The investigation of low-sulfidation epithermal gold deposits presents significant challenges due to their intricate geological frameworks and frequently obscured mineralization. This research details the implementation of the short-offset transient electromagnetic method (SOTEM) to concurrently invert resistivity and chargeability parameters within the Lvyuan Gold Deposit located in Eastern Junggar, China. Utilizing a grounded-wire source alongside dual-base-frequency transmission, high-fidelity electromagnetic data were collected across ten survey lines encompassing the No. 7 alteration zone. One-dimensional inversion of the transient electromagnetic responses elucidated detailed subsurface electrical structures to depths of approximately one kilometer, facilitating the identification of fault systems and alteration zones linked to gold mineralization. Measurements of rock physical properties substantiated that elevated chargeability values (>20%) combined with moderate to low resistivity (<300 Ω·m) are strongly indicative of hydrothermally altered lithologies, particularly those exhibiting pyritization and limonitization. Integration of these geophysical results with drilling data confirmed that mineralized bodies predominantly occur within shallow zones characterized by low resistivity and high chargeability proximal to fault structures. Consequently, four prospective target areas were delineated, underscoring the effectiveness of SOTEM in delineating alteration zones and informing subsequent exploration efforts for epithermal gold deposits.
{"title":"Advanced SOTEM survey for the exploration of low-sulphidation epithermal gold: Insights from Lvyuan, eastern Junggar, China","authors":"Weiying Chen , Xiaoyin Ma , Quanhui Guo , Pengfei Lv","doi":"10.1016/j.oregeorev.2026.107140","DOIUrl":"10.1016/j.oregeorev.2026.107140","url":null,"abstract":"<div><div>The investigation of low-sulfidation epithermal gold deposits presents significant challenges due to their intricate geological frameworks and frequently obscured mineralization. This research details the implementation of the short-offset transient electromagnetic method (SOTEM) to concurrently invert resistivity and chargeability parameters within the Lvyuan Gold Deposit located in Eastern Junggar, China. Utilizing a grounded-wire source alongside dual-base-frequency transmission, high-fidelity electromagnetic data were collected across ten survey lines encompassing the No. 7 alteration zone. One-dimensional inversion of the transient electromagnetic responses elucidated detailed subsurface electrical structures to depths of approximately one kilometer, facilitating the identification of fault systems and alteration zones linked to gold mineralization. Measurements of rock physical properties substantiated that elevated chargeability values (>20%) combined with moderate to low resistivity (<300 Ω·m) are strongly indicative of hydrothermally altered lithologies, particularly those exhibiting pyritization and limonitization. Integration of these geophysical results with drilling data confirmed that mineralized bodies predominantly occur within shallow zones characterized by low resistivity and high chargeability proximal to fault structures. Consequently, four prospective target areas were delineated, underscoring the effectiveness of SOTEM in delineating alteration zones and informing subsequent exploration efforts for epithermal gold deposits.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107140"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-29DOI: 10.1016/j.oregeorev.2026.107145
Qingxuan Wang , Shuo Wang , Zhengping Yan , Wenyuan Li , Yunhua Liu , Huali Guo , Jinhua Du , Yingxing Huang , Tianhong Gao , Zihe Chen
Highly fractionated intrusions plays a key role in the formation of numerous types of ore metal deposits. For example, many large-scale Au deposits are associated with highly fractionated intermediate–silicic intrusions. Since the introduction of Au deposit classification types such as intrusion-related, magmatic, and magmatic–hydrothermal Au deposits, an increasing number of studies have focused on the coupled relationships between magmatic processes (e.g., melt segregation, differentiation, and evolution) and Au mineralization. The magmatism not only provides the energy and ore-forming materials for Au mineralization, but also leads to significant Au enrichment by magmatic fractionation and evolution. Consequently, studies on magmatic fractionation-related mineralization should not be confined to ore types such as W–Sn and rare metals. This paper systematically reviews the nature of Au deposits genetically linked to highly fractionated magmas and discusses the key controls on anomalous Au enrichment during magmatic fractionation. The gold-mineralizing magmas are derived mainly from regions near the crust–mantle boundary. Metasomatic overprinting of the lithospheric mantle and enrichment of the lower crust by metallic elements, fluids, and volatiles from subducted slabs are preconditions for subsequent auriferous mineralization processes. The parental rocks of these Au deposits generally have a high O fugacity and are fractionated I-type or magnetite-series granites that have an affinity with the high-K calc-alkaline series, in which physicochemical parameters such as the O fugacity regulate the S speciation in the magmas and Au distribution. Furthermore, the timing of Au-bearing metallic sulfide saturation in the magmas and subsequent exsolution into the fluid phase is one of the critical controls on Au transportation into the shallow crust and its subsequent deposition in economically viable concentrations. Such Au deposits form mainly in transitional tectonic settings associated with slab subduction (e.g., slab rollback, break off) or during the transition from collisional to post-collisional tectonic settings. The physicochemical processes that govern melt segregation, differentiation, and Au enrichment from the magma source regions to final ore deposition have significant implications for understanding anomalous Au concentration mechanisms. The interrelationships among physicochemical parameters are the critical factor in understanding the coupling relationship between the melt-fluid evolution and Au mineralization, and therefore warrant further investigation.
