Journal of the Geological Society最新文献_第6页

Double arc–continent collision record in the Latest Mesozoic–Cenozoic tectonic history of the Himalayan–Tibetan orogenic belt in Western Pakistan 巴基斯坦西部喜马拉雅-西藏造山带中新生代构造史上的双弧-大陆碰撞记录

IF 2.7 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-25 DOI: 10.1144/jgs2023-076

Inayat Ullah, Chuandong Xue, Tiannan Yang, H. Furnes, Y. Dilek, Wen Wang, Abdul Ghaffar

{"title":"Double arc–continent collision record in the Latest Mesozoic–Cenozoic tectonic history of the Himalayan–Tibetan orogenic belt in Western Pakistan","authors":"Inayat Ullah, Chuandong Xue, Tiannan Yang, H. Furnes, Y. Dilek, Wen Wang, Abdul Ghaffar","doi":"10.1144/jgs2023-076","DOIUrl":"https://doi.org/10.1144/jgs2023-076","url":null,"abstract":"Our recent field investigations in western Pakistan have revealed that serpentinized peridotites here are crosscut by numerous intrusions of gabbro and tonalite. New zircon U–Pb dating of these plutons indicates Late Cretaceous–Early Eocene ages of their crystallization. They have arc-like geochemical signatures and constitute the middle crust of an island arc complex. Together with their extrusive counterparts they form the RasKoh island arc (RIA), defined for the first time in this study. The RIA and the Chaiga continental arc to the north represent the manifestations of two separate subduction zone systems within Neotethys, developed between India and Eurasia. We posit that this Neotethyan domain contained two oceanic plates. Subduction of the leading plate beneath Eurasia generated the Jurassic–Late Oligocene Chaiga continental arc, and the northward subduction of the trailing plate resulted in the development of the Late Cretaceous–Oligocene, ensimatic RasKoh arc. Arrival of the Indian subcontinent at the latitude of the RasKoh arc in the earliest Miocene caused the emplacement of the RasKoh arc onto India via oblique arc–continent collision. The subsequent collision of this composite Indian plate with Eurasia resulted in extensive deformation of Late Cretaceous flysch deposits and the ophiolitic arc basement.\u0000 \u0000 Thematic collection:\u0000 This article is part of the Ophiolites, melanges and blueschists collection available at:\u0000 https://www.lyellcollection.org/topic/collections/ophiolites-melanges-and-blueschists\u0000 \u0000 \u0000 Supplementary material:\u0000 https://doi.org/10.6084/m9.figshare.c.6795686\u0000","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41901921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Incomplete vascular ring of the aortic arch presenting with dysphagia in an adult: case report. 成人主动脉弓血管环不完整伴吞咽困难一例报告。

IF 1.2 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-25 eCollection Date: 2023-01-01 DOI: 10.11604/pamj.2023.45.183.38569

Ndubueze Ezemba, Augustine Chukwudi Onuh, Uchenna Simon Onoh

{"title":"Incomplete vascular ring of the aortic arch presenting with dysphagia in an adult: case report.","authors":"Ndubueze Ezemba, Augustine Chukwudi Onuh, Uchenna Simon Onoh","doi":"10.11604/pamj.2023.45.183.38569","DOIUrl":"10.11604/pamj.2023.45.183.38569","url":null,"abstract":"<p><p>Anomalies of the arterial branches of the arch of the aorta are rare, with the aberrant right subclavian artery being the most common of this anomaly. Majority of the anomalies are asymptomatic and often discovered as incidental findings. In the great majority of the symptomatic cases, the presentation may be either with breathlessness or dysphagia or both. This is in addition to the nature of the intrinsic arterial disease of the aberrant vessel, especially in adult patients; and unless borne in mind, the diagnosis is often missed leading to delays and wrong treatment. In this report we present a case of dysphagia in an adult male Nigerian initially diagnosed as œsophageal stricture from herbal potion ingestion but review of his imaging investigations gave a final diagnosis of dysphagia lusoria from an aberrant right subclavian artery. The difficulty in making a diagnosis and the need for a multidisciplinary review of the imaging investigations are highlighted. The patient was successfully treated by a combined trans-thoracic and cervical approach with division and re-implantation of the aberrant vessel unto the right common carotid artery. He has remained symptom-free for 2 years after surgery. Although the great majority of these anomalies are often asymptomatic, it is important they are borne in mind both in imaging investigations as well as in procedures involving structures in the upper visceral mediastinum. Various surgical approaches have been documented in the management of symptomatic ones; it is however recommended that options that ensure revascularization of the affected limb be selected.</p>","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":"164 1","pages":"183"},"PeriodicalIF":1.2,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10656587/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85978356","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Mineral & whole–rock geochemistry of high-Al podiform chromitites in the Fizh Massif of the Cretaceous Oman ophiolite: Origin of hydrous, N–MORB melts in a nascent forearc setting 白垩纪阿曼蛇绿岩Fizh地块高铝脚状铬铁矿的矿物及全岩地球化学:新生弧前环境中含水N-MORB熔体的成因

