Pub Date : 2026-03-01Epub Date: 2026-02-11DOI: 10.1016/j.oregeorev.2026.107175
Cheng Liu , Yongbao Gao , Gaofeng Ye , Han Li , Yiwei Song , Ke Yang , Chuan Yao , Sheng Jin , Liyong Wei , Baochun Li , Jien Dong
The genesis of the world-class Zhaishang gold deposit in the West Qinling Metallogenic Belt has been debated due to its distal location (>26 km) from potential magmatic sources. This controversy stems largely from the lack of deep structural constraints. To resolve this, we conducted a high-resolution 3-D Magnetotelluric (MT) survey. Our model reveals a conductive channel (C1) connecting the deposit to the distal Jiaochangba pluton, illustrating a primary pathway for the ore-forming fluids. No significant concealed pluton exists beneath Zhaishang; instead, mineralization is hosted within the ancient crystalline basement, which served as both a gold source and a permeability barrier focusing fluids into traps. The data further reveal crustal decoupling at ∼ 25 km depth, explaining the preservation of Mesozoic ore-forming features. We propose a distal magmatic-hydrothermal model in which these mixed fluids ascend through pre-existing structures, without a local magma chamber. This study provides new constraints on gold deposits in the West Qinling Belt by demonstrating that world-class mineralization can result from structural focusing of distal magmatic fluids.
{"title":"Deep structure and metallogenic model of the Zhaishang super-large gold deposit in the West Qinling Metallogenic Belt revealed by a 3-D Magnetotelluric study","authors":"Cheng Liu , Yongbao Gao , Gaofeng Ye , Han Li , Yiwei Song , Ke Yang , Chuan Yao , Sheng Jin , Liyong Wei , Baochun Li , Jien Dong","doi":"10.1016/j.oregeorev.2026.107175","DOIUrl":"10.1016/j.oregeorev.2026.107175","url":null,"abstract":"<div><div>The genesis of the world-class Zhaishang gold deposit in the West Qinling Metallogenic Belt has been debated due to its distal location (>26 km) from potential magmatic sources. This controversy stems largely from the lack of deep structural constraints. To resolve this, we conducted a high-resolution 3-D Magnetotelluric (MT) survey. Our model reveals a conductive channel (C1) connecting the deposit to the distal Jiaochangba pluton, illustrating a primary pathway for the ore-forming fluids. No significant concealed pluton exists beneath Zhaishang; instead, mineralization is hosted within the ancient crystalline basement, which served as both a gold source and a permeability barrier focusing fluids into traps. The data further reveal crustal decoupling at ∼ 25 km depth, explaining the preservation of Mesozoic ore-forming features. We propose a distal magmatic-hydrothermal model in which these mixed fluids ascend through pre-existing structures, without a local magma chamber. This study provides new constraints on gold deposits in the West Qinling Belt by demonstrating that world-class mineralization can result from structural focusing of distal magmatic fluids.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107175"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147423894","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 : 2026-03-01Epub Date: 2026-01-31DOI: 10.1016/j.oregeorev.2026.107148
Minghong Shen , He Wang , Jinheng Liu , Xiaoyu Zhang , Xiaofei Du , Song Zhang , Liang Huang , Mingze Cai , Min Wang
The Kumusayi-Shaliangxi lithium deposit in the Altyn Tagh orogenic belt, NW China, represents a central Late Triassic rare-metal system within the Paleo-Tethyan domain. This study integrates multi-mineral U-Pb geochronology, whole-rock geochemistry, Sr-Nd isotopes, and zircon Lu-Hf analyses to constrain the timing and sources of Li-rich pegmatites. U-Pb dating of cassiterite yields ages of 215.0 ± 6.3 Ma for Li-rich pegmatites and 237.0 ± 8.7 Ma for Li-poor pegmatites; similarly, columbite-group minerals (CGM) provide ages of 213.6 ± 2.1 Ma for Li-rich variants and 235.9 ± 2.5 Ma for Li-poor ones, revealing two discrete pulses of pegmatite magmatism in the Late Triassic, indicating that Li mineralization postdated barren pegmatite emplacement by approximately 25 Myr. Detrital zircon from host schists constrains a Neoproterozoic maximum depositional age (approximately 750 Ma), with inherited grains in pegmatites reflecting predominantly similar patterns but additionally containing subordinate Early Paleozoic zircons (420–460 Ma). The whole-rock geochemistry of the pegmatites displays LCT-type signatures (Li up to 15216 ppm, Cs up to 1581 ppm, Ta up to 499 ppm, A/CNK = 1.11–1.76), low ∑REE (4–13 ppm), and LREE-enriched patterns (LREE/HREE = 1.41–5.59). Nd isotopes (εNd(t) = −11.3 to −9.0; TDM2 = 1735–1949 Ma) and zircon Hf data (εHf(t) = −4.8 to +11.1; TDM2 = 1484–2077 Ma) overlap with host schists, supporting an origin predominantly from ancient metasediments, with subordinate contributions from Early Paleozoic granites. These results indicate that Late Triassic lithium mineralization in the Altyn Tagh represents an independent metallogenic event, distinct from earlier Caledonian lithium mineralization, and linked to post-orogenic transpression along the Altyn Tagh Fault during Late Triassic intracontinental deformation. By establishing a genetic link between this deposit and the vast Triassic West Kunlun-Songpan-Ganzi lithium metallogenic belt via provenance analysis, our study provides a new framework for rare-metal exploration in Tethyan-type orogens and identifies a substantial new frontier for strategic lithium resources amid growing global demand.
