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Latest Carboniferous-Early Permian Rifting of the Northern Gondwanan Margin and the Opening of the Northern Neotethys: New Evidence from the Carboniferous and Permian Foraminiferal Assemblages from the Beyşehir-Hoyran Nappes, Central Taurides(Southern Turkey)

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Journal of Earth Science 2024年第2期35卷 394-415页

作者： Cengiz Okuyucu U.Kagan Tekin Cagri Guzgun Kaan Sayit department of geological Engineering Konya Technical UniversityKonya42250Turkey department of geological Engineering Hacettepe UniversityAnkara06800Turkey department of geological Engineering Middle East Technical UniversityAnkara06800Turkey

The Beyşehir-Hoyran Nappes,one of the tectonostratigraphic units of the Taurides,are thought to be originated from the Izmir-Ankara Ocean(northern branch of Neotethys).In this study,Late Paleozoic rock units from the blocks of Beyşehir-Hoyran Nappes were studied in detail using foraminiferal assemblages in two different locations from the southwest of Karaman City(southern Turkey).In both places,blocks/slices and pebbles of various origins are embedded within a highly sheared matrix of Late Cretaceous Age,and the whole unit can be regarded as a sedimentary mé*** ages of the blocks from the southwest of Karaman City range from the Late Serpukhovian(Late Mississippian)to Late Capitanian(Middle Permian)with some depositional breaks(e.g.,Bashkirian,Kasimovian).Combined with the previous data from the Mersin Mélange,which also include the remnants of the Beyşehir-Hoyran Nappes,our new findings suggest that a shallowing-upward sequence,characterized by a shallow water environment with foraminifera-bearing limestones,was deposited over the Tournaisian pelagic sequence in the Beyşehir-Hoyran Nappes till the Early Moscovian(Early Middle Pennsylvanian).This shallowing-upward sequence in the Beyşehir-Hoyran Nappes could be related to the Late Paleozoic Glaciation on the Gondwana supercontinent(Glacial Ⅱ),which resulted in a sea-level drop and deposition of platform carbonates during the Viséan–Early Moscovian(Middle Mississippian to Early Middle Pennsylvanian)time *** absence of the main part of the Middle-Upper Pennsylvanian deposits(continental phase during the Middle Moscovian–Middle Gzhelian)in the Beyşehir-Hoyran Nappes can be mainly attributed to the occurrence of a mantle plume and partially to the effect of Late Paleozoic Gondwanan Glaciation(Glacial Ⅲ).Progressive uplifting by the buoyant mantle plume material has resulted in rifting at the center of the basin where the Beyşehir-Hoyran Nappes have *** rifting process led to tectonic destabiliz

关键词： foraminifera Carboniferous and Permian Beyşehir-Hoyran Nappes plume rifting Neotethys paleontology

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Scree conglomerate and its derivatives in the Upper Cretaceous Kallankurichchi Limestone,Ariyalur Group,Cauvery Basin,South India

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Journal of Palaeogeography 2024年第3期13卷 495-508页

作者： Shilpa Srimani department of geological Sciences Jadavpur UniversityKolkata700032India

The repetitive influx of coarse clastics of mixed composition,siliciclastics and carbonates,locally common in the lower part of the Upper Cretaceous marine Kallankurichchi Limestone specifies a resurgence of tectonic unrest in the Cauvery rift basin,*** basin-margin scree and its derivatives elicit diverse modes of emplacement and differ in many ways from denoting it only as basal *** study meticulously reveals the depositional history of these basin-margin coarse *** scree conglomerate bodies are wedge-shaped in appearance and often have flat,eroded *** places,their surfaces,tops and flanks,are encrusted with Inoceramus although internally,they are mostly *** are clast-supported and extremely poorly sorted,having interstitial spaces filled by sand-sized grains at the basal *** clasts can be traced into the underlying Sillakuddi Sandstone and the granitic *** clasts derived from the sandstone are angular and measure up to 60 cm in length,while the basement-derived clasts dominate the smaller(maximum diameter measured 5 cm)and more rounded *** elongated clasts are chaotically arranged,even oriented sub-vertically,reclining on other *** lowermost scree conglomerate has a sharp base,and the pebbles sunk into the underlying sandstone,although no discernible impact laminae wrapping their bottom were ever ***,the scree fans were initiated under the sea,which permitted the slow sinking of assorted rock fragments dropped from *** sporadic occurrence of marine fossils further corroborates this *** scree conglomerates at different stratigraphic levels transitioned laterally into conglomerates of mass flow origin and then to massive calcarenite,together forming wedge-shaped *** initial alignment of clasts parallel to bedding transforms to a chaotic alignment representing the transition from internally sheared flow to debris flow and associated ***

