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The Khetri Copper Belt (KCB) in northwestern India contains several economically important hydrothermal Cu–(Au) deposits. Orebodies in these deposits are locally rich in monazite-(Ce). In this study, in situ U–Pb ages and Sm–Nd isotopic compositions of monazite-(Ce) are used to constrain the timing of mineralization and to better understand the genesis of the Cu–(Au) deposits. Monazite-(Ce) crystals were identified in the Madhan-Kudhan and Kolihan deposits in the KCB. Most monazite-(Ce) crystals in the two deposits show close textural associations with hydrothermal minerals (biotite, chlorite, and sulfide) and have low contents of ThO2 (mostly

The Xinqiao deposit is one of several polymetallic deposits in the Tongling ore district. There are two types of mineralization in the Xinqiao: skarn-type and stratiform-type. The skarn-type mineralization is characterized by iron oxides such as magnetite and hematite, whereas stratiform-type mineralization is characterized by massive sulfides with small amounts of magnetite and hematite. We defined three types of ores within the stratiform-type mineralization by the mineral assemblages and ore structures. Type I ore is represented by magnetite crosscut by minor calcite veins. Type II is a network ore composed of magnetite and crosscutting pyrite. Type III is a massive ore containing calcite and hematite. Type I magnetite is characterized by highly variable trace element content, whereas Type II magnetite has consistently higher Si, Ti, V, and Nb. Type III magnetite contains more In, Sn, and As than the other two types. Fluid–rock interaction, oxygen fugacity (fO2), and temperature (T) are the main factors controlling element variation between the different magnetite types. Type I magnetite was formed by more extensive fluid–rock interaction than the other two types at moderate fO2 and T conditions. Type II magnetite is thought to have formed in relatively low fO2 and high-T environments, and Type III in relatively high fO2 and moderate-T environments. Ca + Al + Mn and Ti + V discrimination diagrams show that magnetite in the Xinqiao deposit is hydrothermal in origin and is possibly linked with skarn.

This article studies the seismic response of a symmetric long-span cable-stayed bridge under longitudinal uniform excitations by finite element analysis and shaking table tests. The feasibility and method of performing shaking table tests are examined using a simplified half-bridge scale model. By taking advantage of the symmetry, it is possible to construct a scale model with a larger scale ratio than a full-bridge scale model. The main components of the scale model (i.e. tower, piers, girder, and cables) were fabricated using the same or similar materials as in the prototype. The design and construction of the scale model is presented. Longitudinal structural responses obtained from the finite element analysis and shaking table tests are compared. The seismic mitigation effects of viscous dampers are examined through shaking table tests.

Several Neoproterozoic granitic intrusions, including the Phin Ngan intrusion and some smaller ones from the Sin Quyen Cu mine, have been identified in the Phan Si Pan belt, Northwest Vietnam. Whole-rock geochemical and Sm-Nd isotopic data and zircon U-Pb age and Hf-O isotopes have been determined for these intrusions in order to constrain their ages, petrogenesis and tectonic implications. The Phin Ngan intrusion, mainly composed of syenogranite, was emplaced at 824 ± 4 Ma. Rocks from this intrusion have high SiO 2 (72.1–73.5 wt.%), and K 2 O (5.14–5.52 wt.%), with A/CNK values ranging from 1.02 to 1.06. They have negative whole-rock e Nd ( t ) (−8.4 to −5.2) and zircon e Hf ( t ) values (−8.1 to −5.5), and high zircon δ 18 O values (9.7–10.9‰). These geochemical features suggest that the Phin Ngan intrusion was derived from ancient, K-rich crustal sources. Granitic intrusions from the Sin Quyen mine occur as stocks or dykes intruding ores and ore-hosting rocks. They are composed of monzogranite and granodiorite, emplaced between 736 ± 8 and 758 ± 6 Ma. They have high SiO 2 (68.2–76.7 wt.%) and (K 2 O + Na 2 O) (6.93–8.54 wt.%), and low MgO (0.19–0.87), with A/CNK values ranging from 0.91 to 1.14. Their whole-rock e Nd ( t ) values range from −6.6 to 0, mostly clustered between −6.6 and −4.3. Their zircon e Hf ( t ) values vary from −6.7 to +11.1, mostly lower than −2.0. Such geochemical data indicate that these intrusions were produced mainly through partial melting of ancient crustal materials, coupled with subordinate involvement of mantle-/juvenile crust-derived components. The Phin Ngan intrusion and intrusions from the Sin Quyen mine are sub-alkaline in nature, and have arc-like trace-element compositions. Compiled with other broadly synchronous igneous rocks with arc-like affinities in the region, the Neoproterozoic magmatism in the Phan Si Pan belt was generated in a subduction-related setting. The Neoproterozoic intrusions in the Phan Si Pan belt are geochronologically and geochemically correlated with the Neoproterozoic subduction-related igneous rocks along the western Yangtze Block. Thus, the Phan Si Pan belt represents the southern most part of the giant arc system of the western Yangtze Block.

The Laiziling granitic pluton, located in the Xianghualing district, Hunan Province, China, comprises typical rare-metal granites with a pronounced vertical lithological zonation. This pluton includes three granitic phases comprising, from base to top, medium-grained (MG) alkali feldspar granite, fine-grained (FG) alkali feldspar granite and albite granite. Here we report the results of textural and chemical analyses of W–Nb–Ta oxide minerals from the Laiziling granitic pluton. The chemical compositions of whole-rock samples, rock-forming minerals and zircon have allowed us to identify the magmatic–hydrothermal processes that operated during the formation and rare-metal mineralization of the Laiziling pluton. The granites are slightly peraluminous to peraluminous, highly evolved and fractionated, as inferred from whole-rock geochemical and mineralogical (micas and zircon) signatures. All the micas in different granitic phases are classified into the zinnwaldite group. Li concentration in the primary micas (∼2.6–4 wt% Li2O) and Hf concentration (∼1–8 wt% HfO2) in the zircon increase for the base to the top granitic phases. Both alkali feldspar granites contain oxide mineral aggregates including columbite-group minerals, wolframoixiolite, qitianlingite, wolframite and cassiterite. The columbite-group minerals, wolframite and cassiterite also occur as isolated grains within the albite granite. The presence of the oxide minerals suggests that the W–Nb–Ta mineralization developed during the latter stages of the magmatic evolution, related to fluids that were compositionally evolved from the granites. The composition of the fluids controls the aggregate of the oxide minerals. The wolframite and cassiterite that precipitated within the Laiziling skarn-type deposit are chemically different from those within the granite, indicating a hydrothermal origin for the oxide minerals that formed as a result of pervasive alteration.

Three coordination polymers (CPs), {[Zn(HL)]·2CH3CN}n (1) {[Co(HL)(bimb)]·4H2O}n (2) and {[Cd(HL)(bimb)]·3EtOH·3H2O·DMF}n (3) (H3L = tris(p-carboxyphenyl)phosphane oxide, bimb = 1,4-bis(imidazol-1-ylmethyl)benzene) have been synthesized under solvothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analysis and further characterized by elemental analysis, IR spectra, powder X-ray diffraction (PXRD) and thermogravimetric (TG) analysis. Structural analyses reveal that complex 1 appears a 3D 3,5-connected {4.62}2{42.69.84} net. While 2 and 3 are 1D polymeric chains that were further packed into 3D supramolecular architectures through hydrogen bond interactions. Furthermore, fluorescence measurements indicate that the complex 1 can sensitively sense acetone, nitrobenzene derivatives and Fe3+ ion, which implies that the 1 is expected to be luminescence sensor materials for sensing small molecules and metal ions.

