Ore Geology Reviews最新文献

{"title":"The characteristics of S-wave velocity and mineralization of the “Double Domes” structure in the eastern of the Tethys Himalaya","authors":"Guangwen Wang ,&nbsp;Zhanwu Lu ,&nbsp;Wenhui Li ,&nbsp;Tairan Xu ,&nbsp;Shuai Xue ,&nbsp;Yao Liang ,&nbsp;Yongzhi Cheng ,&nbsp;Si Chen ,&nbsp;Guan Wang ,&nbsp;Wei Cai ,&nbsp;Lifu Cao ,&nbsp;Guowei Wu","doi":"10.1016/j.oregeorev.2024.106225","DOIUrl":"10.1016/j.oregeorev.2024.106225","url":null,"abstract":"<div><p>The Tethys Himalayan belt in the southern Qinghai–Tibet Plateau has been intruded by a large amount of leucogranite due to collisional orogeny. In addition, strong tectonic movements since the Cenozoic era have led to the formation of a series of dome structures accompanied by various types of mineralization. The Cuonadong Dome and Yalaxiangbo Dome, forming the “double dome” structure in the eastern part of the Tethys Himalayan Belt, are affected by different geological processes, resulting in differences in their deep structures and affecting the formation of polymetallic minerals. At present, geophysical research on the fine structure of the crust of the “double dome” structure is limited, making it difficult to fully understand the formation of different deep structures in the Tethys Himalayan dome belt. This hinders the progress of research on the genesis of dome structures and large-scale mineralization mechanisms in continental collisional environments. In this study, the ambient noise tomographic method was used to obtain the S-wave velocity structure of the upper crust of the Cuonadong Dome and the Yalaxiangbo Dome, and the following results were found: 1. there is a significant difference in the velocity structures of the two domes, with the core velocity structure of the Yalaxiangbo Dome showing an overall high velocity, extending downward for more than 9 km, while the core of the Cuonadong Dome exhibits low-velocity characteristics, with some high-velocity bodies occurring locally, which may be related to the later intrusion of leucogranite and extensional activity of the Cuona Rift. 2. There are significant differences in the S-wave velocities between the lead–zinc deposits and rare metal deposits in the study area; the lead–zinc deposits occur in basins and graben margins and have large variations in the S-wave velocity, which may be related to the involvement of basin brine in mineralization; below the tungsten–tin–beryllium deposits, the S-wave velocity exhibits high-velocity protrusions, with mineralization occurring at the front ends of the protrusions, which may be caused by crystallization differentiation of leucogranite. 3. The study area has abundant geothermal resources and obvious geothermal structural features. The low-velocity basin in the upper part of the upper crust is a heat storage layer, the low-velocity channel in the middle is a heat-conducting layer, and the lower part is a low-velocity heat source area that continuously supplies heat, forming a special geothermal structural model for the Cuonadong Dome and Yalaxiangbo Dome.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106225"},"PeriodicalIF":3.2,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003585/pdfft?md5=879a68e669a3c069fbba6e63477df49d&pid=1-s2.0-S0169136824003585-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Machine learning on white mica short-wave infrared (SWIR) spectral data in the Tengjia Au deposit, Jiaodong peninsula (Eastern China): A prospecting indicator for lode gold deposits","authors":"Jiayao Hao ,&nbsp;Liuan Duan ,&nbsp;Yu Zhang ,&nbsp;Hongtao Zhao ,&nbsp;Yongjun Shao ,&nbsp;Yuncheng Guo ,&nbsp;Xu Wang ,&nbsp;Shuling Song","doi":"10.1016/j.oregeorev.2024.106230","DOIUrl":"10.1016/j.oregeorev.2024.106230","url":null,"abstract":"<div><p>Lode gold deposits are the primary source of global gold resources and possess significant mineralization potential at depth, necessitating new strategies to locate deep concealed orebodies. The Tengjia Au deposit, a newly-discovered concealed altered rock-type lode gold deposit (50 t @ 3.89 g/t), is located within the Zhaoping metallogenic belt of the illustrious gold-rich Jiaodong peninsula in Eastern China. It is distinguished by pervasive phyllic alteration associated with gold mineralization, making it an ideal target for mineral geochemical exploration in lode gold deposits. The mineralization and alteration at Tengjia unfold across three distinct stages, delineated by mineral assemblages and textural relationships: K-feldspar-quartz (I), quartz-sericite-native gold-sulfide (Ⅱ), quartz-calcite-galena-sphalerite (Ⅲ) stages.