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South China, India, and their derivative blocks preserve many similar magmatic and sedimentary records related to the tectonic transition from Rodinia to Gondwana. They provide crucial insights into not only the paleogeographic correlation between them but also the geodynamic mechanism for such a transition. Our new results, combined with published data from these blocks, reveal that South China remained linked with India at least from ca. 830 Ma to ca. 510 Ma and formed the South China–India Duo, which is located at the western margin of Rodinia. The identical magmatism and sedimentation reflect that double late Neoproterozoic rift systems in the South China–India Duo developed owing to the rollback of subducting oceanic slab beneath them. For example, an intracontinental rift developed along the Jiangnan–Aravalli–Delhi fold belt, which separated the Yangtze-Marwar block from the Cathaysia-Bundelkhand block. Another intra-arc rift developed contemporaneously along the northern and western margins of the Yangtze block, through the Marwar terrane of western India, and then into the Seychelles and Madagascar terranes. Such an intra-arc rift is the most feasible explanation for the common development of coeval arclike and extension-related magmatic rocks and extensional sedimentary sequences on the western margin of the South China–India Duo, in Seychelles and Madagascar, and even at other subduction zones. South China was finally separated from Indian Gondwana at ca. 510 Ma due to the opening of the Proto-Tethys Ocean.

The magmatic processes beneath the active continental margins are very complicated and affect structures and compositions of the arc roots. Neoproterozoic igneous rocks are widely distributed around the margins of the Tarim Block in NW China. The Xingdier mafic-ultramafic intrusion is a composite body, located at the northern margin of the Tarim Block, and consists of gabbro, pyroxenite, and peridotite units. The gabbro unit has a secondary ion mass spectrometry zircon U-Pb age of 727 ± 5 Ma. Rocks from the Xingdier intrusion have a large range of MgO (12.9–32.8 wt%) and SiO2 (43.0–57.9 wt%), and low K2O + Na2O (0.11–2.25 wt%) contents. They have right inclined chondrite-normalized rare earth element patterns with (La/Yb)N ratios of 2.2–8.6. Their primitive mantle normalized trace element patterns show arc-affinity geochemical features characterized by enrichment in Rb, Ba, Th, U, and Pb and depletion in Nb, Ta, and Ti. They have variable initial 87Sr/86Sr ratios (0.7063–0.7093), εNd(t) values (−2.9 to −7.8), 206Pb/204Pb (17.08–17.80), 207Pb/204Pb (15.42–15.49), and 208Pb/204Pb ratios (37.48–38.05), forming an evolution trend from the peridotite unit to the gabbro and pyroxenite units. Clinopyroxene in the three units is chemically similar to those formed in hydrous magmas. The spinel inclusions in olivine from the peridotite unit show unmixing texture and have high Al contents and oxygen fugacity of ~FMQ+1. Therefore, the parental magma was probably derived from a lithospheric mantle enriched by slab-derived fluids. Rocks from the gabbro and peridotite units are proposed to have been derived from olivine-normative melts, whereas rocks from the pyroxenite unit are cumulates from the quartz-normative melts. Such contrasting parental magmas resulted from variable degrees of crustal contamination and fractional crystallization in the arc root.

Situated between the South China Block and the Simao Block, the Ailaoshan Belt is a significant component of the Jinshajiang–Ailaoshan tectonic-magmatic-metallogenic belt of southwestern China. The formation of the Ailaoshan Belt is closely related to the evolution of the Palaeo-Tethys Ocean. In this study, we constrain ages of sedimentation in the Jinchang Au–Ni deposit in the Ailaoshan Belt, using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U–Pb ages of the youngest populations of detrital zircons separated from a chert layer and two uncomfortably overlying meta-sandstones. The combined data of the meta-sandstone samples from the Yiwanshui Formation yielded a concordant age of 250.8 ± 0.6 Ma (mean square weighted deviation (MSWD), 2.8; n = 26). The chert sample from the Jinchangyan Formation yielded a concordant age of 347.0 ± 1.5 Ma (MSWD, 2.8; n = 16). Detrital zircons from the meta-sandstone are characterized by low rare earth element contents (∑REE) and low Y, and high U and U/Yb ratio, suggesting a continental crustal origin. Zircons in the meta-sandstones were derived mainly from pre-collision subduction zone magmatic rocks related to the closure of the Palaeo-Tethys Ocean. In contrast, detrital zircons from the chert contain relatively high ∑REE and Y, and low U and U/Yb ratio, suggesting an oceanic crust origin. Zircons in the chert bed were derived mainly from ophiolites related to seafloor spreading in a branch of the Palaeo-Tethys Ocean.

This study describes an improved alkaline fusion technique for the Re–Os dating of molybdenite. The molybdenite sample was digested in a zirconium crucible with NaOH and carbonized flour at 700 °C. The flour can reduce Os from a high oxidation state to a lower oxidation state during the high-temperature digestion so that isotope equilibration can be reached between the spike and the sample. Less amount of NaOH was used compared with the previously reported technique, lowering the procedure blank. Rhenium was separated by kinetic absorption with an anion exchange resin, and Os was purified by distillation with aqua regia and H2O2. Both Re and Os isotope compositions were measured via inductively coupled plasma mass spectrometry. The results obtained for the molybdenite reference material, JDC, were in good agreement with certified values, demonstrating that the proposed method is efficient for the Re–Os dating of molybdenite. Compared with Carius tube and high-pressure asher sealed acid digestion methods, the improved alkaline fusion method yields comparable Os blanks but has a more simple, quick, and secure procedure.

Hypoxia is a parameter related to many diseases. Ratiometric hypoxia probes often rely on a combination of an O2 -insensitive fluorophore and an O2 -sensitive phosphor in a polymer matrix, which require high cost and multi-step synthesis of transition metal complexes. The two-chromophore hypoxia probes encounter unfavorable energy transfer processes and different stabilities of the chromophores. Reported herein is a pure organic ratiometric hypoxia nanoprobe, assembled by a monochromophore, naphthalimide ureidopyrimidinone (BrNpA-UPy), bridged by a bis-UPy-functionalized benzyl skeleton. The joint factors of quadruple hydrogen bonding, the rigid backbone of UPy, and bromine substitution of the naphthalimide derivative facilitate bright phosphorescence (ΦP =7.7 %, τP =3.2 ms) and fluorescence of the resultant nanoparticles (SNPs) at room temperature, which enable accurate, ratiometric, sensitive oxygen detection (Ksv =189.6 kPa-1 ) in aqueous solution as well as in living HeLa cells.

