Pub Date : 2025-03-01DOI: 10.1016/j.sesci.2024.100179
Yan Guo , Zhuowu Li , Fujiang Liu , Weihua Lin , Hongchen Liu , Quansen Shao , Dexiong Zhang , Weichao Liang , Junshun Su , Qiankai Gao
Traditional methods of lithological classification often rely on the expertise of appraisers and the use of sophisticated measuring instruments. These methods are susceptible to staff experience and are time-consuming. To overcome these limitations, researchers have explored the use of rock images and intelligent algorithms to automatically identify rocks. However, models developed for automatic rock properties identification often require high-performance equipment that cannot be readily deployed on lightweight edge devices. To address this problem, we significantly extend our previous research and propose a method for automatic rock properties identification called SBR-EfficientViT. The method is based on an efficient vision converter and builds on our previous training framework. We also developed a training and application flow framework for the method, which can run with memory requirements of less than 720 MB and graphics memory of 1.6 GB. Furthermore, the proposed SBR-EfficientViT-M1 method achieves an impressive accuracy of 94.75%.
{"title":"Fast and lightweight automatic lithology recognition based on efficient vision transformer network","authors":"Yan Guo , Zhuowu Li , Fujiang Liu , Weihua Lin , Hongchen Liu , Quansen Shao , Dexiong Zhang , Weichao Liang , Junshun Su , Qiankai Gao","doi":"10.1016/j.sesci.2024.100179","DOIUrl":"10.1016/j.sesci.2024.100179","url":null,"abstract":"<div><div>Traditional methods of lithological classification often rely on the expertise of appraisers and the use of sophisticated measuring instruments. These methods are susceptible to staff experience and are time-consuming. To overcome these limitations, researchers have explored the use of rock images and intelligent algorithms to automatically identify rocks. However, models developed for automatic rock properties identification often require high-performance equipment that cannot be readily deployed on lightweight edge devices. To address this problem, we significantly extend our previous research and propose a method for automatic rock properties identification called SBR-EfficientViT. The method is based on an efficient vision converter and builds on our previous training framework. We also developed a training and application flow framework for the method, which can run with memory requirements of less than 720 MB and graphics memory of 1.6 GB. Furthermore, the proposed SBR-EfficientViT-M1 method achieves an impressive accuracy of 94.75%.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"10 1","pages":"Article 100179"},"PeriodicalIF":2.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510406","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}
This study presents radiogenic Sr–Nd isotopic compositions of eighteen geological Chinese reference materials (RMs) measured on TIMS and MC-ICP-MS independently. These RMs include nine igneous rocks, six sedimentary rocks, two metamorphic rocks, and one fluvial sediment. Among the RMs, eight Nd isotopic ratios and three Sr isotopic ratios of them are first reported. Our results showed that the Sr and Nd isotopic ratios of these RMs measured on TIMS and MC-ICP-MS are consistent within the error range. We also observed that Rb interference can be dramatically reduced using filament burning technique during TIMS measurement, which is significant to achieve accurate Sr isotopic data especially for samples with high Rb content. To evaluate the homogeneity of RMs, Sr and Nd isotopic data reported from various laboratories were clustered together for comparative analysis. Overall, these RMs from various laboratories yielded relatively consistent ratios, except for some anomalies. We concluded that isobaric interference could be probably the main factor that induced the isotopic inconsistency. Therefore, we propose that these RMs are reliable candidates for Sr and Nd isotope analyses. The datasets will play a fundamental role in quality assurance and comparison for radiogenic Sr and Nd isotopic systems.
