Acta Geologica Sinica ‐ English Edition最新文献

{"title":"Hydrocarbon Generation Potential and Organic Matter Enrichment Mechanism of the Cambrian Marine Shale in the Tadong Low Uplift, Tarim Basin","authors":"Huan MIAO,&nbsp;Yanbin WANG,&nbsp;Zhenxue JIANG,&nbsp;Shihu ZHAO,&nbsp;Peng SHANG,&nbsp;Xun GONG,&nbsp;Chuanqi TAO,&nbsp;Yu ZHANG","doi":"10.1111/1755-6724.15163","DOIUrl":"10.1111/1755-6724.15163","url":null,"abstract":"<p>Cambrian shales in China and elsewhere contain abundant oil and gas resources. However, due to its deep burial and limited outcrop, there has been relatively little research conducted on it. The Cambrian shale of the Tadong low uplift in the Tarim Basin of western China, specifically the Xidashan–Xishanbulake Formation (Fm.) and overlying Moheershan Fm. provide a case study through the use of organic petrology, mineralogy, organic and elemental geochemistry, with the aim of analyzing and exploring the hydrocarbon generation potential (PG) and organic matter (OM) enrichment mechanisms within these shale formations. The results indicate that: (1) the Cambrian shale of the Tadong low uplift exhibits relatively dispersed OM that consists of vitrinite-like macerals and solid bitumen. These formations have a higher content of quartz and are primarily composed of silica-based lithology; (2) shale samples from the Xidashan–Xishanbulake and Moheershan formations demonstrate high total organic carbon (TOC) and low pyrolytic hydrocarbon content (<i>S</i>₂) content. The OM is predominantly type I and type II kerogens, indicating a high level of maturation in the wet gas period. These shales have undergone extensive hydrocarbon generation, showing characteristics of relatively poor PG; (3) the sedimentary environments of the Xidashan–Xishanbulake and Moheershan formations in the Tadong low uplift are similar. They were deposited in warm and humid climatic conditions, in oxygen-deficient environments, with stable terrigenous inputs, high paleoproductivity, high paleosalinity, weak water-holding capacity, and no significant hydrothermal activity; and (4) the relationship between TOC and the paleoproductivity parameter (P/Ti) is most significant in the Lower Cambrian Xidashan–Xishanbulake Fm., whereas correlation with other indicators is not evident. This suggests a productivity-driven OM enrichment model, where input of land-derived material was relatively small during the Middle Cambrian, and the ancient water exhibited lower salinity. A comprehensive pattern was formed under the combined control of paleoproductivity and preservation conditions. This study provides valuable guidance for oil and gas exploration in the Tarim Basin.</p>","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"98 5","pages":"1301-1321"},"PeriodicalIF":3.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870274","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}

{"title":"Genesis of the Jianbeigou Gold Deposit on the Southern Margin of the North China Craton: Insights from Fluid Inclusions, H-O-S Isotopes, and Pyrite in situ Trace Element Analyses","authors":"Fengchun LI,&nbsp;Qingdong ZENG,&nbsp;Rixiang ZHU,&nbsp;Shaoxiong CHU,&nbsp;Wei XIE,&nbsp;Bing YU,&nbsp;Jinjian WU,&nbsp;Xinghui LI","doi":"10.1111/1755-6724.15195","DOIUrl":"10.1111/1755-6724.15195","url":null,"abstract":"<p>The Jianbeigou gold deposit is a typical lode gold deposit in the Qinling metallogenic belt, located on the southern margin of the North China Craton. Three stages of the hydrothermal process can be distinguished, including the quartz ± pyrite, quartz-polymetallic sulfide, and quartz-carbonate ± pyrite stages. From the early to late stages, the homogenization temperatures of primary fluid inclusions are 281–362°C, 227–331°C, and 149–261°C, respectively. The corresponding salinities estimated for these fluids are 3.9–9.9 wt%, 0.4–9.4 wt%, and 0.7–7.2 wt% NaCl equiv. Combined with laser Raman spectroscopy data, the ore-forming fluid belongs to a H₂O-CO₂-NaCl ± CH₄ system with medium–low temperature and salinity. The <i>δ</i>¹⁸O_fluid and <i>δ</i>D values for the quartz veins are –1.0‰ to 6.0‰ and –105‰ to –84‰, respectively, which indicates that the ore-forming fluid is of mixed source, mainly derived from magma, with a contribution from meteoric water. Pyrite has been identified into three generations based on mineral paragenetic sequencing, including Py1, Py2, and Py3. The pyrites have <i>δ</i>³⁴S sulfur isotopic compositions from three stages between 3.7‰ and 8.4‰, indicating that sulfur mainly originated from magma. Te, Bi, Sb, and Cu contents in pyrite were all high and showed a strong correlation with Au concentrations. Native gold and the Au-Ag-Bi telluride minerals were formed concurrently, and the As concentration was low and decoupled from the Au content. Therefore, Te, Bi, Sb and other low-melting point chalcophile elements play an important role for gold mineralization in arsenic-deficient ore-forming fluid. Combined with the geological setting, evolution of pyrite, and ore-fluids geochemistry, we propose that the Jianbeigou deposit can be classified as a magmatic–hydrothermal lode gold deposit. Gold mineralization on the southern margin of the North China Craton is related to Early Cretaceous magmatism and formed in an extensional setting.</p>","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"98 4","pages":"969-991"},"PeriodicalIF":3.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870275","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}

