261 million years ago. It suggests that the volcanism occurred in an extensional setting concurrent with the northward subduction of the Palaeo-Tethys beneath the Sakarya and Istanbul zones after the Variscan orogeny.
INTERNATIONAL GEOLOGY REVIEW
(2023)
Article
Geology
Ezgi Saglam, Turgut Duzman, Cemre Ay, Aral I. Okay, Gultekin Topuz, Gursel Sunal, Ercan Ozcan, Demir Altiner, Aynur Hakyemez, Jia-Min Wang, Andrew R. C. Kylander-Clark
Summary: During the Late Cretaceous, a 2700 km-long magmatic arc extended from the Lesser Caucasus through the northern margin of the Pontides into ABTS in the Balkans. The arc magmatism started in the Turonian, peaked in the middle Campanian, and became rare after the late Campanian. The magmatism showed calc-alkaline to high-K calc-alkaline composition and subduction geochemical signatures.
INTERNATIONAL GEOLOGY REVIEW
(2023)
Article
Geochemistry & Geophysics
Aral I. Okay, Ercan Ozcan, Muzaffer Siyako, Kerem A. Burkan, Andrew R. C. Kylander-Clark, Michael D. Bidgood, David Shaw, Michael D. Simmons
Summary: The Thrace Basin, with its complex tectonic history, is a challenging case for classification. New geochronological and biostratigraphic data provide insights into its tectonic evolution, revealing that the basin primarily contains early Oligocene siliciclastic turbidites sourced from the Rhodope Complex. The exhumation of the northern Rhodope Complex coincided with the main subsidence in the Thrace Basin, suggesting a connection between crustal rotation and basin development.
Article
Geosciences, Multidisciplinary
Ali Osman Yucel, Ercan Ozcan, Rita Catanzariti, Aynur Hakyemez, Aral I. Okay, Attila Ciner, Ali Akin
Summary: New field observations and discovery of calcareous nannofossils and planktonic foraminifera in the shallow-marine Cayraz Formation in Haymana Basin, Central Anatolia, allows for the revision of its stratigraphy and the establishment of a biostratigraphic scheme. Calcareous nannofossils in the upper part of the underlying Eskipolatli Formation suggest the initiation of the Cayraz shelf system in the middle Ypresian, while marly parts of the Cayraz Formation indicate Zone CNE6 in the late Ypresian. Hemipelagic marls in the upper part of the formation yield calcareous nannofossils indicating Zone CNE9 and CNE10 in the lower samples, and Zone CNE12 in the upper samples. The same beds also yield planktonic foraminifers indicating Zone E8 and E9. The end of shallow-marine sedimentation in the Cayraz section is proposed to be in the middle Lutetian.
TURKISH JOURNAL OF EARTH SCIENCES
(2023)
Article
Geology
Donna L. Whitney, Jonathan R. Delph, Stuart N. Thomson, Susan L. Beck, Gilles Y. Brocard, Michael A. Cosca, Michael H. Darin, Nuretdin Kaymakci, Maud J. M. Meijers, Aral I. Okay, Bora Rojay, Christian Teyssier, Paul J. Umhoefer
Summary: This study provides insights into the development of the new plate and escape system by using thermochronology data and seismic images. It is found that the rocks near the East Anatolian fault zone are significantly younger, indicating thermal activity triggered by strike-slip faulting. The images also reveal that the underthrusting of the strong Arabian lithosphere played a crucial role in the localization of the fault zone and the formation of the Anatolian plate and escape system.
Article
Paleontology
Ercan Ozcan, Ali Osman Yucel, Simon F. Mitchell, Johannes Pignatti, Michael D. Simmons, Aral Okay, Levent Sina Erkizan, Munire Nur Gultekin
Summary: This article introduces a unique combination of carbonate-clastic and larger benthic foraminifera in the middle to upper Eocene of northwest Turkey, and describes a newly discovered genus of larger benthic foraminifera, Caudriella. The study reveals the distribution of Caudriella in both the Caribbean and Western Neo-Tethys regions. Comparative analysis of the embryonic-nepionic stages of Caudriella and the emendation of its diagnosis are also conducted.
JOURNAL OF FORAMINIFERAL RESEARCH
(2022)