South China is famous for its large-scale mineralization genetically related to widespread Mesozoic granites. The Jiulongnao complex is one of the largest intrusions in southern Jiangxi Province, and is closely associated with W-dominated polymetallic mineralization. The complex comprises four intrusive phases (I-IV). Phase I consists of medium- to coarse-grained, biotite granite, whereas medium- to coarse-grained, porphyritic, biotite granite and muscovite-bearing granite comprise Phase II. Phase III is composed of medium- to fine-grained, porphyritic, biotite granite and Phase IV consists of medium- to fine-grained, garnet- and biotite-bearing granite. These intrusive phases have LA-ICP-MS zircon U-Pb ages of 160.9 ± 0.6 Ma, 158.6 ± 0.7 Ma, 157.0 ± 1.5 Ma and 154.1 ± 1.2 Ma, respectively. All of the granites are enriched in Rb, Th, U, Ta and Pb, and significantly depleted in Eu, Ba, Nb, Sr, P and Ti. They have eHf(t) and eNd(t) values ranging from −17.9 to −8.2, and −10.7 to −9.8, respectively, with two-stage Hf model ages of 1.7–2.3 Ga. They are S-type granites derived by partial melting of Paleo-Proterozoic metasedimentary rocks. The four phases have TZr of 746–760 °C, 712–802 °C, 798–810 °C, and 648–731 °C, respectively. Oxygen fugacities of Phases I to III display a decreasing trend but Phase IV has much higher oxygen fugacity in its early stage, which decreased in the late stage. The four phases have different accessory mineral assemblages: Phase I is characterized by an assemblage of zircon, apatite, fergusonite, thorite and uraninite, whereas Phase II is rich in thorite, uraninite, REE-bearing minerals (e.g., monazite, fergusonite and xenotime) and fluorite. Monazite is the main accessory mineral in Phase III, whereas Phase IV contains a wide range of minerals, including thorite, uraninite, Nb-Ta-bearing minerals (e.g., fergusonite and pyrochlore), cassiterite and rutile. These mineral assemblages, together with other geological and geochemical features, suggest that W mineralization was genetically related to Phases I, II and IV, whereas U mineralization was most extensive in Phase II. Sn, Nb and Ta mineralization was associated with the highly fractionated of magmas of Phase IV.

Rare earth elements are an important strategic resource. However, a trace of Fe(III) impurity has serious adverse impact on the performance of rare earth materials. We synthesized a novel nitrogen-containing carbon material, ACLR-400, using lotus root as raw materials. The ACLR-400 was characterized by surface area analyzer, elemental analysis and FT-IR. The selectivity and removal efficiency of ACLR-400 towards Fe(III) were also investigated. The BET specific surface area of ACLR-400 was 68.44 m2·g−1, and the average pore diameter was 12.54 nm. With abundant nitrogen- containing functional groups and well-developed internal pore structure, ACLR-400 possesses strong adsorption affinity, excellent selectivity and removal efficiency for Fe(III). The adsorption capacity of ACLR-400 towards Fe(III) could reach to 0.46 mmol·g−1, selectivity coefficient with respect to La(III) was 8.9, and removal efficiency was 99.61%. The adsorption isotherm data greatly obey the Freundlich isotherm. In addition, ACLR-400 can be regenerated easily and possesses better regeneration ability and reusability.

High adsorption capacity, short adsorption time, and easy regeneration are very important and urgently needed for qualified adsorbents used in removing toxic heavy metals from wastewater. Based on this, a thiourea modified D301 resin (TD301) was designed and prepared via simple grafting polymerization and modification procedure. The TD301 was characterized by the scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The adsorption performances of TD301 towards low concentration of toxic heavy metal ions from aqueous solution were investigated. By virtue of the abundant amine and C S groups, TD301 possesses strong adsorption ability for Hg(II), Pb(II) and Cd(II). The pH and temperature have a great influence on the adsorption capacity. The adsorption capacities of TD301 towards Hg(II), Pb(II) and Cd(II) could reach 454.1, 436.6 and 254.1 mg g−1 at 293 K and pH of 6, respectively. The adsorption process could be well described by the Lagergren-first-order model and was a Langmuir monolayer chemical adsorption. The adsorption thermodynamic experiment indicated that adsorption of TD301 towards Hg(II), Pb(II) and Cd(II) was an endothermic and spontaneous process drived by entropy. In addition, TD301 could be reused almost without any loss in the adsorption capacity.

The Nanling Range, South China, was world-famous for hosting abundant granitoid-related copper-lead-zinc (Cu-Pb-Zn) polymetallic ore deposits and quartz vein-type wolframite (W) ore deposits, both of which have roughly similar formation ages predominately between 150 and 160 Ma with a peak of ca. 156 Ma. In this study, accessory minerals from typical Cu-Pb-Zn-bearing and W-bearing granitic rocks are compared in terms of elemental and isotopic compositions. Apatite from W-bearing granites in the Xihuashan pluton has lower eNd(t) value (−11.9 to −8.6) than that from Cu-Pb-Zn-bearing granitic rocks in Shuikoushan with eNd(t) value of −8.7 to −4.2 and initial 87Sr/86Sr ratio of 0.7097–0.7109. Zircon grains in Xihuashan, yielded eHf(t) value from −14.9 to −11.4, δ18O value from 8.6‰ to 10.4‰, and highly variable and negative δ7Li value (−45.8‰ to −3.8‰), whereas those in Shuikoushan have relatively higher eHf(t) value (−10.6 to −8.1), lower δ18O value (8.4‰–9.7‰), and highly variable δ7Li values from −12.7‰ to +17.6‰. In situ Hf-O-Li isotopic compositions of zircon and Sr-Nd isotopes of apatite, suggesting that the Shuikoushan granitic pluton was likely generated from dehydration melting of amphibolite from a metal-fertile mafic source in the middle-to-lower crust, whereas the Xihuashan granitic pluton could be derived from partial melting of metapelite with minor amphibolite in the middle to upper crust. The geochemical records in accessory minerals fingerprint that the Shuikoushan granitic magma was characterized by high Cl content (0.11–1.44 wt%) and logfo2 value (>ΔFMQ+1), whereas the Xihuashan granitic magma have elevated F (3.51–4.80 wt%) and Li (3.49–42.4 ppm) contents with low logfo2 value (

The Yamansu Fe deposit (32 Mt at 51% Fe) in the Eastern Tianshan Orogenic Belt of NW China is hosted in early Carboniferous volcano-sedimentary rocks and spatially associated with skarn. The paragenetic sequence includes garnet-diopside (I), magnetite (II), hydrous silicate-sulfide (III), and calcite-quartz (IV) stages. Pyrite associated with magnetite has a Re-Os isochron age of 322 ± 7 Ma, which represents the timing of pyrite and, by inference, magnetite mineralization. Pyrite has δ34SVCDT values of − 2.2 to + 2.9‰, yielding δ34SH2S values of − 3.1 to 2‰, indicating the derivation of sulfur from a magmatic source. Calcite from stages II and IV has δ13CVPDB values from − 2.5 to − 1.2‰, and − 1.1 to 1.1‰, and δ18OVSMOW values from 11.8 to 12.0‰ and − 7.7 to − 5.2‰, respectively. Calculated δ13C values of fluid CO2 and water δ18O values indicate that stage II hydrothermal fluids were derived from magmatic rocks and that meteoric water mixed with the hydrothermal fluids in stage IV. Some ores contain magnetite with obvious chemical zoning composed of dark and light domains in BSE images. Dark domains have higher Mg, Al, Ca, Mn, and Ti but lower Fe and Cr contents than light domains. The chemical zoning resulted from a fluctuating fluid composition and/or physicochemical conditions (oscillatory zoning), or dissolution-precipitation (irregular zoning) via infiltration of magmatic-hydrothermal fluids diluted by late meteoric water. Iron was mainly derived from fluids similar to that in skarn deposits.