IF 2.7 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-23 DOI: 10.1144/jgs2023-047

Ronge Bo, Y. Dilek, S. Nasir, Weiwei Wu, Peng-Jie Cai, Yu-Xiao Lu, D. Lian, Jing S. Yang

{"title":"Mineral & whole–rock geochemistry of high-Al podiform chromitites in the Fizh Massif of the Cretaceous Oman ophiolite: Origin of hydrous, N–MORB melts in a nascent forearc setting","authors":"Ronge Bo, Y. Dilek, S. Nasir, Weiwei Wu, Peng-Jie Cai, Yu-Xiao Lu, D. Lian, Jing S. Yang","doi":"10.1144/jgs2023-047","DOIUrl":"https://doi.org/10.1144/jgs2023-047","url":null,"abstract":"The Oman ophiolite is one of the largest and best-exposed ophiolites in the world with >450 chromitite deposits. We report here a newly identified chromitite deposit in the Wadi Rajmi in Oman. This deposit occurs within a dunitic envelope, which is surrounded by harzburgite, and consists of massive and disseminated chromitite types. The Rajmi peridotites represent depleted upper mantle rocks, which underwent >20% of partial melting and which experienced metasomatism by melts and fluids derived from a subducting slab. They demonstrate geochemical affinities similar to those of the Izu-Bonin-Mariana forearc peridotites, supporting their formation in a forearc environment. The Rajmi chromitites have low Cr# values and are classified as high-Al type. They have geochemical compositions comparable to those of chromitites crystallized from mid-ocean ridge basalt (MORB)-type melts. However, the chromites in these high-Al chromitites contain various silicate inclusions (i.e. amphibole, mica), indicating a hydrous and atypical MORB nature of their parental magmas. Combined with the mineralogical and geochemical characteristics of the country rocks, we posit that the parental melts of the Rajmi high-Al chromitites had a MORB-like affinity, derived from partial melting of a nascent forearc mantle.\u0000 \u0000 Thematic collection:\u0000 This article is part of the Ophiolites, melanges and blueschists collection available at:\u0000 https://www.lyellcollection.org/topic/collections/ophiolites-melanges-and-blueschists\u0000 \u0000 \u0000 Supplementary material:\u0000 https://doi.org/10.6084/m9.figshare.c.6795689\u0000","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43015083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Palaeomagnetism of the mid-Cretaceous red beds from the Tethyan Himalaya: direction discrepancy and tectonic implications 特提斯-喜马拉雅中白垩世红层的古地磁:方向差异及其构造意义

IF 2.7 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-23 DOI: 10.1144/jgs2023-029

