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Zhaxikang is one large Sb–Pb–Zn–Ag deposit located in the North Himalaya of southern Tibet. To date, the genesis of this deposit still remains controversial. Here, we present new pyrite Fe and sphalerite Zn isotopic data for the first three stages of mineralization, Fe–Zn isotopic data for Mn–Fe carbonate that formed during the first two stages of mineralization, and Zn isotopic data for the slate wall rocks of the Jurassic Ridang Formation to discuss the genesis of the Zhaxikang deposit. The overall δ 56 Fe and δ 66 Zn values range from −0.80‰ to 0.43‰ and from −0.03‰ to 0.38‰, respectively. The δ 56 Fe values of Mn–Fe carbonates are lighter than those of associated pyrite in six mineral pairs, indicating that the iron carbonates are preferentially enriched in light Fe isotopes relative to pyrite. The sphalerite has lighter δ 66 Zn values than associated Mn–Fe carbonates in three mineral pairs. The δ 56 Fe values of pyrite that formed during the first three stages of mineralization gradually increase from stage 1 (−0.33‰ to −0.09‰) through stage 2 (−0.30‰ to 0.19‰) to stage 3 (0.16‰–0.43‰). In comparison, the sphalerite that formed during these stages has δ 66 Zn values that gradually decrease from stage 1 (0.16‰–0.35‰) through stage 2 (0.09‰–0.23‰) to stage 3 (−0.03‰ to 0.22‰). These data, in conjunction with the observations of hand specimens and thin sections, suggest that the deposit was overprinted by a second pulse of mineralization. This overprint would account for these Fe–Zn isotopic variations as well as the kinetic Rayleigh fractionation that occurred during mineralization. The temporally increasing δ 56 Fe and decreasing δ 66 Zn values recorded in the deposit are also coincident with an increase in alteration, again supporting the existence of two pulses of mineralization. The δ 56 Fe values of the first pulse of ore-forming fluid were calculated using theoretical equations, yielding values of −0.54‰ to −0.34‰ that overlap with those of submarine hydrothermal solutions (−1‰ to 0‰). However, the δ 56 Fe values of the stage 3 pyrite are heavier than those of typical submarine hydrothermal solutions, which suggests that the second pulse of mineralization was probably derived from a magmatic hydrothermal fluid. In addition, the second pulse of ore-forming fluid has brought some Fe and taken away parts of Zn, which results the lighter δ 66 Zn values of sphalerite and heavier δ 56 Fe values of pyrite from the second pulse of mineralization. Overall, the Zhaxikang deposit records two pulses of mineralization, and the overprint by the second pulse of mineralization causes the lighter δ 66 Zn values and heavier δ 56 Fe values of modified samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • SEDE genesis is most plausible for the first episode of mineralization in the Zhaxikang and Keyue deposits. • A genetic relationship must exist between the Zhaxikang and Keyue deposits. • The Zhaxikang and Keyue deposits have the same metal origins and experience similar ore formation and ore-forming fluid evolution. • Zn–Cd isotopes have the potential to apply in ore deposit research and mineral exploration. The Keyue Sb–Pb–Zn–Ag deposit is a medium-sized deposit near the super-large Zhaxikang Sb–Pb–Zn–Ag deposit within the North Himalayan Metallogenic Belt (NHMB). These two deposits, separated only by a regional NS-trending normal fault with strike-slip properties, have similar ore-forming elements and mineral associations, ore characteristics, ore paragenetic sequence, wall rocks, and H–O–S–Pb isotopic and fluid inclusion characteristics. Herein, we establish Zn–Cd isotopic connections between these two proximal ore deposits. As a means to draw comparisons, we conducted Zn–Cd isotopic research of the Keyue deposit to compare it with that of the Zhaxikang deposit. Both the δ66Zn and δ 114/110Cd values of sphalerite from the Keyue deposit display a temporally decreasing trend from stage 2 (δ66Zn: 0.15‰–0.58‰, average