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Multistage tungsten mineralization was recently discovered in the Mamupu copper‐polymetallic deposit in the southern Yulong porphyry copper belt (YPCB), Tibet. This study reports the results of cathodoluminescence, trace element and Sr isotope analyses of Mamupu scheelite samples, undertaken in order to better constrain the mechanism of W mineralization and the sources of the ore‐forming fluids. Three different types of scheelite are identified in the Mamupu deposit: scheelite A (Sch A) mainly occurs in breccias during the prograde stage, scheelite B (Sch B) forms in the chlorite‐epidote alteration zone in the retrograde stage, while scheelite C (Sch C) occurs in distal quartz sulfide veins. The extremely high Mo content and negative Eu anomaly in Sch A represent high oxygen fugacity in the prograde stage. Compared with ore‐related porphyries, Sch A has a similar REE pattern, but with higher ΣREE, more depleted HREE and slightly lower (87Sr/86Sr)i ratios. These features suggest that Sch A is genetically related to ore‐related porphyries, but extensive interaction with carbonate surrounding rocks affects the final REE and Sr isotopic composition. Sch B shows dark (Sch B‐I) and light (Sch B‐II) domains under CL imaging. From Sch B‐I to Sch B‐II, LREEs are gradually depleted, with MREEs being gradually enriched. Sch C has the highest LREE/HREE ratio, which indicates that it inherited the geochemical characteristics of fluids after the precipitation of HREE‐rich minerals, such as diopside and garnet, in the early prograde stage. The Mo content in Sch B and Sch C gradually decreased, indicating that the oxygen fugacity of the fluids changed from oxidative in the early stages to reductive in the later, the turbulent Eu anomaly in Sch B and Sch C indicating that the Eu anomaly in the Mamupu scheelite is not solely controlled by oxygen fugacity. The extensive interaction of magmatic‐hydrothermal fluids and carbonate provides the necessary Ca2+ for the precipitation of scheelite in the Mamupu deposit. [ABSTRACT FROM AUTHOR]

In order to understand how the metallogenic process of porphyry deposit specifically and directly respond to regional uplifting and exhumation, we compiled previous fluid inclusion data of 32 porphyry deposits in China by recalculating the fluid trapping depths and trapping depth reduction magnitude from early to late mineralization stage veins. The data reveal that the average trapping pressure ratio (Ave TPE/TPL) between early‐ and late‐stage veins of the these deposits are 1.2–18.4, mainly in the range of 1.35–5.83, with average trapping pressure reduction (1–Ave TPL/TPE) from early‐ to late‐ stage veins are 17%–95%, and mainly in the range of 25%–83%. The fluid trapping pressure based mineralization depths most of the porphyry deposits in China had decreased from early to late vein stages by at least 450 m (900–5800 m predominant), or greater than 950 m when take the average depth reduction value, which is greater than the current gap between early‐ and late‐ stage veins of each deposit. We propose that the apparently greater mineralization depth reduction magnitude than the current elevation gaps between early and late veins are likely a consequence of syn‐mineralization uplifting and exhumation process that often occurs in porphyry systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zircon U-Pb dating results refine the emplacement age of the Xikeng pluton at 232.2 ± 1.1 Ma. • Cassiterite and wolframite U-Pb dating constrains the timing of W-Sn mineralization from Xigkeng deposit at 228.4 ± 0.90 Ma and 227.8 ± 1.60 Ma, respectively. • Source of magmatic materials was derived from reworking of crustal materials under an extensional setting. The Chongyi–Shangyou–Dayu ore-concentrated district represents one of the most important wolframite production bases in China, and most of the W-Sn deposits formed in the early Yanshanian period. The Xikeng quartz vein-type W-Sn deposit is located spatially not far from the Triassic Keshuling granitic pluton. The deposit contains 43 ore-bearing quartz veins, in which the ore minerals are mainly cassiterite and wolframite. These ore veins are concentrated in the Sinian metasandstone and sandy slate of the Laohutang Formation and extend down to the top of the concealed granite. The concealed intrusion is composed of medium- to fine-grained muscovite granites, which relate to the Indosinian Keshuling granite, according to geophysical data. Zircon grains from the concealed Xikeng granitic intrusion have a concordant U-Pb age of 232.1 ± 1.1 Ma (MSWD = 0.9). The zircon εHf(t) values range from −11.0 to −7.9, indicating primary reworking of the ancient crustal materials. Wolframite and cassiterite grains yield Tera-Wasserburg concordia intercept ages of 228.4 ± 0.9 Ma (MSWD = 1.2) and 227.8 ± 1.6 Ma (MSWD = 0.3) for the Xikeng deposit, respectively. These data demonstrate that the Indosinian W-Sn mineralization events were genetically related to granitic magma activities that share similar magmatic sources with the Yanshanian W-Sn mineralization-associated granitic intrusions. Combined with previous robust granitic and metallogenic ages, this paper identifies a new Indosinian W-Sn mineralization event in southern Jiangxi Province, Nanling Range. [ABSTRACT FROM AUTHOR]