{"title":"Review of the relationship between highly fractionated intrusions and gold mineralization","authors":"Qingxuan Wang , Shuo Wang , Zhengping Yan , Wenyuan Li , Yunhua Liu , Huali Guo , Jinhua Du , Yingxing Huang , Tianhong Gao , Zihe Chen","doi":"10.1016/j.oregeorev.2026.107145","DOIUrl":"10.1016/j.oregeorev.2026.107145","url":null,"abstract":"<div><div>Highly fractionated intrusions plays a key role in the formation of numerous types of ore metal deposits. For example, many large-scale Au deposits are associated with highly fractionated intermediate–silicic intrusions. Since the introduction of Au deposit classification types such as intrusion-related, magmatic, and magmatic–hydrothermal Au deposits, an increasing number of studies have focused on the coupled relationships between magmatic processes (e.g., melt segregation, differentiation, and evolution) and Au mineralization. The magmatism not only provides the energy and ore-forming materials for Au mineralization, but also leads to significant Au enrichment by magmatic fractionation and evolution. Consequently, studies on magmatic fractionation-related mineralization should not be confined to ore types such as W–Sn and rare metals. This paper systematically reviews the nature of Au deposits genetically linked to highly fractionated magmas and discusses the key controls on anomalous Au enrichment during magmatic fractionation. The gold-mineralizing magmas are derived mainly from regions near the crust–mantle boundary. Metasomatic overprinting of the lithospheric mantle and enrichment of the lower crust by metallic elements, fluids, and volatiles from subducted slabs are preconditions for subsequent auriferous mineralization processes. The parental rocks of these Au deposits generally have a high O fugacity and are fractionated I-type or magnetite-series granites that have an affinity with the high-K calc-alkaline series, in which physicochemical parameters such as the O fugacity regulate the S speciation in the magmas and Au distribution. Furthermore, the timing of Au-bearing metallic sulfide saturation in the magmas and subsequent exsolution into the fluid phase is one of the critical controls on Au transportation into the shallow crust and its subsequent deposition in economically viable concentrations. Such Au deposits form mainly in transitional tectonic settings associated with slab subduction (e.g., slab rollback, break off) or during the transition from collisional to post-collisional tectonic settings. The physicochemical processes that govern melt segregation, differentiation, and Au enrichment from the magma source regions to final ore deposition have significant implications for understanding anomalous Au concentration mechanisms. The interrelationships among physicochemical parameters are the critical factor in understanding the coupling relationship between the melt-fluid evolution and Au mineralization, and therefore warrant further investigation.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107145"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-25DOI: 10.1016/j.oregeorev.2026.107139
Hu Qiaofan , Mo Jiangping , Wei Zhiwei , Qiu ZhengJie , Fang Ke , Zhou Shouyu , Huang Xueqiang , Liu Yaohui , Liu Wei , Li Jiacai , Wang Ailin
This study focuses on the granitic intrusions in the Chambishi-Nkana Basin of the Zambian Copperbelt, aiming to reveal their genesis, tectonic setting, emplacement age, and relationship with Cu-Co mineralization. LA-ICP-MS zircon U-Pb dating shows that the Chambishi granite formed at approximately 1951 Ma, and the Nchanga granite crystallized at approximately 890 Ma. Geochemical analyses indicate that these rocks are peraluminous S-type granites, characterized by high A/CNK values (>1.3), enrichment in light rare earth elements, and significant negative Eu anomalies (Eu/Eu*=21.38–38.28). Zircon Lu-Hf isotopic data suggest that the Chambishi granite originated from the mixing of mantle and crust-derived melts during the collision between the Bangweulu Block and the Tanzania Craton, while the Nchanga granite formed from crustal anatexis without significant mantle input in an intraplate rift environment associated with the breakup of Rodinia in the Neoproterozoic. Molybdenite Re-Os dating reveals that hydrothermal cross-cutting vein-type Cu-Mo mineralization occurred at approximately 496 Ma, coinciding with basin inversion during the late stage of the Lufilian collisional orogeny—this age only represents the timing of the late vein-type mineralization, not the entire mineralization history of the deposit. This study confirms that the late Lufilian orogeny provided tectonic channels for hydrothermal migration, and granitic intrusions provided favorable structural channels for hydrothermal migration, while tectonic-thermal effects of the late Lufilian orogeny supplied the necessary thermal driving force, jointly controlling the formation of hydrothermal cross-cutting vein-type Cu-Mo mineralization. The sedimentary layered Cu-Co mineralization is controlled by the Neoproterozoic sedimentary environment, and its specific formation age requires further dating of sulfides (e.g., carrollite) in the layered mineralization. By integrating geochronological and geochemical data, this research establishes a temporal framework for magmatic events, tectonic evolution, and mineralization in the Zambian Copperbelt, highlighting the critical control of regional tectonic-magmatic activities on Cu-Co mineralization.