</p><p>Systematic analysis of short wavelength infrared (SWIR) spectra, coupled with petrographic observation, has unveiled an abundance of white micas (montmorillonite, muscovite, illite, paragonite, and phengite) within Stage Ⅱ at Tengjia. The Al-OH absorption feature wavelengths (Pos2200), as well as illite crystallinity (IC) values, exhibit a discernible shift towards longer wavelengths (&gt;2204 nm) and higher values (&gt;1.4) in the vicinity of ore deposition, which likely resulted from intense water–rock interaction between ore-forming fluid and wall rocks. Discriminant analysis of the orthogonal partial least squares method (OPLS-DA) shows that the absorption wavelengths corresponding to Water, –OH, and Al-OH effectively differentiate between ore and wall-rock samples. Additionally, analysis using the random forest algorithm (RF) demonstrates that spectral data from Tengjia white micas can reliably classify orebodies, achieving an accuracy of 83.2 %. Hence, the findings suggest that the unique SWIR spectral features of white micas offer a valuable tool for detecting the concealed Tengjia gold mineralization. This study proposes a novel approach that integrates machine learning technology with SWIR analysis for the identification of concealed lode gold deposits.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106230"},"PeriodicalIF":3.2,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003639/pdfft?md5=bea7b47a5b557e28c2051032120278aa&pid=1-s2.0-S0169136824003639-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142232657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Metallogenic model of the Lykling ophiolite-hosted lode Au deposit, Scandinavian Caledonides: Insight from fluid inclusions, mineral chemistry and stable isotope geochemistry","authors":"Sabina Strmić Palinkaš ,&nbsp;Frida Riple Forsberg ,&nbsp;Rolf Birger Pedersen ,&nbsp;Håvard Hallås Stubseid ,&nbsp;Seán H. McClenaghan ,&nbsp;Jorge E. Spangenberg","doi":"10.1016/j.oregeorev.2024.106227","DOIUrl":"10.1016/j.oregeorev.2024.106227","url":null,"abstract":"&lt;div&gt;&lt;p&gt;The Lykling lode Au deposit represents a unique example of gold mineralization in the Upper Allochthone of the Scandinavian Caledonides. The mineralization is hosted by the Early Ordovician Lykling Ophiolite Complex and the intruding trondhjemite unit and spatially associated with two generations of mafic dykes that crosscut both the ophiolitic complex and trondhjemite. Field observations indicate that the mafic dykes did not play an active role in the emplacement of Au at Lykling, however their contacts with the immediate host rocks (i.e., gabbro and trondhjemite) may have focused ore-forming fluids.&lt;/p&gt;&lt;p&gt;Three main stages in the evolution of the hydrothermal system in the Lykling area are documented by two generations of auriferous quartz veins: 1) older quartz-carbonate veins hosted by moderately angled brittle-ductile shear zones and 2) younger quartz-sulfide veins that fill steeply dipping brittle faults. Stage 1 resulted in deposition of barren quartz and gold-free pyrite from moderately saline NaCl-CaCl&lt;sub&gt;2&lt;/sub&gt;-H&lt;sub&gt;2&lt;/sub&gt;O ± CO&lt;sub&gt;2&lt;/sub&gt; fluids at temperatures between ∼310–330 °C and pressures in the range from 2.7 to 3.5 kbars. Under the given physicochemical conditions Au was mobile in the form of its chloride complexes. Stage 2 is associated with multiple episodes of ductile deformation punctuated by concomitant brecciation reflecting brittle-ductile transition processes. Fluid inclusion data reveals a decrease in temperature and pressure that may result in the formation of stable Au-bisulfide complexes and making the hydrothermal mobility of Au sensitive to changes in pressure. Consequently, the fluctuation in pressure controlled by the development of brittle-ductile structures likely resulted in the precipitation of native gold in quartz veins. Stage 3 represents a pure brittle event which is accompanied by a significant decrease in the &lt;em&gt;f&lt;/em&gt;CO&lt;sub&gt;2&lt;/sub&gt;/&lt;em&gt;f&lt;/em&gt;S&lt;sub&gt;2&lt;/sub&gt; ratio. Mixing of higher-temperature and moderate-salinity fluids with cooler fluids has been recognized as the principal trigger for deposition of sulfides and a paragenetically late phase of native gold in the Lykling hydrothermal system.