{"title":"Principle of Hydrogen Isotope Geochemistry Paleo-altimeter and its Potential in Reconstructing Paleo-elevation of the Southeastern Tibetan Plateau","authors":"Fengzhen CUI,&nbsp;Jing LIU-ZENG,&nbsp;Yunshuai LI,&nbsp;Qiang XU,&nbsp;Maoyun TANG,&nbsp;Heng WANG,&nbsp;Zhaotong SUN","doi":"10.1111/1755-6724.15196","DOIUrl":"10.1111/1755-6724.15196","url":null,"abstract":"<p>The reconstruction of paleo-elevation serves a dual purpose to enhance our comprehension of geodynamic processes affecting terrestrial landforms and to contribute significantly to the interpretation of atmospheric circulation and biodiversity. The oxygen (<i>δ</i>¹⁸O_w) and deuterium (<i>δ</i>D_w) isotopes in atmospheric precipitation are systematically depleted with the increase of altitude, which are typical and widely applicated paleo-altimeters. The utilization of hydrogen isotope of hydrous silicate minerals within the shear zone system, volcanic glass, and plant leaf wax alkanes offers valuable insights for addressing evaporation and diagenesis. In this paper, we review the principle, application conditions, and influencing factors of the hydrogen isotope paleo-altimeter. In addition, we discuss the feasibility of utilizing this technique for quantitatively estimating the paleo-elevation of the southeastern Tibetan Plateau, where multiple shear zones extend over hundred kilometers parallel to the topographic gradient.</p>","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"98 4","pages":"1051-1063"},"PeriodicalIF":3.5,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870276","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}

{"title":"Cognate Mafic Enclaves Formed by Cumulated Mush Convection in a Granitic Magma Chamber: Evidence from Mineral Chemistry of the Triassic Zhashui Pluton, Qinling Orogen","authors":"Hongbing ZHANG, Xuchen ZHOU, Shaocong LAI, Hua ZHANG, Jiangfeng QIN","doi":"10.1111/1755-6724.15194","DOIUrl":"https://doi.org/10.1111/1755-6724.15194","url":null,"abstract":"Mafic enclaves in granites are generally considered to represent coeval mafic melts that derived from metasomatized mantle, which can provide valuable information about crust–mantle interaction. Exploring the genetic links between the mafic enclaves and their host monzogranite from the Triassic Zhashui Pluton, Qinling orogenic belt. The enclaves (220 ± 4.6 Ma) and the monzogranite (220 ± 2.8 Ma) display identical zircon U‐Pb ages, and they also share similar trace element and zircon Lu‐Hf isotopes, indicating a cognate source. The monzogranite displays zircon <jats:italic>ε</jats:italic><jats:sub>Hf</jats:sub>(<jats:italic>t</jats:italic>) values of –0.99 to +1.98, while the mafic enclaves show similar values of –0.45 to +3.26; however, differences in mineral chemistry reveal different crystallization conditions. The amphibole from the mafic enclaves has higher temperature and pressure (757°C; 2.65 kbar) compared to those of the host monzogranite (733°C; 1.96 kbar), suggesting that mafic minerals in the enclaves crystallized at an early stage. Moreover, apatite in the mafic enclaves displays slightly higher volatile contents (0.72 wt%) than those of the monzogranite (0.66 wt%), indicating a volatile‐rich condition. These results suggest that the mafic enclaves represent early hydrous mafic cumulates in the granitic chamber, and subsequent magma convection would have led to the formation of the mafic enclaves.","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"6 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141870273","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}