{"title":"Late Triassic lithium mineralization in the Kumusayi-Shaliangxi deposit (Altyn Tagh, NW China): provenance and high-precision timing constraints","authors":"Minghong Shen , He Wang , Jinheng Liu , Xiaoyu Zhang , Xiaofei Du , Song Zhang , Liang Huang , Mingze Cai , Min Wang","doi":"10.1016/j.oregeorev.2026.107148","DOIUrl":"10.1016/j.oregeorev.2026.107148","url":null,"abstract":"<div><div>The Kumusayi-Shaliangxi lithium deposit in the Altyn Tagh orogenic belt, NW China, represents a central Late Triassic rare-metal system within the Paleo-Tethyan domain. This study integrates multi-mineral U-Pb geochronology, whole-rock geochemistry, Sr-Nd isotopes, and zircon Lu-Hf analyses to constrain the timing and sources of Li-rich pegmatites. U-Pb dating of cassiterite yields ages of 215.0 ± 6.3 Ma for Li-rich pegmatites and 237.0 ± 8.7 Ma for Li-poor pegmatites; similarly, columbite-group minerals (CGM) provide ages of 213.6 ± 2.1 Ma for Li-rich variants and 235.9 ± 2.5 Ma for Li-poor ones, revealing two discrete pulses of pegmatite magmatism in the Late Triassic, indicating that Li mineralization postdated barren pegmatite emplacement by approximately 25 Myr. Detrital zircon from host schists constrains a Neoproterozoic maximum depositional age (approximately 750 Ma), with inherited grains in pegmatites reflecting predominantly similar patterns but additionally containing subordinate Early Paleozoic zircons (420–460 Ma). The whole-rock geochemistry of the pegmatites displays LCT-type signatures (Li up to 15216 ppm, Cs up to 1581 ppm, Ta up to 499 ppm, A/CNK = 1.11–1.76), low ∑REE (4–13 ppm), and LREE-enriched patterns (LREE/HREE = 1.41–5.59). Nd isotopes (ε<sub>Nd</sub>(t) = −11.3 to −9.0; T<sub>DM2</sub> = 1735–1949 Ma) and zircon Hf data (ε<sub>Hf</sub>(t) = −4.8 to +11.1; T<sub>DM2</sub> = 1484–2077 Ma) overlap with host schists, supporting an origin predominantly from ancient metasediments, with subordinate contributions from Early Paleozoic granites. These results indicate that Late Triassic lithium mineralization in the Altyn Tagh represents an independent metallogenic event, distinct from earlier Caledonian lithium mineralization, and linked to post-orogenic transpression along the Altyn Tagh Fault during Late Triassic intracontinental deformation. By establishing a genetic link between this deposit and the vast Triassic West Kunlun-Songpan-Ganzi lithium metallogenic belt via provenance analysis, our study provides a new framework for rare-metal exploration in Tethyan-type orogens and identifies a substantial new frontier for strategic lithium resources amid growing global demand.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107148"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192533","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 : 2026-03-01Epub Date: 2026-01-29DOI: 10.1016/j.oregeorev.2026.107144
Jiawei Feng , Jingjing Liu , Kaiyan Teng , Xiaolin Song , Niande Shang , Ning Wang , Rongkun Jia , Shumao Zhao
Natural gamma-ray logging is a key geophysical method used to measure the intensity of natural radioactivity in coal-bearing strata. The Lopingian Nb-Zr-REY-Ga polymetallic clay horizons in eastern Yunnan exhibit significant positive anomalies in gamma-ray logs, with anomaly intensity positively correlated with critical metal concentrations. However, the underlying cause of these geophysical responses has remained unclear. Therefore, this study investigated the distribution and enrichment of radioactive elements in polymetallic clay horizons. The results indicate that Th and U, rather than K2O, are the primary contributors to the gamma-ray anomalies. The radioactive elements (Th, U) and critical metals (Nb, Ta, Zr, Hf, REEs, Y) are primarily concentrated in accessory minerals, including zircon, parisite, monazite, and anatase, with minor amounts occurring in clay minerals. Moreover, Th and U exhibit highly consistent vertical variation trends and show significant positive correlations with critical metal elements. Importantly, the strong spatial overlap in both host minerals and distribution indicates that Th and U were more likely incorporated into these minerals through the substitution of critical metal elements. The symbiotic relationship and common host phases provide a theoretical basis for utilizing natural gamma-ray logging to explore critical metal resources within the Lopingian coal-bearing strata of southwestern China.
{"title":"Distribution and enrichment of radioactive elements (Th, U) in Nb-Zr-REY-Ga polymetallic clay horizons of the Late Permian (Lopingian) coal-bearing strata, eastern Yunnan, SW China: natural gamma-ray anomalies response to critical metals","authors":"Jiawei Feng , Jingjing Liu , Kaiyan Teng , Xiaolin Song , Niande Shang , Ning Wang , Rongkun Jia , Shumao Zhao","doi":"10.1016/j.oregeorev.2026.107144","DOIUrl":"10.1016/j.oregeorev.2026.107144","url":null,"abstract":"<div><div>Natural gamma-ray logging is a key geophysical method used to measure the intensity of natural radioactivity in coal-bearing strata. The Lopingian Nb-Zr-REY-Ga polymetallic clay horizons in eastern Yunnan exhibit significant positive anomalies in gamma-ray logs, with anomaly intensity positively correlated with critical metal concentrations. However, the underlying cause of these geophysical responses has remained unclear. Therefore, this study investigated the distribution and enrichment of radioactive elements in polymetallic clay horizons. The results indicate that Th and U, rather than K<sub>2</sub>O, are the primary contributors to the gamma-ray anomalies. The radioactive elements (Th, U) and critical metals (Nb, Ta, Zr, Hf, REEs, Y) are primarily concentrated in accessory minerals, including zircon, parisite, monazite, and anatase, with minor amounts occurring in clay minerals. Moreover, Th and U exhibit highly consistent vertical variation trends and show significant positive correlations with critical metal elements. Importantly, the strong spatial overlap in both host minerals and distribution indicates that Th and U were more likely incorporated into these minerals through the substitution of critical metal elements. The symbiotic relationship and common host phases provide a theoretical basis for utilizing natural gamma-ray logging to explore critical metal resources within the Lopingian coal-bearing strata of southwestern China.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107144"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146192534","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 : 2026-03-01Epub Date: 2026-02-22DOI: 10.1016/j.oregeorev.2026.107185
Wenxin Wu , Li He , Junkang Zhao , Zhengwei He , Xin Chen , Jiansheng Gong , Yongquan Que
