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The Anle Zn–Pb deposit, hosted by Upper Cambrian dolostone, is located in the southern Songpan–Ganzi Block in southwest China. In this deposit, ore bodies occur as stratiform lenses and consist of galena, sphalerite and pyrite as ore minerals, and quartz, dolomite and calcite as gangue minerals. The mineralization shows mainly vein, banded and brecciated structures. Four ore bodies have been found in the Anle deposit, with a combined 2.0 million tonnes (Mt) of sulfide ores at average grades of 1.64 wt.% Pb, 6.64 wt.% Zn and 45 g/t Ag. Brown, brownish-yellow and yellow sphalerite samples have δ 66 Zn values ranging from + 0.08 to + 0.10‰ (average + 0.09‰, n = 3), + 0.12 to + 0.38‰ (average + 0.24‰, n = 8) and + 0.40 to + 0.50‰ (average + 0.46‰, n = 3), respectively. We interpret the progressively heavier Zn isotopes from brown to yellow sphalerite as being led by kinetic Raleigh fractional crystallization. Calcite samples have δ 13 C PDB and δ 18 O SMOW values ranging from − 4.8 to − 0.2‰ (average − 1.7‰, n = 7) and + 17.9 to + 21.4‰ (average + 19.6‰, n = 7), respectively. Whole-rock δ 13 C PDB and δ 18 O SMOW values of the Cambrian ore-hosting dolostone range from + 0.1 to + 1.1‰ (average + 0.6‰, n = 3) and + 23.2 to + 24.1‰ (average + 23.6‰, n = 3), respectively. This suggests that carbon in the ore-forming fluids was provided by the host dolostone through carbonate dissolution. δ 34 S CDT values of sulfide samples range between − 1.3‰ and + 17.8‰ with an average value of + 6.3‰ ( n = 25), lower than evaporites (such as barite + 19.8‰) in the overlaying Lower Ordovician sedimentary strata. The data suggest that sulfur in the hydrothermal fluids were derived from evaporites by thermo-chemical sulfate reduction (TSR). 206 Pb/ 204 Pb, 207 Pb/ 204 Pb and 208 Pb/ 204 Pb ratios for sulfide minerals range from 17.63 to 17.86, 15.58 to 15.69 and 37.62 to 37.95, respectively. The data are similar to those of the age-corrected Cambrian ore-hosting dolostone ( 206 Pb/ 204 Pb = 17.70–17.98, 207 Pb/ 204 Pb = 15.58–15.65 and 208 Pb/ 204 Pb = 37.67–38.06), but lower than those of age-corrected Ordovician sandstone and slate ( 206 Pb/ 204 Pb = 18.54–19.58, 207 Pb/ 204 Pb = 15.73–15.81 and 208 Pb/ 204 Pb = 38.44–39.60). This indicates that ore Pb was most likely to be derived from the Cambrian ore-hosting dolostone. Therefore, our new geological and isotopic evidence suggests that the Anle Zn–Pb deposit is best classified to be an epigenetic carbonate-hosted Mississippi Valley-type (MVT) deposit. [ABSTRACT FROM AUTHOR]

[Display omitted] • The source and evolution of ore-forming fluids are characterized using lithium and chlorine isotopes. • Magmatic source of ore-forming fluids plays a critical role in the mineralizing systems of the Luziyuan Zn-Pb-Fe-(Cu) deposit. • The increase of δ 7 Li values in the ore-forming fluids during retrograde skarn alteration is the results of Rayleigh fractionation in a closed system. The sources and temporal evolution of fluids related to distal skarn mineralization strongly influence the minerals that form, but remain poorly understood. In this study, we use the lithium and chlorine isotopic compositions of fluid-inclusion leachates (FIL) to elucidate the nature and evolution of fluids that formed the Luziyuan distal skarn Zn–Pb–Fe–(Cu) deposit, China. The δ7Li values of prograde skarn stage rhodonite FIL (+5.37‰–+7.31‰) are similar to those of typical magmatic fluid. The δ7Li values (+11.69‰–+12.54‰) of actinolite FIL are higher than those of rhodonite FIL; this is attributed to Rayleigh fractionation within a closed magmatic–hydrothermal system. It is inferred that up to 70% of fluid-borne Li is sequestered by hydrous minerals during retrograde skarn alteration, consistent with conclusions drawn from previous studies of fluid-inclusions. The δ7Li values of galena FIL (+9.78‰–+13.19‰), black sphalerite FIL (+11.62‰), and reddish-brown sphalerite (+10.44‰–+11.66‰) overlap with those of actinolite FIL, indicating that phase separation occurred during Zn–Pb mineralization at the Luziyuan deposit. The low δ7Li values of light-yellow sphalerite FIL (+6.75‰) and calcite FIL (+3.95‰–+6.49‰) record external fluid input, probably meteoric water. The positive δ37Cl values of rhodonite FIL (+1.82‰–+1.83‰) are consistent with those of magmatic fluids. However, the δ37Cl values of actinolite FIL (+0.49‰) are lower than those of rhodonite FIL, indicating that FIL within hydrous minerals might not record fluid sources reliably. [ABSTRACT FROM AUTHOR]