Troilite-orthopyroxene intergrowths are present as a common material in the brecciated diogenite Northwest Africa (NWA) 7183. In this study, we report on the petrographic, mineralogical, and rare earth element abundances of the troilite-orthopyroxene intergrowths to constrain their origin and assess their implications for the diverse petrogenesis of diogenites. Two groups of troilite-orthopyroxene intergrowths with various grain sizes and mineral chemistry have been observed in NWA 7183. One group of intergrowths contains fine-grained (

Recognition of the sources of metals and fluids is crucial to determine the genesis of gold deposits, especially in distinguishing the orogenic and magmatic hydrothermal deposits. There is no consensus on the source and genetic style of the Mesozoic gold deposits in the North China Craton (NCC). The Taijiying gold deposit in the Chifeng-Chaoyang gold district on the northern margin of the NCC is a medium-sized gold deposit and worth studying for its sources of metals and fluids. It is hosted by amphibole- to granulite-facies metamorphic rocks and Mesozoic intrusions, and controlled by NNE-, NE-trending compressional reverse faults and NW-trending extensional normal faults. The gold mineralization types include auriferous quartz veins and wall rock alterations of phyllic mineralization, pyritization, chloritization, and carbonatization. According to the crosscutting relationships of the veins and the mineral textures within the ore-bearing veins, four mineralization stages are recognized: clouded-white quartz ± pyrite (stage I), gray quartz + pyrite (stage II), quartz + polymetallic sulfides (stage III), and calcite ± quartz (stage IV), among which the stages II and III represent the main gold mineralization stages. The timing of the gold mineralization is constrained to the Middle Triassic by zircon U-Pb ages of a pre-metallogenic diorite (258.0 ± 1.9 Ma) and a ore-related granitic porphyry dike (241.5 ± 2.2 Ma). Three types of fluid inclusions (FIs) in the quartz veins of four stages are identified: vapor-rich (type 1), CO2-H2O three-phase (type 2), and liquid-rich FIs (type 3). Their trapping temperatures gradually decrease from 352 ℃ (stage I) to 124 ℃ (stage IV), with salinities decreasing from 9.8 to 2.0 wt.% NaCl eqv., indicating that the ore-forming fluids belong to a H2O-NaCl-CO2 system. The first three stages were characterized by moderate-high temperatures, a large variation in salinities, akin to those of the magmatic hydrothermal fluids. The H-O isotope compositions from the stage II (δ18Ow = 4.1-4.8‰ and δD = -110 to -87‰) to the stage III (δ18Ow = 3.5 to 3.7‰ and δD = -101 to -98‰), indicate that the ore-forming fluids were mainly magmatic fluids. The δ34SV-CDT (1.7-2.1‰), Pb isotopes (206Pb/204Pb = 15.09-15.90, 207Pb/204Pb = 15.00-15.15, 208Pb/204Pb = 35.76-37.97), and Os isotopes (initial 187Os/188Os = 2.3±1.0) of the Au-bearing pyrite samples at the stages II and III, similar to those of the crust-derived magma, suggest that the gold and other metals were extracted from the partial melting of the lower crust. Accordingly, the Taijiying gold deposit is probably a magmatic hydrothermal deposit. The areas recording the Triassic batholith with a developed fault system would be prospective targets for gold mineralization in the Chifeng-Chaoyang district on the northern margin of the NCC.

The Huayangchuan deposit in the North Qinling alkaline province of Central China is a unique carbonatite-hosted giant U–Nb–REE polymetallic deposit. The mineralization is characterized by the presence of betafite, monazite, and allanite as the main ore minerals, but also exhibit relatively high budgets of heavy rare earth elements (HREE = Gd–Lu and Y). The origin of carbonatites has long been controversial, thus hindering our understanding of the genesis of the deposit. Here, we conducted an in-situ trace elemental, Sr–Nd isotopic, and bulk C–O isotopic analyses of multi-type calcites in the deposit. Two principal types (Cal-I and Cal-II), including three sub-types (Cal-I-1, Cal-I-2 and Cal-I-3) of calcites were identified based on crosscutting relationships and calcite textures. Texturally, Cal-I calcites in carbonatites display cumulates with the grain size decreasing from early coarse- (Cal-I-1) to medium- (Cal-I-2) and late fine-grained (Cal-I-3), whereas Cal-II calcites coexist with zeolite displaying zeolite–calcite veinlets. Geochemically, Cal-I calcites contain relatively high REE(Y) (151–2296 ppm), Sr (4947–9566 ppm) and Na (29–390 ppm) contents, characterized by right- to left-inclined flat distribution patterns [(La/Yb) N = 0.2–4.2] with enrichment of HREE(Y) (136–774 ppm), whereas Cal-II calcites display low REE , Sr and undetectable Na contents, characterized by a right-inclined distribution pattern [(La/Yb) N = 13.5, n = 16]. The U–Nb–REE mineralization, accompanied with intense and extensive fenitization and biotitization, is mainly associated with the Cal-I-3 calcites which show flat to relatively left-inclined flat REE distribution patterns [(La/Yb)N = 0.2–1.0]. Isotopic results show that Cal-I calcites with mantle signatures are primarily igneous in origin, whereas Cal-II are hydrothermal, postdating the U–Nb–REE mineralization. Cal-I calcites (Cal-I-1, Cal-I-2 and Cal-I-3) from mineralized and unmineralized carbonatites, displayed regular changes in REE, Na and Sr contents, but similar trace element distribution patterns and Sr–Nd-C-O isotopic signatures, indicating that these carbonatites originated from the same enriched mantle (EM1) source by low-degree partial melting of HREE-rich carbonated eclogites related to recycled marine sediments. The combination of trace elements and Sr-Nd isotopic composition of calcites further reveals that these carbonatites have undergone highly differentiated evolution. Such differentiation is conducive to the enrichment of ore-forming elements (U–Nb–REE) in the late magmatic–hydrothermal stages owing to extensive ore-forming fluids exsolved from carbonatitic melts. The massive precipitation of the U–Nb–REE minerals from ore-forming hydrothermal fluids may have been triggered by intense fluid–rock reactions indicated by extensive and intense fenitization and biotitization. Therefore, the Huayangchuan carbonatite-related U-Nb-REE deposit may have formed by a combination of processes involving recycled U–Nb–REE–rich marine sediments in the source, differentiation of the produced carbonatitic magmas, and subsequent exsolution of U–Nb–REE–rich fluids that precipitated ore minerals through reactions with wall rocks under the transitional tectonic regime from compression to extension at the end of Late Triassic.