To elucidate the deep metallogenic mechanisms of porphyry–skarn systems and to establish a remote sensing exploration model for high-altitude, cold regions, this study focuses on the Ga’erqiong–Galale Cu–Au mining district in Tibet. We integrated GF-5 hyperspectral data with Landsat-8, Sentinel-2, and GF-2 imagery to conduct mineral-scale alteration mapping, structural analysis, and multi-source data fusion. Employing a Minimum Noise Fraction (MNF)–Pixel Purity Inde (PPI)–n-Dimensional Visualizer (n-D Visualizer) workflow enhanced by geology-guided endmember optimization, the Spectral Angle Mapper method successfully identified 29 hydrothermal alteration minerals. Based on their diagnostic formation temperatures, we reconstructed the thermal zonation of the hydrothermal system. By synthesizing multiple lines of evidence, this study reveals, for the first time, the internal architecture of the mineralizing system: (Ⅰ) the high-temperature alteration core, circular structures, and aeromagnetic highs are spatially coincident, collectively indicating a concealed intrusion acting as the central heat and metal source; (Ⅱ) linear structures serve as preferential pathways for hydrothermal fluid transport, controlling a bead-like distribution of high-temperature minerals along ENE-WSW fault zones; and (Ⅲ) structural intersections and the margins of circular structures represent favorable nodes for ore precipitation. Consequently, we propose a coupled metallogenic system of “concealed intrusion (heat source) — throughgoing faults (fluid pathways) — structural intersections (precipitation nodes) ”. This study demonstrates the powerful capability of GF-5 hyperspectral data to delineate the core and architecture of hydrothermal systems finely. When integrated with geophysical and other multi-source datasets, it provides a robust technical framework for enhancing the understanding of regional metallogeny and defining exploration targets in analogous Tibetan terrains.
{"title":"Alteration mineral mapping and thermal anomaly reconstruction based on GF-5 data: A case study of the Ga’erqiong–Galale Cu–Au mining district, Tibet","authors":"Wenxin Wu , Li He , Junkang Zhao , Zhengwei He , Xin Chen , Jiansheng Gong , Yongquan Que","doi":"10.1016/j.oregeorev.2026.107185","DOIUrl":"10.1016/j.oregeorev.2026.107185","url":null,"abstract":"<div><div>To elucidate the deep metallogenic mechanisms of porphyry–skarn systems and to establish a remote sensing exploration model for high-altitude, cold regions, this study focuses on the Ga’erqiong–Galale Cu–Au mining district in Tibet. We integrated GF-5 hyperspectral data with Landsat-8, Sentinel-2, and GF-2 imagery to conduct mineral-scale alteration mapping, structural analysis, and multi-source data fusion. Employing a Minimum Noise Fraction (MNF)–Pixel Purity Inde (PPI)–n-Dimensional Visualizer (n-D Visualizer) workflow enhanced by geology-guided endmember optimization, the Spectral Angle Mapper method successfully identified 29 hydrothermal alteration minerals. Based on their diagnostic formation temperatures, we reconstructed the thermal zonation of the hydrothermal system. By synthesizing multiple lines of evidence, this study reveals, for the first time, the internal architecture of the mineralizing system: (Ⅰ) the high-temperature alteration core, circular structures, and aeromagnetic highs are spatially coincident, collectively indicating a concealed intrusion acting as the central heat and metal source; (Ⅱ) linear structures serve as preferential pathways for hydrothermal fluid transport, controlling a bead-like distribution of high-temperature minerals along ENE-WSW fault zones; and (Ⅲ) structural intersections and the margins of circular structures represent favorable nodes for ore precipitation. Consequently, we propose a coupled metallogenic system of “concealed intrusion (heat source) — throughgoing faults (fluid pathways) — structural intersections (precipitation nodes) ”. This study demonstrates the powerful capability of GF-5 hyperspectral data to delineate the core and architecture of hydrothermal systems finely. When integrated with geophysical and other multi-source datasets, it provides a robust technical framework for enhancing the understanding of regional metallogeny and defining exploration targets in analogous Tibetan terrains.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107185"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147422363","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 : 2026-03-01Epub Date: 2026-02-15DOI: 10.1016/j.oregeorev.2026.107181
Yu Liu , Binghan Chen , Zhibin Li , Jie Li , Yunlei Feng , Juquan Zhang , Huiqing Geng , Qunfeng Miao
The Huashi Rb deposit on the northern margin of the North China Craton is a super-large, granite-hosted Rb deposit containing ∼ 1.8 Mt Rb2O at an average grade of 0.18 wt%. The deposit is genetically linked to the Madi granitic pluton, which is dominated by fine-grained alkali-feldspar granite and porphyritic amazonite-bearing alkali-feldspar granite. In this study, we integrate whole-rock geochemistry, zinnwaldite geochemistry, and U-Pb geochronology to constrain the mechanisms and age of Rb enrichment. The Madi pluton exhibits high SiO2 (74.22–76.23 wt%) and alkali contents, low MgO, FeO, CaO, TiO2, and P2O5. It is strongly enriched in Rb, Th, Ta, and Hf but markedly depleted in Ba, Sr, and Eu. The rocks have low total rare earth element contents (51.53–61.23 ppm) with light-REE enrichment and pronounced negative Eu anomalies (Eu/Eu* = 0.02–0.06), accompanied by low non-CHARAC (charge‑radius‑controlled) trace-element ratios (e.g., Zr/Hf = 8.08–10.49, Nb/Ta = 3.04–4.59). These geochemical features are indicative of extreme magmatic fractionation. Together with a weakly peraluminous affinity (A/CNK = 1.01–1.06) and a negative correlation between P2O5 and SiO2, they collectively define the pluton as a highly fractionated I-type granite. Rubidium is primarily hosted in potassium feldspar and zinnwaldite, with secondary zinnwaldite containing higher Rb2O (∼1.0 wt%) than primary varieties (∼0.7 wt%). Elevated F and Rb concentrations in metasomatic secondary zinnwaldite, combined with systematic decreases in whole-rock Zr/Hf, Nb/Ta, and K/Rb ratios with increasing TE1,3 values, indicates that fluid-rock interaction during the magmatic-hydrothermal transition significantly upgraded Rb concentrations. U-Pb dating of magmatic monazite and columbite yields concordant ages of 174.3 ± 1.7 Ma and 175.5 ± 3.6 Ma, respectively, constraining the magmatic stage and initial Rb enrichment. In contrast, hydrothermally altered zircon records a younger age of 163.8 ± 1.6 Ma, likely interpreted as a later independent hydrothermal event. We propose a two-stage enrichment model: (1) initial concentration into primary zinnwaldite and K-feldspar by extreme fractional crystallization during the magmatic stage (∼175–174 Ma), followed by (2) further upgrading of Rb into secondary zinnwaldite through fluid-rock interaction with exsolved F-rich hydrothermal fluids. The ∼ 175–174 Ma mineralization age highlights the Middle Jurassic as a significant period of concurrent magmatism and metallogeny in this region.
