Geological Journal最新文献

{"title":"Petrogenesis of Silurian Granitoids in the Western Segment of the North Qilian Accretionary Belt, China: Insights Into the Closure of the Northernmost Branch of the Proto-Tethys Ocean","authors":"Weidong He,&nbsp;Yunpeng Dong,&nbsp;Jiaopeng Sun,&nbsp;Lei He,&nbsp;Zonglin Li,&nbsp;Yukun Qi,&nbsp;Kai Ye,&nbsp;Zhigang Wang,&nbsp;Teng Wang","doi":"10.1002/gj.5090","DOIUrl":"https://doi.org/10.1002/gj.5090","url":null,"abstract":"<div>\u0000 \u0000 <p>The North Qilian Accretionary Belt, situated at the northernmost extent of the Proto-Tethys tectonic domain, preserves key tectonic events such as Proto-Tethys Ocean subduction and accretion. Despite ongoing debates about the closure mechanisms and timing of the North Qilian Ocean, our study presents novel findings on granitoids from the Changma region in the western segment of the North Qilian Accretionary Belt. Zircon U–Pb dating indicates an emplacement age of 436 Ma for the Qingshixia pluton and 425 Ma for the Heixialao pluton. The <i>ε</i>\u0000 _{\u0000 <i>Hf</i>\u0000}(<i>t</i>) values of the Qingshixia granodiorite range from +8.25 to +10.89, with T_DM2 model ages estimated between 614 and 716 Ma. In contrast, the <i>ε</i>\u0000 _{\u0000 <i>Hf</i>\u0000}(<i>t</i>) values of the Heixialao monzogranite range from +1.79 to +4.48, with T_DM2 model ages spanning from 1127 to 1291 Ma. The Qingshixia granodiorite displays adakitic traits, characterised by high Sr, low Y, low Yb, and a low K₂O/Na₂O ratio, whilst the Heixialao monzogranite exhibits peraluminous, high-potassium calc-alkaline features. The low concentrations of Ni and Cr, along with moderate Mg# values, suggest that the Qingshixia granodiorite likely originated from the partial melting of a subducting slab. By comparison with experimental melts, the relatively low Rb/Ba and Rb/Sr ratios and higher zircon saturation temperatures of Heixialao monzogranite suggest that it may have formed from partial melting of the mafic middle and lower crust. Integrating these findings with regional geological features and differences between east and west segments, we propose that the western segment of the North Qilian Ocean basin may have closed during the Late Silurian, contributing to a diachronic closure process from east to west and offering insights into the tectonic evolution of the Proto-Tethys Ocean.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 2","pages":"431-454"},"PeriodicalIF":1.4,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-Parameter Investigation of Cretaceous to Palaeocene Sedimentary Sequences in the Anambra and Niger Delta Basins, Nigeria: Organic Matter Characterisation, Palynofacies and Implications for Palaeoclimate and Sea-Level Changes","authors":"Erepamo J. Omietimi,&nbsp;Nils Lenhardt,&nbsp;Renchao Yang,&nbsp;Annette E. Götz,&nbsp;Aitalokhai J. Edegbai,&nbsp;Adam J. Bumby","doi":"10.1002/gj.5084","DOIUrl":"https://doi.org/10.1002/gj.5084","url":null,"abstract":"<p>The Anambra Basin of Nigeria, part of the larger West and Central African Rift System (WCARS) across Africa, contains primarily Cretaceous to Palaeocene shallow to marginal marine and freshwater sedimentary deposits. The organic-rich deposits of the Cretaceous Nkporo and Mamu formations within the Anambra Basin and the Palaeocene Imo Formation of the Niger Delta Basin constitute important conventional source rocks. Despite its economic significance, research on organic matter characterisation, palynofacies, sea-level fluctuations, palaeoclimate, hydrogeography, basin restriction, palaeobathymetry and the factors controlling organic matter preservation remains largely undocumented. The here presented new inorganic and organic geochemical and organic petrography data of the Cretaceous to Palaeocene deposits serve to refine the regional interpretation at a basinal scale and within the supra-regional context of the WCARS. Geochemical palaeotemperature proxies suggest a warm and humid tropical palaeoclimate during the Late Cretaceous within the study area. Furthermore, the measured TOC values indicate poor to very good organic content. Palynofacies analysis revealed high abundances of opaque and translucent phytoclasts and low amounts of palynomorphs with negligible amorphous organic matter (AOM) in the studied mudrocks. Two palynofacies groups suggest shallow-marine conditions in a proximal shelf setting and a heterolithic oxic basin. The palynofacies of the upper Imo Formation reveal higher percentages of dinoflagellate cysts during the early highstand phase, with equidimensional, opaque phytoclasts representing the maximum flooding phase, accompanied by warmer conditions. Additionally, abundant terrestrial phytoclasts, <i>Deltoidospora</i> spp., <i>Classopollis</i> spp. and geochemical indicators collectively indicate warm tropical climatic conditions consistent with geochemical interpretations. The palaeobathymetry reconstructions suggest a shallow seaway during the Upper Cretaceous in the Anambra Basin.