{"title":"Origin of Felsic Microgranitoid Enclaves in Granite in Zhangjiakou District, China: Implication for Process and Lifespan of Granitic Magma Chambers","authors":"Dazhao WANG, Yuhang LIU, Chengbiao LENG, Shimin ZHEN, Jiajun LIU, Zhongjian ZHA","doi":"10.1111/1755-6724.15183","DOIUrl":"https://doi.org/10.1111/1755-6724.15183","url":null,"abstract":"Sparse felsic microgranitoid enclaves (FMEs) in the Shangshuiquan granite of the Zhangjiakou district, the north margin of the North China Craton, are fine‐grained, dark‐colored and exhibit subangular to subspherical shapes. They share similar mineral assemblages, chemical compositions, and zircon Hf isotope compositions to the host granite. New zircon U‐Pb geochronology reveals that the FMEs crystallized at 156–153 Ma, while the Shangshuiquan granite formed at ca. 146 Ma. The FEMs are, therefore, 10 to 7 Ma older than the host granite. Combined with petrological evidence, we suggest that the FMEs are fragments of rapidly crystalized magmas, which were captured by the younger Shangshuiquan magma. Magmas of the FMEs and Shangshuiquan granite originated from the same reservoir. The Shangshuiquan granite is the result of small batches of magma being built up incrementally, and the FMEs belong to the earlier batches of magma. The lifespan of the Shangshuiquan magma reservoir exceeds 10 Ma. FMEs derived from cogenetic fragments have the potential to offer critical information about the formation process and timescale of granitic plutons.","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"47 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717514","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}

{"title":"The Early Mesozoic NE–SW Extensional Model and Exhumation Processes at the Southeastern Margin of the Central Asian Orogenic Belt: Insights from the Strain and Kinematic Vorticity Analysis of the Sonid Zuoqi Ductile Detachment Zone","authors":"Jianbo LI,&nbsp;Zhijie SONG,&nbsp;Hengcong LEI,&nbsp;Tao ZENG","doi":"10.1111/1755-6724.15191","DOIUrl":"10.1111/1755-6724.15191","url":null,"abstract":"<p>The Sonid Zuoqi ductile detachment zone is located at the southeastern margin of the Central Asian orogenic belt (CAOB), striking EW and dipping to the S. The major rock type of the Sonid Zuoqi ductile detachment zone is mylonite derived from granite. The sequence of mylonite features is: (1) S and C foliations of mylonite, and (2) extensional crenulation cleavage (ecc) or C' and the kinematic vorticity <i>(W_k)</i> value changed from 0.70 to 0.95 and from 0.37 to 0.69, respectively; the strain type of the mylonites within the Sonid Zuoqi ductile detachment zone is compressional to planar strain. The strong deformation mylonite and Halatu plutons yielded a zircon U-Pb age of 244 Ma and a zircon (U-Th)/He age of 214 Ma, respectively. Based on the strain and kinematic vorticity analysis, together with the zircon U-Pb and zircon (U-Th)/He ages and the regional tectonic background, the study area experienced three stage evolution: tangential simple-shear (244 Ma), simple-shear-dominated general shear represented by upper crustal extension (224 Ma) and pure–shear–dominated general shear represented by the Halatu pluton doming (214 Ma), which constrained the early Mesozoic NE-SW crustal extension at the southeastern margin of the CAOB. This NE-SW extension probably originated from the post-orogenic extensional collapse of the CAOB, subsequent exhumation being controlled by the far afield effects of the closure of the Mongol-Okhotsk belt.</p>","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"98 5","pages":"1141-1153"},"PeriodicalIF":3.5,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141722001","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}