{"title":"Rb mineralization mechanisms and age in the Huashi deposit northern margin of the North China Craton: Constraints from zinnwaldite geochemistry, whole-rock geochemistry, and monazite–columbite–zircon geochronology","authors":"Yu Liu , Binghan Chen , Zhibin Li , Jie Li , Yunlei Feng , Juquan Zhang , Huiqing Geng , Qunfeng Miao","doi":"10.1016/j.oregeorev.2026.107181","DOIUrl":"10.1016/j.oregeorev.2026.107181","url":null,"abstract":"<div><div>The Huashi Rb deposit on the northern margin of the North China Craton is a super-large, granite-hosted Rb deposit containing ∼ 1.8 Mt Rb<sub>2</sub>O at an average grade of 0.18 wt%. The deposit is genetically linked to the Madi granitic pluton, which is dominated by fine-grained alkali-feldspar granite and porphyritic amazonite-bearing alkali-feldspar granite. In this study, we integrate whole-rock geochemistry, zinnwaldite geochemistry, and U-Pb geochronology to constrain the mechanisms and age of Rb enrichment. The Madi pluton exhibits high SiO<sub>2</sub> (74.22–76.23 wt%) and alkali contents, low MgO, FeO, CaO, TiO<sub>2</sub>, and P<sub>2</sub>O<sub>5</sub>. It is strongly enriched in Rb, Th, Ta, and Hf but markedly depleted in Ba, Sr, and Eu. The rocks have low total rare earth element contents (51.53–61.23 ppm) with light-REE enrichment and pronounced negative Eu anomalies (Eu/Eu* = 0.02–0.06), accompanied by low non-CHARAC (charge‑radius‑controlled) trace-element ratios (e.g., Zr/Hf = 8.08–10.49, Nb/Ta = 3.04–4.59). These geochemical features are indicative of extreme magmatic fractionation. Together with a weakly peraluminous affinity (A/CNK = 1.01–1.06) and a negative correlation between P<sub>2</sub>O<sub>5</sub> and SiO<sub>2</sub>, they collectively define the pluton as a highly fractionated I-type granite. Rubidium is primarily hosted in potassium feldspar and zinnwaldite, with secondary zinnwaldite containing higher Rb<sub>2</sub>O (∼1.0 wt%) than primary varieties (∼0.7 wt%). Elevated F and Rb concentrations in metasomatic secondary zinnwaldite, combined with systematic decreases in whole-rock Zr/Hf, Nb/Ta, and K/Rb ratios with increasing TE<sub>1</sub>,<sub>3</sub> values, indicates that fluid-rock interaction during the magmatic-hydrothermal transition significantly upgraded Rb concentrations. U-Pb dating of magmatic monazite and columbite yields concordant ages of 174.3 ± 1.7 Ma and 175.5 ± 3.6 Ma, respectively, constraining the magmatic stage and initial Rb enrichment. In contrast, hydrothermally altered zircon records a younger age of 163.8 ± 1.6 Ma, likely interpreted as a later independent hydrothermal event. We propose a two-stage enrichment model:<!--> <!-->(1) initial concentration into primary zinnwaldite and K-feldspar by extreme fractional crystallization during the magmatic stage (∼175–174 Ma), followed by (2) further upgrading of Rb into secondary zinnwaldite through fluid-rock interaction with exsolved F-rich hydrothermal fluids.<!--> <!-->The ∼ 175–174 Ma mineralization age highlights the Middle Jurassic as a significant period of concurrent magmatism and metallogeny in this region.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107181"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147422365","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 : 2026-03-01Epub Date: 2026-02-13DOI: 10.1016/j.oregeorev.2026.107173
Haoran Chen , Huawen Cao , Dianmeng Lin , Fangyue Wang , Shuhao Liang , Feiyang Yao , Jianfang Zhang , Zhen Wang , Yuandong Liu , Gangyang Zhang , Hao Zou
South China hosts numerous fluorite deposits of significant economic value. However, the mechanisms responsible for the extraordinary enrichment of fluorine remain uncertain. The Kengxi hydrothermal vein-type fluorite deposit in Zhejiang, South China, is well known for its high grade and large scale. On the basis of detailed geological field investigations, Sm–Nd isochron dating, cathodoluminescence (CL) observations, fluid inclusion studies, and in situ laser ablation inductively coupled plasma mass spectroscopy (LA‒ICP‒MS) trace element and H–O isotope analyses were conducted for fluorite from different mineralization stages. The results indicated that the ore-forming fluids constitute a medium–low-temperature (homogenization temperatures of 120–170 °C), low-salinity (0–5 wt% NaCl eqv.) H2O–NaCl system. The δD values of fluorite ranged from –75.4‰ to –47.2‰, and the δ18O values ranged from –7.34‰ to –3.72‰. The H–O isotopic compositions suggested that the ore-forming fluids were primarily derived from meteoric water. Fluorite Sm‒Nd isochron dating yielded an age of 16.1 ± 3.1 Ma (MSWD = 0.99), which represents the youngest fluorite mineralization event reported in China to date. Orebody characteristics and ore textures revealed four mineralization stages in the deposit. CL features and in situ LA‒ICP‒MS microanalyses revealed the characteristics of dissolution–reprecipitation of fluorite across the different stages. The fluorite samples exhibited negative εNd(16.1 Ma) values (–8.68 to –8.53), indicating a contribution from crustal materials. In this study, a geothermal water system driven by the geothermal gradient was proposed as the key factor leading to mineralization events. The multistage textures suggest an episodic process of fracture reactivation → fluid convection → mineral precipitation → channel sealing, which constitutes the key mineralization mechanism for the Miocene Kengxi fluorite deposit. We conclude that fluorite deposits controlled by geothermal water systems experienced superimposed mineralization processes. This understanding is crucial for elucidating the genesis of high-grade, compositionally simple fluorite deposits and provides new insights into the reactivation and enrichment processes of fluorite deposits in geothermal water systems.