关键词： Scree conglomerate Kallankurichchi Limestone Tectonic subsidence Flow transformation Cauvery Basin

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A geochemical perspective on the genesis of Cenozoic basic volcanism in northeastern Turkey:an overview of metasomatism and heterogeneity of the sub-continental lithospheric mantle in a post-collisional setting

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Acta Geochimica 2024年第3期43卷 489-506页

作者： Mehmet Arslan Irfan Temizel department of geological Engineering Karadeniz Technical University61080 TrabzonTurkey

The post-collisional Cenozoic basic volcanic rocks in NE Turkey show temporal variations in whole-rock lithophile element and highly siderophile element(HSE)systematics that are mainly associated with the nature of sub-continental lithospheric mantle(SCLM)sources and parental melt *** far,the traditional whole-rock lithophile geochemical data of these basic volcanic rocks have provided important constraints on the nature of SCLM *** lithophile element and HSE geochemical data of these basic volcanic rocks also reveal the heterogeneity of the SCLM source,which is principally related to variable metasomatism resulting from previous subduction(s)and post-collisional mantle-crust interactions in an extensional *** element geochemical features suggest that the parental magmas have derived from metasomatized spinel-to garnet-bearing SCLM sources for Eocene and Miocene basic volcanic rocks with subduction signatures whereas originated from spinel-to garnet-bearing SCLM sources for Mio-Pliocene and Plio-Quaternary basaltic volcanic rocks without the subduction *** element and HSE geo-chemistry also reveal that Eocene and Miocene basic vol-canic rocks were affected by more pronounced crustal contamination than the basaltic volcanic rocks of Mio-Pliocene and ***,the integrated lithophile element and HSE compositions of these basic volcanic rocks,together with the regional asymmetric lithospheric delamination model,reveal that the compositional variation(especially due to metasomatism)was significant temporally in the heterogeneity of the SCLM sources from which parental magmas formed during the Cenozoic era.

关键词： Basalt Lithospheric mantle Metasomatism Mantle heterogeneity Cenozoic volcanics NE Turkey

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Note on Lower Triassic Gondolelloid Conodont Rediversifications with Emphasis on the Spathian Recovery

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Journal of Earth Science 2024年第4期35卷 1236-1242页

作者： Ali Murat Kilic department of geological Engineering Faculty of EngineeringBalikesir UniversityBalikesir99100Turkey

Conodonts,as a biotic group,next to ammonoids,pollen and spores,crustaceans and vertebrates,provide proxy clues for environment and age assessments of the rocks in which they *** are widely used for Triassic marine ***,there are various discussions about their multielement taxonomy and evolutionary lineages(e.g.,generation,speciation).Although first studies reported that most Triassic conodont species were unimembrate,studies carried out in the following years maintained that all Triassic conodonts were *** statistical reconstructions of a number of Triassic apparatuses were attempted,the discovery of fused clusters and natural assemblages has subsequently demonstrated that Triassic conodonts are indeed multimembrate,and all of the elements exist together in the same *** present paper aims to clarify the evolutionary relationship and array of some Lower Triassic *** dagisi *** described.