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 1","pages":"196-222"},"PeriodicalIF":1.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gj.5084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143117614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of Landslide Susceptibility using Geospatial Techniques: A Comparative Evaluation of Machine Learning and Statistical Models","authors":"Subrata Raut,&nbsp;Dipanwita Dutta,&nbsp;Debarati Bera,&nbsp;Rajeeb Samanta","doi":"10.1002/gj.5080","DOIUrl":"https://doi.org/10.1002/gj.5080","url":null,"abstract":"<p>This study delineates landslide susceptibility zones in the Kalimpong district by integrating multi-sensor datasets and assessing the effectiveness of statistical and machine learning models for precision mapping. The analysis utilises a comprehensive geospatial dataset, including remote sensing imagery, topographical, geological, and climatic factors. Four models were employed to generate landslide susceptibility maps (LSMs) using 16 influencing factors: two bivariate statistical models, frequency ratio (FR) and evidence belief function (EBF) and two machine learning models, random forest (RF) and support vector machine (SVM). Out of 1244 recorded landslide events, 871 events (70%) were used for training the models, and 373 events (30%) for validation. The distribution of susceptibility classes predicted by The RF and SVM models produced similar susceptibility distributions, predicting 13.30% and 14.30% of the area as highly susceptible, and 2.42% and 2.82% as very highly susceptible, respectively. In contrast, the FR model estimated 20.98% of the area as highly susceptible and 4.30% as very highly susceptible, whereas the EBF model predicted 17.42% and 5.89% for these categories, respectively. Model validation using receiver operating characteristic (ROC) curves revealed that the machine learning models (RF and SVM) had superior prediction accuracy with AUC values of 95.90% and 86.60%, respectively, compared to the statistical models (FR and EBF), which achieved AUC values of 74.30% and 76.80%. The findings indicate that Kalimpong-I is most vulnerable, with 6.76% of its area categorised as very high susceptibility and 24.80% as high susceptibility. Conversely, the Gorubathan block exhibited the least susceptible, with 0.95% and 6.48% of its area classified as very high and high susceptibility, respectively. This research provides essential insights for decision-makers and policy planners in landslide-prone regions and can be instrumental in developing early warning systems, which are vital for enhancing community safety through timely evacuations and preparedness measures.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 5","pages":"1129-1149"},"PeriodicalIF":1.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Instability Mechanism of Cohesive Soil Slope Based on Discrete-Continuous Coupled Method","authors":"Yuqi Li,&nbsp;Yuting Jing,&nbsp;Zhaoyu Yang","doi":"10.1002/gj.5088","DOIUrl":"https://doi.org/10.1002/gj.5088","url":null,"abstract":"<div>\u0000 \u0000 <p>This paper employed PFC^3D and FLAC^3D to conduct a three-dimensional discrete-continuous dual-scale coupled simulation and stability analysis of cohesive soil slope through discrete-continuous coupled algorithm and the gravity increase method. In the discrete element model zone, the progressive failure process of cohesive soil slope was studied by setting particles with different displacements to different colours, the evolutions of porosity and coordination number in the shear, sliding and stability zones of slope were analysed by arranging measurement spheres, and the variation law of particle position was obtained by the vertical layering of the soil. In the continuous model zone of coupled slope model, the horizontal and vertical stresses were verified with those of a pure FLAC^3D model of slope. Furthermore, a comparative instability analysis of cohesive soil slope and gravelly soil slope was also performed. The safety factor for the cohesive soil slope in this work was determined to be 1.7 according to the mesoscopic fabric evolution of slope particles and the gravity increase method. The work in this paper broadens the application scope of the dual-scale coupled algorithm, highlights the differences in the mesoscopic instability mechanism between cohesive soil slop and gravelly soil slop, and provides new theoretical support for slope design and risk assessment in engineering practice.