{"title":"Multistage F-rich hydrothermal fluids led to a large-scale high-grade fluorite deposit during the Miocene (16Ma) in South China","authors":"Haoran Chen , Huawen Cao , Dianmeng Lin , Fangyue Wang , Shuhao Liang , Feiyang Yao , Jianfang Zhang , Zhen Wang , Yuandong Liu , Gangyang Zhang , Hao Zou","doi":"10.1016/j.oregeorev.2026.107173","DOIUrl":"10.1016/j.oregeorev.2026.107173","url":null,"abstract":"<div><div>South China hosts numerous fluorite deposits of significant economic value. However, the mechanisms responsible for the extraordinary enrichment of fluorine remain uncertain. The Kengxi hydrothermal vein-type fluorite deposit in Zhejiang, South China, is well known for its high grade and large scale. On the basis of detailed geological field investigations, Sm–Nd isochron dating, cathodoluminescence (CL) observations, fluid inclusion studies, and in situ laser ablation inductively coupled plasma mass spectroscopy (LA‒ICP‒MS) trace element and H–O isotope analyses were conducted for fluorite from different mineralization stages. The results indicated that the ore-forming fluids constitute a medium–low-temperature (homogenization temperatures of 120–170 °C), low-salinity (0–5 wt% NaCl eqv.) H<sub>2</sub>O–NaCl system. The δD values of fluorite ranged from –75.4‰ to –47.2‰, and the δ<sup>18</sup>O values ranged from –7.34‰ to –3.72‰. The H–O isotopic compositions suggested that the ore-forming fluids were primarily derived from meteoric water. Fluorite Sm‒Nd isochron dating yielded an age of 16.1 ± 3.1 Ma (MSWD = 0.99), which represents the youngest fluorite mineralization event reported in China to date. Orebody characteristics and ore textures revealed four mineralization stages in the deposit. CL features and in situ LA‒ICP‒MS microanalyses revealed the characteristics of dissolution–reprecipitation of fluorite across the different stages. The fluorite samples exhibited negative εNd<sub>(16.1 Ma)</sub> values (–8.68 to –8.53), indicating a contribution from crustal materials. In this study, a geothermal water system driven by the geothermal gradient was proposed as the key factor leading to mineralization events. The multistage textures suggest an episodic process of fracture reactivation → fluid convection → mineral precipitation → channel sealing, which constitutes the key mineralization mechanism for the Miocene Kengxi fluorite deposit. We conclude that fluorite deposits controlled by geothermal water systems experienced superimposed mineralization processes. This understanding is crucial for elucidating the genesis of high-grade, compositionally simple fluorite deposits and provides new insights into the reactivation and enrichment processes of fluorite deposits in geothermal water systems.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107173"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147423293","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 : 2026-03-01Epub Date: 2026-02-15DOI: 10.1016/j.oregeorev.2026.107182
Yike He, Jiahao Zheng
Layered intrusions are primary reservoirs for Fe–Ti oxide mineralization, preserving crucial records of the crystallization and solidification of mafic magmas. Notably, symplectites, a widespread microstructure in these intrusions, serve as key evidence for melt migration and post-cumulus disequilibrium. However, the formation of symplectites remains unclear. This study investigates symplectites from two representative layered intrusions associated with Fe–Ti oxide ores (Niumaoquan and Weiya) in the eastern Tianshan, comparing primocryst and symplectite Fe–Ti oxide textures. We infer that symplectite formation preceded Fe–Ti oxide re-equilibration and was driven by melt percolation and reaction. This interpretation is supported by Fe–Ti oxide-based thermo-oxybarometric estimates, which indicate that both types of Fe–Ti oxides underwent re-equilibration at temperatures of approximately 500–700°C and corresponding fO2 (ΔFMQ −4 to 0). Mass-balance calculations indicate that symplectite formation required an external input of Fe and Si. Based on these constraints, we propose a model in which a late-stage residual melt, relatively poor in Fe but rich in Si, reacted with primocryst Fe–Ti oxides, progressively dissolving them while becoming enriched in Fe and retaining Si. Subsequently, the Fe-Si-bearing melt reacted with primocryst olivine: Si facilitated its replacement by orthopyroxene, while Fe precipitated as Fe–Ti oxides within the symplectites. Our results demonstrate that the formation of Fe–Ti oxide–orthopyroxene symplectites reflects both the behavior of immiscible Fe- and Si-rich melt components and late-stage re-equilibration, and emphasizes melt migration and reaction during post-magmatic evolution.