关键词： Triassic Spathian conodont Columbitella Siberia environmental geology

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Substrate control in track registration and preservation:insights across the Triassic—Jurassic boundary in southern Africa

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Journal of Palaeogeography 2024年第2期13卷 351-371页

作者： Loyce Mpangala Miengah Abrahams Emese M.Bordy department of geological Sciences University of Cape TownCape TownSouth Africa

Tracks registration is influenced by the dynamic interplay between the pedal anatomy of the trackmaker,its behaviour,and the substrate conditions it interacts *** in substrate conditions,especially those linked to grain size and moisture content,often result in the most dramatic variations in track *** the upper Stormberg Group,main Karoo Basin of southern Africa,diverse trace fossils,primarily comprising Late Triassic—Early Jurassic dinosaur tracks,are *** studies have extensively documented individual ichnosites,investigating variations between sites over time,with recent studies suggesting that track abundance and anatomical fidelity increase *** the well-established link between substrate and track morphology,past studies have not specifically focused on substrate conditions,often emphasizing macro-sedimentary features ***,we examine the micro-sedimentary features of track-bearing units in the upper Stormberg Group using petrographic techniques to better understand the palaeosubstrate and its effect on fossil track registration and *** analysis revealed that very fine-grained sandstones and substrates modified by microbial activity tend to preserve tracks with greater abundance and/or higher anatomical ***,the prevalence of very fine-grained and microbially modified strata,and their associated track trends increases in younger stratigraphic *** the Triassic—Jurassic boundary in southern Africa,a boom in dinosaur track abundances is observed and credited to the proliferation of dinosaur populations during the Early *** findings,however,suggest that the observed local increase in track abundance(and anatomical fidelity)up-stratigraphy may be linked to substrate composition differences,which were ultimately controlled by large-scale changes in the palaeoenvironment from high-energy meandering fluvial to lower-energy aeolian-lacustrine settings in the L

关键词： Dinosaur tracks Footprint anatomical fidelity Micro-sedimentary features Substrate conditions Track registration Palaeoenvironmental context

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Geomorphological responses of rivers to active tectonics along the Karahay?t Fault, Western Türkiye

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Journal of Mountain Science 2024年第5期21卷 1464-1474页

作者： Savaş TOPAL Pamukkale University Department of Geological EngineeringKınıklıCampusDenizli 20160Türkiye

Understanding the topography in active tectonic areas and assessing the rates and models of active deformation in the upper crust are primary objectives in tectonic geomorphology studies. The drainage pattern of river systems is highly sensitive to tectonically induced changes, and it often preserves the records of the formation and progression of most tectono-geomorphic processes within its boundaries. Therefore, the evolution of landforms is a consequence of the evolution of individual drainage basins in which they are formed. Assessing the rates of tectonic deformation using geomorphic data is a traditionally adopted method to characterize the nature of active faults. Globally, the Digital Elevation Model(DEM) is widely used as a crucial tool to analyze the morphotectonic features of drainage basins. In this study, some geomorphic indices were applied to investigate the impact of tectonism on landscape along the Karahay?t Fault and its associated drainage areas. These geomorphic indices are mountain front sinuosity(Smf values between 1.17-1.52), valley floor width-to-height ratio(Vf values between 0.25-1.46), basin asymmetry factor(AF values between 15-72), drainage basin shape(Bs values between 3.18-6.01), hypsometric integral and curve(HI values between 0.32-047), channel sinuosity(S values between 1-1.6), normalized steepness index(Ksn values between 1-390) and Chi integral(χ values between 200-4400). The development of drainage areas on the hanging wall and footwall block of the Karahayit Fault differs depending on the uplift. The drainage areas developed on the hanging wall present different patterns depending on the regional uplift caused by the fault. This reveals that the fault contributed significantly to the development of drainage areas and regional uplift in the region. In addition, the maximum earthquake magnitude that may occur in the future on the Karahayit Fault, whose activity is supported by geomorphic indices, is calculated as 6.23. Since an ea

关键词： Drainage basins Geomorphic indices Normalized steepness index(Ksn) Chi integral(χ) Morphotectonic features Karahayıt Fault

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A bounding surface visco-plasticity model considering generalized spacing ratio of soils

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第5期16卷 1832-1846页

作者： Xiaosen Kang Hongjian Liao Qiangbing Huang Jianbing Peng department of geological Engineering Chang’an UniversityXi’an710054China department of Civil Engineering Xi’an Jiaotong UniversityXi’an710049China