&lt;/p&gt;&lt;p&gt;The Lykling ophiolite-hosted lode Au deposit shows numerous similarities with orogenic gold deposits elsewhere, including structural controls during mineralizing events, deposition from moderately to low salinity CO&lt;sub&gt;2&lt;/sub&gt;-bearing aqueous solutions, deposition from a focused fluid flow along &lt;em&gt;trans&lt;/em&gt;-crustal fault zones with a mixed brittle-ductile character and the spatial association with regionally metamorphosed terranes. In contrast to the great majority of the known orogenic gold deposits, the Lykling ophiolite-hosted lode Au deposit records a magmatic origin of volatiles. Therefore, taking into consideration field relationships and the regional setting of the Lykling deposit, we argue that its formation is concomitant with emplacement of the Sunnhordland Batholith during post-co","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106227"},"PeriodicalIF":3.2,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003603/pdfft?md5=723e57e8dc68b51b9800f15e3e2c3ef9&pid=1-s2.0-S0169136824003603-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142239616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Unraveling the genesis of wolframite mineralization in the West Qinling Belt, China: Evidence from geochronology, geochemistry, and fluid inclusion study","authors":"Jize Li ,&nbsp;Jiajun Liu ,&nbsp;Emmanuel John M. Carranza ,&nbsp;Degao Zhai ,&nbsp;Delong Zhao ,&nbsp;Yanwen Tang ,&nbsp;Xi Diao ,&nbsp;Fangfang Zhang ,&nbsp;Yinhong Wang ,&nbsp;Jianping Wang","doi":"10.1016/j.oregeorev.2024.106229","DOIUrl":"10.1016/j.oregeorev.2024.106229","url":null,"abstract":"<div><p>The West Qinling Belt is a pivotal part of the Central China Orogenic Belt renowned for producing abundant Au-polymetallic deposits. Nonetheless, reports of wolframite mineralization within this region were absent. The Xuehuashan deposit is the premier documented quartz-vein type wolframite deposit in West Qinling, which has significant implications of W mineralizing potential in the West Qinling Belt. The ore bodies are predominantly composed of wolframite-quartz veins and/or veinlets which are proximal or within the Late Triassic Baijiazhuang granitoid. To elucidate the age and genesis of the Xuehuashan wolframite mineralization, we presented analyses of U-Pb dating and chemical composition on wolframite, fluid inclusion study, and hydrogen–oxygen isotopes on wolframite and quartz. The Xuehuashan wolframite U-Pb dating yielded an age of 213.0 ± 6.7 Ma, which is consistent with the age of the Baijiazhuang granitoid. The correlation among trace elements and the Y/Ho vs. Zr/Hf diagram suggests trace elements in wolframite were influenced by crystalline chemical factors and the geochemistry of parental ore-forming fluid. Homogeneous texture and stable chemical composition of wolframite, as well δD vs. δ¹⁸O isotopes, suggest a single magmatic fluid from the Baijiazhuang granitoid. Fluid inclusions in wolframite and quartz have high homogenization temperatures and varying salinities of 0.4 – 16.4 wt%, suggesting that intense decompression and fluid boiling during fracture open caused the wolframite precipitation. Compared with the Late Triassic granitoids in the Qinling Belt, the Baijiazhuang granitoid shows higher ratios of Rb/Sr and lower ratios of Zr/Hf, K/Rb, Nb/Ta, LREE/HREE, as well as negative Eu anomalies, which are consistent with the W-related highly evolved granitoids but distinct to W-barren granitoids. Hence, this study highlights W mineralization potential in the Qinling belt associated with the highly evolved Late Triassic granitoids.