To observe the effect of electroacupuncture (EA) on the proliferation of endogenous neural stem cells in the hippocampus of young mice with Alzheimer's disease (AD), so as to explore its mechanisms underlying improvement of AD.Forty 1.5-month-old APP/PS1 transgenic male mice were randomly divided into an EA group and a model group, 20 mice in each group, and other 20 C57BL/6J male mice of the same age were used as the normal control group. EA (intermittment wave 10 Hz, 2 mA) was applied to "Baihui" (GV 20), "Fengfu" (GV 16) and "Shenshu" (BL 23) for 20 min, once a day, 6 days a week for 16 weeks. H.E. staining was used to assess histopathological changes of neurons of the hippocampal dentate gyrus. Immunohistochemical stain was used to detect the expression of 5-bromodeoxyuridine (BrdU)-positive in the hippocampus, and immunofluorescence double-labeled technique was used to detect the number of proliferated positive neurons of hippocampal neural stem cells. The expression levels of brain derived neurotrophic factor (BDNF) and Nestin mRNA and protein were detected by using real-time PCR and Western blot, separately.The immunoactivity of BrdU, and the expression levels of BDNF and Nestin mRNA and protein in the hippocampus in the model group were significantly lower than in the normal control group (EA can activate the proliferation of neural stem cells in the hippocampus in AD mice, which may contribute to its function in improving the neuronal structure by upregulating the expression of BDNF.

The Maoping tungsten deposit is located in the Nanling W–Sn metallogenic belt in South China. Greisen and quartz vein types of mineralization developed in this deposit. Protolithionite occurs in the granite. Zinnwaldite is occurs mainly in greisen and wolframite–quartz veins whereas phengite is found in the underground quartz veinlets. In granite and greisen, protolithionite, and zinnwaldite are partly replaced by Li-phengite. LA-ICP-MS trace element analyses of micas and wolframite are employed to characterize the ore-forming source and evolution of ore-forming fluids. Micas show compositional variation trend in vertical directions with a decrease of W, Sn, Nb, and Ta and an increase of MgO, V, Ni, and Co. Wolframite in greisen has higher Mo, Sn, Nb, Ta, and REEs than those in quartz veins. All wolframites show similar REE patterns with enrichment of HREE. Wolframites in greisen and quartz veins have negative Eu anomalies, while wolframites in quartz veinlet display positive Eu anomalies. Compositions of mica and wolframite from different mining levels of the Maoping deposit suggest that the ore-forming fluids are dominated by magmatic hydrothermal fluids in the deep with a slight addition of meteoric water in the shallow. Brittle fracture-induced depressurization and fluid mixing controlled the evolution of ore-forming fluids and possibly lead to the wolframite deposition.

Direct dating of W and W Sn deposits by wolframite is more reliable relatively to gangue mineral and important for understanding their timing and genesis. However, such analysis still lacks of homogeneous wolframite standard recently. Due to containing considerable and variable common lead, and inhomogeneous in different grains, the wolframite sample of MTM, which is a promising candidate reference material proposed by previous studies, is not suitable as a primary standard for wolframite U Pb dating by LA-ICP-MS using the normal normalization method as zircons. In this contribution, a modified normalization method is established for wolframite U Pb dating, in which NIST612 or 614 and MTM are used for correction of Pb Pb and U Pb ratios, respectively. Wolframite U Pb dating are performed on the Langcun, Xihuashan, Piaotang, Shamai W or W Sn deposits and the Baiganhu ore district, the obtained lower intercept 206Pb/238U ages are comparable with the ages from syngenetic molybdenite, cassiterite, muscovite and the genetically related granites, as well as wolframite by water vapor-assisted ns-LA-ICP-MS U Pb dating method. The results of this analysis demonstrate that the robust age for W mineralization can be determined by LA-ICP-MS U Pb dating of wolframite using this modified calibration method. Mineralization ages of 125–130 Ma by directly dating of metal minerals for the Langcun W, Jianfengpo Sn and large-size Xianglushan W deposits confirm that there exists an important W Sn mineralization event in this period. The close temporal and spatial correlation indicates the granites and W-Cu-Mo-Pb-Zn-Sn mineralization have a genetic relationship with each other and are resulted from the same tectonic-magmatic-hydrothermal events during 140 to 120 Ma in South China.

Diogenites are a group of meteorites that are derived from the interior of the largest protoplanet Vesta. They provide a unique opportunity to understanding together the internal structure and dynamic evolution of this protoplanet. Northwest Africa (NWA) 8321 was suggested to be an unbrecciated noritic diogenite meteorite, which is confirmed by our oxygen and chromium isotopic data. Here, we find that olivine in this sample has been partly replaced by orthopyroxene, troilite, and minor metal. The replacement texture of olivine is unambiguous evidence of sulfur-involved metasomatism in the interior of Vesta. The presence of such replacement texture suggests that in NWA 8321, the olivine should be of xenolith origin while the noritic diogenite was derived from partial melting of pre-existing rocks and had crystallized in the interior of Vesta. The post-Rheasilvia craters in the north-polar region on Vesta could be the potential source for NWA 8321., The authors here analyse the petrology of the meteorite NWA 8321 (parent body Vesta). They find sulfidation processes of olivine suggesting metasomatism in the Vestan interior and a partial melting origin for the host noritic diogenite.

Viscous dampers have been widely used for seismic mitigation of long-span double-tower cable-stayed bridges, and the effectiveness of seismic mitigation of cable-stayed bridges depends on t...

The giant Yulong porphyry Cu Mo deposit was formed in postsubduction setting in eastern Tibet. Origin of the ore-related Yulong intrusion remains a matter of debate. This study presents new whole-rock major and trace element geochemistry, in-situ apatite Sr Nd and zircon Hf O isotopes, and mineralogical chemistry of the Yulong intrusion. Least-altered samples from the Yulong intrusion have high SiO2 (66.3–69.5 wt%) and Al2O3 (14.9–15.5 wt%) contents, high La/Yb (36.4–68.0) and Sr/Y (46.0–76.3) ratios, and low MgO (0.63–1.24 wt%) and Cr ( Nd isotopes show limited variations ((87Sr/86Sr)i = 0.7060–0.7068, eNd(t) = −4.8–0.2), which plot between Paleo-Tethys ocean-related arc magmas and the ancient crust in eastern Tibet. Zircon grains from this study and published studies have mostly positive yet variable eHf(t) values (−20.6 to +12.2) and young Hf model ages that overlap those of the Paleo-Tethys ocean-related arc magmas. The above Sr-Nd-Hf isotopes, together with the elevated zircon δ18O values (6.4 to 9.3‰) and arc-like trace element patterns, collectively suggest that the Yulong intrusion may have originated from partial melting of juvenile lower arc crust related to the subduction of the Paleo-Tethys ocean, with incorporation of a small amount of ancient crustal materials. Two generations of amphibole were recognized at Yulong. Their compositions are used to calculate crystallization depths, magmatic oxidation states, and water contents. The caculated results show that the early-stage euhedral high-Al (5.87–8.51 wt%) amphibole phenocrysts may have crystallized in the underlying magma chamber (7.1–12.5 km in depth), whereas the late-stage xenomorphic low-Al (3.47–4.87 wt%) amphibole grains may have crystallized in the porphyritic stock (4.0–5.6 km). Magmatic water contents decrease from early- (3.5–4.6 wt%) to late-stage (2.8–3.5 wt%) amphibole, which is interpreted to indicate fluid exsolution from the magma chamber during emplacement of the Yulong intrusion. Caculated oxidation states increase from early- (ΔNNO = 0.6–1.5) to late-stage (ΔNNO = 1.9–2.3) amphibole. Plagioclase phenocrysts show periodic or reverse core-to-rim zonation of An contents (range up to 25 mol%), which are coupled by FeO contents, probably suggesting magma recharge events. Collectively, we propose that the magma chamber beneath Yulong was recharged by a less evolved magma, and was saturated in fluids to produce intensive alteration and mineralization. The relatively high oxidation states allow the metals to be enriched in the evolving magma, and to be deposited in the hydrothermal alteration stage.