W. Bian, Tianshui Yang, Suo Wang, Wenxiao Peng, Xianwei Jiao, Shihong Zhang, Huaichun Wu, Haiyan Li, Pan Zhao

{"title":"Palaeomagnetism of the mid-Cretaceous red beds from the Tethyan Himalaya: direction discrepancy and tectonic implications","authors":"W. Bian, Tianshui Yang, Suo Wang, Wenxiao Peng, Xianwei Jiao, Shihong Zhang, Huaichun Wu, Haiyan Li, Pan Zhao","doi":"10.1144/jgs2023-029","DOIUrl":"https://doi.org/10.1144/jgs2023-029","url":null,"abstract":"\u0000 Understanding the northern extension of Greater India is vital for modeling the India-Asia collision process and the formation of the Tibetan Plateau. We present new palaeomagnetic data from the mid-Cretaceous (ca. 106 Ma) Gyabula Formation red beds in the Tethyan Himalaya. Well-defined high laboratory unblocking temperature component magnetizations were isolated from 19 sites and pass the fold tests, indicating that they are pre-folding magnetizations. The tilt-corrected site-mean direction is D\u0000 s\u0000 = 222.9°, I\u0000 s\u0000 = +39.4° with\u0000 \u0000 \u0000 α\u0000 \u0000 \u0000 95\u0000 = 4.2°. The site-mean inclination increases from 39.4° to 45.8° after anisotropy-based inclination shallowing correction. The declination and inclination differ considerably from those of neighboring sections. This directional discrepancy of the red beds may be attributed to the fact that the sampled section (sites ZB1–11, 40–52) is overturned and local vertical axis rotation. The combination of our new and previously published palaeomagnetic data shows that the Tethyan Himalaya was located at 27.5° ± 2.4°S for the sampled area. Our new results, together with the reliable Cretaceous palaeomagnetic data obtained from the Tethyan Himalaya as well as coeval palaeolatitudes expected from the Indian craton, support a smaller Greater India and that the Tethyan Himalaya did not rift from the Indian craton during the mid-Cretaceous.\u0000 \u0000 \u0000 Thematic collection:\u0000 This article is part of the Mesozoic and Cenozoic tectonics, landscape and climate change collection available at:\u0000 https://www.lyellcollection.org/topic/collections/mesozoic-and-cenozoic-tectonics-landscape-and-climate-change\u0000 \u0000 \u0000 Supplementary material:\u0000 https://doi.org/10.6084/m9.figshare.c.6795683\u0000","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42028035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Morphological evidence of the extension of the Zabargad Transform Fault Zone to the Saudi Arabian Red Sea margin Zabargad转换断层带向沙特阿拉伯-红海边缘延伸的形态学证据

IF 2.7 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-22 DOI: 10.1144/jgs2023-009

A. Petrovic, Y. Panara, V. Vahrenkamp

{"title":"Morphological evidence of the extension of the Zabargad Transform Fault Zone to the Saudi Arabian Red Sea margin","authors":"A. Petrovic, Y. Panara, V. Vahrenkamp","doi":"10.1144/jgs2023-009","DOIUrl":"https://doi.org/10.1144/jgs2023-009","url":null,"abstract":"Fault locations and orientation of the Zabargad Transform Fault Zone, also called the Zabargad Fracture Zone (ZFZ) have, so far, only been delineated by satellite-based geophysical data, causing intense debate over the last decades. Newly recognized geomorphological features identified in bathymetry and lidar data from the NE Red Sea margin present the first ground evidence for the northern extent of the ZFZ. The features are aligned over 84 km starting from the Mabahiss Deep, near the spreading axis, and continue to the shallow Saudi Arabian shelf, along the northern termination of the Al Wajh carbonate platform. Analysis of the seafloor morphology revealed three geomorphic terrains: (1) a deep incised canyon feeding into the Mabahiss Deep, which is characterized by dozens of amphitheatre-shaped scarps, (2) a 22 km-wide head-scarp that follows the Al Wajh platform edge, (3) and multiple fault scars and graben-like structures on the shallow shelf. We interpret these morphological features as deformation indicators in association with the deformation processes in the ZFZ, and postulate that they represent the northern end of the ZFZ. In addition, the fault zone delineates the northwest margin of the Al Wajh carbonate platform, and most likely continues to shape it. This paper gives new insights in the interaction between fracture zones and continental margins and their role in the seafloor morphogenesis.","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46522083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Biological extinction and photic-zone anoxia across the Triassic-Jurassic transition: Insights from the Qiangtang Basin, eastern Tethys 特提斯东部羌塘盆地三叠系—侏罗系生物灭绝和光带缺氧

IF 2.7 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-09 DOI: 10.1144/jgs2022-108

Fangzhi Hu, X. Fu, Jian Wang, Hengye Wei, Ying Nie, Jian Zhang, Kangzhi Tian

引用次数: 0

Recognizing different types of Ocean Plate Stratigraphy at the southeastern South Qilian Accretionary Belt, northeastern Tibet Plateau 青藏高原东北部南祁连增生带东南部不同类型海洋板块地层识别

IF 2.7 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-09 DOI: 10.1144/jgs2023-035