{"title":"Geochemical and geochronological constraints on granitoids from the Chambishi-Nkana Basin, Zambian Copperbelt","authors":"Hu Qiaofan , Mo Jiangping , Wei Zhiwei , Qiu ZhengJie , Fang Ke , Zhou Shouyu , Huang Xueqiang , Liu Yaohui , Liu Wei , Li Jiacai , Wang Ailin","doi":"10.1016/j.oregeorev.2026.107139","DOIUrl":"10.1016/j.oregeorev.2026.107139","url":null,"abstract":"<div><div>This study focuses on the granitic intrusions in the Chambishi-Nkana Basin of the Zambian Copperbelt, aiming to reveal their genesis, tectonic setting, emplacement age, and relationship with Cu-Co mineralization. LA-ICP-MS zircon U-Pb dating shows that the Chambishi granite formed at approximately 1951 Ma, and the Nchanga granite crystallized at approximately 890 Ma. Geochemical analyses indicate that these rocks are peraluminous S-type granites, characterized by high A/CNK values (>1.3), enrichment in light rare earth elements, and significant negative Eu anomalies (Eu/Eu*=21.38–38.28). Zircon Lu-Hf isotopic data suggest that the Chambishi granite originated from the mixing of mantle and crust-derived melts during the collision between the Bangweulu Block and the Tanzania Craton, while the Nchanga granite formed from crustal anatexis without significant mantle input in an intraplate rift environment associated with the breakup of Rodinia in the Neoproterozoic. Molybdenite Re-Os dating reveals that<!--> <!-->hydrothermal cross-cutting vein-type Cu-Mo mineralization<!--> <!-->occurred at approximately 496 Ma, coinciding with basin inversion during the late stage of the Lufilian collisional orogeny—this age only represents the timing of the late vein-type mineralization, not the entire mineralization history of the deposit. This study confirms that the late Lufilian orogeny provided tectonic channels for hydrothermal migration, and granitic intrusions provided favorable structural channels for hydrothermal migration, while tectonic-thermal effects of the late Lufilian orogeny supplied the necessary thermal driving force, jointly controlling the formation of hydrothermal cross-cutting vein-type Cu-Mo mineralization. The sedimentary layered Cu-Co mineralization is controlled by the Neoproterozoic sedimentary environment, and its specific formation age requires further dating of sulfides (e.g., carrollite) in the layered mineralization. By integrating geochronological and geochemical data, this research establishes a temporal framework for magmatic events, tectonic evolution, and mineralization in the Zambian Copperbelt, highlighting the critical control of regional tectonic-magmatic activities on Cu-Co mineralization.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107139"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-19DOI: 10.1016/j.oregeorev.2026.107126
Shu Yang , Hongrui Zhang , Zhiming Yang , Pinghua Liu , Mehraj Aghazadeh , Zengqian Hou , Tiannan Yang , Zahra Badrzadeh
Zarshuran is the largest gold deposit in the Middle East. However, the sources of ore-forming materials at Zarshuran remain poorly understood. This study presents detailed descriptions of paragenetic sequence, in situ calcite U-Pb data, sulfide trace elements and sulfur isotope data to trace the sources of ore-forming materials and track the ore-forming processes. Calcite U-Pb results suggest the gold mineralization occurred during ca. 21–12.0 Ma. Five stages of mineralization can be divided at Zarshuran. They are characterized by pyrite grains with different textures. LA-ICP-MS analyses of the different types of pyrite demonstrate that Au is enriched in ore-stage Ⅰ, ore-stage Ⅱ, and late-ore stage. LA-ICP-MS analyses of the different types of sphalerite show an increasing trend for In and Sn contents but a decreasing trend for Ge and Tl contents from Sp1a to Sp1c. The S isotope compositions of sulfides from different stages yield positive values, suggesting these sulfides were precipitated by thermochemical sulfate reduction. Most δ34S values of sulfide minerals of the ore-stages are in the ranges between magmatic sulfur and redbeds sulfates sulfur, suggesting contributions of magmatic and basinal materials during mineralization. The shift of δ34S values during late-ore stage indicates the addition of Miocene seawater sulfates sulfur. We propose the Zarshuran gold mineralization was formed by mixing of magmatic fluids with basinal brines during the exhumation of the Iman Khan metamorphic core complex (MCC). The development of MCC and coeval fertile magmatism and basinal brine flow are important for exploration of Zarshuran-type gold ores.