The article presents a study to determine geological importance of rhenium (Re)-osmium (Os) isotopic dating of molybdenites in the Galale skarn copper (Cu)-gold (Au) deposit in Tibet, China. Topics discussed include determination of the age of granodiorite by using the laser ablation-inductively coupled plasma-mass spectrometry, isochron ages of Re-Os testing, and galale deposit and gaerqiong deposit resulting from magma-mineralization.

The Xiongcun district, a unique area where oxidized porphyry copper-gold deposits (OPCD) and reduced porphyry copper-gold deposits (RPCD) coexist, is located in the central part of the Gangdese porphyry copper belt (GPCB) in Tibet, China, and hosts the only known mineralization related to the Neo-Tethyan oceanic subduction. Apatite and zircon major and trace elements, in situ oxygen isotopes in zircon from fertile quartz diorite porphyry (QDP) of the No. I deposit, fertile hornblende quartz diorite porphyry (HQDP) of the No. II deposit, and barren hornblende quartz diorite porphyry with coarse quartz eyes (QQDP) in the Xiongcun district were determined by EPMA, LA-ICP-MS, and SHRIMP II ion microprobe to investigate the petrogenesis, magma oxidation state, and mineralization differences between the No. I and No. II deposits, as well as the potential of apatite as a metallogenic indicator. The results from this study show that a combination of REE, Ti, oxygen isotopes, and the Th/U ratios in zircon and REE as well as Sr in apatite can be used to track the magma compositions and crystallization histories in porphyry systems. Multiple indicators, including the apatite SO 3 content, apatite Mn oxybarometer, and zircon Ce 4+ /Ce 3+ ratio, indicate that (1) the parental magmas of fertile QDP and HQDP containing Cu and Au mineralization were more reduced than that of barren QQDP; (2) despite barren QQDP having higher oxygen fugacity than QDP and HQDP, the lower Cu and water contents in the magma result in a lower potential for ore formation; and (3) the similar oxidation states of QDP and HQDP show that the mineralization differences between RPCD (No. I deposit) and OPCD (No. II deposit) were not caused by the oxidation states of the magmas but were likely caused by the different processes of hydrothermal fluid evolution. Apatite grains from fertile porphyries (QDP and HQDP) have much higher Cl/F ratios than those from barren porphyry (QQDP), indicating that the Cl/F ratio of apatite can be used as a proxy for porphyry Cu-Au mineralization related to the Jurassic porphyry intrusions in the Gangdese porphyry copper belt. [ABSTRACT FROM AUTHOR]

The article discusses a study that focuses on the geological characteristics of Rongna copper-gold-silver epithermal ore deposits located in Duolong copper ore concentration area in Northern Tibet, China. Topics discussed include classification of epithermal-porphyry copper mineralization system into high-sulfidation, medium sulfidation and low sulfidation types; composition of copper sulfides including digenite, enargite, bornite; and impact of deposits discovery on mineral prospecting.