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 5","pages":"1093-1105"},"PeriodicalIF":1.4,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143914764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Mesozoic Tectonic Evolution of the Baiyun Sag, Northern South China Sea Margin","authors":"Wei Guan,&nbsp;Lei Huang,&nbsp;Guangrong Peng,&nbsp;Chiyang Liu,&nbsp;Han Li,&nbsp;Chao Liang","doi":"10.1002/gj.5092","DOIUrl":"https://doi.org/10.1002/gj.5092","url":null,"abstract":"<div>\u0000 \u0000 <p>The northern South China Sea (SCS) divergent margin developed on a heterogeneous crust that inherited the structures of the Mesozoic convergent margin. However, in the past, studies focused mainly on Cenozoic structures and neglected Mesozoic basement structures. On the basis of the latest high–resolution 3D seismic volumes, we first identify the fault features and evidence in the granite basement. We then identify three sets of Mesozoic fault systems in the northern SCS and discuss their properties and genesis. The NE–trending thrust system (Seismic Reflection 1), formed by forward compression, corresponds to the NW-ward subduction of the palaeo-Pacific plate; the NE–trending extensional system (Seismic Reflection 2 and small residual half-grabens) is related to post-orogenic extension caused by slab rollback and retreat of the palaeo-Pacific plate; and the NNE–trending thrust system (Seismic Reflection 3) formed by a transpressional effect related to the palaeo-Pacific plate and the Eurasian plate changed from the long-term NW-ward orthogonal convergence to a NNW-ward oblique convergence. Finally, by combining previous results on the regional tectonic evolution of onshore and offshore South China, we establish a model for the late Mesozoic evolution of the northern SCS from the Andean-type margins to the western Pacific-type margins.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 3","pages":"629-641"},"PeriodicalIF":1.4,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"New Euungulate Fossils from the Middle Siwalik Subgroup of the Potwar Plateau of Northern Pakistan","authors":"Chaman Ara,&nbsp;Riffat Yasin,&nbsp;Hafiz M. Ishaq,&nbsp;Shakila Naz,&nbsp;Tayyaba Sultana,&nbsp;Khizar Samiullah,&nbsp;Fahad A. Al-Misned,&nbsp;Kifayait Ullah,&nbsp;Holly E. Anderson,&nbsp;Sergi López-Torres,&nbsp;Asghar Abbas","doi":"10.1002/gj.5081","DOIUrl":"https://doi.org/10.1002/gj.5081","url":null,"abstract":"<div>\u0000 \u0000 <p>This article provides a detailed taxonomic study of mammalian fossil fauna from five localities situated within the Middle Siwalik subgroup including the Nagri and Dhok Pathan formations in Punjab, Pakistan. Twenty-three euungulate specimens comprised of isolated teeth, and maxillary and mandibular fragments, are described. This collection includes the bovid, <i>Elachistoceras</i>; a very rare faunal element in the Siwaliks of Pakistan, as well as <i>Elachistoceras khauristanensis</i>, <i>Pachyportax latidens</i>, <i>Giraffa punjabiensis</i>, <i>Bramatherium grande</i>, <i>Merycopotamus dissimilis</i>, <i>Dorcatherium minus</i>, <i>Dorcatherium majus</i>, <i>Hippopotamodon sivalense</i>, <i>Sivalhippus theobaldi</i>, <i>Sivalhippus nagriensis</i> and <i>Brachypotherium perimense</i> These fossil remains add important new insights into the taxonomy and diversity of Late Miocene mammal faunas of the Middle Siwaliks. The data is important for understanding the biogeographical and palaeoenvironmental history of the region. The characteristics of the fossils described in this study further support the currently hypothesised presence of a massive open land environment with variable wet and dry seasons alike to that of the current climate in Eurasia and Africa. The variable habitat niches of these co-existing fauna also give further support to the supposition that there was a much more mixed array of palaeoenvironments ranging from a prevalence of woodland to expansive savannah territory during the deposition of Nagri and Dhok Pathan formations.