{"title":"Strontium–Neodymium isotopic compositions of eighteen geological Chinese reference materials measured on TIMS and MC-ICP-MS","authors":"Wenke Wang, Jiaojiao Wu, Fang Liu, Xin Li, Yajun An, Zhaofeng Zhang","doi":"10.1016/j.sesci.2025.100230","DOIUrl":"10.1016/j.sesci.2025.100230","url":null,"abstract":"<div><div>This study presents radiogenic Sr–Nd isotopic compositions of eighteen geological Chinese reference materials (RMs) measured on TIMS and MC-ICP-MS independently. These RMs include nine igneous rocks, six sedimentary rocks, two metamorphic rocks, and one fluvial sediment. Among the RMs, eight Nd isotopic ratios and three Sr isotopic ratios of them are first reported. Our results showed that the Sr and Nd isotopic ratios of these RMs measured on TIMS and MC-ICP-MS are consistent within the error range. We also observed that Rb interference can be dramatically reduced using filament burning technique during TIMS measurement, which is significant to achieve accurate Sr isotopic data especially for samples with high Rb content. To evaluate the homogeneity of RMs, Sr and Nd isotopic data reported from various laboratories were clustered together for comparative analysis. Overall, these RMs from various laboratories yielded relatively consistent ratios, except for some anomalies. We concluded that isobaric interference could be probably the main factor that induced the isotopic inconsistency. Therefore, we propose that these RMs are reliable candidates for Sr and Nd isotope analyses. The datasets will play a fundamental role in quality assurance and comparison for radiogenic Sr and Nd isotopic systems.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"10 1","pages":"Article 100230"},"PeriodicalIF":2.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526871","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}
The Makassar Strait, located in central Indonesia, serves as a divider between Western and Eastern Indonesia and remains a subject of ongoing debate regarding its formation. Two primary theories have been proposed: (1) the Makassar Strait opening established a mid-ocean ridge (MOR) and led to a double subduction, and (2) it was formed through intracontinental rifting accompanied by mantle-plume magmatism. In this study, we present findings on the Adang Volcanic Complexes in Western Sulawesi, situated on the eastern side of the Makassar Strait, which have exposures of the Middle to Late Miocene age interspersed with crystalline limestone and carbonate rocks, indicating a correlation with a marine environment. The rocks investigated in this study are predominantly low-silica mafic rock, mainly composed of leucite/pseudoleucite-bearing trachytic tuff, agglomerate volcanic breccia, lavas, peralkaline dykes, and multiple mafic and leucitic intrusions. Geochemical analysis of the 12 drill core samples of leucite-bearing Adang Volcanics reveals their alkaline nature, characterized by high TiO2 relative to Al2O3 [TiO2 > (−1.1610 + 0.1935 × Al2O3)]. The samples also display geochemical signatures of Nb/Zr > 0.0627, Th/Nb > 0.67, a high ratio of Nb/Y (>0.6561) with an enrichment of light rare earth elements (LREE; La/Yb > 20), low Nb/La <0.6, and a low negative Tantalum anomaly (δTa 0.36–0.41), suggesting the magmatism was generated from the tectonics of continental extension stretching rather than subduction arc-related or mature continental rifts, where the magmatism was triggered by decompression melting during the extensional processes. Furthermore, the magmatism is thought to originate from partial melting of enriched subcontinental lithospheric mantle (SCLM), which is uncorrelated with the source of asthenospheric mantle. We propose that the formation process of the Adang Volcano is a product of the tectonic processes of the Makassar Strait opening in Central Indonesia during the Paleogene to the Early Neogene era.