Laparoscopic transcystic common bile duct exploration (LTCBDE) is the minimally traumatic surgical method for the treatment of choledocholithiasis secondary to cholecystolithiasis with dilated common bile duct (CBD). However, no report exists concerning LTCBDE in patients with nondilated CBD. The purpose of this study was thus to explore the safety, efficacy, and feasibility of LTCBDE in patients with choledocholithiasis secondary to cholecystolithiasis with nondilatation of the CBD.We retrospectively analyzed 47 patients with choledocholithiasis secondary to cholecystolithiasis who were treated with LTCBDE at the Second Affiliated Hospital of Nanchang University from January 2017 to August 2021 (all the patients had undergone endoscopic retrograde cholangio-pancreatography treatment, but this failed due to various reasons). Clinical data on disease characteristics, methods for cystic duct incision and CBD stone extraction, and surgical outcomes were collected and reviewed. Each patient was followed up for more than 3 months.There were 47 patients in this study, including 21 females and 26 males, with their ages ranging from 15 to 82 years (51±15 years). All patients were treated with surgery, and the CBD stones were removed successfully. Among these patients, 45 underwent LTCBDE for the removal of stones in the CBD, with failure occurring in 2 patients who then accepted laparoscopic common bile duct stone removal (LCBDE) + T tube drainage. The diameter of the cystic duct was 0.30-0.73 cm (0.60±0.07 cm), the diameter of the CBD was 0.60-0.80 cm (0.73±0.05 cm), the operation time was 75-220 minutes (159±33 minutes), and the postoperative hospital stay was 2-13 days (6±2 days). None of the patients experience any serious postoperative complications, and all were discharged safely. During the follow-up, no postoperative biliary stenosis, bile leakage, or other complications occurred.LTCBDE is feasible to treat patients with choledocholithiasis secondary to cholecystolithiasis with nondilatation of the CBD. This choice of treatment plan reduces the length of hospital stay and the occurrence of postoperative complications. However, it is recommended that this be attempted on the basis of the experience of LTCBDE with dilated CBD.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies with high mortality and short survival time. Computed tomography (CT) plays an important role in the diagnosis, staging and treatment of pancreatic tumour. Pancreatic cancer generally shows a low enhancement pattern compared with normal pancreatic tissue.To analyse whether preoperative enhanced CT could be used to predict postoperative overall survival in patients with PDAC.Sixty-seven patients with PDAC undergoing pancreatic resection were enrolled retrospectively. All patients underwent preoperative unenhanced and enhanced CT examination, the CT values of which were measured. The ratio of the preoperative CT value increase from the nonenhancement phase to the portal venous phase between pancreatic tumour and normal pancreatic tissue was calculated. The cut-off value of ratios was obtained by the receiver operating characteristic (ROC) curve of the tumour relative enhancement ratio (TRER), according to which patients were divided into low- and high-enhancement groups. Univariate and multivariate analyses were performed using Cox regression based on TRER grouping. Finally, the correlation between TRER and clinicopathological characteristics was analysed.The area under the curve of the ROC curve was 0.768 (TRER ≤ 0.7 in patients with PDAC may represent a tumour with higher clinical stage and result in a shorter overall survival.

To screen protein target in prevention and treatment with electroacupuncture (EA) for Alzheimer's disease (AD) and explore the potential mechanism of EA in prevention of AD.A total of 40 APP/PS1 transgenic young male mice, 1.5-month old, were randomized into an EA group and a model group, 20 mice in each one, and 20 C57BL/6J mice were chosen as the normal control group. After adaptive housing for 1 week, the mice in the EA group were stimulated with EA at "Baihui" (GV 20), "Fengfu" (GV 16) and "Shenshu" (BL 23), with intermittent wave, 10 Hz in frequency and 2 mA in electric intensity. EA was given once daily, 20 min each time. There was 1 day at interval after EA for 6 days each week. Totally, the intervention lasted for 16 weeks. On day 3 after the end of EA intervention, Morris water maze test was adopted to detect learning and memory abilities of mice in each group. After water maze test, the label-free method was used to measure the difference expressions in cerebral cortex and hippocampus. Using Western blot method, the expressions of guanylate binding protein beta 5 (GNB 5) and histone-H 3 in cerebral cortex and hippocampus were verified. Using immunohistochemical method, the expressions of amyloid beta protein (Aβ) in cerebral cortex and hippocampus were detected.Compared with the normal control group, the escape latency (on day 2, 3 and 4) was prolonged, the frequency of crossing platform and the duration of platform stay were decreased in the mice of the model group (The intervention with EA effectively prevents from the decline of learning and memory ability and the formation of Aβ senile plaques in cerebral cortex and hippocampus in young mouse models of AD after growing up. Besides, EA plays a regulatory function for protein expression differences induced by AD model.

Two novel adsorbents (AGD301 and ArgD301) were successfully prepared through ring-opening reaction. The adsorption performance and recognition selectivity of AGD301 and ArgD301 towards AuCl4− were ...