{"title":"Fe–Ti oxide–orthopyroxene symplectites in the eastern Tianshan layered intrusions, NW China: Insights into late-stage reactive melt flow and re-equilibration","authors":"Yike He, Jiahao Zheng","doi":"10.1016/j.oregeorev.2026.107182","DOIUrl":"10.1016/j.oregeorev.2026.107182","url":null,"abstract":"<div><div>Layered intrusions are primary reservoirs for Fe–Ti oxide mineralization, preserving crucial records of the crystallization and solidification of mafic magmas. Notably, symplectites, a widespread microstructure in these intrusions, serve as key evidence for melt migration and post-cumulus disequilibrium. However, the formation of symplectites remains unclear. This study investigates symplectites from two representative layered intrusions associated with Fe–Ti oxide ores (Niumaoquan and Weiya) in the eastern Tianshan, comparing primocryst and symplectite Fe–Ti oxide textures. We infer that symplectite formation preceded Fe–Ti oxide re-equilibration and was driven by melt percolation and reaction.<!--> <!-->This interpretation is supported by Fe–Ti oxide-based thermo-oxybarometric estimates, which indicate that both types of Fe–Ti oxides underwent re-equilibration at temperatures of approximately 500–700°C and corresponding <em>f</em>O<sub>2</sub> (ΔFMQ −4 to 0). Mass-balance calculations indicate that symplectite formation required an external input of Fe and Si. Based on these constraints, we propose a model in which a late-stage residual melt, relatively poor in Fe but rich in Si, reacted with primocryst Fe–Ti oxides, progressively dissolving them while becoming enriched in Fe and retaining Si. Subsequently, the Fe-Si-bearing melt reacted with primocryst olivine: Si facilitated its replacement by orthopyroxene, while Fe precipitated as Fe–Ti oxides within the symplectites. Our results demonstrate that the formation of Fe–Ti oxide–orthopyroxene symplectites reflects both the behavior of immiscible Fe- and Si-rich melt components and late-stage re-equilibration, and emphasizes melt migration and reaction during post-magmatic evolution.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107182"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147423895","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 : 2026-03-01Epub Date: 2026-02-14DOI: 10.1016/j.oregeorev.2026.107176
Jing Wu , Yue Wu , Dengfei Duan , Feng Sun , Junqin Wang , Fanyan Zhou , Yan Liu
The South China host various types of uranium deposits, including granite-hosted, volcanic-hosted, and sedimentary rock-hosted (carbonaceous-siliceous-pelitic rocks) uranium deposits. However, the genesis of carbonate-hosted uranium deposits, an important subtype of the sedimentary rock-hosted uranium deposit, remains insufficiently investigated. Here, we conducted in situ U-Pb dating, Sr isotopes analysis, trace elements and fluid inclusion on the Shaping uranium deposit hosted in the Ordovician dolostone in Guizhou Province. The calcite U-Pb age of 80.5–83.0 Ma indicates Late Cretaceous mineralization, classifying the deposit as epigenetic. The ore-stage calcite exhibits 87Sr/86Sr ratios ranging from 0.70851 to 0.70888, comparable to unaltered host rocks (0.70910–0.70948). The coupled relationship between high U contents in unaltered host rocks and Sr isotopic signatures indicates that uranium mineralization originated from fluid extraction of U from the carbonate rocks. Ore-stage calcite exhibiting low Fe concentrations (288–348 ppm) and strong negative Eu anomaly, which suggests an oxidizing fluid environment. Simultaneously, low-salinity fluid inclusions (<4.6 wt% equiv. NaCl) demonstrate meteoric water-dominated ore-forming fluids.
Based on our study and integrating previous research, we present a revised metallogenic model for the Shaping deposit. During the late Cretaceous (∼80 Ma), the study area experienced lithospheric extension induced by the rollback of the Paleo-Pacific Plate (or Neo-Tethyan slab), resulting in regional thermal anomalies. The high heat flow heats meteoric water infiltrating along shallow crustal fault systems, forming a deep-circulation hydrothermal system. These oxided (high fO2) fluids leached U from marine carbonates strata and subsequently migrated upward along fault systems, where they interacted with reducing agents (e.g., organic matter) in the host strata to induce U mineralization.
{"title":"The genesis of the Shaping carbonate-hosted uranium deposit, South China: Constraints from in situ calcite U-Pb dating and Sr isotopes","authors":"Jing Wu , Yue Wu , Dengfei Duan , Feng Sun , Junqin Wang , Fanyan Zhou , Yan Liu","doi":"10.1016/j.oregeorev.2026.107176","DOIUrl":"10.1016/j.oregeorev.2026.107176","url":null,"abstract":"<div><div>The South China host various types of uranium deposits, including granite-hosted, volcanic-hosted, and sedimentary rock-hosted (carbonaceous-siliceous-pelitic rocks) uranium deposits. However, the genesis of carbonate-hosted uranium deposits, an important subtype of the sedimentary rock-hosted uranium deposit, remains insufficiently investigated. Here, we conducted in situ U-Pb dating, Sr isotopes analysis, trace elements and fluid inclusion on the Shaping uranium deposit hosted in the Ordovician dolostone in Guizhou Province. The calcite U-Pb age of 80.5–83.0 Ma indicates Late Cretaceous mineralization, classifying the deposit as epigenetic. The ore-stage calcite exhibits <sup>87</sup>Sr/<sup>86</sup>Sr ratios ranging from 0.70851 to 0.70888, comparable to unaltered host rocks (0.70910–0.70948). The coupled relationship between high U contents in unaltered host rocks and Sr isotopic signatures indicates that uranium mineralization originated from fluid extraction of U from the carbonate rocks. Ore-stage calcite exhibiting low Fe concentrations (288–348 ppm) and strong negative Eu anomaly, which suggests an oxidizing fluid environment. Simultaneously, low-salinity fluid inclusions (<4.6 wt% equiv. NaCl) demonstrate meteoric water-dominated ore-forming fluids.</div><div>Based on our study and integrating previous research, we present a revised metallogenic model for the Shaping deposit. During the late Cretaceous (∼80 Ma), the study area experienced lithospheric extension induced by the rollback of the Paleo-Pacific Plate (or Neo-Tethyan slab), resulting in regional thermal anomalies. The high heat flow heats meteoric water infiltrating along shallow crustal fault systems, forming a deep-circulation hydrothermal system. These oxided (high <em>f</em>O<sub>2</sub>) fluids leached U from marine carbonates strata and subsequently migrated upward along fault systems, where they interacted with reducing agents (e.g., organic matter) in the host strata to induce U mineralization.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107176"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147423290","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}