L. Tao, Hongfei Zhang, Zhongning Gao, Zhuo Lu, He Yang, Liqi Zhang

{"title":"Recognizing different types of Ocean Plate Stratigraphy at the southeastern South Qilian Accretionary Belt, northeastern Tibet Plateau","authors":"L. Tao, Hongfei Zhang, Zhongning Gao, Zhuo Lu, He Yang, Liqi Zhang","doi":"10.1144/jgs2023-035","DOIUrl":"https://doi.org/10.1144/jgs2023-035","url":null,"abstract":"\u0000 Dissection of relicts of Ocean Plate Stratigraphy (OPS) at orogens could provide important insights into oceanic evolution, orogenic formation, and continental growth. Here we put forward a study of petrology, geochronology, geochemistry, and Sr–Nd isotopes for OPS at the South Qilian Accretionary Belt (SQAB) with aim to provide new constraints on evolution of the Proto-Tethys Ocean (PTO). Three types of OPS units were recognized by their discrepant petrological, geochemical, and isotopic features. Type 1 OPS as relicts of ocean islands/seamounts comprises OIB-type basalt and gabbro (t = 525 ± 4 Ma, (\u0000 87\u0000 Sr/\u0000 86\u0000 Sr)\u0000 i\u0000 = 0.7035–0.7039, and ε\u0000 Nd\u0000 (\u0000 t\u0000 ) = +3.63 to +4.16) and (siliceous) carbonate rocks. Type 2 OPS, representing fragments of normal oceanic crusts, consists of N-MORB-like basalt and basaltic andesite ((\u0000 87\u0000 Sr/\u0000 86\u0000 Sr)\u0000 i\u0000 = 0.7059–0.7063, and ε\u0000 Nd\u0000 (\u0000 t\u0000 ) = +6.33 to +7.44), chert, and siliceous mudstone. Type 3 OPS could be oceanic plateau-derived and comprises E-MORB-like basalt and dolerite ((\u0000 87\u0000 Sr/\u0000 86\u0000 Sr)\u0000 i\u0000 = 0.7051–0.7064 and ε\u0000 Nd\u0000 (\u0000 t\u0000 ) = +4.81 to +6.24), carbonate-siliceous mudstone, and carbonate rock. These OPS witnessed evolution of the PTO. By available studies on regional arc-type magmatism and U-Pb geochronological data of detrital zircon in this study, a model of “trench jam accompanying with subduction flip induced by accretion of the OPS” is put forward.\u0000 \u0000 \u0000 Thematic collection:\u0000 This article is part of the Ophiolites, melanges and blueschists collection available at:\u0000 https://www.lyellcollection.org/topic/collections/ophiolites-melanges-and-blueschists\u0000 \u0000 \u0000 Supplementary material:\u0000 https://doi.org/10.6084/m9.figshare.c.6764637\u0000","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44590852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Organic geochemistry of in situ thermal-based analyses on Mars: the importance and influence of minerals 火星原位热分析的有机地球化学:矿物的重要性和影响

IF 2.7 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-04 DOI: 10.1144/jgs2022-152

M. Sephton, Jonathan S W Tan, J. Watson, K. Hickman‐Lewis, J. M. Madariaga

{"title":"Organic geochemistry of in situ thermal-based analyses on Mars: the importance and influence of minerals","authors":"M. Sephton, Jonathan S W Tan, J. Watson, K. Hickman‐Lewis, J. M. Madariaga","doi":"10.1144/jgs2022-152","DOIUrl":"https://doi.org/10.1144/jgs2022-152","url":null,"abstract":"A high priority goal for past, present and future missions to Mars is the search for evidence of past or present life. Some of the most information-rich signals are those represented by organic biomarkers. Thermal extraction has historically been the most popular in situ analysis technique employed on Mars owing to its elegance and ability to liberate both small compounds and large macromolecular networks. The geological record of Mars contains a variety of minerals, some of which can interact with organic matter when subjected to thermal extraction. Here we discuss the organic records that may be associated with these mineral hosts and the problems encountered when mineral-organic mixtures are analysed by thermal-based methods. We also suggest potential mitigations for future experiments of a similar nature and note that these mitigating steps can be applied not only in situ on Mars but also after samples are returned to Earth as part of Mars Sample Return where more resources and time for sample preparation are available.\u0000 \u0000 Thematic collection:\u0000 This article is part of the Astrobiology: Perspectives from the Geology of Earth and the Solar System collection available at:\u0000 https://www.lyellcollection.org/topic/collections/astrobiology\u0000","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44329216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The Sommerodde (Telychian, Silurian) positive carbon isotope excursion: why is its magnitude so variable? Sommerodde（Telychian，志留纪）正碳同位素漂移：为什么它的震级如此多变？

IF 2.7 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-03 DOI: 10.1144/jgs2023-037