The Alta Floresta Mineral Province (AFMP), southern Amazonian Craton, experienced extensive magmatic activity from ca. 2.03 to 1.75 Ga in an uncertain geodynamic setting. New and pre-existing geological, petrographic, geochemical, and zircon geochronological data show that magmatic rocks in the eastern AFMP comprise three magmatic sequences: 2.03–1.93, 1.90–1.85, and 1.83–1.75 Ga. Earlier magmas had garnet-bearing sources, whereas younger ones were derived from shallow, garnet-free sources. We propose a new, four-stage geological framework, comprising five domains, and featuring an accretionary orogen with tectonic switching that alternates between flat subduction and slab-rollback. During flat subduction and crustal thickening in stages A (2.03–1.97 Ga) and C (1.90–1.81 Ga), calc-alkalic to alkali-calcic I-type magmatism was produced, whereas alkali-calcic to alkalic A-type magmatism, and localized I-type granites, were generated during slab-rollback and crustal extension in stages B (1.96–1.94 Ga) and D (1.83–1.75 Ga). The last stage is associated with precious- and base metal porphyry- and epithermal-style systems. We interpret the eastern AFMP as a remaining cratonic block of the eastward Tapajos Domain within the ca. 1.95–1.80 Ga Ventuari-Tapajos Province, and recording 1.85–1.74 Ga magmatism of the Western Amazonia Igneous Belt within the ca. 1.80–1.55 Ga Rio Negro-Juruena Province. Similarities between the AFMP and the Svecofennian orogen (Fennoscandian Shield) suggest that parts of the Columbia supercontinent margins might have operated in similar fashion to Andean-type accretionary orogens.

Recent advances in high-precision in-situ analysis of zircon U-Pb-Hf-O isotopes have significantly improved our approach to studying the origin and evolution of Archean crust. This study presents high-precision in-situ zircon U-Pb-Hf-O isotopes for the Southern Jilin Complex (SJC) on the northeastern margin of the North China Craton (NCC) and explores the potential of such an integrated approach in understanding the Archean crust evolution and its tectonic implications. The SJC consists mainly of Archean granitoid gneisses hosting minor supracrustal rock xenoliths. Zircon U-Pb data from representative lithologies reveal three episodes of magmatism at ~2.78, ~2.69 and ~2.55 Ga, respectively. The former two granitoid magmatic events are recognized for the first time in NE NCC, while the latest one is widespread over the NCC. All metamorphic zircon domains document similar metamorphic ages of 2.51–2.48 Ga, consistent with the widespread metamorphism of ~2.50 Ga in the NCC. Most concordant magmatic zircons preserve “mantle-like” O isotopic signatures, indicating the magma sources were not contaminated by large amounts of high δ18O supracrustal sediments. Hf depleted mantle model ages of magmatic zircons display one predominant peak at 2.9–2.8 Ga and two subordinate peaks at 3.3–3.2 Ga and 2.7–2.6 Ga, indicating possible episodic crust-mantle differentiation in Southern Jilin. Integrated zircon U-Pb-O-Hf data from the SJC suggest that magma sources were mainly derived from multiple episodes of reworking of juvenile or ancient crust with mantle component addition, while recycling of sediments was trivial during the Neoarchean in this region. The spatial–temporal relations of magmatism, lack of supracrustal addition to magma sources, and other geological evidence from the NCC are in favor of a bottom-up geodynamic regime possibly related to plume activities, arguing against a widespread top-down mechanism involving modern-style subduction in the NCC during the Neoarchean.

The Xuefeng Uplift Belt (XUB), in the western part of the Jiannan Orogenic Belt (JOB) South China, hosts numerous low-temperature W-Sb-Au deposits, including the Woxi W-Sb-Au deposit, the Zhazixi Sb-W deposit and the Darongxi W deposit. In order to understand the origin of these low-temperature W deposits and the difference from other moderate-high temperature tungsten deposits in the South China Block, Cathodoluminescene (CL) and LA-ICP-MS are employed to investigate the detailed texture of scheelite , and to identify trace element composition and distribution in scheelite, especially rare earth elements (REEs). LA-ICP-MS results show that the most abundant trace elements in scheelite in this study were Sr, Y, Nb, Mo, Zr, Hf, Ta and REEs. Six types of scheelite can be classified according to variations of REEs pattern. Type I and II scheelites from the Zhazixi Sb-W deposit and the Woxi W-Sb-Au deposit have elevated concentration of Sr, low concentrations of Nb, Mo and variable Nb/Ta ratio, reflecting low temperature ( skarn deposit, Type IV scheelite from the Dabaoshan polymetallic deposit, Type V scheelite from the Niutangjie skarn W deposit and Type VI scheelite from the Daping W deposit have relatively higher Nb, Mo and relatively constant Nb/Ta ratios, and lower Sr concentration, consistent with the feature of moderate to high temperature oxidizing environments. Type I scheelite from the Zhazixi Sb-W deposit can be subdivided into Ia, Ib and Ic, which cover a wide range from MREE-rich to MREE-depleted, indicating a complete dynamic evolution process. Type II scheelite from the Woxi W-Sb-Au deposit has uniform patterns with significant depletion of LREE and enrichment of MREE, revealing that the substitutions of MREE into scheelite lattices are dominated by crystallographic factors, especially the Ca-site size in scheelite crystals rather than the REE concentrations and REE complex stability in hydrothermal fluids . Type III scheelite from the Darongxi W deposit shows two distinctive REE patterns, types IIIa and IIIb, which are likely to be two end members, suggesting that successive precipitation results in changes in REE concentrations and Eu anomalies. Type IV scheelite from the Dabaoshan polymetallic deposit inherited the signature of the granitic porphyry . Type IV b and IVc are similar to those Type V scheelites from Niutangjie, both showing the characteristics of skarn type scheelite mineralization. Trace element variations suggest the predominant control factors differ according to temperature. Trace element concentrations and distribution of scheelite formed at low temperature were mainly controlled by crystallographic factors, which contrasted with fluid-controlled feature of the medium–high temperature scheelite mineralization.

High adsorption capacity, fast adsorption rate, easy regeneration and good reusability were very important for qualified adsorbents used in removing toxic heavy metals from wastewater. Based on this, a novel adsorbent was well designed and synthesized by functionalizing D301 resin with iminodiacetic acid (IDA). The physicochemical characteristics of IDA-functionalized D301 (ID301) were characterized by the scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The adsorption performances of ID301 towards toxic heavy metal ions were systematically performed from kinetics to isotherms and thermodynamics by batch technique. The effects of contact time, initial metal concentration, pH, temperature and adsorbent dosage on adsorption performance were investigated. ID301 possesses strong adsorption ability for Cu(II), Pb(II) and Cd(II). pH and temperature has a great influence on the adsorption capacity. The adsorption capacities of ID301 towards Cu(II), Pb(II) and Cd(II) could reach 4.48, 2.99 and 2.26 mmol·g− 1 at 293 K and pH of 5, respectively. Langmuir isotherm and pseudo-second-order equation could satisfactorily describe the experimental data. The adsorption thermodynamic experiment indicated that adsorption of ID301 towards Cu(II), Pb(II) and Cd(II) was an endothermic and spontaneous chemisorption process driven by entropy. In addition, ID301 could be reused without losing adsorption capacity significantly.