{"title":"Formation of the Zarshuran gold deposit in northwest Iran resulted from the mixing of fertile magmatic fluids with basinal brines: Evidence from sulfide trace elements and sulfur isotopes","authors":"Shu Yang , Hongrui Zhang , Zhiming Yang , Pinghua Liu , Mehraj Aghazadeh , Zengqian Hou , Tiannan Yang , Zahra Badrzadeh","doi":"10.1016/j.oregeorev.2026.107126","DOIUrl":"10.1016/j.oregeorev.2026.107126","url":null,"abstract":"<div><div>Zarshuran is the largest gold deposit in the Middle East. However, the sources of ore-forming materials at Zarshuran remain poorly understood. This study presents detailed descriptions of paragenetic sequence, in situ calcite U-Pb data, sulfide trace elements and sulfur isotope data to trace the sources of ore-forming materials and track the ore-forming processes. Calcite U-Pb results suggest the gold mineralization occurred during ca. 21–12.0 Ma. Five stages of mineralization can be divided at Zarshuran. They are characterized by pyrite grains with different textures. LA-ICP-MS analyses of the different types of pyrite demonstrate that Au is enriched in ore-stage Ⅰ, ore-stage Ⅱ, and late-ore stage. LA-ICP-MS analyses of the different types of sphalerite show an increasing trend for In and Sn contents but a decreasing trend for Ge and Tl contents from Sp1a to Sp1c. The S isotope compositions of sulfides from different stages yield positive values, suggesting these sulfides were precipitated by thermochemical sulfate reduction. Most δ<sup>34</sup>S values of sulfide minerals of the ore-stages are in the ranges between magmatic sulfur and redbeds sulfates sulfur, suggesting contributions of magmatic and basinal materials during mineralization. The shift of δ<sup>34</sup>S values during late-ore stage indicates the addition of Miocene seawater sulfates sulfur. We propose the Zarshuran gold mineralization was formed by mixing of magmatic fluids with basinal brines during the exhumation of the Iman Khan metamorphic core complex (MCC). The development of MCC and coeval fertile magmatism and basinal brine flow are important for exploration of Zarshuran-type gold ores.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107126"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-23DOI: 10.1016/j.oregeorev.2026.107136
Jiale Wang , Xiang Sun , Changhai Luo , Yong Fu , Weiming Ma , Tong Pei , Ke Xiao
The Triassic period has been suggested to be the main metallogenic epoch in the Qimantagh area of Qinghai Province. However, the porphyry copper mineralization potential of this region remains poorly constrained. Here we present zircon U–Pb ages, trace-element data, and Hf isotopic compositions from granites in the Yazigou skarn Cu–Pb–Zn deposit. The zircon U–Pb age of the mineralization-related K-feldspar granitic porphyry at Yazigou is 230 ± 2 Ma, whereas the granodiorite yields an age of 416.7 ± 4.2 Ma. The K-feldspar granitic porphyry exhibits εHf(t) values of -0.4 to +4.0 and two-stage Hf model ages (TDM2) of 1.0–1.3 Ga, suggesting derivation from melting of Mesoproterozoic to crust, accompanied by minor contributions from mantle material. Zircon trace element signatures further indicate highly magmatic oxygen fugacity (ΔFMQ = +1.0 to +2.3), consistent with typical of oxidized skarn systems. The extremely low Eu anomalies (0.01–0.03) suggest that the magma system underwent intense plagioclase fractional crystallization, implying a low water content. Although the Yazigou deposit shares a similar magma source with other metallic deposits in the Qimantagh region, comparison with the Eu anomalies of Tibet porphyry Cu deposits suggests that the low water content resulted in its limited mineralization potential.
{"title":"Zircon geochronology, geochemistry, and Hf isotopes of granites in the Yazigou skarn Cu–Pb–Zn deposit: Insights into Triassic skarn mineralization potential in the Qimantagh area, Qinghai Province, NW China","authors":"Jiale Wang , Xiang Sun , Changhai Luo , Yong Fu , Weiming Ma , Tong Pei , Ke Xiao","doi":"10.1016/j.oregeorev.2026.107136","DOIUrl":"10.1016/j.oregeorev.2026.107136","url":null,"abstract":"<div><div>The Triassic period has been suggested to be the main metallogenic epoch in the Qimantagh area of Qinghai Province. However, the porphyry copper mineralization potential of this region remains poorly constrained. Here we present zircon U–Pb ages, trace-element data, and Hf isotopic compositions from granites in the Yazigou skarn Cu–Pb–Zn deposit. The zircon U–Pb age of the mineralization-related K-feldspar granitic porphyry at Yazigou is 230 ± 2 Ma, whereas the granodiorite yields an age of 416.7 ± 4.2 Ma. The K-feldspar granitic porphyry exhibits ε<sub>Hf</sub>(t) values of -0.4 to +4.0 and two-stage Hf model ages (T<sub>DM2</sub>) of 1.0–1.3 Ga, suggesting derivation from melting of Mesoproterozoic to crust, accompanied by minor contributions from mantle material. Zircon trace element signatures further indicate highly magmatic oxygen fugacity (ΔFMQ = +1.0 to +2.3), consistent with typical of oxidized skarn systems. The extremely low Eu anomalies (0.01–0.03) suggest that the magma system underwent intense plagioclase fractional crystallization, implying a low water content. Although the Yazigou deposit shares a similar magma source with other metallic deposits in the Qimantagh region, comparison with the Eu anomalies of Tibet porphyry Cu deposits suggests that the low water content resulted in its limited mineralization potential.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107136"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-31DOI: 10.1016/j.oregeorev.2026.107151
Shenghu Li , Yuxin Xiong , Dapeng Li , Xuefeng Yu , Taitao Liang , Rongjun Li , Zhiming Wang , Xiangxian Ma , Zengsheng Li , Naijie Chi , Yingyu Xue , Guodong Chen , Chuanyuan Zhuo , Ge Hu