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106229"},"PeriodicalIF":3.2,"publicationDate":"2024-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003627/pdfft?md5=96bb92dc5ca84ae1276bd412d692e94d&pid=1-s2.0-S0169136824003627-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142230435","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Identifying the genesis of hydrothermal activities in the Xiangcheng fault belt, southwestern China: Evidence from hydrochemistry and stable isotopes","authors":"Jinhang Huang ,&nbsp;Yunhui Zhang ,&nbsp;Chengdong Deng ,&nbsp;Xingze Li ,&nbsp;Xiaoyan Zhao ,&nbsp;Tao Feng ,&nbsp;Ying Wang ,&nbsp;Yangshuang Wang","doi":"10.1016/j.oregeorev.2024.106221","DOIUrl":"10.1016/j.oregeorev.2024.106221","url":null,"abstract":"<div><p>Regional faults are beneficial structures for the formation of hydrothermal activities and have thus become target areas for geothermal resource utilization. Numerous hydrothermal activities have been reported along the Xiangcheng fault belt, particularly concentrating in the Batang, Xiangcheng and Shangri-La areas. In this study, hydrochemistry and stable isotopes were used to identify the genesis of hydrothermal activities in the Xiangcheng fault belt. The pH values of the geothermal water in these regions gradually decreases in this order, while the total dissolved solids gradually increase. The δD and δ¹⁸O values indicate the geothermal waters are mainly originated from snowmelt water and meteoric water. The recharge elevation of geothermal waters in Batang, Xiangcheng, and Shangri-La was 4415–4904 m, 4585–5038 m, and 3673–3969 m, respectively. Most geothermal waters belong to the hydrochemical type HCO₃-Na, however some Batang geothermal water is of the SO₄·HCO₃-Na type, influenced by deep geothermal gas, and some Shangri-La geothermal water is of HCO₃-Ca·Na type, influenced by shallow cold water and dissolution of carbonate rocks. Correlations of major ions suggest that HCO₃-Na type geothermal waters are determined by the dissolution of paragonite, K-feldspar and albite as well as positive ion exchange. According to Na-K-Mg triangle diagram and mineral saturation indices, the geothermal waters do not reach full equilibrium and are mixed with shallow cold. Geothermometers, including cationic and SiO₂, and geochemical thermodynamic calculations indicate that the deep and shallow reservoir temperatures are 200–240 °C and 169–193 °C for the Batang area, 194–201 °C and 119–131 °C for the Xiangcheng area, and 156–178 °C and 100–109 °C for the Shangri-La area. Conceptual models of the genesis of hydrothermal activities in the Batang, Xiangcheng, and Shangri-La areas were constructed, respectively. CaCO₃ scaling is dominated in the study area. The hydrothermal activities of Batang and Xiangcheng areas with enriched deep materials and high reservoir temperatures are beneficial for rare-alkali metal (e.g., Li). The findings of this study provide a scientific basis for the development and utilization of geothermal resources in the high-temperature hydrothermal activity areas of western Sichuan.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106221"},"PeriodicalIF":3.2,"publicationDate":"2024-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003548/pdfft?md5=aa4d3c55d2abcea9abf96ccd4a2b5147&pid=1-s2.0-S0169136824003548-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142167648","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Mechanisms of Co enrichment in the Zhubu Ni–Co–PGE deposit in the Emeishan LIP, SW China: Constraints from mineral geochemistry and Fe–S isotopes of sulfides","authors":"Yawen Bao ,&nbsp;Mingjie Zhang ,&nbsp;Hongfu Zhang ,&nbsp;Yantong Feng ,&nbsp;Xiaofei Li ,&nbsp;Jie He","doi":"10.1016/j.oregeorev.2024.106224","DOIUrl":"10.1016/j.oregeorev.2024.106224","url":null,"abstract":"<div><p>The Zhubu Ni–Co–PGE sulfide deposit in the Permian Emeishan Large Igneous Province (LIP), SW China is hosted by a mafic–ultramafic intrusion that comprises two morphologically distinct ore-forming spaces: a central, layered sequence that represents a magma chamber surrounded by a marginal sub-vertical conduit zone. The marginal conduit zone contains significant Ni–Co–PGE sulfide mineralization, suggesting that high volumes of sulfide-bearing silicate