{"title":"Geochemistry of the Adang Volcanics in Western Sulawesi: Unveiling the tectonic evolution of the opening of the Makassar Strait","authors":"Shaban Godang , Sugeng Purwo Saputro , Huan Li , Awang Harun Satyana , Weerapan Srichan","doi":"10.1016/j.sesci.2025.100228","DOIUrl":"10.1016/j.sesci.2025.100228","url":null,"abstract":"<div><div>The Makassar Strait, located in central Indonesia, serves as a divider between Western and Eastern Indonesia and remains a subject of ongoing debate regarding its formation. Two primary theories have been proposed: (1) the Makassar Strait opening established a mid-ocean ridge (MOR) and led to a double subduction, and (2) it was formed through intracontinental rifting accompanied by mantle-plume magmatism. In this study, we present findings on the Adang Volcanic Complexes in Western Sulawesi, situated on the eastern side of the Makassar Strait, which have exposures of the Middle to Late Miocene age interspersed with crystalline limestone and carbonate rocks, indicating a correlation with a marine environment. The rocks investigated in this study are predominantly low-silica mafic rock, mainly composed of leucite/pseudoleucite-bearing trachytic tuff, agglomerate volcanic breccia, lavas, peralkaline dykes, and multiple mafic and leucitic intrusions. Geochemical analysis of the 12 drill core samples of leucite-bearing Adang Volcanics reveals their alkaline nature, characterized by high TiO<sub>2</sub> relative to Al<sub>2</sub>O<sub>3</sub> [TiO<sub>2</sub> > (−1.1610 + 0.1935 × Al<sub>2</sub>O<sub>3</sub>)]. The samples also display geochemical signatures of Nb/Zr > 0.0627, Th/Nb > 0.67, a high ratio of Nb/Y (>0.6561) with an enrichment of light rare earth elements (LREE; La/Yb > 20), low Nb/La <0.6, and a low negative Tantalum anomaly (δTa 0.36–0.41), suggesting the magmatism was generated from the tectonics of continental extension stretching rather than subduction arc-related or mature continental rifts, where the magmatism was triggered by decompression melting during the extensional processes. Furthermore, the magmatism is thought to originate from partial melting of enriched subcontinental lithospheric mantle (SCLM), which is uncorrelated with the source of asthenospheric mantle. We propose that the formation process of the Adang Volcano is a product of the tectonic processes of the Makassar Strait opening in Central Indonesia during the Paleogene to the Early Neogene era.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"10 1","pages":"Article 100228"},"PeriodicalIF":2.0,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437733","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}
Pub Date : 2025-02-18DOI: 10.1016/j.sesci.2024.100210
Ngong Roger Ngia , Elie Fosso Menkem , Christopher Fuanya , Christopher M. Agyingi
The formation and preservation conditions of organic matter-rich mudrocks in the Edki-Mabonji and Mbalangi-Bombe area of the Northwestern section of Douala sub-basin, Cameroon, can play an important role in the accumulation of hydrocarbon. This study integrated detailed geochemical techniques such as total organic carbon content (TOC), Total sulfur (TS), stable isotopes (δ13Corg. and δ34S), elemental geochemistry, and Scanning electron microscope (SEM) to reconstruct marine paleoredox conditions, paleoweathering conditions and primary productivity thereby, promoting the understanding of the sedimentary model of organic matter accumulation and enrichment in mudrocks in the study areas. Elemental compositions and their ratios suggest that the mudrocks were dominantly derived from a source area mainly consisting of felsic igneous rock with more silica (granitic rock) than an average granodiorite. Paleoweathering proxies suggest that during sediment production, the source area experienced mostly moderate chemical weathering as a result of variation in climate and sea-level changes. The proxies to reconstruct paleoredox conditions demonstrates fluctuating redox variations from mildly suboxic-to dominantly anoxic, most probably sulphidic benthic conditions, which describes anoxic organicmudrocks sandwiched between the oxygenated sandstone/claystone strata. Paleoproductivity parameters like biogenic barium (Babio), TOC, Porg/Al, Cu/Al and S/13Corg ratios, and δ34Spy, δ34SOS, δ13Corg suggest that the deposition of the mudrocks was with a high primary productivity. Consequently, the conceptual model of organic matter accumulation and enrichment reveals that moderate-to high primary productivity, suboxic-to dominantly anoxic sulphidic bottom water, organo–mineral complexes, bacterial sulfate reduction (BSR) and deposition of claystone capping bed isolating the benthic sediments influenced the accumulation and preservation of organic matter at shortened exposure duration in dominantly anoxic deeper water setting.