Carbonatite-related rare earth element (REE) deposits are the world’s primary source of light REEs. The Weishan deposit in Shandong Province, China—ranked third in the country in rare earth oxide reserves—exemplifies such mineralization. Petrographic studies reveal abundant CO2-bearing fluid inclusions in its high-grade ore bodies. Due to their high-internal pressure, these inclusions frequently decrepitate or leak when heated on conventional heating-freezing stages (e.g., the Linkam THMSG600) at atmospheric pressure, preventing the acquisition of total homogenization temperature (Th,tot) data. This limitation has hindered understanding of the evolutionary process and thermodynamic properties of the ore-forming fluids. To address this, we employed a hydrothermal diamond anvil cell (HDAC) to perform high pressure microthermometry on CO2-bearing boiling fluid inclusion assemblages (FIAs) from the Weishan deposit. By maintaining external pressure on the high-internal pressure fluid inclusions throughout heating, we successfully obtained the Th,tots and introduced a newly established two fitted lines intersection method to correct the Th,tots measured with the HDAC, minimizing the influence of external pressures on the measured Th,tots. As a result, the trapping temperatures and pressures of the CO2-bearing boiling FIAs in the Weishan deposit were determined to be 682–692 °C and 646–734 MPa, respectively. These results define the temperature and pressure conditions under which depressurization immiscibility and fluid exsolution occurred within the magmatic system, and confirmed the existence of CO2-bearing supercritical fluids in the deposit. In the future, the experimental method established herein is well-suited for thermodynamic measurements of CO2-bearing boiling FIAs in carbonatite-related REE deposits, which often contain high-internal pressure fluid inclusions with complex multicomponent system such as H2O-Na2SO4-Na2CO3–CO2.
{"title":"Determination of the trapping temperatures and pressures of high-internal pressure CO2-bearing boiling fluid inclusion assemblages in the carbonatite-related REE deposit at Weishan, Shandong Province, China","authors":"Shenghu Li , Yuxin Xiong , Dapeng Li , Xuefeng Yu , Taitao Liang , Rongjun Li , Zhiming Wang , Xiangxian Ma , Zengsheng Li , Naijie Chi , Yingyu Xue , Guodong Chen , Chuanyuan Zhuo , Ge Hu","doi":"10.1016/j.oregeorev.2026.107151","DOIUrl":"10.1016/j.oregeorev.2026.107151","url":null,"abstract":"<div><div>Carbonatite-related rare earth element (REE) deposits are the world’s primary source of light REEs. The Weishan deposit in Shandong Province, China—ranked third in the country in rare earth oxide reserves—exemplifies such mineralization. Petrographic studies reveal abundant CO<sub>2</sub>-bearing fluid inclusions in its high-grade ore bodies. Due to their high-internal pressure, these inclusions frequently decrepitate or leak when heated on conventional heating-freezing stages (e.g., the Linkam THMSG600) at atmospheric pressure, preventing the acquisition of total homogenization temperature (<em>T</em><sub>h,tot</sub>) data. This limitation has hindered understanding of the evolutionary process and thermodynamic properties of the ore-forming fluids. To address this, we employed a hydrothermal diamond anvil cell (HDAC) to perform high pressure microthermometry on CO<sub>2</sub>-bearing boiling fluid inclusion assemblages (FIAs) from the Weishan deposit. By maintaining external pressure on the high-internal pressure fluid inclusions throughout heating, we successfully obtained the <em>T</em><sub>h,tot</sub>s and introduced a newly established two fitted lines intersection method to correct the <em>T</em><sub>h,tot</sub>s measured with the HDAC, minimizing the influence of external pressures on the measured <em>T</em><sub>h,tot</sub>s. As a result, the trapping temperatures and pressures of the CO<sub>2</sub>-bearing boiling FIAs in the Weishan deposit were determined to be 682–692 °C and 646–734 MPa, respectively. These results define the temperature and pressure conditions under which depressurization immiscibility and fluid exsolution occurred within the magmatic system, and confirmed the existence of CO<sub>2</sub>-bearing supercritical fluids in the deposit. In the future, the experimental method established herein is well-suited for thermodynamic measurements of CO<sub>2</sub>-bearing boiling FIAs in carbonatite-related REE deposits, which often contain high-internal pressure fluid inclusions with complex multicomponent system such as H<sub>2</sub>O-Na<sub>2</sub>SO<sub>4</sub>-Na<sub>2</sub>CO<sub>3</sub>–CO<sub>2</sub>.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107151"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-13DOI: 10.1016/j.oregeorev.2025.107049
Nynke Keulen, Benjamin Heredia, Diogo R.N. Rosa, Sebastian N. Malkki, Tonny B. Thomsen, David Whitehead
Efficient mineral exploration requires early tailoring to target deposit types. Mineral assemblages of 12 different W-Sn occurrences in the East-Greenland Caledonides with scheelite and cassiterite were investigated with automated quantitative mineralogy on SEM and for their trace elements with LA-ICPMS and integrated observations were correlated through statistical analyses on literature data. Results indicate that scheelite and cassiterite trace element geochemistry can differentiate between skarn, greisen, and quartz-scheelite vein deposit types. The mineralization processes are influenced enough by specific geological settings and fluid compositions to allow for the differentiation of deposit types from mineral trace element geochemistry. These data assist in understanding complex geological histories and varied mineralization processes in the East-Greenland Caledonides. U-Pb dating of scheelite, apatite and cassiterite of samples from multiple locations reveal three distinct mineralization pulses around 425 Ma, 400 Ma, and 370 Ma, the first two linked to magmatic fluids and finally a third metamorphic fluid phase. Analyses also suggest that the scheelite closure temperature lies in the same range as the one for apatite. This approach supports more efficient and effective exploration strategies by improving the understanding of the timing and nature of mineralization events in the East-Greenland Caledonides.