The Kukaazi Pb–Zn–Cu–W polymetallic deposit, located in the Western Kunlun orogenic belt, is a newly discovered skarn-type deposit. Ore bodies mainly occur in the forms of lenses and veins along beddings of the Mesoproterozoic metamorphic rocks. Three ore blocks, KI, KII, and KIII, have been outlined in different parts of the Kukaazi deposit in terms of mineral assemblages. The KI ore block is mainly composed of chalcopyrite, scheelite, pyrrhotite, sphalerite, galena and minor pyrite, arsenopyrite, and molybdenite, whereas the other two ore blocks are made up of galena, sphalerite, magnetite and minor arsenopyrite and pyrite. In this study, we obtained a molybdenite isochron Re–Os age of 450.5 ± 6.4 Ma (2σ, MSWD = 0.057) and a scheelite Sm–Nd isochron age of 426 ± 59 Ma (2σ, MSWD = 0.49) for the KI ore block. They are broadly comparable to the ages of granitoid in the region. Scheelite grains from the KI ore block contain high abundances of rare earth elements (REE, 42.0–95.7 ppm) and are enriched in light REE compared to heavy REE, with negative Eu anomalies (δEu = 0.13–0.55). They display similar REE patterns and Sm/Nd ratios to those of the coeval granitoids in the region. Moreover, they also have similar Sr and Nd isotopes [87Sr/86Sr = 0.7107–0.7118; eNd(t) = −4.1 to −4.0] to those of such granitoids, implying that the tungsten-bearing fluids in the Kukaazi deposit probably originate from the granitic magmas. Our results first defined that the Early Paleozoic granitoids could lead to economic Mo–W–(Cu) mineralization at some favorable districts in the Western Kunlun orogenic belt and could be prospecting exploration targets.

Cenozoic basalts in SE China may be derived from a mixture of depleted MORB mantle (DMM) and enriched mantle 2 (EM2) sources, but whether these basalts share a common mantle source or magmatic history remains unknown. To investigate these unresolved issues, this study sampled basalts from Niutoushan and Mingxi (Fujian province), Xilong (Zhejiang province), and Penghu (Taiwan) for geochemical analysis. The basalt samples show OIB-like trace element patterns and have low PGE contents, with 0.02–0.7 ppb Ir and Pd, 0.05–1.4 ppb Ru, 0.01–0.2 ppb Rh, and 0.06–1.1 ppb Pt. All samples have high Cu/Pd ratios ranging from ~ 69,000 to 3,500,000, and low Cu/Zr ratios ranging from 0.1 to 0.8, suggesting sulfur-saturated fractionation. Model calculations indicate that the basalts are depleted in PGE due to the retention of 0.001% to 0.1% sulfide in the mantle and the removal of up to 0.0022% sulfide during magma ascent. The crystallization of olivine and spinel, and partial melting are insufficient to account for the observed PGE variation in these basalts. Thus, the distinct PGE patterns in basalts with different ages may reflect the heterogeneity of the mantle source beneath SE China. The source heterogeneity may be due to compositional heterogeneity, particularly variations in oxygen fugacity and PGE mineral phases, or due to variable fluid/melt metasomatic agents in the sub-continental lithospheric mantle. This heterogeneity is possibly related to the westward subduction of the Paleo-Pacific Plate.

The Lanuoma and Cuona sediment-hosted Pb-Zn deposits hosted by Upper Triassic limestone and sandstone, respectively, are located in the Changdu area, SW China. Mercury concentrations and Hg isotopic compositions from sulfide minerals and potential source rocks (e.g., the host sedimentary rocks and the metamorphic basement) were investigated to constrain metal sources and mineralization processes. In both deposits, sulfide minerals have higher mercury (Hg) concentrations (0.35 to 1185 ppm) than the metamorphic basement rocks (0.05 to 0.15 ppm) and sedimentary rocks (0.02 to 0.08 ppm). Large variations of mass-dependent fractionation (3.3‰ in δ202Hg) and mass-independent fractionation (0.3‰ in Δ199Hg) of Hg isotopes were observed. Sulfide minerals have Hg isotope signatures that are similar to the hydrothermal altered rocks around the deposit, and similar to the metamorphic basement, but different from barren sedimentary rocks. The variation of ∆199Hg suggests that Hg in sulfides was mainly derived from the underlying metamorphic basement. Mercury isotopes could be a geochemical tracer in understanding metal sources in hydrothermal ore deposits.

In this study, two new adsorbents, D301- g -EDAPGMA and D301- g -THIOPGMA, were obtained successfully on the basic of chemically modified D301 resin using ethylenediamine and thiourea. The adsorption, recognition and recovery properties of these two adsorbents for AuCl 4 − were studied through batch method. The experimental results showed that these two adsorbents possess strong adsorption ability and excellent selectivity for AuCl 4 − , and pH has a great influence on the adsorption capacity in the studied pH range. The maximum adsorption capacity of D301- g -EDAPGMA and D301- g -THIOPGMA for AuCl 4 − reaches 298 and 326 mg·g − 1 at pH of 2, respectively. D301- g -EDAPGMA and D301- g -THIOPGMA possess very high selectivity coefficients for AuCl 4 − and these two adsorbents can be used to recover AuCl 4 − selectively from gold-bearing chloride solution. The extraction rate of these two adsorbents for AuCl 4 − could reach 98%. D301- g -EDAPGMA and D301- g -THIOPGMA have excellent regeneration property, and the consecutive adsorption-desorption experiments showed that they could be reused almost without any loss in the adsorption capacity.

South China hosts the most abundant and largest tungsten (W) deposits in the world, being a famous W metallogenic region. Located at the eastern part of the South China Block, which was formed by amalgamation of the Yangtze and Cathaysia Blocks during the Neoproterozoic, these W deposits were mainly formed during the Mesozoic. The W mineralization is dominanted by greisen, quartz-vein, skarn, and porphyry types, all of which are genetically related to the evolution of highly fractionated granitoids. Four episodes of W mineralization are recognized: (1) Late Triassic (230–210 Ma) in the central and western parts of South China; (2) Middle Jurassic (ca. 170 Ma) to Early Cretaceous (ca. 140 Ma) in the interior of South China, with the mineralization being concentrated in southern Jiangxi Province between 165 and 150 Ma; (3) Early Cretaceous (136–120 Ma) with deposits across South China; and (4) Late Cretaceous (100–80 Ma) mainly in the southwestern parts of South China. These four periods of mineralization are closely related to the closure of paleo-Tethys and subduction of the paleo-Pacific plate. In the Late Triassic, these two events caused local extensional environments, facilitating emplacement of the peraluminous granitoids, and formation of the W deposits. In the Middle Jurassic, break-off of the subducting oceanic plate resulted in emplacement of highly fractionated granites in the Nanling region. Later anticlockwise rotation of the paleo-Pacific plate created widespread S-type granitoids and associated Middle Jurassic to Early Cretaceous W mineralization in the interior of South China. Since 136 Ma, rollback of the subducting Pacific plate resulted in weak W mineralization across South China. Finally, a change of direction in the retreating plate from SE to ESE resulted in intensive mineralization of the southwestern part of South China.