The Yulong porphyry Cu-Mo ore district in eastern Tibet features a series of Eocene felsic porphyry intrusions, only one of which is intensively mineralized. In this study, zircon U-Pb ages, and major and trace element compositions of whole rock samples and in-situ accessory minerals (zircon, apatite and titanite) from these various intrusions were analyzed to determine the factors controlling Cu mineralization. New zircon U-Pb dating, together with published zircon U-Pb ages, suggest that these porphyry intrusions were emplaced over a relatively short period of time (43.9 ± 0.6 Ma to 40.9 ± 0.3 Ma), with the mineralized Yulong intrusion emplaced at a late stage of the magmatic activity (41.1 ± 0.3 Ma to 40.9 ± 0.3 Ma). These intrusions have indistinguishable whole-rock major and trace element compositions, but the mineralized Yulong intrusion has higher apatite and titanite La/Yb ratios (average apatite La/Yb = 115.1 ± 28.5, n = 52; average titanite La/Yb = 22.4 ± 4.9, n = 38) than the earlier subeconomic intrusions (average apatite La/Yb = 50.4 ± 12.3, n = 72; average titanite La/Yb = 12.4 ± 3.5, n = 58), suggesting more fractionation of amphibole from the magmas that sourced it. Additionally, a negative relationship between La/Yb and CeN/CeN* ratios in apatite and titanite are interpreted to reflect increasing oxidation states through magma evolution. Indistinguishable zircon EuN/EuN* values and apatite core SO3 contents from the mineralized (zircon EuN/EuN* = 0.69 ± 0.06, n = 25; apatite SO3 = 0.65 ± 0.24 wt%, n = 21) and subeconomic intrusions (zircon EuN/EuN* = 0.62 ± 0.05, n = 64; apatite SO3 = 0.61 ± 0.27 wt%, n = 15) suggest that the entire magmatic suite was relatively oxidized, hydrous and sulfur-rich, and was therefore fertile for ore-formation. However, apatite crystals from the mineralized Yulong intrusion have significantly lower Cl contents (0.08 ± 0.03 wt%, n = 72) and higher F/Cl ratios (47.80 ± 21.97, n = 72) than those from the subeconomic intrusions (Cl = 0.29 ± 0.29 wt%; F/Cl = 12.87 ± 5.16; n = 78). These data may reflect more extensive fluid exsolution from the parental magma chamber at the time of emplacement of the mineralizing Yulong magmas. Sudden and voluminous release of volatiles coeval with emplacement of the Yulong intrusion was triggered by an as yet unidentified process, but possibly including magmatic recharge.

Early Cretaceous granitoids are widespread on the Tibetan Plateau and record the tectonic evolution of several Tethyan oceans. We describe Early Cretaceous high-Mg (Mg# > 50) and low-Mg (Mg#

Recent exploration revealed a number of rare earth element (REE) deposits that are distributed along the Qinling Orogenic Belt, Central China. These deposits have an estimated total reserve of about 2 Mt. REE2O3, thus making this belt a world-class REE metallogenic province. Understanding the metallogenesis of the belt requires direct dating of REE minerals. In this study, LA-ICP-MS U-Th-Pb dating on bastnasite and monazite from the Huangshuian, Taipingzhen, and Miaoya deposits in different units of the belt was used to precisely determine the timing of the REE mineralization. The Huangshuian deposit in the north is a carbonatite-related Mo-(REE) deposit in which the REE minerals are closely associated with molybdenite. After correction for common Pb and excessed 206Pb decayed from 230Th, a weighted average 206Pb/238U age of 207 ± 4 Ma (n = 17; MSWD = 1.9) is obtained for bastnasite grains from this deposit. Such an age is slightly younger than that of the final collision (peak at 230–220 Ma) of the Qinling Orogenic Belt, thus indicating that the Mo-REE mineralization is likely related to a post-collisional extension setting. The Taipingzhen REE deposit in the middle contains sheet-like ore bodies composed of veins where bastnasite, the dominant REE mineral, is closely associated with quartz, fluorite, and barite. In situ bastnasite U-Th-Pb dating shows that the REE mineralization in this deposit has formed at 421 ± 7 Ma (n = 17; MSWD = 1.5), synchronous with extension-related magmatism in the region. The Miaoya deposit in the south is the largest one in the belt, and it is essentially a REE-mineralized syenite-carbonatite complex. In this deposit, the monazite grains are closely associated with major minerals of the syenites or carbonatites (e.g., K-feldspar or calcite), but commonly exhibit complex internal textures. Different domains of monazite yield two groups of U-Pb ages at 414 ± 11 Ma (n = 5; MSWD = 0.91) and 231 ± 2 Ma (n = 21; MSWD = 3.1), whereas the bastnasite has an age of 206 ± 4 Ma (n = 14; MSWD = 1.5). The early age of 414 Ma is obtained from homogenous monazite grains and in good agreement with zircon U-Pb ages of the Miaoya syenite-carbonatite complex, and thus is considered to represent the timing of the major REE mineralization in the deposit. The younger ages of 231–206 Ma are obtained from monazite grains with complex internal textures and bastnasite in late veinlets, thus recording secondary, consecutive REE remobilization events likely related to the compression process during formation of the Qinling Orogenic Belt. Our new U-Th-Pb ages, in combination with previously geochronological data, demonstrate that there are two episodes of REE mineralization at 440–410 Ma and 220–200 Ma in the Qinling Orogenic Belt.

The Huize Zn–Pb–Ag deposit in SW China has an ore reserve in excess of 5 Mt. with an ore grade of ≥25 wt% Zn + Pb and 46–100 g/t Ag. This deposit is hosted in Carboniferous dolostone and limestone. Sulfide mineralization is dominated by sphalerite, galena, and pyrite. Four types of pyrite (Py1 to Py4) are temporally and spatially related to mineralization distinguished on the basis of textural features and mineral associations. Pyrite 1 to 3 corresponds to the pyrite-sphalerite sub-stage, whereas Py4 corresponds to sphalerite-galena-pyrite sub-stage. Pyrite 1 shows zoned texture composed of an inclusion-rich core and an inclusion-free rim, whereas Py2, Py3, and Py4 show replacement relic or overgrowth textures. The zoned texture in Py1 was formed by multiple stages of ore fluids, whereas replacement relic texture in Py2 to Py4 was formed by replacement of pyrite by late Pb-Zn-rich fluids. Trace element variation in pyrite results from a combination of mineral inclusions, co-precipitating minerals, and various fluid compositions. Sphalerite, pyrite, and galena have δ34S values of 10.4–23.5‰, suggesting that sulfur was probably derived from the thermochemical reduction of marine sulfates. The Huize pyrite has Co and Ni concentrations (0.02–9.5 ppm and 0.08–143 ppm, respectively) and Co/Ni ratios (~0.01–2.63) similar to pyrite from sedimentary exhalative deposits, submarine hydrothermal vents, and sedimentary pyrite, which may be due to pyrite precipitation from low-temperature (

In this paper, a novel surface molecularly imprinting technique with higher imprinting efficiency is well designed. It really realizes the synchronization of polymer crosslinking and template imprinting. Then the surface molecularly imprinted polymers (SMIPs) are synthesized using 2-nitrophenol (2-NP), 3-nitrophenol (3-NP), 4-nitrophenol (4-NP), and 4-methylphenol (4-MP) as template, respectively. The physicochemical characteristics of SMIPs are characterized by Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The adsorption performances and recognization selectivity of SMIPs towards template are systematically investigated by batch method. The experimental results show that the SMIPs possess strong adsorption ability and excellent selectivity towards template. The selectivity coefficients of 2-NP, 3-NP, 4-NP and 4-MP relative to 4-chlorophenol (4-CP) are 132.2, 124.5, 157.3 and 37.8, respectively. The adsorption process could be well described by the Lagergren-first-order model and Langmuir-monolayer adsorption model. SMIPs have good chemical stability and reusability. The consecutive adsorption-desorption experiments show that the exhausted SMIPs could be effectively regenerated, and the regenerative SMIPs could be reused without significant reduction of adsorption capacity and selectivity coefficient.