{"title":"Fingerprinting W-Sn mineralization processes in the East Greenland Caledonides using scheelite and cassiterite U-Pb dating and trace element composition","authors":"Nynke Keulen, Benjamin Heredia, Diogo R.N. Rosa, Sebastian N. Malkki, Tonny B. Thomsen, David Whitehead","doi":"10.1016/j.oregeorev.2025.107049","DOIUrl":"10.1016/j.oregeorev.2025.107049","url":null,"abstract":"<div><div>Efficient mineral exploration requires early tailoring to target deposit types. Mineral assemblages of 12 different W-Sn occurrences in the East-Greenland Caledonides with scheelite and cassiterite were investigated with automated quantitative mineralogy on SEM and for their trace elements with LA-ICPMS and integrated observations were correlated through statistical analyses on literature data. Results indicate that scheelite and cassiterite trace element geochemistry can differentiate between skarn, greisen, and quartz-scheelite vein deposit types. The mineralization processes are influenced enough by specific geological settings and fluid compositions to allow for the differentiation of deposit types from mineral trace element geochemistry. These data assist in understanding complex geological histories and varied mineralization processes in the East-Greenland Caledonides. U-Pb dating of scheelite, apatite and cassiterite of samples from multiple locations reveal three distinct mineralization pulses around 425 Ma, 400 Ma, and 370 Ma, the first two linked to magmatic fluids and finally a third metamorphic fluid phase. Analyses also suggest that the scheelite closure temperature lies in the same range as the one for apatite. This approach supports more efficient and effective exploration strategies by improving the understanding of the timing and nature of mineralization events in the East-Greenland Caledonides.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107049"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145950228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-21DOI: 10.1016/j.oregeorev.2026.107129
Qingyang Bao , Hongfei Cheng , Yang Wang , Shaoxian Liang
Significant illite clay deposits, which are of considerable economic interest and genetic importance, are found in Chunhua area along the southern margin of the Ordos Basin. This study takes the Yanjiagou deposit as a representative case and integrates geological survey, mineralogy, X-ray diffraction (XRD) , scanning electron microscopy, geochemistry, K-Ar isotopic dating, and illite crystallinity analysis to systematically investigate its geological characteristics, age of mineralization, and genesis. The results indicate that the mineralized clay layers are predominantly hosted in the lower segment of the Upper Carboniferous Taiyuan Formation. The protolith is identified as a kaolinite claystone that formed through chemical precipitation, which was subsequently altered to illite through hydrothermal processes. K-Ar dating of illite yields an age of 146.8 ± 2.5 Ma, and crystallinity-based geothermometry indicates a formation temperature of approximately 210 °C, constraining the mineralization to a medium–low temperature hydrothermal event during the Late Jurassic to Early Cretaceous. A genetic model of “hydrothermal diagenetic mineralization” is proposed, wherein potassium-rich fluids migrated along structural pathways and triggered selective illitization of kaolinite precursor, resulting in zoned illite horizons. These findings not only provide key insights into Late Mesozoic hydrothermal mineralization on the southwestern margin of the North China Craton, but also offer practical guidelines for the exploration of clay mineral deposits in similar geological settings.