{"title":"Multiproxy analysis of paleoredox conditions, paleoproductivity and organic matter enrichment in Cretaceous mudrocks of Bombe-Ediki and environs in the Douala sub-basin","authors":"Ngong Roger Ngia , Elie Fosso Menkem , Christopher Fuanya , Christopher M. Agyingi","doi":"10.1016/j.sesci.2024.100210","DOIUrl":"10.1016/j.sesci.2024.100210","url":null,"abstract":"<div><div>The formation and preservation conditions of organic matter-rich mudrocks in the Edki-Mabonji and Mbalangi-Bombe area of the Northwestern section of Douala sub-basin, Cameroon, can play an important role in the accumulation of hydrocarbon. This study integrated detailed geochemical techniques such as total organic carbon content (TOC), Total sulfur (TS), stable isotopes (δ<sup>13</sup>C<sub>org.</sub> and δ<sup>34</sup>S), elemental geochemistry, and Scanning electron microscope (SEM) to reconstruct marine paleoredox conditions, paleoweathering conditions and primary productivity thereby, promoting the understanding of the sedimentary model of organic matter accumulation and enrichment in mudrocks in the study areas. Elemental compositions and their ratios suggest that the mudrocks were dominantly derived from a source area mainly consisting of felsic igneous rock with more silica (granitic rock) than an average granodiorite. Paleoweathering proxies suggest that during sediment production, the source area experienced mostly moderate chemical weathering as a result of variation in climate and sea-level changes. The proxies to reconstruct paleoredox conditions demonstrates fluctuating redox variations from mildly suboxic-to dominantly anoxic, most probably sulphidic benthic conditions, which describes anoxic organicmudrocks sandwiched between the oxygenated sandstone/claystone strata. Paleoproductivity parameters like biogenic barium (Ba<sub>bio</sub>), TOC, P<sub>org</sub>/Al, Cu/Al and S/<sup>13</sup>C<sub>org</sub> ratios, and δ<sup>34</sup>S<sub>py</sub>, δ<sup>34</sup>S<sub>OS</sub>, δ<sup>13</sup>C<sub>org</sub> suggest that the deposition of the mudrocks was with a high primary productivity. Consequently, the conceptual model of organic matter accumulation and enrichment reveals that moderate-to high primary productivity, suboxic-to dominantly anoxic sulphidic bottom water, organo–mineral complexes, bacterial sulfate reduction (BSR) and deposition of claystone capping bed isolating the benthic sediments influenced the accumulation and preservation of organic matter at shortened exposure duration in dominantly anoxic deeper water setting.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"10 1","pages":"Article 100210"},"PeriodicalIF":2.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430174","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}
Pub Date : 2025-02-18DOI: 10.1016/j.sesci.2024.100212
Jing Sun
{"title":"Reactive transport modeling: A powerful tool for assessing the interactions between biogeochemical and hydrogeological processes","authors":"Jing Sun","doi":"10.1016/j.sesci.2024.100212","DOIUrl":"10.1016/j.sesci.2024.100212","url":null,"abstract":"","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"10 1","pages":"Article 100212"},"PeriodicalIF":2.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430213","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}
The dissolution behavior of feldspar is fundamental to understand geological processes such as surface mass cycling, chemical weathering, mineral deposition and global climate change. In this study, we select oxalic acid – one of the most popular organic acids in nature as a buffer solution to simulate the chemical weathering process of feldspar under natural environments. A total of 34 fluid–feldspar reaction experiments are performed to investigate the effects of temperature, pH, and specific surface area (SSA) on the dissolution mechanism of feldspar. Based on PHREEQC modelling of saturation index of secondary minerals, we obtain the overall dissolution rate of feldspar, which is predominantly influenced by pH and temperature, with SSA exerting a secondary effect. The dissolution rates of Na, K, Ca and Si show a positive correlation with temperature and SSA, whereas that of Al exhibits a negative correlation with SSA and a weak correlation with temperature. Based on chemical reaction kinetics, the reaction order of feldspar dissolution in oxalic acid is estimated to be approximately 0.47, suggesting that the dissolution rate of feldspar is primarily controlled by a desorption process. Our new experimental results reveal that the anomalous Al dissolution behavior, which are likely due to the formation of aluminum complexes on the feldspar surface, have potentially significant for understanding the Al enrichment mechanism during the chemical weathering of the continental crust.