The Xiongcun district, located in the western segment of the Gangdese porphyry copper belt (GPCB), hosts the only known Jurassic mineralization in the GPCB, Tibet, PRC. The No. I deposit in the Xiongcun district is related to the Middle Jurassic quartz diorite porphyry (167–161 Ma) and the mineralization was formed at ca. 161.5 ± 2.7 Ma. Ore-bearing Middle Jurassic quartz diorite porphyry emplaced into the Early Jurassic volcano-sedimentary rock sequences of the Xiongcun Formation. Veinlets and disseminated mineralization developed within the Middle Jurassic quartz diorite porphyry and the surrounding metamorphosed tuff, hosting a measured and indicated resource of 1.04 Mt copper, 143.31 t gold and 900.43 t silver with an average grade of 0.48% copper, 0.66 g/t gold, and 4.19 g/t silver. The mineralization can be assigned to four stages, including three main stages of hypogene mineralization and one epigenetic stage. The main alteration associated with mineralization is potassic. Seven mineralization-related hydrothermal veins have been recognized, including quartz–sulfide, biotite–sulfide, magnetite–sulfide, quartz–molybdenite–sulfide, chalcopyrite–pyrite–pyrrhotite, pyrite and polymetallic veins. The S and Pb isotopic compositions of the ore sulfides and the Re contents of the molybdenite suggest a mantle source for the ore-forming materials with minor contamination from the subducted sediments. Hydrogen and oxygen isotope compositions of quartz in the ores suggest that both magmatic and meteoric waters were involved in the ore-forming process. The ore-bearing porphyry (167–161 Ma) and ore-forming (161.5 ± 2.7 Ma) ages of the No. I deposit correspond to the time of northward subduction of Neo-Tethys oceanic slab. The geochemical data of the ore-bearing porphyry indicate that the No. I deposit formed in an intra-oceanic island arc setting and the ore-bearing porphyry originated from the partial melting of mantle with limited contribution of subducted sediments. The genesis of the ore-bearing porphyry and No. I deposit is interpreted as being related to northward intra-oceanic subduction of Neo-Tethys oceanic slab in the Middle Jurassic time (167–161 Ma). [ABSTRACT FROM AUTHOR]

The Bangpu porphyry Mo–Cu deposit is a representative Mo-dominated deposit besides the Sharang porphyry Mo deposit in the Gangdese metallogenic belt. The Mo–Cu mineralization has a close relationship with the monzogranite porphyry and diorite porphyrite. We identify three stages during the ore formation: a pre-ore stage, a main-ore stage with Mo–Cu deposited dominantly, and a post-ore stage. In this study, He–Ar, H–O, S and Pb isotopic compositions of the Bangpu deposit were determined. Based on these determinations, integrated isotope geochemistry studies were performed to constrain the possible sources of the ore-forming fluids and metals. The 3 He/ 4 He and 40 Ar/ 36 Ar ratios of fluid inclusions exhibit a range of 0.12209–0.36370 Ra and 275.6–346.1, respectively. The 4 He and 40 Ar concentrations vary from 1.51 to 3.57 (10 −7 cm 3 STP g −1 ) and 0.49 to 9.31 (10 −7 cm 3 STP g −1 ), respectively. He–Ar isotopic compositions suggest dominantly crustal-derived fluid with minor amount of meteoric water in the main ore stage. The δ 18 O fluid and δD fluid values vary from −1.3‰ to 3.9‰ and −140.5‰ to −73.7‰, respectively, indicating that magma fluids mixed with meteoric water. The average δ 34 S value of the sulfides (0.3‰) in the main-ore stage is close to the ore-forming porphyries, indicating a magmatic source. The lead isotopic components of ore sulfides exhibit restricted ranges with 206 Pb/ 204 Pb, 207 Pb/ 204 Pb, and 208 Pb/ 204 Pb ratios of 18.450–18.728, 15.602–5.672, and 38.715–39.211, respectively and μ values in the range of and 9.46–9.58, indicating ore-forming metals of primarily an upper crust source with a small amount of mantle materials. Compared to the Bangpu deposit, the ore metals derived from mantle are even greater in the Jiama and Qulong deposits, which leads to Cu being the dominant mineralization in the Jiama and Qulong deposit. [ABSTRACT FROM AUTHOR]