{"title":"Mechanism of hydrothermal illite clay mineralization in the southern Ordos Basin, central China","authors":"Qingyang Bao , Hongfei Cheng , Yang Wang , Shaoxian Liang","doi":"10.1016/j.oregeorev.2026.107129","DOIUrl":"10.1016/j.oregeorev.2026.107129","url":null,"abstract":"<div><div>Significant illite clay deposits, which are of considerable economic interest and genetic importance, are found in Chunhua area along the southern margin of the Ordos Basin. This study takes the Yanjiagou deposit as a representative case and integrates geological survey, mineralogy, X-ray diffraction (XRD) , scanning electron microscopy, geochemistry, K-Ar isotopic dating, and illite crystallinity analysis to systematically investigate its geological characteristics, age of mineralization, and genesis. The results indicate that the mineralized clay layers are predominantly hosted in the lower segment of the Upper Carboniferous Taiyuan Formation. The protolith is identified as a kaolinite claystone that formed through chemical precipitation, which was subsequently altered to illite through hydrothermal processes. K-Ar dating of illite yields an age of 146.8 ± 2.5 Ma, and crystallinity-based geothermometry indicates a formation temperature of approximately 210 °C, constraining the mineralization to a medium–low temperature hydrothermal event during the Late Jurassic to Early Cretaceous. A genetic model of “hydrothermal diagenetic mineralization” is proposed, wherein potassium-rich fluids migrated along structural pathways and triggered selective illitization of kaolinite precursor, resulting in zoned illite horizons. These findings not only provide key insights into Late Mesozoic hydrothermal mineralization on the southwestern margin of the North China Craton, but also offer practical guidelines for the exploration of clay mineral deposits in similar geological settings.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107129"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-31DOI: 10.1016/j.oregeorev.2025.107092
Ying Wang , Zhaochong Zhang , Shu Zhang , Zhiguo Cheng , He Huang
Sediment-hosted Zn-Pb deposits are the most important global source of Pb and Zn, yet their genesis and timing remain central questions in economic geology. Direct geochronological constraints are often difficult to obtain due to the general absence of suitable datable minerals, hindering the understanding of ore-forming processes and regional metallogenic models. The Hoxbulak Zn-Pb deposit in Xinjiang, a typical sediment-hosted Zn-Pb deposit in the southwestern Tianshan Mountains of the Central Asian metallogenic domain, has long been controversial with respect to its genetic type and mineralization age, primarily focusing on whether it is related to adjacent Permian magmatism and whether it formed syngenetically or epigenetically. In this study, we conducted precise Sm-Nd isochron dating of sphalerite, galena, and associated calcite/dolomite from the main mineralization stage, yielding a mineralization age of 55 ± 2 Ma. This result indicates that the deposit formed during the Paleogene and shows no genetic relationship with the neighboring Permian Hoxbulak pluton (261.5 ± 2.7 Ma; 273.6 ± 2.0 Ma and 274.8 ± 1.5 Ma), supporting its classification as an epigenetic Mississippi Valley-type (MVT) deposit. Integrated regional structural analysis suggests that this mineralization event was likely controlled by transpression tectonics triggered during the initial India-Eurasia collision (∼60–50 Ma). Our findings demonstrate that the Hoxbulak deposit represents a critical northwestern extension of the Tethyan MVT metallogenic belt (spanning Yunnan-Tibet-Xinjiang) and serves as its easternmost component within the Central Asian metallogenic domain—linking the classic Tethyan MVT system with the interior of the Central Asian Orogenic Belt. This study provides important constraints for exploring Paleogene MVT-type Zn-Pb deposits in Late Paleozoic carbonate formations of the South Tianshan, offering significant insights into the metallogenic patterns of Zn-Pb deposits in the junction zone between the Tethyan and Central Asian orogenic belts.
{"title":"Sm-Nd geochronology of the Hoxbulak Zn-Pb deposit in Xinjiang (NW China) and its link to Paleogene Mississippi Valley-type mineralization in the Tethyan domain","authors":"Ying Wang , Zhaochong Zhang , Shu Zhang , Zhiguo Cheng , He Huang","doi":"10.1016/j.oregeorev.2025.107092","DOIUrl":"10.1016/j.oregeorev.2025.107092","url":null,"abstract":"<div><div>Sediment-hosted Zn-Pb deposits are the most important global source of Pb and Zn, yet their genesis and timing remain central questions in economic geology. Direct geochronological constraints are often difficult to obtain due to the general absence of suitable datable minerals, hindering the understanding of ore-forming processes and regional metallogenic models. The Hoxbulak Zn-Pb deposit in Xinjiang, a typical sediment-hosted Zn-Pb deposit in the southwestern Tianshan Mountains of the Central Asian metallogenic domain, has long been controversial with respect to its genetic type and mineralization age, primarily focusing on whether it is related to adjacent Permian magmatism and whether it formed syngenetically or epigenetically. In this study, we conducted precise Sm-Nd isochron dating of sphalerite, galena, and associated calcite/dolomite from the main mineralization stage, yielding a mineralization age of 55 ± 2 Ma. This result indicates that the deposit formed during the Paleogene and shows no genetic relationship with the neighboring Permian Hoxbulak pluton (261.5 ± 2.7 Ma; 273.6 ± 2.0 Ma and 274.8 ± 1.5 Ma), supporting its classification as an epigenetic Mississippi Valley-type (MVT) deposit. Integrated regional structural analysis suggests that this mineralization event was likely controlled by transpression tectonics triggered during the initial India-Eurasia collision (∼60–50 Ma). Our findings demonstrate that the Hoxbulak deposit represents a critical northwestern extension of the Tethyan MVT metallogenic belt (spanning Yunnan-Tibet-Xinjiang) and serves as its easternmost component within the Central Asian metallogenic domain—linking the classic Tethyan MVT system with the interior of the Central Asian Orogenic Belt. This study provides important constraints for exploring Paleogene MVT-type Zn-Pb deposits in Late Paleozoic carbonate formations of the South Tianshan, offering significant insights into the metallogenic patterns of Zn-Pb deposits in the junction zone between the Tethyan and Central Asian orogenic belts.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107092"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146039412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-30DOI: 10.1016/j.oregeorev.2026.107142