{"title":"Dissolution behavior of feldspar in oxalic acid at 40–100 °C: Implications for Al enrichment during chemical weathering","authors":"Xin Huang , Feng Guo , Xing Ding , Liang Zhao , Feng Zhang , Yaqian Wen","doi":"10.1016/j.sesci.2024.100201","DOIUrl":"10.1016/j.sesci.2024.100201","url":null,"abstract":"<div><div>The dissolution behavior of feldspar is fundamental to understand geological processes such as surface mass cycling, chemical weathering, mineral deposition and global climate change. In this study, we select oxalic acid – one of the most popular organic acids in nature as a buffer solution to simulate the chemical weathering process of feldspar under natural environments. A total of 34 fluid–feldspar reaction experiments are performed to investigate the effects of temperature, pH, and specific surface area (SSA) on the dissolution mechanism of feldspar. Based on PHREEQC modelling of saturation index of secondary minerals, we obtain the overall dissolution rate of feldspar, which is predominantly influenced by pH and temperature, with SSA exerting a secondary effect. The dissolution rates of Na, K, Ca and Si show a positive correlation with temperature and SSA, whereas that of Al exhibits a negative correlation with SSA and a weak correlation with temperature. Based on chemical reaction kinetics, the reaction order of feldspar dissolution in oxalic acid is estimated to be approximately 0.47, suggesting that the dissolution rate of feldspar is primarily controlled by a desorption process. Our new experimental results reveal that the anomalous Al dissolution behavior, which are likely due to the formation of aluminum complexes on the feldspar surface, have potentially significant for understanding the Al enrichment mechanism during the chemical weathering of the continental crust.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"10 1","pages":"Article 100201"},"PeriodicalIF":2.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430216","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}
Pub Date : 2025-02-18DOI: 10.1016/j.sesci.2024.100180
ZhiYong Xu , WenQiang Ao , Yi Liu
In underground construction operations, there are different types of rocks in repeated loading and unloading environments. For this reason, in this paper, two rock samples—slate and metamorphic sandstone, which contain different properties, were subjected to cyclic splitting experiments and were analyzed for damage using scanning electron microscopy, acoustic emission (AE) and stress–strain. It can be seen that the internal grains of the slate are angular and distributed in a directional arrangement, and the metamorphic sandstone has a large difference in size and shape between the grains, and it is a small-sized nodular step-like; Slate is dominated by damage forms of single shear and conjugate shear composite damage forms, with sudden changes in cumulative energy occurring just prior to the peak stress in each cyclic phase, and in metamorphic sandstone at the location of the peak stress in each cyclic phase, and the total energy of the loading phase accounts for more than 90 per cent of the entire cycle phase; Dissipation energy obtained damage value D in the cyclic loading process, there is an obvious turning point when a large damage, and the later stages of loading damage will be more serious when the slope of slate is significantly larger than the metamorphic sandstone, the trend of change in the value of damage D is more obvious, the difference in slope between the two is nearly double, and it is more representative of the pattern of changes in the rock damage process.
{"title":"Damage analysis of rocks with different properties under cyclic splitting action","authors":"ZhiYong Xu , WenQiang Ao , Yi Liu","doi":"10.1016/j.sesci.2024.100180","DOIUrl":"10.1016/j.sesci.2024.100180","url":null,"abstract":"<div><div>In underground construction operations, there are different types of rocks in repeated loading and unloading environments. For this reason, in this paper, two rock samples—slate and metamorphic sandstone, which contain different properties, were subjected to cyclic splitting experiments and were analyzed for damage using scanning electron microscopy, acoustic emission (AE) and stress–strain. It can be seen that the internal grains of the slate are angular and distributed in a directional arrangement, and the metamorphic sandstone has a large difference in size and shape between the grains, and it is a small-sized nodular step-like; Slate is dominated by damage forms of single shear and conjugate shear composite damage forms, with sudden changes in cumulative energy occurring just prior to the peak stress in each cyclic phase, and in metamorphic sandstone at the location of the peak stress in each cyclic phase, and the total energy of the loading phase accounts for more than 90 per cent of the entire cycle phase; Dissipation energy <span><math><mrow><msubsup><mi>u</mi><mi>n</mi><mi>d</mi></msubsup></mrow></math></span> obtained damage value <em>D</em> in the cyclic loading process, there is an obvious turning point when a large damage, and the later stages of loading damage will be more serious when the slope of slate is significantly larger than the metamorphic sandstone, the trend of change in the value of damage <em>D</em> is more obvious, the difference in slope between the two is nearly double, and it is more representative of the pattern of changes in the rock damage process.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"10 1","pages":"Article 100180"},"PeriodicalIF":2.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143429763","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}