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 1","pages":"133-162"},"PeriodicalIF":1.4,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143115194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geology of Mudstones Atop the Sangonghe Formation, Shuixigou Group, Turpan-Hami Basin: New Insights and Their Implications for Petroleum Geology","authors":"Weiming Wang,&nbsp;Meishuo Hu,&nbsp;Xuan Chen,&nbsp;Qingguo Liu,&nbsp;Weihao La,&nbsp;Hua Zhang,&nbsp;Yuzhong Yang,&nbsp;Changsheng Miao,&nbsp;Tingting Li","doi":"10.1002/gj.5094","DOIUrl":"https://doi.org/10.1002/gj.5094","url":null,"abstract":"<div>\u0000 \u0000 <p>As the exploration of deep-seated oil and gas resources in the Turpan-Hami Basin intensifies, there is an urgent need to thoroughly depict the geological characteristics of newly uncovered, underexplored strata in sub-sag centers. This study undertakes the inaugural systematic geochemical analysis of mudstones atop the Sangonghe Formation, including palynological identification, maceral identification, biomarker analysis, total organic carbon (TOC) analysis, and pyrolysis. The findings reveal that the mudstone sequence, as the target layer, was deposited in a warm and moist paleoclimate and a weakly reducing to weakly oxidising saline water environment, fostering the growth of prolific algae and bacteria, thus ensuring substantial foundational materials for source rock formation. The organic matter in the mudstone sequence displays pronounced laminar accumulation. Despite the overall modest abundance, the organic matter features notable hydrocarbon-generating potential per unit of organic carbon and favourable types. Humic-sapropelic kerogens (type II₁) are found in the mudstones, with organic matter generally reaching a mature to highly mature stage. These characteristics establish the mudstones as effective source rocks, furthermore, the hydrocarbon expulsion in the Xishanyao Formation precedes that of the Sangonghe Formation and that both formations constitute a sequential process in terms of hydrocarbon generation and expulsion timing and hydrocarbon contribution. Reanalyzing this mudstone sequence not only revises prior geological understanding of it as direct cap rocks, but also facilitates the reclassification of deep-seated strata into three distinct petroleum systems. Centered around this source rock layer, dual modes, namely the “lower-source rock and upper-reservoir” and the “ lower-reservoir and upper-source rock” modes can be formed. These new insights will offer profound implications for hydrocarbon resource evaluation and future hydrocarbon exploration endeavours in the Shuixigou Group within the Taibei sag.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 3","pages":"659-673"},"PeriodicalIF":1.4,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143530751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RAMAN Analysis of Carbonaceous Material and Deduced Peak Metamorphic Temperatures of Metasediments From Western Himalaya, NW Pakistan","authors":"Nasir Ahmad,&nbsp;Shah Faisal,&nbsp;Asad Khan,&nbsp;Hafiz U. Rehman","doi":"10.1002/gj.5083","DOIUrl":"https://doi.org/10.1002/gj.5083","url":null,"abstract":"<p>Raman spectroscopy of carbonaceous materials (RSCM) was applied to 10 carbonaceous material (CM) -rich low- to medium-grade metasedimentary rock samples of Western Himalaya, Pakistan to assess their optimum thermal evolution. The RSCM thermometry is based on the degree of graphitisation of CM as a function of peak metamorphic temperature. Petrographic observations of the studied samples revealed two dominant CM morphologies. Type-I CM, represented by fine-grained discontinuous dust-like and scattered to thin sporadic layers, was more prevalent in low-grade metamorphic samples. Type-II CM, corresponding to continuous and extended thick fibres and elongated grain constellations, was dominant in medium- to high-grade metamorphic samples. The degree of crystallinity of CM and subsequent metamorphic temperatures were quantified by considering the intensity-based <i>R</i>1 and the area-based <i>R</i>2 ratio parameters. Low-grade samples from the Lesser Himalayan Sequence (LHS), having Type-I CM, resulted in RSCM peak temperatures between 306°C and 403°C. Medium- to high-grade samples from Higher Himalayan Crystalline (HHC), containing Type-II CM, yielded peak temperatures in the 482°C–560°C range. The extremely deformed sample from a fault zone in the LHS produced relatively higher temperature of 403°C, thereby suggesting heat associated with shearing due to fault activities resulting in CM recrystallisation and elevated temperature values. The study revealed that the peak metamorphic temperatures increase from south towards north following a progressive path of metamorphism in the region.