[Display omitted] • New Sr-Nd-Pb isotopes and detrital zircon U-Pb ages of samples from the Paleoproterozoic to Lower Permian Daoshitou Formation (P 1 d) in Central Yunnan are reported. • The Li-rich claystone of the Daoshitou Formation (P 1 d) are mainly derived from the underlying Weining Formation (C 2 w) basement. • Detrital zircon crystals of the Daoshitou Formation (P 1 d) primary sourced from the Early Ordovician strata. A new lithium-rich claystone from the Lower Permian has been detected in Central Yunnan, Southwestern China that could be great potential for Lithium (Li) exploration, yet the origin of the claystone is still being debated. To study it further, new geochronological, geochemical, and Sr–Nd–Pb isotopic analyses were systematically conducted on the Daoshitou Formation (P 1 d) claystone, as well as on the underlying strata. Through detrital zircon U–Pb dating of the claystone in the Daoshitou Formation, three major age peaks were revealed, at ∼960 Ma, ∼790 Ma, ∼550 Ma, respectively, along with three minor peaks of ∼2500 Ma, ∼1500 Ma, and ∼1200 Ma. Detrital zircons in the claystone have age spectra that closely match those of the Lower Ordovician sedimentary rocks in Central Yunnan, indicating these rocks are the major contributor of detrital zircons. However, the rock source determined by geochemical features decouples with the zircon source determined by detrital zircon data. The A–CN–K ternary diagram obviously reveals analogous predicted weathering trends between the Weining Formation (C 2 w) and Daoshitou Formation, suggesting a potential provenance link. Furthermore, the weathering trends of samples from three drill cores indicate that the transformation of clay mineral (smectite–illite–chlorite/kaolinite) may facilitate Li enrichment. Smectite, as the precursor mineral for Li enrichment, typically forms and preserves in a slightly alkaline environment, which suggests that the Li-rich claystone is likely to formed in this environment. Low Na/Li and K/Li ratios indicate low cation exchange selectivity in sedimentary environments, which promote the proliferation of adsorption sites for Li on smectite. The weathering products from the Weining Formation, composed of impure carbonates, could provide a slightly alkaline environment with low ion strength for the adsorption of Li. In addition, Sr–Nd–Pb isotopic compositions also reveal the significant similarity between the Daoshitou Formation and Weining Formation. Therefore, we suggest that the weathering of the Weining Formation provided the primary material to Daoshitou Formation claystone. [ABSTRACT FROM AUTHOR]

Yinzishan Au deposit was discovered in the Simao block that is dominated by telluride minerals, and is just 25 km from the Dapingzhang deposit, contains a total resource of ≥20 t Au and ore grading at 8.90 g/t Au. Through SWIR mapping reveal that dominant alteration minerals in the Yinzishan deposit are alunite, kaolinite and/or pyrophyllite, dickite, and topaz. The spatial distribution of alteration mineral combination topaz + alunite has a good relationship with Au mineralization. The SWIR Scalars of topaz (Dep2086>0.2), alunite (Dep1470>0.06), chlorite (Pos2250>2250 nm), and kandite/pyrophyllite (Dep2170>0.07) can be used as effective exploration indicators and visualization tools to explain the metallogenic environment and determine the location of hydrothermal/mineralization centers in the Yinzishan deposit. [Display omitted] • SWIR data and detailed petrography proves that the Yinzishan deposit is a typical HS deposit. The Au mineralization was caused by later magmatic-hydrothermal overprinting events. • Tellurium was introduced into the site of ore deposition by vapor dominantly F-rich