Pub Date : 2024-12-06DOI: 10.1016/j.sesci.2024.100213
Xi Liu, Xinhao Sui, Xinjian Bao, Mingyue He
{"title":"Fate of the last drops of serpentinizing fluid: Crystallization of unusual minerals","authors":"Xi Liu, Xinhao Sui, Xinjian Bao, Mingyue He","doi":"10.1016/j.sesci.2024.100213","DOIUrl":"10.1016/j.sesci.2024.100213","url":null,"abstract":"","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"10 1","pages":"Article 100213"},"PeriodicalIF":2.0,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143148021","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}
Collisional orogeny produces large volumes of tonalitic melts at two stages: first, during the oceanic subduction below the continent (continental arc), and again, during the post-collisional stage. In a polydeformed and polymetamorphosed terrain, it would be challenging to distinguish between arc tonalites and post-collisional tonalites (and their metamorphosed equivalents, enderbites). The Chhotanagpur Gneissic Complex (CGC) belongs to the EW to ENE-WSW tending, 1500 km long Grenvillian collisional belt amalgamating the North and South Indian cratonic blocks. We discuss the field disposition, petrography, mineral chemistry, geochemistry, the physical condition of crystallization and metamorphism, and the petrogenetic model of enderbites from the CGC. Enderbites sporadically occur as cm-to-dm-thick leucosomal bands in migmatitic gneisses (migmatitic enderbites) and as small stock-sized plutons (massive enderbites) intruding migmatitic gneisses. Both of these types intruded before the end of the regional deformation. Both the massive and migmatitic enderbites predominantly contain plagioclase, quartz, biotite (with a higher abundance in the migmatitic type), minor orthopyroxene, clinopyroxene, hornblende, K-feldspar, and accessories such as opaque minerals, apatite, and zircon. Garnets rarely occur in migmatitic enderbites. Thermodynamic modeling suggests a low liquidus temperature (∼750 °C), intermediate pressure of emplacement (∼5.5 kb), moderate oxygen fugacity (ΔQFM = +1 to +2), and low water (∼4.0 wt%) of the parental tonalite magma. The two enderbite types have been derived from two distinct crustal (amphibolites) sources by water-fluxed partial melting at <10 kb pressure, shallower than the garnet stability field. About 20–40 % of batch-melting of shoshonitic basaltic sources yielded migmatitic enderbites, while about 40–70 % of batch-melting of within-plate basaltic sources produced massive enderbites. Discrimination diagrams display a post-collision tectonic setting of these enderbites. The migmatitic enderbites and magma of enderbite plutons formed during regional anatexis due to thermal relaxation in the lower crust after attaining peak pressure during the decompressive phase of regional granulite facies metamorphism (1000–950 Ma) related to slab breakoff at the post-collisional stage of the orogeny. Mantle-derived magmas formed by adiabatic decompression in the upper mantle supplied the heat.
{"title":"Petrogenesis of post-collisional mesozonal enderbite in the Proterozoic Chhotanagpur Gneissic Complex, Eastern India: Implications of slab-break-off","authors":"Poulami Roy, Bapi Goswami, Ankita Basak, Chittaranjan Bhattacharyya","doi":"10.1016/j.sesci.2024.100217","DOIUrl":"10.1016/j.sesci.2024.100217","url":null,"abstract":"<div><div>Collisional orogeny produces large volumes of tonalitic melts at two stages: first, during the oceanic subduction below the continent (continental arc), and again, during the post-collisional stage. In a polydeformed and polymetamorphosed terrain, it would be challenging to distinguish between arc tonalites and post-collisional tonalites (and their metamorphosed equivalents, enderbites). The Chhotanagpur Gneissic Complex (CGC) belongs to the EW to ENE-WSW tending, 1500 km long Grenvillian collisional belt amalgamating the North and South Indian cratonic blocks. We discuss the field disposition, petrography, mineral chemistry, geochemistry, the physical condition of crystallization and metamorphism, and the petrogenetic model of enderbites from the CGC. Enderbites sporadically occur as cm-to-dm-thick leucosomal bands in migmatitic gneisses (migmatitic enderbites) and as small stock-sized plutons (massive enderbites) intruding migmatitic gneisses. Both of these types intruded before the end of the regional deformation. Both the massive and migmatitic enderbites predominantly contain plagioclase, quartz, biotite (with a higher abundance in the migmatitic type), minor orthopyroxene, clinopyroxene, hornblende, K-feldspar, and accessories such as opaque minerals, apatite, and zircon. Garnets rarely occur in migmatitic enderbites. Thermodynamic