The coexistence of aqueous fluid inclusions and silicate melt inclusions in quartz phenocrysts from porphyrites at the Bangpu porphyry Mo–Cu deposit, Tibet, China were examined to characterize the immiscibility processes during the magmatic to hydrothermal transition. The physical and chemical environment during crystallization of the magmas has been reconstructed on the basis of microthermometric experiments and trace element microanalysis. Compositions of melt and brine fluid phases are determined using Synchrotron radiation X-ray fluorescence analysis, SEM–EDS and Laser Raman spectroscopy analyses. Brine fluids were directly exsolved by a crystallizing melt, and the simultaneous entrapment of volatile-rich (brine fluid) and volatile-poor immiscible phases (silicate melt) occurred at 670–700 °C and 1.6–1.95 kbar when the magma had H 2 O contents between 5 and 6 wt% and crystal contents of 60–80%. A later low-density fluid with a higher Mo concentration exsolved after about 80–90% crystallization had occurred. This fluid contained significant concentrations of Cl, Na, K, Ca, Fe, Cu, Zn, Rb, and small amounts of Mn, Br and Pb. Immiscibility of magmatic fluids can lead to different metal partitioning behaviors between residual melt and volatile phases, which generate variable metal ratios. Copper was partitioned preferentially into the brine phase, in contrast to the behavior observed in other porphyry Cu deposits. Ore deposition by a dense brine could explain the partially deep Cu mineralization. Condensation of brine from a later low-density parental fluid could be an efficient mechanism to concentrate shallow Cu mineralization and broadly distributed Mo mineralization. The source of the Mo mineralizing fluids probably was a particularly large magma chamber that crystallized and fractionated at depth greater than upper continental crust level. [ABSTRACT FROM AUTHOR]

The Jiama copper deposit is one of the largest deposits recently found in Tibet and is composed of three types of mineralization including skarn, hornfels and porphyry. To investigate the relationship between mineralization, structure and alteration, we report new zircon U-Pb age and present field observations on the deformation characteritics associated with the copper mineralization in Jiama. Two main periods of deformation were identified, represented by D1 and D2 in Jiama. The first deformation ( D1) occurred around 50 Ma, whereas the second deformation ( D2) that was closely related to mineralization occurred later. Previous zircon U-Pb and molybnite Re-Os dating results indicate that the mineralizatoin occurred at ∼15 Ma and thus the D1 regional deformation significantly occurred before the mineralization time, although the D1 deformation probably provided important space for the development of significant copper deposition. Our new mapping and observations on the D2 deformation demonstrate that the mineralization was closely coeval with or slightly later than the time of D2 deformation. The new U-Pb zircon age further indicates that the aplite formed in ∼17.0 Ma and thus the D2 deformation happened later than this time because the D2 deformation cut across the aplite, which is proposed to be the key control for copper mineralization. Altered laminated hornfels including three types of alteration ( A-, K- and S-type) were found spatially associated with the D2 deformation. The type- A is mainly silicification, with fine sericite or chlorite, as well as abundant disseminated sulphides on fracture surfaces; the type- S is mainly fine-grained silicification with patches of chlorite, epidote and common sulphides; the type- K (potassic alteration) appears to be fine-grained biotite. Such types of alteration indicate the presence of skarns at depth where ore shoots are located. Taken together, the multiple structural-magmatic-mineralization events contributed to the formation of the supergiant Jiama porphyry copper deposit in Tibet. The results have general implication for regional exploration. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Jiaoxi tungsten deposit comprises three stages, i.e., the oxide, sulfide, and fluorite stage. • Mineralization involves a low-salinity aqueous fluid. • Mineralization occurred as a result of fluid-fluid mixing induced cooling and dilution. The Jiaoxi deposit, located in the western part of the Lhasa terrane, is the first discovered Miocene (ca. 13 Ma) quartz vein-type tungsten deposit in this belt. Ore bodies mainly occur as wolframite-bearing veins hosted in the shales and granite. Three stages were identified for the formation of the Jiaoxi deposit, including the oxide stage (dominated by wolframite and quartz), the sulfide stage (quartz-sulfides veins) and the fluorite stage (late veins comprising fluorite, calcite, and quartz). Here, we investigate the genesis of this deposit based on fluid inclusion and H-O-S-Pb isotope studies. Fluid inclusion microthermometry and oxygen isotope data reveal that the wolframite precipitated from a moderate temperature (340–380 °C), low salinity (2.1–7.5 wt% NaCl equivalent) hydrothermal fluid at a depth of ∼ 6 km. The sulfides from the oxide and sulfide stage have uniform δ34S CDT values (+2.5 to + 3.7‰), and consistent Pb isotope compositions with the coeval granites (206Pb/204Pb: 17.866–18.789; 207Pb/204Pb: 15.555–15.743; 208Pb/204Pb: 37.157–39.335). The δ18O VSMOW value of the hydrothermal fluid decreased from the oxide (δ18O VSMOW = +7.2 to +14.2‰) to the fluorite stage (δ18O VSMOW = +2.1 to +5.7‰), indicating that the exsolved magmatic hydrothermal fluid mixed with meteoric water. This is also suggested by the positive correlation between the salinity and homogenization temperature of the aqueous fluid inclusions. LA-ICP-MS analysis of individual fluid inclusion reveals that the W concentrations of ore-forming fluid in the oxide stage (1.2–70.2 ppm) are much higher than those in the sulfide and fluorite stage (1.1–2.2 ppm) and show positive correlations with the homogenization temperatures and the Cl concentrations. We propose that fluid dilution and cooling due to fluid mixing played an important role during the wolframite precipitation in the Jiaoxi deposit. [ABSTRACT FROM AUTHOR]