value = 0.29‰; δ 114/110Cd: –0.23‰ to 0.38‰, average value = 0.05‰) to stage 3 (δ66Zn: –0.28‰ to 0.12‰, average value = –0.06‰; δ 114/110Cd: –0.38‰ to –0.32‰, average value = –0.35‰), which was also found in the Zhaxikang deposit. A simple three-phase separation distillation models this temporally decreasing trend, which resulted from the Zn–Cd isotopic fractionation that is most likely related to vapor–liquid-solid dynamics of ore-forming fluid. This distillation model was further augmented by the general geochemical characteristics and fluid inclusion data. A congruence among several geological and geochemical evidence points to the genetic relationships between these two ore deposits that have the same metal origins and experience similar ore formation processes. A three-phase separation model has been established to imitate this evolution, which reveals substantial exploration potential for Zn–Cd at depths below 4100 m within the Zhaxikang orefield. In summary, Zn–Cd isotopes have the potential to trace metal sources, monitor fluid evolution, constrain ore formation, and provide insights into mineral exploration. [ABSTRACT FROM AUTHOR]

Redox reactions, biological processes, evaporation and precipitation processes, adsorption, and Rayleigh distillation mechanisms have been proposed to account for the fractionation of antimony (Sb) isotopes in natural materials. However, only one paper was published to support and characterize the Rayleigh distillation induced Sb isotopic fractionation in a hydrothermal system. Therefore, the Sb isotopic fractionation mechanism research in the epithermal system is still negligible, which severely restricts future application. The Zhaxikang Sb–Pb–Zn–Ag deposit is the only super-large deposit within the North Himalayan Metallogenic Belt (NHMB), which comprises two episodes of mineralization (First episode: Pb–Zn mineralization, Stages 1 and 2; Second episode: Sb mineralization, Stages 3 to 6). Herein, we measured the δ123Sb NIST 3102A values of stage 4 sulfosalt minerals and stage 5 stibnite from the Zhaxikang Sb–Pb–Zn–Ag deposit, to resolve the fractionation direction and relative magnitude of Sb isotopes caused by these aforesaid geologically prominent mechanisms in the epithermal systems with an auxiliary investigation of Fe–Cu isotopes. The second episode of Sb-containing hydrothermal fluid has leached metals (e.g., Pb, Ag, Fe, Cu) from pre-existing Pb–Zn orebodies, to initiate the formation of stage 4 sulfosalt minerals. According to XPS (X-ray Photoelectron Spectroscopy) analyses, the Cu isotopic variation of stage 4 bournonite (0.08‰ – 0.89‰) must be controlled primarily by the reduction reaction (Cu2+ + e− → Cu+) during leaching and precipitation. Keeping in mind a good linear correlation between δ123Sb and δ65Cu values (R2 = 0.99) for bournonite, the same mechanism was used to decipher the variation in δ123Sb values (0.10‰ – 0.48‰) of bournonite (Sb5+ + 2e− → Sb3+). Abundant native sulfur within the orefield allowed for the overall reaction equation of CuFeS 2 + FeS 2 + PbS + Sb5+(aq) = CuPbSbS 3 + Fe2+(aq) + 2S to describe the bournonite formation. Accordingly, the Sb isotopic variations (−0.27‰ to 0.48‰) of Sb-bearing minerals (boulangerite, bournonite and stibnite) were empirically attributed to redox reactions. The Rayleigh distillation model indicated that the observed fractionation was most likely induced by redox reactions, while the related theoretical calculations revealed a great antimony exploration potential in deeper parts of the orefield. Overall, the Sb isotopes could be used to identify redox changes in the epithermal system, and exhibit great potential in tracing metal sources, monitoring fluid evolution and ore formation, and providing insights into mineral exploration. [ABSTRACT FROM AUTHOR]