The eastern Gangdese-Nyainqêntanglha belt is a major Pb-Zn province in China, yet persistent debates over ore genesis—specifically the links between mineralization, metal sources, and multiple magmatic events—have hindered robust metallogenic model and exploration targeting. To resolve these uncertainties, we present an integrated study of the Dongzhongla deposit (∼0.5 Mt Pb + Zn @ 13 wt%; 15,000 t Cu @ 0.5 wt%) within this belt, combining detailed geological fieldwork, ore geology, geochronology (zircon, garnet, apatite, titanite U-Pb), and S-Pb-Sr-Nd isotope geochemistry of sulfides and apatite. Orebodies occur as veins and lenses (sphalerite, galena, chalcopyrite) localized at granite porphyry–limestone/marble contacts, slate interfaces, and fracture zones, with main mineralization progressing through prograde/retrograde skarn, quartz-sulfide stages. Zircon U-Pb dating reveals an Early Cretaceous magmatic event from 128 ± 1 Ma to 124 ± 2 Ma for the spatially associated granite porphyry. Crucially, hydrothermal garnet (60.7 ± 2.6 Ma), apatite (60.6 ± 3.7 Ma), and titanite (60.8 ± 3.5 Ma) yield consistent Paleocene U-Pb ages. This significant age discrepancy demonstrates the granite porphyry is genetically unrelated to mineralization, directly linking ore formation instead to the Indian-Asian main collisional stage and regional Paleocene skarn Pb-Zn deposits. Sulfide δ34S values (−3.5‰ to 4.8‰) indicate a dominantly magmatic sulfur source. In situ sulfide Pb isotopes (206Pb/204Pb: 18.642–18.671, 207Pb/204Pb:15.701–15.731, 208Pb/204Pb:39.109–39.251) show limited variation, plotting within the Nyainqêntanglha Group crystalline basement field and above the upper crustal evolution curve, supporting a lead source from this ancient basement. Hydrothermal apatite Sr-Nd isotopes resemble Paleocene-Eocene Gangdese-Nyainqêntanglha skarn-related granitoids, confirming Pb-Zn deposit related to Paleocene granitoids derived from ancient Lhasa terrane continental crust. These results demonstrate that the Dongzhongla deposit is a fault-controlled, distal skarn system genetically linked to a concealed Paleocene intrusion, which sourced from the ancient crust of the Lhasa terrane. Consequently, fault extensions proximal to the concealed intrusion represent key targets for future regional exploration.
{"title":"Age, alteration, and mineralization of fault-controlled distal skarn Pb-Zn deposit: Example from Dongzhongla deposit of eastern Gangdese-Nyainqêntanglha belt, Xizang","authors":"Zezhang Yu , Xin Chen , Yong Zhang , Shunli Zheng , Xiaoyi Wang , Shunbao Gao , Youye Zheng , Fuzhi Gong","doi":"10.1016/j.oregeorev.2026.107165","DOIUrl":"10.1016/j.oregeorev.2026.107165","url":null,"abstract":"<div><div>The eastern Gangdese-Nyainqêntanglha belt is a major Pb-Zn province in China, yet persistent debates over ore genesis—specifically the links between mineralization, metal sources, and multiple magmatic events—have hindered robust metallogenic model and exploration targeting. To resolve these uncertainties, we present an integrated study of the Dongzhongla deposit (∼0.5 Mt Pb + Zn @ 13 wt%; 15,000 t Cu @ 0.5 wt%) within this belt, combining detailed geological fieldwork, ore geology, geochronology (zircon, garnet, apatite, titanite U-Pb), and S-Pb-Sr-Nd isotope geochemistry of sulfides and apatite. Orebodies occur as veins and lenses (sphalerite, galena, chalcopyrite) localized at granite porphyry–limestone/marble contacts, slate interfaces, and fracture zones, with main mineralization progressing through prograde/retrograde skarn, quartz-sulfide stages. Zircon U-Pb dating reveals an Early Cretaceous magmatic event from 128 ± 1 Ma to 124 ± 2 Ma for the spatially associated granite porphyry. Crucially, hydrothermal garnet (60.7 ± 2.6 Ma), apatite (60.6 ± 3.7 Ma), and titanite (60.8 ± 3.5 Ma) yield consistent Paleocene U-Pb ages. This significant age discrepancy demonstrates the granite porphyry is genetically unrelated to mineralization, directly linking ore formation instead to the Indian-Asian main collisional stage and regional Paleocene skarn Pb-Zn deposits. Sulfide δ<sup>34</sup>S values (−3.5‰ to 4.8‰) indicate a dominantly magmatic sulfur source. In situ sulfide Pb isotopes (<sup>206</sup>Pb/<sup>204</sup>Pb: 18.642–18.671, <sup>207</sup>Pb/<sup>204</sup>Pb:15.701–15.731, <sup>208</sup>Pb/<sup>204</sup>Pb:39.109–39.251) show limited variation, plotting within the Nyainqêntanglha Group crystalline basement field and above the upper crustal evolution curve, supporting a lead source from this ancient basement. Hydrothermal apatite Sr-Nd isotopes resemble Paleocene-Eocene Gangdese-Nyainqêntanglha skarn-related granitoids, confirming Pb-Zn deposit related to Paleocene granitoids derived from ancient Lhasa terrane continental crust. These results demonstrate that the Dongzhongla deposit is a fault-controlled, distal skarn system genetically linked to a concealed Paleocene intrusion, which sourced from the ancient crust of the Lhasa terrane. Consequently, fault extensions proximal to the concealed intrusion represent key targets for future regional exploration.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107165"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147423292","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 : 2026-03-01Epub Date: 2026-02-22DOI: 10.1016/j.oregeorev.2026.107183