The article offers information on the geochemical features and prospecting development of Southern Tiegelong Giant Epithermal Copper Deposit in Tibet, China. Topics discussed include types of metallic sulphides ores detected by energy spectroscopy scanning; metallogenic stages of mineralization such as sedimentary diagenesis and hydrothermal mineralization; and formation of deposits in Early Cretaceous era.

The article presents brief information on the geological characteristics of Xiachahe aluminum deposit at Zhenyuan, in Yunnan, China. Topics discussed include geological overview of mineral deposit in the north western region of the Ailaoshan golden belt in China, brief information on the characteristics of mineral orebody and ores, and impact of mineral alternation on the gathering and mineralization of the gold.

The article offers information on the Rhenium-Osmium (Re-Os) dating techniques of molybdenite present in the Lakange Porphyry Copper-Molybdenum deposit of Tibet, China. It mentions that the technique aimed to find the metallogenic age of Lakange deposit with mineralization process. It mentions that the crystallization of molybdenite can be analyzed by calculating the model age of Re-Os isotopic system.

The article discusses mineralization and metallogenic process of the orogenic gold deposits in Ailaoshan, Yunnan, China. Topics include types of genesis of orogenic deposits including hydrothermal, metamorphic hydrothermal and simultaneous sedimentation, Ailaoshan metallogenic belt undergoing three major geological processes including hyperplasia orogeny, collision orogeny and superposition, and characteristic of Ailaoshan tectonic style.