fluid and HS-complexes are thought to be main carriers of the Au. • The alteration mineral combination topaz + alunite has a good relationship with Au mineralization. The SWIR Scalars of topaz (Dep2086 > 0.2), alunite (Dep1470 > 0.06), chlorite (Pos2250 > 2250 nm), and kandite/pyrophyllite (Dep2170 > 0.07) can be used as a vector tool for mineral exploration. The Yinzishan epithermal Au deposit discovered in the Simao block, is dominated by telluride minerals, and contains a total of ≥ 20 t of Au with ore grading at 8.90 g/t Au. The mineralization is hosted within thick accumulations of steeply dipping andesitic to rhyodacitic volcaniclastic units. The distribution of Au orebodies in this deposit is largely controlled by NNW-oriented faults and the higher porosity and permeability of the volcaniclastic host rocks. A detailed study of the Yinzishan deposit geology, occurrence of gold, and short wavelength infrared (SWIR) data from the northern to southern sections of the deposit was performed to characterize the hydrothermal minerals and alteration zonation, and assess the deposition mechanisms of the metal. The dominant country-rock alteration of the deposit is silicification, advanced argillic alteration, chloritization, sericitization, and pyritization and the main ore mineral combination is pyrite–enargite–covellite–chalcopyrite–calaverite. Au mainly occurs as native gold and calaverite or micronsized inclusions in tellurides (e.g., melonite and tetradymite) and pyrite. The characteristics of the ore minerals and alteration assemblages indicate that the ore-forming fluid was relatively oxidized, with SO 2 -, H 2 S-, and F-rich acidic hydrothermal fluids. This feature supports the high-sulfidation origins of the Yinzishan Au deposit. Tellurium was introduced into the site of ore deposition via vapor in F-rich fluid and HS–complexes are thought to have been the main carriers of Au. The mixing of magmatic fluids with meteoric waters was the crucial control on the precipitation of the Au telluride ore. The SWIR spectroscopy revealed that the mineral combination of topaz + alunite has a good coupling relationship with Au mineralization. Moreover, the SWIR scalars of four characteristic single minerals/mineral assemblages, including topaz (Dep2086 > 0.2), alunite (Dep1470 > 0.06), chlorite (Pos2250 > 2250 nm), and kandite and/or pyrophyllite (Dep2170 > 0.07), provide a visualization tool for determining the ore-forming environment and the location of hydrothermal/mineralization centers. Therefore, we proposed that the combined application of detailed SWIR-based analyses of alteration minerals and interpretations of the SWIR scalars of characteristic minerals is an effective approach for the exploration of epithermal hydrothermal deposits. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Luobushan deposit is controlled by both structure and lithology. • The sulfides have micro- to fine-grained textures. • The reduction of marine sulfate has undergone a shift from BSR to TSR. • The main source of metal is the lower Permian bioclastic limestone. • The Luobushan deposit is similar to MVT deposits. The Luoboshan Pb-Zn deposit (0.2 Mt Pb + Zn metal reserves, @ 0.94 % Pb and 5.33 % Zn) is located in the Lanping-Simao Basin in the southern part of the Sanjiang Tethys metallogenic domain in Yunnan Province, SW China. The deposit comprises three ore bodies hosted in the lower Permian bioclastic and micritic limestone. Ore body I is stratiform (mineralization is small in scale and ores have been mined out), with average grades of 0.02–1.44 % Pb and 1.5–14.88 % Zn. Ore bodies II and III are lens-like, the average grades of them are 0.10–5.07 % Pb and 1.68–12.39 % Zn, and 0.10–1.71 % Pb and 1.14–11.79 % Zn, respectively. Two hydrothermal stages were identified in the Luoboshan deposit: Pyrite-I-sphalerite-galena-calcite (stage I) and Pyrite-II-calcite (stage II). The in-situ δ34S values of pyrite and sphalerite reveals a medium range of −8.80 ‰ to +10.1 ‰. Furthermore, Py-I and sphalerite exhibit low δ34S values from −8.80 ‰ to −3.04 ‰, but Py-II displays high δ34S values (+2.37 ‰ to +10.0 ‰). These results