Amino acid functionalized D301 resins (Tyr-D301, Phe-D301, and Ala-D301) are successfully prepared to remove phenols. The influences of adsorption condition on adsorption ability and the practical ...

Titanium (Ti) is typically hosted in detrital minerals in marine sediments and has long been considered to be immobile during diagenesis. In this study, the authigenic titania minerals, brookite and anatase, are observed in early Cambrian carbonaceous shales from the Meishucun and Zhajin sections of South China, respectively. Black shales in the Meishucun section have total organic carbon (TOC) contents from 1.6 to 3.9 wt% and HI (hydrogen index) values from 3.8 to 20 mg HC/g TOC, whereas black shales in the Zhajin section have much higher TOC (7.1–15.6 wt%) but lower HI (

The giant Yulong porphyry Cu (Mo Au) deposit, located in the eastern Tibetan Plateau, is a typical post-subduction porphyry Cu ± Mo ± Au deposit formed in an intracontinental strike-slip fault system, and it is also one of the largest porphyry Cu deposits in China with reserves of 6.5Mt Cu @ 0.62% and 0.41Mt Mo @ 0.042%, respectively. In this study, sulfur and lead isotopic compositions of sulfides and ore-related porphyry samples were determined to constrain the sources of ore-forming materials and ore-forming process. Sulfides (e.g., pyrite, chalcopyrite and molybdenite) from phyllic alteration zone, where the Cu and Mo mineralization mainly occurred, have uniform δ34S values ranging from −0.6 to +2.1‰ (average + 1.1‰), which indicates a magmatic origin of the sulfur. In situ Nano-SIMS sulfur isotope analysis further reveals that pyrites formed in potassic alteration stage have systematically negative δ34S values ranging from −0.2 to −9.7‰ (average − 4.5‰), whereas pyrites formed in phyllic alteration stage have systematically positive δ34S values ranging from +1.1 to +3.2‰ (average + 2.1‰). This regular variation is considered to be resulted from disproportionation of aqueous SO2 and subsequent sulfate reduction, further suggesting a magmatic origin of the sulfur. The sulfides have initial Pb isotopic compositions ((206Pb/204Pb)i = 18.616–18.812, (207Pb/204Pb)i = 15.670–15.740, (208Pb/204Pb)i = 38.956–39.080) deviating from those of the ore-related porphyries ((206Pb/204Pb)i = 18.549–18.718, (207Pb/204Pb)i = 15.647–15.662, (208Pb/204Pb)i = 38.794–39.888), but more close to those of the ore-hosting strata ((206Pb/204Pb)i = 18.423–18.761, (207Pb/204Pb)i = 15.654–15.713, (208Pb/204Pb)i = 38.867–39.062). The shift of Pb isotopic compositions of sulfide minerals toward those of ore-hosting strata indicates that the ore-hosting strata had provided a significant amount of Pb for ore formation, and most probably suggests fluid-rock interaction processes in the hydrothermal system. Our study represents a case study in which ore-hosting strata had provided a significant amount of ore-forming materials for porphyry Cu ± Mo ± Au formation in the post-subduction setting.

Genesis of magnetite from Gol-Gohar iron deposit (GGID) of southeastern Iran is studied with reference to elemental composition. More than 1.2 billion tonnes of magnetite ore at 58% total Fe is hosted by greenschist- to amphibolite-facies metapelites and magnesian marbles. The GGID occurs in the mainly-metamorphic terrain of Sanandaj-Sirjan geological province, with continental-margin tectonic setting. The magnetite-bearing ore is divided into two distinct types of massive and banded; the latter hosted mainly by magnesian marbles. Both subtypes of the ore bodies are associated with mineral assemblages consisting of calcite, dolomite, forsterite, tremolite-actinolite, talc, serpentine, and chlorite. The ore minerals in both subtypes are magnetite, hematite with minor amounts of pyrite, pyrrhotite, and chalcopyrite. Concentrations of temperature-dependent elements, Ti, Al, and Ga in the two subtypes would suggest that temperature of formation was higher for the massive magnetite (with Ti = 626 ppm, Al = 69 ppm and Ga = 56 ppm, on average) and relatively lower for the banded magnetite (with Ti = 60 ppm, Al = 62 ppm and Ga = 4 ppm, on average). The multi-element diagrams, for massive magnetite, show patterns closer to those of magmatic-hydrothermel iron deposits (Kiruna-type), whereas, patterns of the banded magnetite match better with those of skarn deposits, particularly the magnesian skarns. Average concentrations of V (>1000 ppm) and Cr (∼4 ppm) of the massive subtype fall within the range of those of Kiruna-type deposits, and the in average lower concentrations of V (∼10 ppm) and Cr (∼1 ppm) of the banded magnetite match the values of skarn deposits. The average V content of the massive magnetite (1342 ppm) is consistent with the global range of magmatic-hydrothermal magnetite (up to 3880 ppm), but different from global values of purely-magmatic magnetites (up to 6600 ppm). The banded magnetites contain 0.21–25 ppm V, which is only consistent with the lowest values of hydrothermal magnetites. We contend that the massive magnetite was formed by magmatic-hydrothermal processes (i.e., Kiruna type) and the banded magnetites were generated via metasomatic reactions between iron-rich residual magmatic fluids and the magnesian carbonate host rocks (i.e., skarn type).