Magnetite is a very common mineral in various types of iron deposits and some sulfide deposits. Recent studies have focused on the use of trace elements in magnetite to discriminate ore types or trace ore-forming process. Germanium is a disperse element in the crust, but sometimes is not rare in magnetite. Germanium in magnetite can be determined by laser ablation ICP-MS due to its low detection limit (0.0X ppm). In this study, we summary the Ge data of magnetite from magmatic deposits, iron formations, skarn deposits, iron oxide copper-gold deposits, and igneous derived hydrothermal deposits. Magnetite from iron formations contains relatively high Ge (up to approximate to 250 ppm), whereas those from all other deposits mostly contains Ge less than 10 ppm, indicating that iron formations can be discriminated from other Fe deposits by Ge contents. Germanium in magmatic/hydrothermal magnetite is controlled by a few factors. Primary magma/fluid composition may be the major control of Ge in magnetite. Higher oxygen fugacity may be beneficial to Ge partition into magnetite. Sulfur fugacity and temperature may have little effect on Ge in magnetite. The enrichment mechanism of Ge in magnetite from iron formations remains unknown due to the complex ore genesis. Germanium along with other elements (Mn, Ni, Ga) and element ratios (Ge/Ga and Ge/Si raios) can distinguish different types of deposits, indicating that Ge can be used as a discriminate factor like Ti and V. Because of the availability of in situ analytical technique like laser ablation ICP-MS, in situ Ge/Si ratio of magnetite can serve as a geochemical tracer and may provide new constraints on the genesis of banded iron formations.

Some trace of non-rare earth impurities has serious damage on the performance of rare earth material. Therefore, efficient removing these impurities from rare earth is very significant. In this paper, a novel activated carbon (AC UF 700) was synthesized by homemade urea formaldehyde resin carbonized at 700 °C. The surface properties, chemical functional groups, element content, surface morphology, and XPS of AC UF 700 were investigated. The adsorption behavior of AC UF 700 towards Fe(III) were investigated by batch and column method. The BET specific surface area of AC UF 700 was 712 cm 3 g −1 , and the average pore diameter was 2 nm. The AC UF 700 possesses strong adsorption affinity and excellent recognition selectivity for Fe(III). The adsorption capacity could reach to 13 mg g −1 , and relative selectivity coefficients relative to La(III) and Ce(III) was 28.0 and 25.3, respectively. Besides, AC UF 700 could be regenerated easily and reused without losing significantly adsorption capacity.

In this study, Poly(glycidyl methacrylate) (PGMA) was grafted onto the surface of the weak basic D301 resin. Subsequently, two new adsorbents, D301- g -EDAPGMA and D301- g -THIOPGMA, were obtained successfully through ringopening reactions between the epoxide rings of PGMA and the amine of ethylenediamine and thiourea. The adsorption and recognition properties of these two adsorbents for AuCl 4 − were studied through batch method. The experimental results showed that D301- g -EDAPGMA and D301- g -THIOPGMA possess strong adsorption ability and excellent recognition selectivity for AuCl 4 − , and pH has a great influence on the adsorption capacity in the studied pH range. The adsorption of D301- g -EDAPGMA and D301- g -THIOPGMA towards AuCl 4 − is a typical monomolecular layer adsorption. The adsorption capacity of D301- g -EDAPGMA and D301- g -THIOPGMA for AuCl 4 − reaches 274.7 and 300.4 mg g −1 at 298 K and pH of 2, respectively. D301- g -EDAPGMA and D301- g -THIOPGMA can be used to adsorb AuCl 4 − electively from gold-bearing chloride solution. In addition, the desorption of AuCl 4 − from adsorbent is effective using mixture of acetone and 1 mol L −1 of hydrochloric acid as eluent. Consecutive adsorption-desorption experiments showed that D301- g -EDAPGMA and D301- g -THIOPGMA could be reused with 1.9% of adsorption capacity loss.

Core-shell SiO2/Ag composite spheres with dense, complete and nanoscaled silver shell were prepared by using a novel facile chemical reduction method without surface modification of silica at room temperature. The core-shell composites were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy and energy dispersive X-ray spectroscopy (EDX). The photocatalytic properties towards the degradation of methyl orange (Mo) of the prepared SiO2/Ag composites were also tested. The studies showed that the surface of SiO2microspheres was homogeneously and completely covered by Ag nanoparticles and the composite exhibited excellent photocatalytic activities. The possible reaction mechanisms for the formation of the silica-silver core-shell spheres were also discussed in this paper.

To observe the influence of different courses of electroacupuncture (EA) intervention on recognition memory and the proliferation and differentiation of hippocampal neural stem cells in mice with radiation-induced brain injury, so as to explore its mechanisms underlying improving radiation-induced brain injury.Se-venty 30-day old C57BL/6J mice were randomly divided into control, model and EA groups, and the latter two groups were further divided into 1 week (W), 2 W and 3 W subgroups (After modeling, the TN at 90 min and 24 h and RI of the model subgroup 3 W at 90 min and RI of the model subgroup 1, 2 and 3 W at 24 h were significantly decreased in comparison with those of the control group (EA of GV20, GV14 and BL23 can improve the recognition memory ability of mice with radiation-induced brain injury, which may be related to its effect in promoting the proliferation and differentiation of stem cells in the hippocampus.

The present study was aimed to investigate the effects and mechanisms of electro-acupuncture (EA) on proliferation and differentiation of neural stem cells in the hippocampus of C57 mice exposed to different doses of X-ray radiation. Thirty-day-old C57BL/6J mice were randomly divided into control, irradiation, and EA groups. The control group was not treated with irradiation. The irradiation groups were exposed to different doses of X-ray (4, 8 or 16 Gy) for 10 min. The EA groups were electro-acupunctured at Baihui, Fengfu and bilateral Shenyu for 3 courses of treatment after X-ray radiation. Immunohistochemistry was used to evaluate proliferation and differentiation of the hippocampal neural stem cell. RT-PCR and Western blot were used to detect mRNA and protein expressions of Notch1 and Mash1 in the hippocampus, respectively. The results showed that, compared with the control group, the numbers of BrdU positive cells (4, 8 Gy subgroup) and BrdU/NeuN double-labeling positive cells (3 dose subgroups) were decreased significantly in the irradiation group, but the above changes could be reversed by EA. Compared with the control group, the number of BrdU/GFAP double-labeling positive cells in each dose subgroup of irradiation group was decreased significantly, while EA could reverse the change of 4 and 8 Gy dose subgroups. In addition, compared with the control group, the expression levels of Notch1 mRNA and protein in hippocampus were up-regulated, and the expression levels of Mash1 mRNA and protein were significantly decreased in each dose subgroup of irradiation group. Compared with irradiation group, the expression levels of Notch1 mRNA and protein in hippocampus of EA group were decreased significantly in each dose subgroup, and the expression levels of Mash1 mRNA and protein were increased significantly in 4 and 8 Gy subgroups. These results suggest that irradiation affects the proliferation and differentiation of neural stem cells in hippocampus of mice, whereas EA may significantly increase the proliferation and differentiation of hippocampal neural stem cells via the regulation of Notch signaling pathway.

Traditional bulk polymerization imprinted technology and existing surface imprinted technology have some congenital defects. Therefore, it is necessary to design more efficient surface imprinted technology. In this paper, novel surface imprinting technology with higher imprinting efficiency is well designed. It fully realizes the synchronization of polymer crosslinking and template imprinting. Then the surface imprinted polymers (SIPs) are synthesized using metal ions as a template. The physicochemical characteristics of the SIPs are characterized by scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) studies, Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The adsorption performances and recognition selectivity of the SIPs towards the template are investigated by a batch method. The experimental results show that the SIPs possess excellent adsorption ability and selectivity towards the template. The selectivity coefficients of the SIPs prepared in this study are higher than those of IIPs prepared by other imprinting methods. The adsorption process could be well described by the Lagergren-first-order model and Langmuir monolayer chemical adsorption. The SIPs have good chemical stability and reusability. Consecutive adsorption–desorption experiments show that the exhausted SIPs could be effectively regenerated, and the regenerated SIPs could be reused without a significant reduction in adsorption capacity or selectivity coefficient.