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 2","pages":"387-403"},"PeriodicalIF":1.4,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gj.5083","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143439229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Tale of Evolution of the Central Indian Tectonic Zone (CITZ) With Glimpses on Pre-Suture Plate Margin Depositional History","authors":"A. Sharma,&nbsp;P. P. Chakraborty,&nbsp;A. K. Pandey,&nbsp;K. Das","doi":"10.1002/gj.5087","DOIUrl":"https://doi.org/10.1002/gj.5087","url":null,"abstract":"<p>Comprehending pre-suture geological setting and post-suture intricate tectono-thermal chronicle in a crustal-scale orogeny and discerning the temporal connections among different tectonic domains within an orogen yields valuable insights into worldwide tectonic phenomena leading to the reconstruction of paleogeographic configurations of fragmented crustal components within erstwhile supercontinents. Since the tectonic evolution of the Indian subcontinent during the Proterozoic remains a topic of discussion due to multiple controversial views, the Central Indian Tectonic Zone (CITZ) offers a great archive for the protracted geological history of subduction, collision, and suturing of northern Indian cratonic blocks (NIC; composed of Bundelkhand and Aravalli cratons) and southern Indian cratonic blocks (SIC; composed of Bastar, Singhbhum, and Dharwar cratons). Events belonging to two Supercontinents namely, Columbia (ca. 2100 to 1800 Ma) and Rodinia (ca. 1200 to 900 Ma) are embedded within the geological history of CITZ, as it records multiple events that occurred between the Paleoproterozoic and Neoproterozoic. In this backdrop, the present contribution attempts (i) the deconvolution of pre-suture (pre-CITZ formation) plate margin basin depositional history including tracking of detrital provenance, and (ii) a review of different stages of collision and suturing as the plate margin evolved in the form of an orogen subsequent to the closure of the basin. A back-arc basin setup in a subduction margin is recommended for the Mahakoshal Basin which witnessed several tectonic pulses resulting in the formation of alluvial fans/fan deltas along the basin shoreline. It is suggested that the basin was open, at places, even after ca. 1700 Ma, and received sediments.</p>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 2","pages":"404-430"},"PeriodicalIF":1.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/gj.5087","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143438724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tectonic Evolution and Sedimentary Responses of Palaeocene–Eocene Tethys Himalayan Foreland Basin in Southern Tibet","authors":"Songtao Yan,&nbsp;Ailing Ding,&nbsp;Lidong Zhu,&nbsp;Jie Wang,&nbsp;Hu Li,&nbsp;Xuejian Dai,&nbsp;Yangchun Wei,&nbsp;Hao Huang,&nbsp;Qingsong Wu","doi":"10.1002/gj.5082","DOIUrl":"https://doi.org/10.1002/gj.5082","url":null,"abstract":"<div>\u0000 \u0000 <p>The tectonic evolution of the Palaeocene–Eocene Tethys Himalayan foreland basin plays a crucial role in reshaping the collisional orogenic process of the Yarlung–Tsangpo oceanic basin. However, studies examining the sedimentary response during the tectonic evolution of the foreland basin are lacking. In this study, through a detailed field investigation and analysis of Palaeocene–Eocene strata in the Tingri area, we clarified the evolution of the Tethys Himalayan tectonic regions and its sedimentary response. Carbon and oxygen isotopes, geochemistry and detrital zircon U–Pb dating demonstrated that the lower Palaeocene Jidula Formation and upper Palaeocene–lower Eocene Zongpu Formation were deposited in a coastal–shallow marine environment, with the detritus sourced from the northern Indian passive margin. The upper Eocene Pengqu Formation was deposited in a deltaic environment, with its detritus sourced from the Gangdese arc and the Yarlung–Tsangpo suture zone at the active continental margin. Combined with the nearshore subaqueous fan branch channel of the Jidula Formation and the slump deformation of the Zongpu Formation, the Palaeocene–Early Eocene southern Tethys Himalaya in the Tingri area was located in the forebulge of the peripheral foreland basin. The marine–continental interactive delta of the Pengqu Formation and its provenance from the Gangdese magmatic arc indicate that the Tingri area was situated in the foredeep of the peripheral foreland basin during the Late Eocene. The study provides valuable insights into the collisional orogenic processes between the Indian and Eurasian plates.</p>\u0000 </div>","PeriodicalId":12784,"journal":{"name":"Geological Journal","volume":"60 1","pages":"163-195"},"PeriodicalIF":1.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143120596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}