The Laochang polymetallic deposit is located in the Sanjiang Tethyan metallogenic province of southwestern China. This deposit contains stratabound (and locally vein-type) Pb–Zn–Ag mineralization and underlying porphyry–skarn Mo mineralization. The stratabound Pb–Zn–Ag mineralization is characterized by massive sulfide ores composed mainly of pyrite, sphalerite, galena, and minor chalcopyrite, whereas the underlying porphyry–skarn Mo mineralization is characterized by quartz–sulfide veins comprising mainly pyrite, chalcopyrite, molybdenite, and minor sphalerite and galena. The age and origin of the stratabound Pb–Zn–Ag mineralization has long been debated, and its relationship to the porphyry–skarn Mo mineralization remains unknown. Integrated pyrite Re-Os isotope, sulfur isotope, and in situ trace element data are used here to constrain the age and origin of both types of mineralization and their genetic relationships. Pyrite related to porphyry–skarn Mo mineralization yields a Re-Os isochron age of 47.3 ± 4.8 Ma, which is consistent with a previous molybdenite Re-Os age of the quartz–sulfide ores and zircon U-Pb ages of the granite porphyry (~44–50 Ma). Pyrite from the stratabound Pb–Zn–Ag mineralization failed to yield a geologically meaningful age, but associated sphalerite and galena have a Re-Os isochron age of 308 ± 25 Ma (Liu et al., 2015), which is consistent with the Carboniferous age of the host basalts. Pyrite, sphalerite, galena, and chalcopyrite from the stratabound Pb–Zn–Ag mineralization have δ34S values (−2.1 to 0.5‰; average 0.48‰) indistinguishable from those of sulfides from the porphyry–skarn Mo mineralization (−4 to 1.9‰; average 0.52‰). Initial Os isotope ratios indicate a mainly crustal origin for both types of mineralization. The calculated (Se/S)fluid and Co/Ni values of pyrite from the stratabound Pb–Zn–Ag mineralization indicate a mixed sedimentary and hydrothermal origin, with a significant magmatic contribution. The identification of a magmatic component, Eocene sulfide mineralization, and phyllic and propylitization alteration in stratabound Pb–Zn–Ag ores indicates that the magmatic–hydrothermal component reflects the overprinting of Carboniferous volcanogenic massive sulfide mineralization by magmatic–hydrothermal fluids derived from an Eocene granite porphyry.

Cretaceous granites are widely exposed in the Tengchong Terrane that is the southern extension of the Tibetan Plateau, resulting from the evolution of the Tethys. They, therefore, play a critical role in deciphering the Tethys evolution and the growth of the Tibetan Plateau. In this paper, we present new zircon U Pb dating and Hf isotopic results, along with whole-rock elemental and Sr Nd isotopic data of the granitoids from the Lushui-Pianma (LP) batholith and its mafic enclaves and the strongly deformed granites from the Gaoligong shear zone in the northern Tengchong Terrane. The dating results show that both the LP granitic batholith and the strongly deformed granites in the Gaoligong shear zone formed in the Early Cretaceous of 122–110 Ma. They are composed of granodiorite, quartz monzodiorite and monzogranite with minor gabbroic enclaves. Mineralogically and geochemically, the granitoids in the LP batholith, particularly for the less evolved ones, display a metaluminous nature and an affinity to I-type granite. All the granitoids are characterized by similar rare and trace patterns and whole-rock Nd and zircon Hf isotopic compositions, indicating a common origin. The sodium-rich feature for the less evolved dioritic rocks and the predominantly negative zircon eHf(t) and whole-rock eNd(t) values for all the granitoids demonstrate that they were derived mainly from the partial melting of the Mesoproterozoic metabasic rocks (likely the basement rocks of the Gaoligong Group) in the lower crust of the Tengchong Terrane. In the case of the mafic enclaves, they share similar mineralogical assemblages and Nd Hf isotopic compositions to its host granodiorite, indicating a cognate origin with the latter. In combination with previous data for the granitoids in the Tengchong Terrane, our study further illustrates that the Early Cretaceous granitic rocks are dominated by metaluminous I-type granites with minor highly fractionated peraluminous I-type granites, rather than the dominant S-type granites as assumed before. The new identification of the Myitkyina Meso-Tethys ophiolitic suite in eastern Myanmar, together with regional Early Cretaceous magmatic and sedimentation patterns, indicate that these Early Cretaceous magmatic rocks were the products of the evolution of the Myitkyina Tethys Ocean, which was related to post-collisional slab breakoff.

A new model of porphyry Cu system, which involves pre-enrichment of Cu through sulfide accumulation near the mantle-crust boundary, has been recently proposed to account for variations of Cu endowment in different magmatic arcs. To test this model and explore the possible controlling factors of porphyry Cu metallogeny, we studied the mineralogy and platinum-group elements (PGE) geochemistry of the giant Pulang porphyry Cu-Au system in the Sanjiang Region, SW China. The Late Triassic Pulang intrusive complex comprises five phase of porphyrtic stocks and dikes (ca. 217–212 Ma), which intruded a slightly older (ca. 230–218 Ma) volcanic-sedimentary sequence of the Tumugou Formation. Both the intrusive complex and the related volcanic wall rocks have similar PGE concentrations, Pd/Pt ratios and primitive mantle-normalized PGE patterns, indicating that no discernible sulfide cumulates were lost or gained during magmatic differentiation. The variation in PGE concentrations between different types of rocks at Pulang is probably ascribed to magma mixing between mafic and felsic end-members. Two types of amphibole, i.e., high-Al (Al2O3 = 9.4–11.8 wt%) and low-Al (5.9–7.3 wt%) types, have been identified in the Pulang complex. It is estimated that the magma equilibrated with the high-Al amphibole may have contained up to 6.2 wt% H2O, and was formed under 334–538 MPa (ca. 11–18 km deep eqv.) with oxygen fugacity (fO2) between NNO + 0.2 and NNO + 1.5. In contrast, the magma that equilibrated with the low-Al amphibole was likely formed at a much shallower depth (89–202 MPa, ca. 3–7 km eqv.), and was more oxidized (NNO + 1.0–NNO + 1.7) with a low H2O content (4.2–4.9 wt%). High fO2 would increase sulfur solubility in the magma, thus prohibiting early removal of metals via sulfide precipitation. In addition, the higher H2O content may have enhanced volatile exsolution from the evolving magmas at Pulang. We suggest that oxygen fugacity and H2O content of the magma are two critical factors that controlled the Pulang porphyry Cu-Au metallogeny.