melt flowed through the magma conduit system. Determining the hosts of Co is key to understanding the Co enrichment process in the Zhubu deposit, as well as in the Emeishan LIP as a whole. We assess this here using the geochemistry and Fe–S isotope compositions of sulfides in the Zhubu deposit. Cobalt is mainly concentrated in pentlandite sulfide in the websterite, with Co contents increasing in the order pyrrhotite &lt; chalcopyrite &lt; pyrite &lt; pentlandite &lt; violarite; the abundance of violarite, however, is notably lower than that of the other sulfides. The Co contents of pentlandite, pyrite, and chalcopyrite are negatively correlated with their Ni and Fe contents, suggesting that Co substitutes isomorphically for Ni and Fe in the sulfide structure. The δ⁵⁶Fe values of sulfides increase in the order pyrrhotite &lt; chalcopyrite &lt; pentlandite &lt; pyrite resulted from kinetic fractionation of Fe isotopes. The δ⁵⁶Fe values of pentlandite and chalcopyrite in lherzolite are higher than those in websterite, implying that lherzolite and websterite formed in compositionally distinct magmas, Fe isotope compositions become heavier with crystal fractionation. The δ³⁴S values of sulfides increase in the order pyrrhotite &lt; pentlandite &lt; chalcopyrite &lt; pyrite, similar to the fractionation sequence of sulfide melts, suggesting that externally derived S was added to the magma and contributed to its sulfide saturation. The Co contents of chalcopyrite and pyrite vary positively with δ⁵⁶Fe values, and negatively with δ³⁴S values, indicating that the addition of externally derived S and resulting sulfide segregation were critical to Co enrichment.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106224"},"PeriodicalIF":3.2,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003573/pdfft?md5=49a4512b8ee4e8f2a7d11e0d6c2bbfee&pid=1-s2.0-S0169136824003573-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142271515","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Advanced soil-gas geochemical exploration methods for orogenic gold deposits: A case study of Chalapu deposit, Xizang","authors":"Xiaofang Dou ,&nbsp;Youye Zheng ,&nbsp;Shunli Zheng ,&nbsp;Xin Chen","doi":"10.1016/j.oregeorev.2024.106226","DOIUrl":"10.1016/j.oregeorev.2024.106226","url":null,"abstract":"<div><p>Orogenic gold deposits play a significant role in the world’s gold reserves, and their distinctive characteristics pose challenges for exploration. The low sulfide content and narrow, fault-controlled sulfide-quartz veins hinder the use of traditional mineral exploration methods to locate deeply buried ore bodies, particularly in regolith-covered areas. Enhanced methods are required to detect deposits at greater depths. Soil gas composition shows promising potential for mineral exploration by conveying information about sulfur-rich and carbon-rich gases related to deep-seated mineralization into surface soils. However, the prospects of this method for gold deposits remain uncertain. In this study, a novel method was introduced to perform an integrated H₂S, SO₂, CH₄, and CO₂ soil-gas geochemical survey on gold ore bodies of different scales at the Chalapu deposit in Tibet. The results unveiled notable gas geochemical anomalies of H₂S, SO₂, CH₄, and CO₂ above the multi-layered or thick gold ore bodies. For instance, on exploration line 16 at point A1607, H₂S reached the regional maximum value of 1.064 ppm, coinciding with the surface exposure of the thickest gold ore body, measuring 19.81 m. While the presence of CH₄ and CO₂ anomalies alone may not signify potential mineralized zones, the combined presence of anomalous H₂S and SO₂ values along with CH₄ and CO₂ concentrations appears to be effective in identifying mineralization. These combinations of geochemical anomalies not only uncover concealed ore bodies, but also delineate the trend and extension direction in strike and dip of ore bodies. Gas intensity may provide insights into the scale of the ore bodies, with stronger gas anomalies observed in areas with thicker ore bodies at similar depths. Thus, the study reveals that soil-gas exploration shows great promise as an exploration technique for orogenic gold deposits, especially in areas with regolith cover hindering traditional methods from detecting mineralized zones for gold exploration.