The non-unique critical state of soils with time-dependent behaviors is a significant issue in geotechnical engineering ***,previous bounding surface plasticity models cannot predict accurately the non-unique critical state of soils,because the distance between the compression line and critical state line charged by strain-rate effect is basically *** fill this gap,a generalized spacing ratio of soils is defined in the elasto-viscoplastic framework,and a bounding surface visco-plasticity model is formulated and verified,which can consider the generalized spacing ***,the generalized spacing ratio of soils reflects the distance between the compression line and the critical state line of soils with time-dependent ***,the generalized spacing ratio is introduced into an improved anisotropic bounding surface.A new expression of the visco-plastic multiplier is derived by solving the consistency equation of an anisotropic bounding *** the expression,a strain rate index is proposed to account for the strain-rate effect on visco-plastic strain increment,and a visco-plastic hardening modulus is derived to predict the visco-plastic response of soils in overconsolidation *** model is then verified through constant strain rate tests and creep ***,it can capture the non-unique critical states of soils with time-dependent behaviors due to the generalized spacing ratio and the creep rupture of soils due to the visco-plastic multiplier that considers the stress ratio and visco-plastic strain rate.

关键词： Soil Constitutive model Visco-plastic behavior Strain rate Creep Anisotropic

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Triassic integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

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Science China Earth Sciences 2024年第4期67卷 1152-1194页

作者： Guichun WU Zhansheng JI Gary GLASH Qinggao ZENG Jianxin YAO Key Laboratory of Stratigraphy and Palaeontology Ministry of Natural ResourcesInstitute of GeologyChinese Academy of Geological SciencesBeijing 100037China SinoProbe Laboratory Chinese Academy of Geological SciencesBeijing 100094China department of Geology and Environmental Sciences State University of New York-FredoniaFredoniaNY 14063USA Xizang Autonomous Region geological and Mineral Exploration and Development Burea Lhasa 850010China

Rocks of the Qinghai-Tibetan Plateau(QTP)host abundant Triassic *** far,the well established marine fossil sequences based on ammonoids,conodonts,bivalves,brachiopods,radiolarians,and terrestrial spora-pollen sequence have become standard for biostratigraphic correlation of the *** much of Triassic time,the QTP occupied a marine setting as suggested by the dominance of marine *** main sedimentary types represented in the Triassic successions include littoral to shallow marine clastic rocks,shallow marine carbonate platform carbonates,bathyal to abyssal slope carbonates intercalated with clastic and siliceous deposits,coal-bearing clastic strata contained within paralic facies deposits,and littoral and terrestrial volcaniclastic *** deposits are organized into four stages in ascending order:(1)Early Triassic deposits that record marine transgression,including extensive shallow marine carbonate platform strata.(2)Middle Triassic Ladinian to Late Triassic Carnian deposits,including thin-bedded limestone,fine clastics,and siliceous rocks,that accumulated at greater depths than underlying Early Triassic strata and reflect the peak of the *** activity appears to have occurred in some areas during this stage.(3)Late Triassic Norian deposits that record the onset of marine regression as suggested by the widespread occurrence of platform *** is noteworthy that stage 3 deposits of the Qin-Qi-Kun area in the northernmost region of the QPT is dominated by terrestrial strata and displays evidence of local erosion.(4)Late Triassic Rhaetian littoral and shallow marine clastic and coal-bearing deposits that preserve the record of continued marine regression *** Indus-Yarlungzangbo Suture Zone(IYSZ)appears to have been the rifting axis during Triassic time as suggested by sedimentary facies trends that reflect deepening to south and ***,the Himalaya Block to the south of the IYSZ was part of the passive margin

关键词： Qinghai-Tibetan Plateau Triassic Biostratigraphy Lithostratigraphy Palaeobiogeography Sedimentary palaeogeography

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Significant lake expansion has accelerated permafrost degradation on the Qinghai-Tibet Plateau

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Journal of Mountain Science 2024年第1期21卷 68-83页

作者： LI Qingpeng LIU Wenhui LIU Hairui ZHOU Guanghao SONG Xianteng LI Qing LUO Bingnan SONG Bangxu ZHANG Qi department of geological Engineering Qinghai UniversityXining 810016China College of Eco-Environmental Engineering Qinghai UniversityXining 810016China Xining Center for Integrated Natural Resources Survey China Geological SurveyXining 810000China