Chong Cao , Shujing Wu , Ping Shen , Haoxuan Feng , Shuzhi Wang , Xinming Liu , Yaoqing Luo , Wenzhe Zuo , Zhihua Guo , Lina Liu
This study investigates apatite geochemistry and textures in the Koktokay pegmatites (No. 1, No. 2, No. 3) and associated muscovite-albite granite (NW China) to constrain magmatic evolution and controls on Li mineralization. The results demonstrate that lithium content in apatite robustly indicates mineralization potential. Pegmatite No. 3 exhibits the strongest Li enrichment (6.33–13.67 ppm; average: 10.68 ppm), followed by No. 1 pegmatite (4.05–7.56 ppm; avg. 5.75 ppm) and muscovite-albite granite (2.54–11.77 ppm; avg. 5.05 ppm). In contrast, the barren No. 2 pegmatite shows significantly lower values (0.28–5.91 ppm; avg. 2.08 ppm). Chondrite-normalized REE patterns delineate two distinct apatite groups (Group I and Group II), indicating derivation from highly differentiated melts through feldspar accumulation (Group I apatite: ∑REE+Y typically < 200 ppm with positive Eu anomalies) and prolonged feldspar-monazite fractionation (Group II apatite: ∑REE+Y typically > 200 ppm with negative Eu anomalies). Geochemical coherence (e.g., CaO, MnO, FeO, ∑REE+Y, HREE/LREE ratios of 2.2–2.4), nearly identical REE contents and distribution patterns in Group II apatite, concordant geochronological evidence, and analogous crystallization temperatures collectively support a cogenetic relationship between No. 3 pegmatite and the muscovite-albite granite. Notably, No. 3 pegmatite crystallized earlier, as evidenced by primitive Group I apatite. The divergent evolutionary paths revealed by apatite HREE/LREE fractionation diagram across the three pegmatites, when integrated with previously documented significantly distinct δ7Li values and mica Li vs. K/Rb trends, collectively confirm multiphase magmatism as the genesis of these pegmatites. Li enrichment in pegmatites from the Koktokay field is predominantly governed by source-region Li abundance and partial melting processes, rather than the extent of magmatic differentiation. This is evidenced by Li exhibiting no significant correlation with key indicators such as apatite MnO, FeO, ΣREE+Y, Y/Ho, or trace element indices (TE1,3). The Li compositional contrast between the cogenetic No. 3 pegmatite and muscovite-albite granite originates from liquid immiscibility: Li, Mn, Fe, and Be preferentially partition into volatile-rich B-type melts. These melts form high-BSE-intensity, Mn-Fe-rich apatite – a critical phase for No. 3 pegmatite mineralization – whereas conjugate volatile-poor A-type melts generate the granite.
{"title":"Apatite chemistry as an indicator of pegmatitic magmatic evolution and rare-metal mineralization: Evidence from the Koktokay pegmatite field, Xinjiang, NW China","authors":"Chong Cao , Shujing Wu , Ping Shen , Haoxuan Feng , Shuzhi Wang , Xinming Liu , Yaoqing Luo , Wenzhe Zuo , Zhihua Guo , Lina Liu","doi":"10.1016/j.oregeorev.2026.107183","DOIUrl":"10.1016/j.oregeorev.2026.107183","url":null,"abstract":"<div><div>This study investigates apatite geochemistry and textures in the Koktokay pegmatites (No. 1, No. 2, No. 3) and associated muscovite-albite granite (NW China) to constrain magmatic evolution and controls on Li mineralization. The results demonstrate that lithium content in apatite robustly indicates mineralization potential. Pegmatite No. 3 exhibits the strongest Li enrichment (6.33–13.67 ppm; average: 10.68 ppm), followed by No. 1 pegmatite (4.05–7.56 ppm; avg. 5.75 ppm) and muscovite-albite granite (2.54–11.77 ppm; avg. 5.05 ppm). In contrast, the barren No. 2 pegmatite shows significantly lower values (0.28–5.91 ppm; avg. 2.08 ppm). Chondrite-normalized REE patterns delineate two distinct apatite groups (Group I and Group II), indicating derivation from highly differentiated melts through feldspar accumulation (Group I apatite: ∑REE+Y typically < 200 ppm with positive Eu anomalies) and prolonged feldspar-monazite fractionation (Group II apatite: ∑REE+Y typically > 200 ppm with negative Eu anomalies). Geochemical coherence (e.g., CaO, MnO, FeO, ∑REE+Y, HREE/LREE ratios of 2.2–2.4), nearly identical REE contents and distribution patterns in Group II apatite, concordant geochronological evidence, and analogous crystallization temperatures collectively support a cogenetic relationship between No. 3 pegmatite and the muscovite-albite granite. Notably, No. 3 pegmatite crystallized earlier, as evidenced by primitive Group I apatite. The divergent evolutionary paths revealed by apatite HREE/LREE fractionation diagram across the three pegmatites, when integrated with previously documented significantly distinct δ<sup>7</sup>Li values and mica Li<!--> <!-->vs.<!--> <!-->K/Rb trends, collectively confirm multiphase magmatism as the genesis of these pegmatites. Li enrichment in pegmatites from the Koktokay field is predominantly governed by source-region Li abundance and partial melting processes, rather than the extent of magmatic differentiation. This is evidenced by Li exhibiting no significant correlation with key indicators such as apatite MnO, FeO, ΣREE+Y, Y/Ho, or trace element indices (TE<sub>1,3</sub>). The Li compositional contrast between the cogenetic No. 3 pegmatite and muscovite-albite granite originates from liquid immiscibility: Li, Mn, Fe, and Be preferentially partition into volatile-rich B-type melts. These melts form high-BSE-intensity, Mn-Fe-rich apatite – a critical phase for No. 3 pegmatite mineralization – whereas conjugate volatile-poor A-type melts generate the granite.</div></div>","PeriodicalId":19644,"journal":{"name":"Ore Geology Reviews","volume":"190 ","pages":"Article 107183"},"PeriodicalIF":3.6,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147422361","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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