Amirabbas Karbalaeiramezanali , Faranak Feizi , Alireza Jafari Rad , Mohammad Lotfi , David R. Lentz
This study investigates the mineralization characteristics and ore genesis of the Kuhsiah-e-Urmak area in the central Urumieh-Dokhtar Magmatic Belt, Iran, through fluid inclusion and isotope analyses. The intrusive units in the region, which are hosted within a marginally older volcanic series, reflect a transitional geodynamic environment, with the Kuh-Ghadeh diorite (∼18 Ma) showing arc-related features and the Marfioun tonalite (∼18 Ma) displaying a mix of arc and slab break-off characteristics, indicating an evolution from arc-related to post-arc slab failure regimes. Mineralization at the Kuhsiah-e-Urmak deposit occurs in two stages: Stage 1 (hypogene), marked by chalcopyrite-pyrite-bornite-sphalerite-galena-tetrahedrite with quartz-calcite, and Stage 2 (hypogene to supergene), characterized by chalcocite-digenite-covellite-goethite-maghemite-malachite with hematite-limonite ± jarosite ± illite. Fluid inclusion studies reveal low- to intermediate-temperature (191–230°C) and low- to medium-salinity (4–8.5 wt%) Stage 1 fluids. Stable isotope results indicate that the strongly negative δ34S values of sulfides and the significantly higher δ34S values of barite reflect reduction of seawater- or evaporite-derived sulfate, rather than sulfur input from magmatic volatiles. The magnitude of sulfur isotope fractionation is inconsistent with thermochemical sulfate reduction and instead supports microbial sulfate reduction and/or multistage sulfur cycling as the dominant sulfur-generating processes. The δ18O and δ13C values further record extensive fluid–rock interaction with meteoric waters and limestones in the region. Fluid inclusion salinity–temperature trends exhibit a positive correlation, consistent with dilution of hydrothermal fluids by infiltrating meteoric water. Stage 1 mineralization was driven by high-temperature magmatic hydrothermal fluids, while Stage 2 resulted from progressive mixing with cooler meteoric waters at shallow crustal levels to supergene weathering. These findings classify the Kuhsiah-e-Urmak deposit as a low-sulfidation epithermal Cu (Ag–Pb–Zn) deposit, and highlight the dominant role of seawater- or evaporite-derived oxidized sulfur and meteoric water mixing in the evolution of its hydrothermal system.
{"title":"Ore genesis of the Kuhsiah-e-Urmak base-metal epithermal deposit, Iran","authors":"Amirabbas Karbalaeiramezanali , Faranak Feizi , Alireza Jafari Rad , Mohammad Lotfi , David R. Lentz","doi":"10.1016/j.oregeorev.2026.107142","DOIUrl":"10.1016/j.oregeorev.2026.107142","url":null,"abstract":"<div><div>This study investigates the mineralization characteristics and ore genesis of the Kuhsiah-e-Urmak area in the central Urumieh-Dokhtar Magmatic Belt, Iran, through fluid inclusion and isotope analyses. The intrusive units in the region, which are hosted within a marginally older volcanic series, reflect a transitional geodynamic environment, with the Kuh-Ghadeh diorite (∼18 Ma) showing arc-related features and the Marfioun tonalite (∼18 Ma) displaying a mix of arc and slab break-off characteristics, indicating an evolution from arc-related to post-arc slab failure regimes. Mineralization at the Kuhsiah-e-Urmak deposit occurs in two stages: Stage 1 (hypogene), marked by chalcopyrite-pyrite-bornite-sphalerite-galena-tetrahedrite with quartz-calcite, and Stage 2 (hypogene to supergene), characterized by chalcocite-digenite-covellite-goethite-maghemite-malachite with hematite-limonite ± jarosite ± illite. Fluid inclusion studies reveal low- to intermediate-temperature (191–230°C) and low- to medium-salinity (4–8.5 wt%) Stage 1 fluids. Stable isotope results indicate that the strongly negative δ<sup>34</sup>S values of sulfides and the significantly higher δ<sup>34</sup>S values of barite reflect reduction of seawater- or evaporite-derived sulfate, rather than sulfur input from magmatic volatiles. The magnitude of sulfur isotope fractionation is inconsistent with thermochemical sulfate reduction and instead supports microbial sulfate reduction and/or multistage sulfur cycling as the dominant sulfur-generating processes<strong>.</strong> The δ<sup>18</sup>O and δ<sup>13</sup>C values further record extensive fluid–rock interaction with meteoric waters and limestones in the region. Fluid inclusion salinity–temperature trends exhibit a positive correlation, consistent with dilution of hydrothermal fluids by infiltrating meteoric water. Stage 1 mineralization was driven by high-temperature magmatic hydrothermal fluids, while Stage 2 resulted from progressive mixing with cooler meteoric waters at shallow crustal levels to supergene weathering. These findings classify the Kuhsiah-e-Urmak deposit as a low-sulfidation epithermal Cu (Ag–Pb–Zn) deposit, and highlight the dominant role of seawater- or evaporite-derived oxidized sulfur and meteoric water mixing in the evolution of its hydrothermal system.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"189 ","pages":"Article 107142"},"PeriodicalIF":3.6,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146189368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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