Graphical abstract Highlights • Zircon U–Pb dating indicates the emplacement of Ruocuo adakitic porphyries during the Early–Middle Jurassic (182–170 Ma). • Ruocuo adakitic porphyries were generated by the partial melting of the Neo-Tethys oceanic slab. • Formation of Early Mesozoic magmatic rocks in the southern Lhasa subterrane in a magmatic arc setting. • The northern Xigaze forearc basin has a potential for subduction-related porphyry Cu–Au mineralization. Abstract Jurassic adakitic rocks in the southern Lhasa subterrane are relatively rare, poorly documented, and their petrogenesis and geodynamic setting are unclear. To explore these issues, we present zircon U–Pb ages along with Hf isotopic, whole-rock geochemical, and Sr–Nd–Pb isotopic data for hornblende quartz diorite porphyry (HQDP) and quartz diorite porphyry (QDP) in the Ruocuo area, southern margin of the Lhasa terrane, Tibet. Zircon U–Pb dating for these rocks indicates that they were emplaced in the Early–Middle Jurassic (182–170 Ma). Geochemically, HQDP and QDP both show characteristics of adakites, with intermediate SiO 2 (60.62–65.63 wt% and 57.46–60.04 wt%, respectively), relatively high Al 2 O 3 (14.23–18.23 wt% and 18.32–20.14 wt%, respectively) and Sr (344–571 ppm and 514–614 ppm, respectively), and low Y (9.12–13.0 ppm and 11.0–14.9 ppm, respectively) and Yb (0.93–1.31 ppm and 1.08–1.52 ppm, respectively). In addition, they show relatively low ratios of (87Sr/86Sr) i (0.7038–0.7045), (206Pb/204Pb) i (18.31–18.42), (207Pb/204Pb) i (15.56–15.66), and (208Pb/204Pb) i (38.36–38.77) and relatively high values of ε Nd (t) (+5.54 to +6.33) and ε Hf (t) (+11.8 to +17.3). The Sr–Nd–Pb–Hf isotopes of HQDP and QDP are similar to those of the Yarlung Tsangpo ophiolites, indicating that they were predominantly generated by the partial melting of the subducted Neo-Tethys oceanic slab. The subducted Neo-Tethys oceanic slab-derived adakitic rocks that are present in the southern Lhasa subterrane provide strong evidence for proving the presence of oceanic subduction during the Early–Middle Jurassic. By combining our results with the previously reported results, we suggest that the Ruocuo adakitic rocks and Early Mesozoic (Late Triassic to Middle Jurassic) magmatic rocks in the southern Lhasa subterrane formed in a magmatic arc setting related to the northward subduction of the Neo-Tethys oceanic slab, that the initial subduction of the Neo-Tethys oceanic slab occurred prior to the Early Jurassic, and that the upwelling asthenosphere, triggered by the roll-back of the subducted Neo-Tethys oceanic slab, provided the heat that was required for slab melting. However, contrasting these results with the geochemical characteristics of the No. 2 deposit in the Xiongcun Cu–Au district leads us to consider that the Early–Middle Jurassic subducted oceanic slab-derived adakitic porphyries contain a greater potential for porphyry Cu–Au mineralization than the Early Mesozoic normal magmatic rocks in the southern Lhasa subterrane. Furthermore, mineralized Jurassic porphyry has been reported in the Ruocuo area, adjacent to the northern Xigaze forearc basin, indicating that the northern Xigaze forearc basin also has the potential for subduction-related porphyry Cu–Au mineralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Estabalish a "quantitative data + machine learning + expert experience" MPM workflow. • SA-BPNN was introduced for MPM, and achieved superior performance. • Identify 5 target areas of Cu (Au) deposits in the Duolong district, Tibet. Machine learning (ML) is emerging as a highly effective technique for mineral exploration. However, mineral exploration poses several unique challenges to ML application, such as uncertain geological information in remote regions and imbalanced labeled training data. In this study, we developed a deep-learning framework — a self-attention back-propagation neural network (SA-BPNN) — which is used to automatically explore relationships among diverse features and improve the capability of information extraction. Moreover, we proposed a mineral prospectivity modeling workflow involving "quantitative data + ML + expert experience" for porphyry-epithermal deposits. Using quantitative data obtained from hyperspectral remote sensing, geochemistry, and geophysics, we predicted ore-prospecting targets by applying the SVM, SA-BPNN, and U-Net models. Thereafter, we combined the model-based prediction with geological data to delineate the target areas. The model-based prediction by SVM, SA-BPNN, and U-Net occupy 1.73%, 1.40%, and 2.21% of the study area and contain 100%, 100%, and 80% of the known Cu-Au mineralization in the Duolong ore district in Tibet, respectively. The proposed SA-BPNN method, thus, achieved superior performance for mineral prospectivity modeling compared with alternative methods. [ABSTRACT FROM AUTHOR]