suggest distinct formation mechanism for reduced sulfur during different stages of Pb-Zn mineralization. A reasonable explanation is that a transition from bacterial sulfate reduction (BSR) in the early stage to thermochemical sulfate reduction (TSR) in the late stage as the likely mechanism for the formation of reduced sulfur. In addition, the in-situ Pb isotopes exhibit a narrow range (206Pb/204Pb = 18.660–18.672, 207Pb/204Pb = 15.665–15.677 and 208Pb/204Pb = 38.940–38.980), indicating that the metals originated from either a single source or a uniform mixture of different sources. Comparison of geological charateristics and isotopic geochemical data (S and Pb) indicates that the basin sedimentary strata (wall rocks) is the only and most probable source. Hence, we propose that the formation of the Luoboshan deposit involved biogenic in-situ acid generation of marine sulfates, which subsequently mixed with Pb-and-Zn-rich hydrothermal fluids, initiating TSR and resulting in Pb-Zn mineralization. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metallogenic materials and reduced sulfur primarily originated from ore-bearing carbonate rocks. • The precipitation of sulfides was jointly controlled by the W/R reaction and TSR process. • The metallogenic fluids exhibit an evolutionary trend from the metamorphic basement to ore-hosting carbonate rocks. • The Maoping deposit was formed within the late Triassic compressive tectonic setting, with the involvement of Emeishan magmatism. The Maoping Pb-Zn deposit is spatially associated with the late Permian Emeishan basalts and structurally controlled by the NE-trending reverse fault-anticline tectonic system. Nevertheless, there remains limited comprehension of its genetic association with the Emeishan magmatism, as well as the coupling relationship between the overall metallogenic processes and geodynamic evolution. In order to clarify these scientific issues, the syn -ore hydrothermal calcites, sulfides, and sulfates were systematically collected from the representative No. I ore body at different elevations in the Maoping deposit for bulk C-O-S and in situ S-Pb isotopic analyses. Bulk C-O isotopic compositions of syn -ore calcite (δ13C V-PDB = − 4.94 to −0.81‰, δ18O SMOW = +17.66 to +21.16‰) and associated fluids (δ13C V-PDB = −4.56 to −0.48‰, δ18O SMOW = +8.63 to +12.13‰) indicate that C in fluids was mainly derived from ore-bearing carbonate rocks, whereas O was generated by fluid/rock (W/R) interaction process between initial fluids and carbonate rocks. Such process also triggered carbonate dissolution and syn -ore calcite precipitation. In situ Pb isotopic ratios of galena (208Pb/204Pb = 39.116–39.425, 207Pb/204Pb = 15.742–15.767 and 206Pb/204Pb = 18.603–18.753) are more comparable with those of ore-bearing sedimentary rocks, while in situ and bulk S isotopic compositions (δ34S Py+Sp = +20.06 to +23.86‰; δ34S Gn = +17.26 to +18.44‰) of sulfides exhibit high consistency with those of sulfates (δ34S Brt = +17.01 to +19.07‰) within the ore-bearing strata. This suggests that the majority of metallogenic materials and reduced sulfur originated from this source. Meanwhile, the S-Pb isotopic data and relatively high ore-forming temperature (206 ℃) further reveal that the ore-bearing fluids underwent gradual migrated and evolved from the basement to the ore-hosting strata. The Emeishan magmatism not only provided the majority of the thermal power for the fluid circulation, but also contributed a portion of the ore-forming fluids and materials. During the late Triassic, ore-forming fluids migrated along compresso-shear reverse faults to coeval secondary extensional ore-hosting structures due to regional compressive tectonic stresses caused by the Indosinian orogeny and Xuefengshan intraplate orogeny. The mixing of metal-rich hydrothermal fluids with the marine evaporites (mainly gypsum) within sedimentary rocks first triggered thermos-chemical sulfate reduction (TSR) process. The subsequent continuous W/R interaction resulted in a decrease in fluid acidity and temperature, ultimately leading to the precipitation of metal sulfides. [ABSTRACT FROM AUTHOR]