Chalcophile elements hosted by black shales of the Lower Cambrian Niutitang Formation, South China Block, contribute to low-temperature mineralisation in southwest China. To study the mobilisation and migration of ore-forming elements, hydrothermal experiments were performed to simulate leaching of Au, As, Sb and Ag from an Au-rich black shale from the Kaiyang Phosphate Mine (KYPM), China. The experiments were designed to simulate low-temperature mineralisation at 150 °C, with solvent concentrations of ~5%, durations of 15 d and 30 d, and water/rock mass ratios of 13:1 and 26:1. Reagent-grade NaCl, NaHCO3 and Na2S were used to provide the common anions found in hydrothermal systems. The results show that solutions containing Cl− ions in oxidised acidic systems leached Au most effectively. Weakly alkaline systems containing HCO3− ions leached Au less effectively. Solutions containing HS− ions did not leach Au effectively, and Au precipitated within the HS−-bearing system. The results for Ag were similar to those for Au, and Ag-leaching was most effective in the oxidised acidic system containing Cl− ions. As-leaching does not occur in the Cl−-bearing system, but As is leached effectively by HS−-bearing and HCO3−-bearing solutions. Sb was not leached by our experiments. Oxidised fluids produced by deep-sourced magma during the Indosinian and Yanshanian tectonic events infiltrated black shales affected by extensional deformation through faults, joints and fractures. Fluid–rock interaction leached a range of elements in these structural settings. These experiments provide insights into migration of chalcophile elements, particularly Au and Ag, and the source of large-scale low-temperature mineralisation within the South China Block.

Garnet becomes an important tool to analyze the timing and genesis of metamorphic rocks (especially skarn deposits), clastic sediments, and igneous rocks due to its common occurrence. However, for in-situ U-Pb dating of garnet, is there any difference to use 91500 or Willsboro as a primary standard and can a robust age be obtained for low-U (≤ 10 ppm) garnet as Willsboro and Mali in small spot sizes of 32–16 μm? Can garnet U-Pb dating be used to exactly identify the ore-related intrusive unit in an intrusive complex and its related distal skarn system setting? In this contribution, Willsboro, Mali, QC04, and three other andradite samples WMQ-2(3), WSG-1, and YJ-4(2) from the Anji polymetallic skarn deposit were analyzed to discuss these questions. In our analysis, zircon 91500 is confirmed as reliable reference material for these garnets in spot sizes of 32–16 μm. Notably, both 91500 and Willsboro are suitable as primary standards for the garnets as Mali and QC04, which have extremely low common lead and are mainly plotted at the lower intersection in the Tera-Wasserburg Concordia diagram; Willsboro is not suitable to calibrate the garnets as WMQ-2(3), WSG-1, and YJ-4(2), which contain relatively high common lead and fall along a mixing line between initial common Pb and radiogenic components in the Tera-Wasserburg Concordia diagram. In the Anji polymetallic system, based on garnet U-Pb, mica Ar-Ar and previous zircon U-Pb dating, proximal Pb-Zn-Ag-Cu and distal Fe and Fe-Zn-Cu skarn deposits were formed by the same magmatic-hydrothermal-mineralization event at 137–138 Ma. These ages, geological evidences, our and previous lead isotopic compositions confirm that Fe, Fe-Zn-Cu, Pb-Zn-Ag-Cu, Mo, and fluorite-chalcedony mineralization have genetic relationships with fine-grained granite. Compared with other units of the Wushanguan complex, the lead isotopic compositions indicate that fine-grained granite supplies most ore-forming materials, and the increased mantle-sourced materials may play an important role in the formation of the Anji skarn system.

Magnetite occurs as an ore mineral in many types of deposits and its trace element characteristics can be used to fingerprint various types of mineral deposits and distinguish different ore forming processes. The Lengshuikeng Ag–Pb–Zn deposit (LSKD) is one of the largest silver deposits in China, but the ore forming processes involved in its formation are still unclear. In this study, magnetites from six representative samples of different mineralization types were examined. Their trace element contents were analyzed using in situ laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS), to better understand the genesis and evolution of the ore-forming fluids responsible for Ag–Pb–Zn mineralization. The studied magnetites were divided into two types based on their spatial occurrence, associated minerals and distinctive textures. Type A magnetites are large, display subhedral to euhedral forms and appear inclusion-free. They coexist with siderites and formed early, preceding the formation of surrounding sulphides. Type B magnetites are small, exhibit irregular and anhedral forms that feature as wall-rock alterations, and were formed during the main mineralization stage. They coexist with main-stage sulphides and Fe-Mn-bearing carbonate minerals, in which Mn content increases corresponding to the evolution of the mineralization process. Generally, magnetites from the LSKD contain low amounts of Ti and V, and widely variable Al and Mn contents, which resulted from multiple influxes of low-temperature hydrothermal fluid. Type A magnetites are inferred to have formed paragenetically early at relatively high temperatures without coeval precipitation of base-metals. Conversely, Type B magnetites are interpreted to have formed during the early (B1, stage 1) and main (B2, stage 2) stages of Ag–Pb–Zn mineralization under alteration and dissolution–reprecipitation processes (DRP) from the later ore-forming hydrothermal fluids. Trace element characteristics of magnetite suggest the late hydrothermal fluid was characterized by low temperatures, and was enriched of Cl and Mn. The wide range of contents of trace elements (e.g. Ga, Mo and Sn) in magnetite that underwent DRP can be explained by different wall-rock types and water/rock ratios. Characteristics of the late hydrothermal fluids, including those from detailed microscopic observations, indicate that the ingress of Ag, Pb and Zn occurred as metal–Cl complexes, and that dissolution of early Fe, Pb, and Zn sulphides supplied the S required for the final precipitation of silver.

The Middle Jiangnan orogenic belt is a very important tungsten (W) polymetallic belt in China. There are many types of W deposits in the belt, including veinlet-disseminated and stratabound deposits, which have different origins. The veinlet-disseminated Dahutang W deposit has undergone extensive alteration, such as biotitization (potassic alteration), and greisenization. Scheelite in veinlet-disseminated W mineralization displays a zoned texture indicating at least two generations. The early generation (D1) from the Dahutang W deposit exhibits magmatic hydrothermal characteristics with comparatively high Nb, Ta, and Mo concentrations, but a low Sr concentration (44 to 95 ppm). In contrast, the scheelite samples from the Xi’an W deposit has relatively low Nb, Ta, and Mo concentrations, but a high Sr concentration (582 to 861 ppm), mainly originating from a metamorphic fluid that mixed with meteoric water. The composition of the late generation of scheelite (D2) samples from the Dahutang deposit are intermediate between the composition of scheelite (D1) and scheelite of the Xi’an depsoit. The mineral chemistry of the scheelite samples indicate that the ore-forming fluids of the Dahutang deposit were dominated by magmatic hydrothermal fluids during the early stage, and that meteoric water was added during fluid evolution. The rare earth elements (REEs) in the scheelite samples, especially the variation of the δEu (EuN/((SmN × GdN)0.5)) values, record the change in oxygen fugacity. The ore-forming fluids in the early stage of the Dahutang deposit were reduced becoming oxidized during the precipitation of the D2 scheelite, whereas the ore-forming fluids of the Xi’an deposit were oxidized. An increased oxygen fugacity of the ore-forming fluids of the Dahutang deposit restricted the precipitation of wolframite and promoted the formation of scheelite. Extensive alteration resulted in the decomposition of plagioclase, thus releasing Ca and Sr for the crystallization of scheelite at the Dahutang tungsten deposit.