The Chuankou tungsten ore field is situated in the central area of the Xuefeng Uplift Belt in South China. The deposit is characterized by two types of tungsten mineralization: quartz-scheelite veins in both the Neoproterozoic Banxi Group and Devonian Yanglin&rsquo, ao Formation and quartz-wolframite (scheelite) veins in the Chuankou granite. The host rocks of the Chuankou tungsten Deposit of South China are similar to the stratigraphic sequence of Au-Sb-W deposits in the Xuefeng Uplift Belt. It is thus an appropriate location for the study of scheelite mineralization in the belt, especially the relative contributions of surrounding rocks, magma and hydrothermal fluids. Optical Microscope-Cathodoluminescene (OM-CL) and Laser Ablation Inductively Coupled Mass Spectrometers (LA ICPMS) were used to examine scheelite textures and trace element concentrations in the Chuankou deposits. Scheelite in quartz-scheelite veins was formed over three generations. In situ LA-ICPMS trace elemental analyses of scheelite I show light rare earth element (LREE)-rich REE patterns and negative Eu anomalies, suggesting a relatively close fluid system. Significantly positive Eu anomalies of scheelite II and III indicate variable degrees of addition of meteoric water during scheelite precipitation. Therefore, ore-forming fluids of the Chuankou deposit were dominantly magma-derived, with different contributions of recycled meteoric water in the surrounding strata.

To investigate the effect of electroacupuncture (EA) at "Baihui"(GV20), "Fengfu"(GV16) and bilateral "Shenshu"(BL23) on learning-memory ability, apoptosis in the hippocampus and expression of Aβ, Caspase 3, Bax and Bcl-2 proteins in the hippocampus and cerebral cortex in immature mice with Alzheimer's disease (AD), so as to explore its mechanism underlying improvement of AD.Forty APP/PS1 transgenic male young mice were equally randomized into model and EA groups and 20 C57BL/6J male young mice were used as the normal control. EA (10 Hz, about 2 mA) was applied to GV20-BL23 and GV16-BL23 for 20 min, once daily, 6 days a week for 16 weeks. The Morris water maze swimming test was used to evaluate the animals' learning-memory ability. Congo red staining and immunohistochemical staining were used to detect senile plaques in the hippocampus (dentate gyrus) and cerebral cortex tissues. Terminal deoxynucleotidyl transferase-mediated dUTP Nick-end Labeling (TUNEL) was used to detect the cellular apoptosis of hippocampus. The expression levels of apoptosis related factors Caspase 3, Bax and Bcl-2 were detected by Western blot.After modeling, the escape latency of place navigation test of Morris water maze swimming tasks was significantly increased (EA of GV20, GV16 and BL23 can effectively improve the learning-memory ability in AD mice, which may be related to its function in inhibiting neuronal apoptosis in the hippocampus and down-regulating the expression levels of Aβ, Caspase 3 and Bax proteins in both hippocampus and cerebral cortex.

Calcitonin gene-related peptide (CGRP) is a neuropeptide coded by the calcitonin gene and divided into α and β subtypes. CGRP is widely distributed throughout the human body and highly expressed in the peripheral and central nervous system. Studies have shown that CGRP plays a role in a variety of physiological and pathophysiological activities, such as the formation and transmission of nociceptive signal, as well as the regulation of cardiovascular function. Recently, more and more researches have shown that CGRP is involved in the regulation of synaptic plasticity, cognitive function and learning memory in the central nervous system. This paper reviews the role of CGRP in regulation of synaptic plasticity and process of emotional memory, hoping to provide a new molecular target and theoretical basis for clinical treatment of neurological diseases.

The Neoproterozoic (840 Ma) Sin Quyen deposit in northwestern Vietnam contains replacement Cu-LREE-Au orebodies in Proterozoic metasedimentary rocks. In this deposit, LREE-bearing minerals include allanite-(Ce), monazite-(Ce), chevkinite-(Ce), and fluorapatite. Fluorapatite from orebodies has undergone variable degrees of metasomatic alteration. Samarium-neodymium isotopic analyses were conducted on altered fluorapatite, and also on allanite-(Ce) and monazite-(Ce), to investigate whether such metasomatism can affect the Sm-Nd isotope system. Allanite-(Ce) and monazite-(Ce) have Sm-147/Nd-144 ratios ranging from 0.0359 to 0.0549, and Nd-143/Nd-144 ratios from 0.51147 to 0.51172. Their initial Nd-143/Nd-144 values at the time of mineralization range from 0.51126 to 0.51148, but mostly cluster between 0.51135 and 0.51145. Thus, the primary ore-forming fluids were relatively homogeneous in their Sm-Nd isotopic compositions. In the Sm-147/Nd-144 vs. Nd-143/Nd-144 diagram, the compositions of allanite-(Ce) and monazite-(Ce) generally plot along a Sm-Nd isochron of 840 Ma, implying that the Sm-Nd isotopic systems of these minerals were either closed or only slightly modified. In contrast, altered fluorapatite crystals have Sm-147/Nd-144 ratios varying from 0.0667 to 0.1348, and Nd-143/Nd-144 ratios from 0.51160 to 0.51199. The calculated initial Nd-143/Nd-144 ratios range widely from 0.51114 to 0.51141, with most values lower than those of the allanite-(Ce) and monazite-(Ce). In the Sm-147/Nd-144 vs. Nd-143/Nd-144 diagram, their compositions mostly plot below the 840-Ma Sm-Nd isochron. Petrographic observations and trace elemental analyses show that metasomatic modification of fluorapatite grains led to increases of their Sm/Nd ratios. The unaltered domains in the grains have Sm/Nd ratios varying from 0.114 to 0.200, with an average value of 0.161; whereas the altered domains have Sm/Nd ratios varying from 0.111 to 0.254, with an average value of 0.183. The increased Sm/Nd ratios can cause the calculated initial Nd-143/Nd-144 ratios to be lower than actual initial isotopic ratios, and can also result in compositional deviations from the reference Sm-Nd isochron. This study demonstrates that the traditionally assumed inert Sm-Nd isotopic system can be metasomatically disturbed due to changes in the Sm/Nd ratio. Therefore, care must be taken when interpreting the Sm-Nd isotopic data from apatite/apatite-rich rocks that have undergone metasomatic alteration.