In recent years, lakes on the Qinghai-Tibet Plateau have become more responsive to climate change. In September 2011, Zonag Lake in Hoh Xil experienced sudden drainage, the water eventually flowed into Yanhu Lake, which caused Yanhu Lake to continue to expand. The potential collapse of Yanhu Lake could directly threaten the operational safety of the adjacent Qinghai-Tibet Highway, Qinghai-Tibet Railway. To explore the implications of expanding lakes on the surrounding permafrost, we selected Hoh Xil Yanhu Lake on the Qinghai-Tibet Plateau to study the effect of lake expansion on permafrost degradation. The permafrost degradation in the Yanhu Lake basin from October 2017 to December 2022 was inverted using Sentinel-1 satellite image data and small baseline subset interferometry synthetic aperture radar(SBAS-In SAR) technology. Additionally, permafrost degradation from February 2007 and February 2010 was analyzed using advanced land observing satellite phased array-type L-band synthetic aperture radar(ALOS PALSAR) satellite images and differential interferometric synthetic aperture radar(D-In SAR) technique. The results showed that the permafrost around Yanhu Lake experienced accelerated degradation. Prior to the expansion of Yanhu Lake, the average annual deformation rate along the line of sight(LOS) direction was 6.7 mm/yr. After the expansion, the rate increased to 20.9 mm/yr. The integration of spatial-temporal distribution maps of surface subsidence, Wudaoliang borehole geothermal data, meteorological data, Yanhu Lake surface area changes, and water level changes supports the assertion that the intensified permafrost degradation could be attributed to lake expansion rather than the rising air temperature. Furthermore, permafrost degradation around Yanhu Lake could impact vital infrastructure such as the adjacent Qinghai-Tibet Highway and Qinghai-Tibet Railway.

关键词： Lake expansion SBAS-InSAR D-InSAR Permafrost deformation Qinghai-Tibet Plateau

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Determining the surface fault-rupture hazard zone for the Pazarcık segment of the East Anatolian fault zone through comprehensive analysis of surface rupture from the February 6,2023,Earthquake(Mw 7.7)

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Journal of Mountain Science 2024年第8期21卷 2646-2663页

作者： Mustafa SOFTA Dokuz Eylul University department of geological Engineering Izmir 35390Türkiye Kansas State University department of Geology Manhattan 66506KansasUSA

Following surface rupture observations in populated areas affected by the KahramanmaraşEarthquake(Mw 7.7)on February 6th,2023,along the Pazarcık segment of the East Anatolian Fault Zone(EAFZ),this study presents novel insights into physical criteria for delineating surface fault-rupture hazard zones(SRHZs)along ruptured strike-slip *** achieve this objective,three trench studies across the surface rupture were conducted on the Pazarcık segment of the EAFZ to collect field data,and earthquake recurrence intervals were interpreted using Bayesian statistics from previously conducted paleoseismological *** results of the proposed model indicate that the Pazarcık segment produced five significant surface-rupturing earthquakes in the last∼11 kyr:E1:11.13±1.74 kyr,E2:7.62±1.20 kyr,E3:5.34±1.05 kyr,E4:1.82±0.93 kyr,and E5:0.35±0.11 *** addition,the recurrence intervals of destructive earthquakes on the subject in question range from 0.6 kyr to 4.8 *** that the last significant earthquake occurred in 1513,the longest time since the most recent surface fault rupturing earthquake on this particular segment was 511 *** results indicate that,in terms of the theoretical recurrence interval of earthquakes that can create surface ruptures on the Pazarcık segment,the period in which the February 6,2023,earthquake occurred was within the end of the expected return *** a result,the potential for a devastating earthquake in the near future is not foreseen on the same ***,the SRHZ proposed for the Pazarcık section of Gölbaşıvillage was calculated as a 61-meter-wide offset on the fault lineament to reduce the negativities that may occur in the ruptured area in the *** is recommended to take into account this width in the settlement of this area and nearby areas.

关键词： Surface rupture Earthquake mitigation Recurrence interval Pazarcık segment East Anatolian Fault Zone(EAFZ)

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