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106226"},"PeriodicalIF":3.2,"publicationDate":"2024-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003597/pdfft?md5=e846cbdda7026a64a7f9c2484bb529b8&pid=1-s2.0-S0169136824003597-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Alteration and mineralization of the giant Pulang porphyry Cu–Au deposit, southwest China: Evidence from biotite mineralogy","authors":"Jia-Wen Jiang ,&nbsp;Hai-Jun Yu ,&nbsp;Wen-Chang Li","doi":"10.1016/j.oregeorev.2024.106222","DOIUrl":"10.1016/j.oregeorev.2024.106222","url":null,"abstract":"<div><div>The Pulang porphyry Cu–Au deposit is the largest Indosinian porphyry Cu deposit in the Geza porphyry belt. Magmatic and hydrothermal biotite crystals are widely distributed across ore bodies in the central part of the deposit. Determining the compositions of these biotite crystals can help us to understand the ore-forming fluids and processes. Here we present chemical analyses of biotite from samples collected from the ZK0406 borehole, which traverses the center of the ore bodies and the various alteration zones. We identified three types of biotite (types<!--> <!-->I, II, and<!--> <!-->III). Type<!--> <!-->I biotite is primary magmatic biotite and is surrounded by limited chalcopyrite. Type<!--> <!-->II biotite is alterated biotite surrounded by chalcopyrite and pyrite. The edges and cleavage planes of type<!--> <!-->II biotite are commonly replaced by chlorite. Type<!--> <!-->III biotite is hydrothermal biotite distributed in porphyries along fissures and is associated with large amounts of chalcopyrite and pyrite. All three biotite types are Mg-biotite. Geothermometer and oxybarometer results using the compositions of the type<!--> <!-->I biotite crystals suggest that the magmas in the Pulang deposit had temperatures of 720–766 °C and oxygen fugacities of FMQ+2.3 to FMQ+3.2. The melt/fluid fugacities estimated using the compositions of the three biotite types suggest that the fluids present during the Potassic alteration stage may have had the high transport capacity for Cu and Au in the Pulang deposit. As a result of alteration, Al and Fe were enriched in the type<!--> <!-->I biotite, whereas Si, Ti, Mg, and Na were leached, then foremed type II biotite. Type<!--> <!-->III biotite crystals have high Cu and K contents and formed during Potassic alteration. Combining these data with field observations suggests that the Cu enrichment was closely related to the type<!--> <!-->II and III biotite, which formed during the potassic–silicate alteration stage; i.e., the major ore-forming stage of the Pulang deposit.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106222"},"PeriodicalIF":3.2,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142320326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"Fluid evolution of the Nulasai Cu deposit, Xinjiang, NW China: Evidence from fluid inclusions and O-H-C isotopes","authors":"Renke Wang ,&nbsp;Xiaobo Zhao ,&nbsp;Chunji Xue ,&nbsp;Haixia Chu ,&nbsp;Yun Zhao ,&nbsp;Qing Sun ,&nbsp;Wanjin Zhu","doi":"10.1016/j.oregeorev.2024.106220","DOIUrl":"10.1016/j.oregeorev.2024.106220","url":null,"abstract":"<div><p>The Nulasai deposit is the earliest Cu mine in Xinjiang, NW China, and has been mined and smelted since the warring state period. Another striking characteristic of the deposit is the high-grade (ave. 1.34 % Cu) with bornite, chalcopyrite and chalcocite as main ore minerals. Through a field and petrographic investigation, three phases of hydrothermal evolution have been recognized at the Nulasai Cu deposit, including the stage I magnetite – quartz ± chalcopyrite ± bornite veins, the stage II calcite – barite ± chalcopyrite ± chalcocite ± pyrite ± bornite veins, and the stage III calcite – barite ± chalcopyrite ± sphalerite ± pyrite ± galena veins. Fluid inclusions of the stage I veins were captured under two-phase condition indicates that existence of both contemporaneous daughter mineral-bearing and liquid-rich fluid inclusions; they have an intermediate-high salinity (11.5 ∼ 38.5 wt% NaCl equiv) and homogenization temperature (266 ∼ 376 °C), with entrapment pressures from 47 to 167 bar (depth of approximately 0.5 to 1.7 km). The coexistence of vapor-rich and liquid-rich fluid inclusions was a defining feature of the stage II fluid inclusions, and they have an intermediate salinity (6.2 ∼ 10.7 wt.