modeling suggests a low liquidus temperature (∼750 °C), intermediate pressure of emplacement (∼5.5 kb), moderate oxygen fugacity (ΔQFM = +1 to +2), and low water (∼4.0 wt%) of the parental tonalite magma. The two enderbite types have been derived from two distinct crustal (amphibolites) sources by water-fluxed partial melting at <10 kb pressure, shallower than the garnet stability field. About 20–40 % of batch-melting of shoshonitic basaltic sources yielded migmatitic enderbites, while about 40–70 % of batch-melting of within-plate basaltic sources produced massive enderbites. Discrimination diagrams display a post-collision tectonic setting of these enderbites. The migmatitic enderbites and magma of enderbite plutons formed during regional anatexis due to thermal relaxation in the lower crust after attaining peak pressure during the decompressive phase of regional granulite facies metamorphism (1000–950 Ma) related to slab breakoff at the post-collisional stage of the orogeny. Mantle-derived magmas formed by adiabatic decompression in the upper mantle supplied the heat.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"9 4","pages":"Article 100217"},"PeriodicalIF":2.0,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700557","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}
Pub Date : 2024-11-06DOI: 10.1016/j.sesci.2024.100216
Shuangfei Han , Xijun Liu , Haodong Wei , Yaoming Wei , Yao Xiao , Zhiguo Zhang
The early Paleozoic tectonic evolution of the Qinghai-Tibetan Plateau remains not fully understood. The Longmu Co-Shuanghu Suture Zone within the Qiangtang block of northern Qinghai-Tibetan Plateau, records important evidence of the early Paleozoic evolutionary history of the plateau. In this study, we investigated early Paleozoic amphibolites exposed in the Taoxinghu area of central Qiangtang, using zircon U–Pb dating, mineral chemistry, whole-rock geochemistry, and zircon Hf–O isotopes. The objective was to identify the characteristics of the protoliths and the metamorphic processes. Two types of zircons with different characteristics occur in the amphibolites, yielding zircon U–Pb ages of 490 and 440 Ma attained using kernel density estimation, which represent the ages of the protolith and subsequent metamorphism, respectively. The amphibolites have SiO2 (42.4–55.7 wt.%), and Al2O3 (14.4–18.7 wt.%) and MgO (3.62–8.80 wt.%) contents. Their geochemical characteristics show large ion lithophile elements enriched and high field strength elements depleted. The zircon U–Pb age and rock geochemical data suggest the protoliths of the amphibolites were late Cambrian supra-subduction zone-type ophiolites that organized in association with Proto-Tethyan subduction. The subsequent Late Ordovician metamorphic event might be associated with the collision between continental blocks after oceanic closure. We favor that amphibolites provide essential constraints on the early Paleozoic tectonic evolutionary history of the Qinghai-Tibetan Plateau.
{"title":"Late Ordovician amphibolites in the Taoxinghu area of central Qiangtang, northern Tibet, and their tectonic significance","authors":"Shuangfei Han , Xijun Liu , Haodong Wei , Yaoming Wei , Yao Xiao , Zhiguo Zhang","doi":"10.1016/j.sesci.2024.100216","DOIUrl":"10.1016/j.sesci.2024.100216","url":null,"abstract":"<div><div>The early Paleozoic tectonic evolution of the Qinghai-Tibetan Plateau remains not fully understood. The Longmu Co-Shuanghu Suture Zone within the Qiangtang block of northern Qinghai-Tibetan Plateau, records important evidence of the early Paleozoic evolutionary history of the plateau. In this study, we investigated early Paleozoic amphibolites exposed in the Taoxinghu area of central Qiangtang, using zircon U–Pb dating, mineral chemistry, whole-rock geochemistry, and zircon Hf–O isotopes. The objective was to identify the characteristics of the protoliths and the metamorphic processes. Two types of zircons with different characteristics occur in the amphibolites, yielding zircon U–Pb ages of 490 and 440 Ma attained using kernel density estimation, which represent the ages of the protolith and subsequent metamorphism, respectively. The amphibolites have SiO<sub>2</sub> (42.4–55.7 wt.%), and Al<sub>2</sub>O<sub>3</sub> (14.4–18.7 wt.%) and MgO (3.62–8.80 wt.%) contents. Their geochemical characteristics show large ion lithophile elements enriched and high field strength elements depleted. The zircon U–Pb age and rock geochemical data suggest the protoliths of the amphibolites were late Cambrian supra-subduction zone-type ophiolites that organized in association with Proto-Tethyan subduction. The subsequent Late Ordovician metamorphic event might be associated with the collision between continental blocks after oceanic closure. We favor that amphibolites provide essential constraints on the early Paleozoic tectonic evolutionary history of the Qinghai-Tibetan Plateau.</div></div>","PeriodicalId":54172,"journal":{"name":"Solid Earth Sciences","volume":"9 4","pages":"Article 100216"},"PeriodicalIF":2.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593125","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}
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