[Display omitted] • The alteration zone patterns have been identified based on the SWIR data at Demingding. • The relationship between Pos2200 and compositions of white mica has been demonstrated by EPMA and determined the subspecies in the ore and barren zone. • We predicted the center of hydrothermal/mineralization based on the spatial variations of the white mica SWIR scalars. The Demingding Cu–Mo deposit, found in the eastern Gangdese metallogenic belt in China, has a significant exploration potential. Detailed field studies coupled with short-wavelength infrared (SWIR) spectroscopy and electron probe micro analyses (EPMA) identified a total of 15 alteration minerals such as white mica group minerals, chlorite, kandite, and smectite groups. The study also discovered the spatial distribution of alteration zone patterns, including phyllic, propylitic, and intermediate argillic alterations. Furthermore, variations were observed in the Al-OH absorption position (Pos2200) of the white mica group with variable Al-Si-Fe-Mg content. Most of the white micas in the ore zone were muscovitic series, whereas the barren zone contained phengitic series micas. Some micas have undergone a transition to illite due to low-temperature alteration overprinting. The western part of the deposit exhibited lower Pos2200, higher SWIR-IC, and higher Dep2200 values, implying an intense phyllic alteration and higher paleotemperatures. These characteristics suggest that the area is in close proximity to the hydrothermal center and fluid channel. Therefore, it was identified as an exploratory target for buried copper ore bodies. The SWIR spectra of the white mica group can be used for exploration in other similar porphyry deposits. Under acidic conditions, shorter Pos2200 and higher SWIR-IC can be used as indicators for hydrothermal or mineralization centers. [ABSTRACT FROM AUTHOR]

Ruyi Zhenbao Pill (RZP) is a prescribed Tibetan formulation for the treatment of white-pulse-disease, yellow-water-disease as well as pain-related disease. RZP is composed of 30 medicinal materials including herbal medicine, animal medicine and mineral medicine. They are widely used in the Tibetan area to treat cerebrovascular disease, hemiplegia, rheumatism, and pain diseases for centuries. The aim of the present study was to evaluate the anti-osteoarthritis function of RZP and to clarify the underlying mechanisms. The active components in RZP were identified using HPLC methods. Osteoarthritis (OA) animal model was established via intra-articular injection of papain in rat knees. After the administration of RZP (0.45, 0.9 g/kg) for 28 days, the clinical observation was conducted, and pathological changes as well as serum biochemical indexes were detected. Moreover, therapeutic targets and pathways of RZP were discussed. The results showed that RZP could suppress knee joint swelling and arthralgia, thus relieving joint pain and inflammation in OA rats. Microcomputed tomography (μCT)-based physiological imaging and staining pictures confirmed the therapeutic effects of RZP on OA symptoms including knee joint swelling and structural changes with progressive inflammation in OA rats. RZP could promote the synthesis or inhibit the degradation of COLⅡ, attenuate OA-induced OPN up-regulation and thus relieve the OA symptom. Furthermore, RZP (0.45–0.9 g/kg) could all ameliorate the imbalance of biomarkers related to OA such as MMP1, TNF-α, COX2, IL-1β and iNOS in knee joints or serum. In conclusion, RZP could effectively relieve inflammatory reaction induced by OA injury and the formulation could be applied to the treatment of OA therapy. [Display omitted] • Ruyi Zhenbao Pill (RZP), a prescribed formulation based on the theory of Tibetan medicine, could suppress knee joint swelling and hyperalgesia. • Microcomputed tomography (μCT)-based physiological imaging and staining pictures confirmed the therapeutic effects of RZP on OA symptoms. • RZP could promote the synthesis or inhibit the degradation of COLⅡ, attenuate OA-induced OPN up-regulation. • RZP (0.45–0.9 g/kg) could all ameliorate the imbalance of biomarkers related to OA such as MMP1, TNF-α, COX2, IL-1β and iNOS in knee joints or serum. [ABSTRACT FROM AUTHOR]