D. Loydell, J. C. Gutiérrez-Marco, P. Štorch

{"title":"The Sommerodde (Telychian, Silurian) positive carbon isotope excursion: why is its magnitude so variable?","authors":"D. Loydell, J. C. Gutiérrez-Marco, P. Štorch","doi":"10.1144/jgs2023-037","DOIUrl":"https://doi.org/10.1144/jgs2023-037","url":null,"abstract":"\u0000 The Sommerodde positive organic carbon isotope excursion (SOCIE), within the\u0000 Oktavites spiralis\u0000 graptolite Biozone (Telychian, Silurian), was first identified in the Sommerodde-1 core, Bornholm, Denmark, where it is the largest positive excursion within the Upper Ordovician–lower Silurian part of the core. Other published occurrences of the SOCIE are discussed here, together with new δ\u0000 13\u0000 C\u0000 org\u0000 data from the Jabalón River section, Corral de Calatrava, central Spain where the SOCIE is only a very minor positive excursion. Very unusually, the SOCIE is best developed in deeper water settings, contrary to the typical pattern of declining excursion magnitude offshore. In the Sommerodde-1 core (Bornholm), and where it has been tentatively identified in the Vežaičiai-2 core (Lithuania), the SOCIE is developed in pale, organic-poor mudstones. It is considered likely that the SOCIE's magnitude has been enhanced in the Sommerodde-1 core record by a change in organic matter composition in the deep marine environment that did not affect shallower marine environments so significantly.\u0000 \u0000 \u0000 Thematic collection:\u0000 This article is part of the Chemical Evolution of the Mid-Paleozoic Earth System and Biotic Response collection available at:\u0000 https://www.lyellcollection.org/topic/collections/chemical-evolution-of-the-mid-paleozoic-earth-system\u0000 \u0000 \u0000 Supplementary material:\u0000 A table of organic carbon isotope data from the Jabalón River section, Corral de Calatrava, central Spain is available at\u0000 https://doi.org/10.6084/m9.figshare.c.6769514\u0000","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44997090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Extreme enrichment of Arsenic and Antimony during alteration of serpentinised peridotites to form listvenite-like dolomite-quartz rocks and Ni-Cr-rich jasper and quartzites in the Highland Border Complex of Scotland 苏格兰高地边界杂岩蛇纹橄榄岩蚀变过程中砷和锑的极度富集，形成了类橄榄石白云岩-石英岩和富镍铬的碧玉和石英岩

IF 2.7 3区地球科学

Journal of the Geological Society Pub Date : 2023-08-03 DOI: 10.1144/jgs2023-054

H. Austrheim, Torgeir B. Andresen

{"title":"Extreme enrichment of Arsenic and Antimony during alteration of serpentinised peridotites to form listvenite-like dolomite-quartz rocks and Ni-Cr-rich jasper and quartzites in the Highland Border Complex of Scotland","authors":"H. Austrheim, Torgeir B. Andresen","doi":"10.1144/jgs2023-054","DOIUrl":"https://doi.org/10.1144/jgs2023-054","url":null,"abstract":"\u0000 Alteration of serpentinised peridotites of Highland Border Complex in Scotland took place in two steps. Listvenite-like dolomite-quartz rocks formed by addition of CaO, Sr and CO\u0000 2\u0000 at constant MgO and SiO\u0000 2\u0000 involving a mass increase of ca. 140 %. Stage-two involved the dissolution of dolomite evinced by the abundant pores and rhombohedral-shaped grains of quartz to form Cr- and Ni-rich jasper and quartzites. Formation of the jasper-quartzites involve a mass reduction of ca. 80%. The listvenite-like and jasper-quartzite rocks have enrichment in the fluid mobile elements Ba, Sr, Cs, As and Sb. The As is present in the Aluminium-Phosphate-Sulphate group of minerals formed during alteration of Cr-spinel. Cr-spinel also alters to porous hematite and ferrihydrite with patches containing up to 5.5 wt% As\u0000 2\u0000 O\u0000 3\u0000 . Enrichment of As, related to alteration of chromite, is previously unknown from natural rocks, but strongly resembles efficient methods used for remediation of this toxic element. Formation of quartzite and jasper from peridotite and their common presence as pebbles both in the Devonian Old Red conglomerates, in the Highland Border Complex and in Devonian Basins in the Scandinavian Caledonides, highlights their importance and potential for provenance- and tectono-stratigraphic correlations.\u0000 \u0000 \u0000 Thematic collection:\u0000 This article is part of the Ophiolites, melanges and blueschists collection available at:\u0000 https://www.lyellcollection.org/topic/collections/ophiolites-melanges-and-blueschists\u0000 \u0000 \u0000 Supplementary material:\u0000 https://doi.org/10.6084/m9.figshare.c.6764598\u0000","PeriodicalId":17320,"journal":{"name":"Journal of the Geological Society","volume":" ","pages":""},"PeriodicalIF":2.7,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44554546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0