{"title":"Geochronology and Petrogenesis of Late Carboniferous to Early Permian Basalts in the Central Lhasa Subterrane, Southern Tibet: Implications for the Evolution of the Sumdo Paleo-Tethys Ocean","authors":"Wang MA,&nbsp;Yingchao LIU,&nbsp;Zhusen YANG,&nbsp;Jan-Marten HUIZENGA,&nbsp;Zhenqing LI,&nbsp;Longlong YUE,&nbsp;Sibo ZHAO","doi":"10.1111/1755-6724.15178","DOIUrl":"10.1111/1755-6724.15178","url":null,"abstract":"<p>Basalts from the Late Carboniferous to Early Permian are extensively developed in the central Lhasa subterrane, southern Tibet. Studying the petrogenesis of these rocks may have implications for the late Paleozoic arc magmatism along the central Lhasa subterrane uncovering more of the evolution of the Sumdo Paleo-Tethys Ocean and its dynamic mechanism. Basalt samples from the Luobadui Formation in the Leqingla area, NW of Linzhou City in the central Lhasa subterrane, southern Tibet exhibit arc-like geochemical signatures in a subduction-zone tectonic setting characterized by high Al₂O₃ and low TiO₂ contents, fractionated REE patterns with low Nb/La ratios and high LREE concentrations, and negative HFSE anomalies. Based on their higher Th/Ce, Nb/Zr, and lower Ba/Th, Pb/Nd ratios, slightly negative to positive <i>ε</i>_Nd(<i>t</i>) values, and the relatively high Sr-Pb isotopic compositions, these samples were probably derived from partial melting of a depleted mantle source of garnet + spinel lherzolite, metasomatized by subducted sediments around 297 Ma. Modeling of the trace elements indicates that these basalts experienced fractional crystallization of olivine, clinopyroxene and minor plagioclase during magma ascent and eruption. It is proposed that these Late Carboniferous–Early Permian basalts are associated with the northward subduction of the Sumdo Paleo-Tethys Ocean seafloor along the southern margin of the central Lhasa subterrane.</p>","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"98 4","pages":"955-968"},"PeriodicalIF":3.5,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717489","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}

{"title":"The Geology, Fluid Inclusions, and O-S Isotopes of the Mibei Gold Deposit, Hunan Province, Southern China","authors":"Wenhao XUE,&nbsp;Yayun LIANG,&nbsp;Xiaofeng LI,&nbsp;Mingyi LI,&nbsp;Wenbo XIE,&nbsp;Xue PENG,&nbsp;Rui XIA,&nbsp;Hongsheng HE,&nbsp;Jincheng XIAO","doi":"10.1111/1755-6724.15184","DOIUrl":"10.1111/1755-6724.15184","url":null,"abstract":"<p>The Mibei gold deposit, located in the southwestern part of the Xuefengshan uplift zone, the middle section of the Jiangnan orogenic belt in southern China, has estimated gold resources of approximately seven tons. This deposit is primarily a quartz vein-type gold deposit, with ore bodies occurring mainly within Neoproterozoic metasediments. The main metallic minerals in the ore are pyrite, chalcopyrite, and arsenopyrite. In this study, the petrography and microthermometry of ore-forming fluid inclusions, oxygen isotopes of gold-bearing quartz, and sulfur isotopes of gold-bearing sulfides and arsenopyrite were analyzed. Three types of fluid inclusions were identified: type Ia three-phase inclusions comprising vapor and two phases of liquids (V_CO2 + L_CO2 + L_H2O), type Ib two-phase liquids (L_CO2 + L_H2O), type II two-phase vapor-rich inclusions (V/V + L &gt; 50%), and type III pure liquid inclusions. Type I inclusions were heated uniformly to the liquid phase, type II inclusions were heated uniformly to the gas phase, and type III inclusions were heated without change. In general, the temperature range of homogenization to liquid phase of fluid inclusions in the Mibei gold deposit is 204–227°C. The salinity of the inclusion ranges from 4.6 to 12.2 wt% NaCl equiv. The <i>δ</i>¹⁸O_SMOW of gold-bearing quartz varies from 16.9‰ to 17.5‰. The <i>δ</i>¹⁸O_H2O of gold-bearing quartz are varied from 6.5‰ to 7.5‰. The <i>δ</i>³⁴S values of gold-bearing pyrite range from 1.7‰ to 6.8‰. The <i>δ</i>³⁴S values of gold-bearing arsenopyrite range from 5.6‰ to 5.9‰. The <i>δ</i>³⁴S values of pyrite from wall rocks slate range from 6.4‰ to 11.6‰. This evidence implies that the ore-forming fluids of the Mibei gold deposit originated from magmatic-hydrothermal processes, mixing with minor S from the surrounding metasediments. Combined with the evolution of the Jiangnan orogenic belt, due to the magmatic and tectonic activities of the Xuefengshan uplift during the Caledonian period, the fault seal mechanism controlled the ore-forming process. Overall, the Mibei gold deposit is more akin to a magmatic-hydrothermal gold deposit.</p>","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"98 4","pages":"992-1006"},"PeriodicalIF":3.5,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141717490","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}