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Abstract: The Jiangla'angzong granite in the northern part of the Central Lhasa Terrane is composed of syenogranite and adamellite. LA‐ICP‐MS zircon U‐Pb analyses suggest that syenogranite has a weighted mean 206Pb/238U age of 86±1 Ma (mean square weighted deviation=0.37), which is in accordance with the muscovite Ar‐Ar age (85±1 Ma) of Cu‐Au ore‐bearing skarns and the zircon U‐Pb age (84±1 Ma) of adamellite. This suggests that the Jiangla'angzong magmatism and Cu–Au mineralization events took place during the Late Cretaceous. The granite contains hornblende, biotite, and pyroxene, and does not contain Al‐bearing minerals, such as muscovite, cordierite, and garnet. It has high contents of SiO2 (65.10–70.91wt%), K2O (3.44–5.17wt%), and total K2O+Na2O (7.13–8.15wt%), and moderate contents of A12O3 (14.14–16.45wt%) and CaO (2.33–4.11wt%), with a Reitman index (σ43) of 2.18 to 2.33, and A/CNK values of 0.88 to 1.02. The P2O5 contents show a negative correlation with SiO2, whereas Pb contents show a positive correlation with SiO2. Th and Y contents are relatively low and show a negative correlation with the Rb contents. These characteristics suggest that the Jiangla'angzong granite is a high K calc–alkaline metaluminous I–type granite. It is enriched in light rare earth elements (LREE) and large ion lithofile elements (LILE), and depleted in heavy rare earth elements (HREE) and high field strength elements (HFSE), with LREE/HREE ratios of 11.7 to 18.1. The granite has negative Eu anomalies of 0.58 to 0.94 without obvious Ce anomalies (δCe=1.00–1.04). The relatively low initial 87Sr/86Sr ratios of 0.7106 to 0.7179, positive εHf(t) values of 1.0 to 4.1, and two‐stage Hf model ages (TDM2) ranging from 889 Ma to 1082 Ma, These geochemical features indicate that the granite derived from a juvenile crust. The (143Nd/144Nd)t values from the Jiangla'angzong granite range from 0.5121 to 0.5123, its εNd(t) values range from –10.17 to –6.10, its (206Pb /204Pb)t values range from 18.683 to 18.746, its (207Pb /204Pb)t values range from 15.695 to 15.700, and its (208Pb /204Pb)t values range from 39.012 to 39.071. These data indicate that the granite was formed by melting of the upper crust with the addition of some mantle materials. We propose that the Jiangla'angzong granite was formed during the post‐collision extension of the Qiangtang and Lhasa terranes. [ABSTRACT FROM AUTHOR]

Abstract: The Zhaxikang Pb‐Zn‐Ag‐Sb deposit, the largest polymetallic deposit known in the Himalayan Orogen of southern Tibet, is characterized by vein‐type mineralization that hosts multiple mineral assemblages and complicated metal associations. The deposit consists of at least six steeply dipping vein‐type orebodies that are hosted by Early Jurassic black carbonaceous slates and are controlled by a Cenozoic N–S‐striking normal fault system. This deposit records multiple stages of mineralization that include an early period (A) of massive coarse‐grained galena–sphalerite deposition and a later period (B) of Sb‐bearing vein‐type mineralization. Period A is only associated with galena–sphalerite mineralization, whereas period B can be subdivided into ferrous rhodochrosite–sphalerite–pyrite, quartz–sulfosalt–sphalerite, calcite–pyrite, quartz–stibnite, and quartz‐only stages of mineralization. The formation of brecciated galena and sphalerite ores during period A implies reworking of pre‐existing Pb–Zn sulfides by Cenozoic tectonic deformation, whereas period B mineralization records extensive open‐space filling during ore formation. Fluid inclusion microthermometric data indicate that both periods A and B were associated with low–medium temperature (187–267°C) and low salinity (4.00–10.18% wt. NaCl equivalent) ore‐forming fluids, although variations in the physical–chemical nature of the period B fluids suggest that this phase of mineralization was characterized by variable water/rock ratios. Microprobe analyses indicate that Fe concentrations in sphalerite decrease from period A to period B, and can be divided into three groups with FeS concentrations of 8.999–9.577, 7.125–9.109, 5.438–1.460 mol.%. The concentrations of Zn, Sb, Pb, and Ag within orebodies in the study area are normally distributed in both lateral and vertical directions, and Pb, Sb, and/or Ag concentrations are positive correlation within the central part of these orebodies, but negatively correlate in the margins. Sulfide S isotope compositions are highly variable (4‰–13‰), varying from 4‰ to 11‰ in period A and 10‰ to 13‰ in period B. The Pb isotope within these samples is highly radiogenic and defines linear trends in 206Pb/204Pb vs. 207Pb/204Pb and 206Pb/204Pb vs. 208Pb/204Pb diagrams, respectively. The S and Pb isotopic characteristics indicate that the period B orebodies formed by mixing of Pb–Zn sulfides and regional Sb‐bearing fluids. These features are indicative of overprinting and remobilization of pre‐existing Pb–Zn sulfides by Sb‐bearing ore‐forming fluids during a post‐collisional period of the Himalayan Orogeny. The presence of similar ore types in the north Rhenish Massif that formed after the Variscan Orogeny suggests that Zhaxikang‐style mineralization may be present in other orogenic belts, suggesting that this deposit may guide Pb–Zn exploration in these areas. [ABSTRACT FROM AUTHOR]