%NaCl equiv) and homogenization temperature (211 ∼ 287 °C), with entrapment pressures from 18 to 70 bar (depth of approximately 0.2 to 0.7 km). Fluid inclusions of the stage III veins were captured under two-phase condition, and intermediate-low salinity (3.2 ∼ 9.2 wt.%NaCl equiv) and homogenization temperature (155 ∼ 241 °C), with entrapment pressures of 6 to 32 bar (depth of 0.1 to 0.6 km). According to the stable isotope (O-H-C) data for the three mineralization phases, magmatic water containing organic carbon made up the majority of the early ore-forming fluids, whereas abundant meteoric water has been involved during the late stage of mineralization. Therefore, we suggest that fluid mixture between magmatic water and meteoric water may have led to simultaneous decrease of fluid temperature, salinity and their stable isotope values, and finally facilitates the Cu ore precipitation. This study emphasizes how high-grade Cu deposition in orogenic belts is initiated by fluid dilution.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"173 ","pages":"Article 106220"},"PeriodicalIF":3.2,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003536/pdfft?md5=bddde4a4e8a5b850e7688236d3cc4dbe&pid=1-s2.0-S0169136824003536-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142163576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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":"The occurrence and enrichment of cobalt in skarn Pb-Zn deposits: A case study of the Niukutou Co-rich deposit, East Kunlun metallogenic belt, western China","authors":"Yu-Ying Che ,&nbsp;Hui-Min Su ,&nbsp;Tong Liu ,&nbsp;Hua Li ,&nbsp;Shu-Yue He","doi":"10.1016/j.oregeorev.2024.106210","DOIUrl":"10.1016/j.oregeorev.2024.106210","url":null,"abstract":"<div><p>The East Kunlun orogenic belt is one of the most important Co-rich polymetallic metallogenic belts in China. Niukutou, a typical Pb-Zn-(Fe) skarn deposit, is situated within the marble formations of the Ordovician-Silurian Qimantagh Group in this belt. Six distinct stages of mineralization have been identified: (1) prograde skarn stage, (2) hydrous mineral-oxide stage, (3) pyrrhotite stage, (4) chalcopyrite stage, (5) sphalerite-galena stage, and (6) carbonate stage. Co enrichment predominantly manifests at chalcopyrite stage, with two distinct Co minerals identified: glaucodot and cobaltite. Co is also present as isomorphous substitution in sulfides (mostly arsenopyrite) and as inclusions in chalcopyrite. Variations in As and S contents in arsenopyrite suggest a steady decrease in ore-forming fluid temperature from the pyrrhotite stage to sphalerite-galena stage. Variations in the Co, Ni, Se, As, Sb, Cu, Sn, Ag, and Zn contents in pyrite indicate fluctuations in temperature, oxygen fugacity, and fluid composition during ore formation. Sulfur isotope compositions (δ³⁴S) through the pyrrhotite stage to the sphalerite-galena stages show a limited range from +3.4 to +7.0 ‰, suggesting a predominantly magmatic source. Whereas, the δ³⁴S of pyrite and marcasite in carbonate stage exhibit significant variations from −22.5 to +22.7 ‰. We propose that this significant variation may be caused by mixing of sulfur from the surrounding rocks and the large fluctuations in oxygen fugacity due to the influx of meteoric water at the carbonate stage. Overall, Co in Pb-Zn skarn system may occur either as independent minerals or as lattice substitution in sulfides such as arsenopyrite. The deposition of Co-bearing minerals is related to decreases in temperature and <em>f</em>O₂ during the chalcopyrite stage.</p></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"172 ","pages":"Article 106210"},"PeriodicalIF":3.2,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0169136824003433/pdfft?md5=47afabf606f049637756d17d7480b699&pid=1-s2.0-S0169136824003433-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142128386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}