{"title":"Geochemical and Isotopic Techniques Constraints on the Origin, Evolution, and Residence Time of Low-enthalpy Geothermal Water in Western Wugongshan, SE China","authors":"Luyao WANG,&nbsp;Kai LIU,&nbsp;Yan MA,&nbsp;Yaoyao ZHANG,&nbsp;Jue TONG,&nbsp;Wuhui JIA,&nbsp;Shouchuan ZHANG,&nbsp;Junliang SUN","doi":"10.1111/1755-6724.15161","DOIUrl":"https://doi.org/10.1111/1755-6724.15161","url":null,"abstract":"<p>Geothermal resources are increasingly gaining attention as a competitive, clean energy source to address the energy crisis and mitigate climate change. The Wugongshan area, situated in the southeast coast geothermal belt of China, is a typical geothermal anomaly and contains abundant medium- and low-temperature geothermal resources. This study employed hydrogeochemical and isotopic techniques to explore the cyclic evolution of geothermal water in the western Wugongshan region, encompassing the recharge origin, water–rock interaction mechanisms, and residence time. The results show that the geothermal water in the western region of Wugongshan is weakly alkaline, with low enthalpy and mineralization levels. The hydrochemistry of geothermal waters is dominated by Na-HCO₃ and Na-SO₄, while the hydrochemistry types of cold springs are all Na-HCO₃. The hydrochemistry types of surface waters and rain waters are Na-HCO₃ or Ca-HCO₃. The <i>δ</i>D and <i>δ</i>¹⁸O values reveal that the geothermal waters are recharged by atmospheric precipitation at an altitude between 550.0 and 1218.6 m. Molar ratios of major solutes and isotopic compositions of ⁸⁷Sr/⁸⁶Sr underscore the significant role of silicate weathering, dissolution, and cation exchange in controlling geothermal water chemistry. Additionally, geothermal waters experienced varying degrees of mixing with cold water during their ascent. The <i>δ</i>¹³C values suggest that the primary sources of carbon in the geothermal waters were biogenic and organic. The <i>δ</i>³⁴S value suggests that the sulfates in geothermal water originate from sulfide minerals in the surrounding rock. Age dating using ³H and ¹⁴C isotopes suggests that geothermal waters have a residence time exceeding 1 kaBP and undergo a long-distance cycling process.</p>","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"98 3","pages":"801-818"},"PeriodicalIF":3.5,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488449","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}

{"title":"The Weixi High-silica Granitoids in the Central Sanjiang Orogenic Belt, Southwest China: Implications for Growth of the Continental Crust","authors":"Qiuyu WANG,&nbsp;Shouming CHEN,&nbsp;Hongrui ZHANG,&nbsp;Saisai LI","doi":"10.1111/1755-6724.15182","DOIUrl":"https://doi.org/10.1111/1755-6724.15182","url":null,"abstract":"<p>High-silica granitoids record the formation and evolution of the continental crust. A new intrusive complex has been recognized among silicic volcanic rocks of the Weixi arc, Southwest China. The intrusions consist of granites, granitic porphyries, and granodiorites. Zircon U-Pb age data indicate that the Weixi granitoids formed at 248–240 Ma and were coeval with silicic volcanic rocks of the Weixi arc. The Weixi granitoids are enriched in Rb, Th, and U, depleted in Ba, Sr, Nb, Ta, and Ti, and have high light/heavy rare earth element ratios and slightly negative Eu anomalies. The Weixi granitoids have negative <i>ε</i>_Nd(<i>t</i>) values (–9.8 to –7.8) and negative zircon <i>ε</i>_Hf(<i>t</i>) values (–12.02 to –5.11). The geochemical and isotopic features suggest the Weixi granitoids were derived by partial melting of ancient crustal material. The Weixi granitoids and silicic volcanic rocks were derived from the same magma by crystal accumulation and melt extraction, respectively, and they record the formation of a continental arc in the central Sanjiang orogenic belt.</p>","PeriodicalId":7095,"journal":{"name":"Acta Geologica Sinica ‐ English Edition","volume":"98 3","pages":"641-656"},"PeriodicalIF":3.5,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141488451","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}