Abstract: The West Mine of the Bayan Obo deposit, located in the northern‐central part of Inner Mongolia, China, is enriched in Nb, rare earth elements and iron (Nb‐REE‐Fe) mineral resources. This paper presents a combined method to explore metallogenic correlation of the Nb‐REE‐Fe mineralization at the Bayan Obo West Mine. The method integrates factor analysis and Back Propagation (BP) neural network technology into processing and modeling of geological data. In this study, the Nb and REE contents of samples were transformed into discrete values to analyze the correlations among the metallogenic elements. The results show weak mineralization correlations between Nb and REEs. Nb and U are closely related in the geochemical patterns, while Fe is closely related to both Th and Mn. LREEs are an important factor for the mineralization of the Bayan Obo deposit, while Fe and Nb can be considered as the results of passive mineralization. On the basis of a metallogenic correlation analysis, the factors affecting the Fe‐REE‐Nb mineralization were extracted, and the Nb mineralization model was established by the BP neural network. Based on the BP neural network data computing, the variability of the Nb concentration displays a coupled multi‐factor nonlinear relationship, which can be used to reveal the inherent metallogenic elemental regularities and predict the degree of element mineralization enrichment in the mining area. [ABSTRACT FROM AUTHOR]

The article focuses on the presence of Methane rich fluids in the No.1 porphyry copper-gold deposit in the Xiongcun district, and Gangdese porphyry copper belt in Tibet, China. Topics discussed include diamond drilling in Xiongcun completed by firm Tianyuan Minerals Exploration Ltd., the link between copper-gold mineralization and potassic alteration, and Raman spectroscopy used to detect gaseous composition of fluid inclusion in quartz.

In this paper, 1:50 000 scale geological interpretation of remote sensing pictured compiled as the primary means, based on the understanding of geological data, based on the different characteristics remote sensing images, we interpreted geological boundary layer over the region and construct different types of remote sensing, Delineated ore-forming stratums and main mineralisation rocks from Caledonian period. At last, we summarised the mineralisation characteristics images and structures which associated with tungsten, copper, lead and zinc polymetallic of Yinsheng regional metallogenic belt. [ABSTRACT FROM AUTHOR]

The article reports on geological study of Pb-Zn deposits located in Narusonghuo, China. Topics discussed include several Pb-Zn mineralization formed by various physical processes chloritization, silicification and carbonation, found in the region, associated with quartz syenite porphyry, geochemical analysis on the same and role of Neo Tethys oceanic crust and wedge mantle in formation of Narusongduo porphyry magma, with characteristic chemical geology.

The article presents a study focusing on several tectonomagmatic events and mineralization process taking place in the Zhunuo Porphyry Copper (Cu)-Molybdenum (Mo)-Gold (Au) Deposit in South Tibet. Topics discussed include subduction of the Neo-Tethys oceanic crust leading to formation of magmatic arcs, association of continental magmatic plates with Porphyry molybdenum deposit and skarn deposit, and association of Miocene magmatism mineralization event with extension of Gangdese magmatic arc.

The article focuses on a research paper examining the Gaerqing copper-gold deposit in the Duolong ore-concentrated area along the Bangong-Nujiang Suture Zone in Tibet, China. It mentions that the diagenesis and mineralization ages in the area are similar to the diagenesis age of the granite-porphyry from the Gaerqing region. It also suggests that the deposit could qualify to be a large-scale epithermal deposit in the area.

The article presents a study that highlights vein type and characteristic of Tiegelongnan copper-gold deposit in Duolong Ore District, Tibet. Topics include pyrite- quartz veins in which content of pyrites is about 25 percent, molybdenite- pyrite vein whose width is small, and pyrite- dickite vein whose width is about 11 centimeter (cm).