Precisely dating different generations of mineralization is important for understanding the origin and tectonic environment of ore formation. In this study, we have dated two generations of sulfides from the Lala Fe-Cu deposit, SW China, using in situ Pb-Pb isotopic data obtained by the LA-MC-ICPMS technique. The Lala deposit is composed of Fe-Cu ore bodies hosted in sedimentary-volcanic rocks of the Paleoproterozoic Hekou Group. It has a paragenetic sequence of pre-ore banded pyrite (Stage I) and Na alteration (Stage II), followed by early Fe (Stage III) and late Cu (Stage IV) mineralization. The sulfides in the deposit have dominantly formed in two stages, including pyrite from stratiform pyrite bands in the host rocks (i.e., Stage I) and epigenetic pyrite-chalcopyrite in Fe-Cu ore (i.e., Stage IV). The sulfides of both stages have highly radiogenic Pb isotopic ratios which form linear trends in the 207Pb/204Pb versus 206Pb/204Pb diagram. The regression trend for Stage I pyrite grains defines an errorchron age of 1669 ± 110 Ma (MSWD = 32), undistinguishable from zircon LA-ICPMS U-Pb ages of volcanic rocks in the Hekou Group (i.e., ~ 1700 Ma). The regressions for Stage IV pyrite and chalcopyrite yield younger errorchron ages of 1088 ± 88 Ma (MSWD = 93) and 1053 ± 220 Ma (MSWD = 15), respectively. Taking pyrite and chalcopyrite together, an errorchron age of 1053 ± 75 Ma (MSWD = 108) is obtained. These errorchron ages agree well with the molybdenite Re-Os age of the Fe-Cu ore (1086 ± 8 Ma). Despite the large error and MSWD values that are interpreted to be related to the small variation of initial ratios, or post-ore open system behavior, the good agreement with the precise zircon U-Pb and molybdenite Re-Os ages indicates that the Pb-Pb errorchron ages for Stage I and IV sulfides are geologically meaningful. Therefore, this study shows that the in situ Pb isotopic analyses can yield geologically meaningful Pb-Pb ages for radiogenic Pb-rich sulfide minerals. We also propose that in situ Pb-Pb isotopic dating may be more promising for Precambrian deposits containing sulfides with ingrown Pb, particularly for those involving multiple mineralization/hydrothermal events but without relevant minerals for precise Re-Os or U-Pb dating.

The Late Triassic Muguayuan W deposit is located in the middle of the Jiangnan Orogen, South China. This deposit is characterized by veinlet-disseminated W mineralization that developed in the Sanxianba granitic porphyry stock. The ore minerals are mainly scheelite with minor molybdenite and wolframite. Scheelite mineralization was closely related to greisenization and phyllic alteration, and took place in two stages. Stage I involved scheelite ± wolframite ± molybdenite + quartz veinlet and disseminated mineralization, whereas Stage II resulted in scheelite + quartz + sericite veinlet mineralization. Sulfide and quartz + calcite ± pyrite veinlets formed during the post-ore stage. Scheelites from the two mineralization stages have different textures and compositions. Cathodoluminescence (CL) images of Stage I scheelites reveal two generations of growth (I-a and I-b). Stage I-a scheelite is dark under CL with oscillatory zoning, and has light rare earth element (LREE)-enriched chondrite-normalized patterns, negative Eu anomalies, and high total REE contents. Stage I-b scheelite forms rim overgrowths on Stage I-a scheelite, is bright under CL, and shows positive Eu anomalies and relatively low REE contents. Although Stage II scheelites are nearly uniform under CL, they can be subdivided into two generations according to their REE systematics. Stage II-a scheelite yields middle REE (MREE)-enriched chondrite-normalized patterns, with negative Eu anomalies, whereas Stage II-b scheelite has MREE-depleted patterns with positive Eu anomalies. Minor amounts of apatite formed in both stages of mineralization. Stage I apatite contains 1370–1930 ppm Mn and 97.7–127 ppm Sr, whereas Stage II apatite has lower Mn (111–158 ppm) and higher Sr (2170–4690 ppm) concentrations. The distinct trace elements compositions of the scheelite and apatite from the two stages identify two ore-forming fluids that had different origins and compositions. The ore-forming fluids in Stage I-a were relatively reduced magma-derived fluids with high Mo, Mn, Nb, and Ta, and low Sr. Fluid modeling shows that the initial fluids of Stage I-a were LREE-enriched with negative Eu anomalies, similar to the Sanxianba granitic porphyry. Precipitation of early apatite and scheelite, as well as plagioclase decomposition, altered the fluid composition and led to relative depletions in REE, Nb, and Ta, and increases of Eu and Sr in the Stage I-b fluids. Cooling of these fluids and the addition of recycled meteoric water led the fluids to become relatively oxidized and Sr-rich; Stage II scheelite precipitated from these fluids. Precipitation of Stage II-a scheelite resulted in the Stage II-b fluids becoming progressively MREE-depleted. Extensive alteration, especially greisenization and phyllic alteration, led to plagioclase decomposition, which provided the Ca necessary for scheelite mineralization. This process was important in generating the W mineralization in the Muguayuan deposit, and perhaps for other granite-hosted, veinlet-disseminated scheelite deposits in the Jiangnan Orogen.

Veinlet-disseminated and vein-type tungsten deposits are important tungsten resources in South China and show remarkable diversity in dominant tungsten minerals. To better understand their genesis, scheelite from the Shimensi veinlet-disseminated deposit and wolframite from the Xihuashan and Piaotang vein-type deposits were selected to conduct in-situ laser ablation-inductively coupled plasma-mass spectrometry trace element analyses. The Shimensi tungsten mineralization occurs in intensively altered granitic rocks and is characterized by scheelite. Two generations of scheelite in a single grain can be identified by cathodoluminescence (CL) imaging. The early scheelite (dark domains in CL images) is characterized by nearly flat chondrite-normalized REE (REEN) patterns with significantly negative Eu anomalies, whereas the late one (bright domains in CL images) shows light rare earth element (LREE)-enriched REEN patterns and obviously positive Eu anomalies. The former has higher REE, Na, Nb and Ta and lower Sr contents than the latter. The Xihuashan and Piaotang wolframite-quartz veins are developed in greisenized granite (type I) and metasedimentary rocks (type II). Both types of wolframite show LREE-depleted patterns, but type I exhibits strongly negative Eu anomalies and type II positive Eu anomalies. Type I contains higher REE, Nb and Ta concentrations, and lower FeO/MnO ratios than type II. Variations of Eu anomalies and trace element compositions in both scheelite and wolframite can be used to decipher the origin and processes of tungsten mineralization. Both the early scheelite and wolframite (type I) display significantly negative Eu anomalies and have high REE, Nb and Ta contents, suggesting that the initial ore-forming fluids were of magmatic origin. Precipitation of tungsten minerals and alteration would effectively modify the composition of ore-forming fluids. Deposition of the early tungsten minerals would lower REE, Nb and Ta in the mineralizing fluids, leading to depletion of these elements in the late ones. Although both the type I and II wolframite have different REE contents and Eu anomalies, they show similar left-dipped REEN patterns, implying that compositional variation of fluids is likely driven by crystallization of wolframite during the processes of fluid evolution. In contrast, the elevated LREE/HREE (heavy rare earth element) ratios, δEu (EuN/EuN∗) values and Sr abundances in the late scheelite are possibly caused by the decomposition of plagioclase and K-feldspar. Alteration plays an important role in the formation of veinlet-disseminated scheelite deposits. It can be concluded that vein-type wolframite mineralization is mainly formed by filling and that veinlet-disseminated scheelite mineralization is associated with metasomatism.