Soil secondary minerals are important scavengers of rare earth elements (REEs) in soils and thus affect geochemical behavior and occurrence of REEs. The fractionation of REEs is a common geochemical phenomenon in soils but has received little attention, especially fractionation induced by secondary minerals. In this study, REEs (La to Lu and Y) associated with soil-abundant secondary minerals Fe-, Al-, and Mn-oxides in 196 soil samples were investigated to explore the fractionation and anomalies of REEs related to the minerals. The results show right-inclined chondrite-normalized REE patterns for La–Lu in soils subjected to total soil digestion and partial soil extraction. Light REEs (LREEs) enrichment features were negatively correlated with a Eu anomaly and positively correlated with a Ce anomaly. The fractionation between LREEs and heavy REEs (HREEs) was attributed to the high adsorption affinity of LREEs to secondary minerals and the preferred activation/leaching of HREEs. The substantial fractions of REEs in soils extracted by oxalate and Dithionite-Citrate-Bicarbonate buffer solutions were labile (10 %–30 %), which were similar to the mass fraction of Fe (10 %–20 %). Furthermore, Eu was found to be more mobile than the other REEs in the soils, whereas Ce was less mobile. These results add to our understanding of the distribution and geochemical behavior of REEs in soils, and also help to deduce the conditions of soil formation from REE fractionation.

The first example of a ratiometric optical oxygen nanoprobe based on a hydrogen-bonded supramolecular polymer has been reported. The supramolecular polymer based nanoprobe (SPNP) is prepared from the co-assembly of a bis-ureidopyrimidinone (bis-UPy)-containing phosphorescent indicator (Por(Pd)-bisUPy), fluorescent reference dye (BF2-bisUPy), and skeleton unit (DPA-bisUPy) through quadruple hydrogen bonds by a mini-emulsion method. The water-dispersible SPNP is highly sensitive to oxygen (Q = 95%), with full reversibility, excellent storage stability and photostability, and good cell-penetrating ability, and exhibits low cytotoxicity toward living cells. The preparation of the SPNP is straightforward and its function is easily tuned by changing the monomeric structure. This work is expected to lead to the design of other SPNPs for other important analytes in biological systems.

The Northern Liaoning Complex in northeastern China constitutes an important component of the Eastern Block in the North China Craton. The major lithologies consist of Archean granitoid gneisses with minor supracrustal rocks occurring as tectonic lenses. This study presents zircon Lu–Hf isotopic data for the first time as well as new SHRIMP zircon U–Pb data of the major lithologies from the Northern Liaoning Complex, in order to elucidate the crustal evolution of the complex and provide new constraints on the Neoarchean crustal evolution of the Eastern Block in the North China Craton. Magmatic zircon U–Pb data from this study show that the protolith magmas of the supracrustal rocks and granitoid gneisses were generated during ∼2.55–2.50 Ga. Metamorphic zircons document consistent metamorphic ages at 2.49–2.48 Ga, suggesting a regional metamorphic event immediately after the magmatism at the end of the Neoarchean in the Northern Liaoning Complex. Inherited/detrital zircons of 2.79–2.60 Ga suggest possible existence of ancient crust in this region. Zircon Lu–Hf isotopic compositions show that the magmatic zircons have variable ɛHf(t) values from −4.0 to +9.0 with depleted mantle model ages of 3.6–2.5 Ga, of which most ɛHf(t) values are positive with a model age peak at 2.9–2.7 Ga. These zircon Hf signatures reveal major juvenile crustal growth with additions of older crustal materials during 2.9–2.7 Ga, and a crustal reworking event with minor juvenile additions at 2.6–2.5 Ga in the studied area. Integrated with previous data from other Neoarchean complexes in the Eastern Block, both the major juvenile crustal growth during 2.9–2.7 Ga and the strong crustal reworking at 2.6–2.5 Ga contribute to the extensive Neoarchean crust formation of the Eastern Block in the North China Craton. The North China Craton share similar Neoarchean continental crustal evolution to other cratons in the world, though it is distinctively featured by intensive tectonothermal overprinting at the end of the Neoarchean.

The Fenghuangshan deposit is a typical Cu–Fe–Au skarn deposit in the Tongling area, Anhui province, Eastern China. The deposit has a paragenetic sequence of a prograde skarn stage, followed by a retrograde skarn stage, and a final quartz–sulfide and carbonate stages. Magnetite in the Fenghuangshan deposit mainly formed in the retrograde and carbonate stages. According to the morphology of magnetite and mineral assemblage of ores, we divided magnetite-bearing ores into three groups. Group 1 (early retrograde skarn stage) is represented by a mineral assemblage of magnetite and chalcopyrite. Group 2 (late retrograde skarn stage) has a mineral assemblage of magnetite, chalcopyrite, and wollastonite with characteristic ring-like magnetite. Group 3 (carbonate stage) is characterized by large amounts of calcite veins crosscut or associated with magnetite and intensive hematization of magnetite crosscut by the veins. Laser ablation (LA)–ICP–MS was used to determine trace element concentrations of magnetite from the three mineralization stages. Positive correlations among Mg, Al, Ca, and Si in magnetite indicate that these lithophile elements have similar behavior during the skarn formation process. Calcium is an important discriminant element for magnetite in skarn deposits. Positive correlations are also evident for Pb, Sn and W in magnetite, which also indicates their similar behavior. In general, magnetite grains of different stages have similar normalized trace element patterns, indicating that they share a common source. However, some elements such as Co and Mn in magnetite decrease from early retrograde skarn stage, late retrograde skarn stage to carbonate stage, which may be attributed to the precipitation of coexisting minerals (sulfides and carbonates) or the decreasing temperature. Magnetite grains of the retrograde stage have higher Mg + Mn and Si + Al contents than those of the carbonate stage, indicating a decreasing degree of fluid–rock interaction during the skarn formation process. Trace element data of skarn magnetite indicate a more widely compositional variation than previously suggested. Magnetite from the Fenghuangshan Cu–Fe–Au deposit has similar composition to those from other Cu, Cu–Fe or Cu polymetallic skarn deposits, but different from those from Fe skarn deposits, such that magnetite composition is very powerful in establishing the origin of skarn deposits.

Chemically crosslinked recyclable photodeformable azobenzene (azo) polymer actuators with good stability (toward organic solvents and higher temperatures) and high processability and reconstruction ability hold great promise in many applications, but their development remains a challenging task. Herein, we report on for the first time a facile and highly efficient post-crosslinking method for addressing this issue. It involves first the synthesis of side-chain polymers bearing N-hydroxysuccinimide (NHS) carboxylate-substituted azo mesogens, fabrication of uniaxially oriented fibers from these azo polymers by the simple melt spinning method, and their subsequent post-crosslinking with cystamine (a diamine containing a disulfide bond) under mild conditions. The resulting chemically crosslinked fibers not only showed rapid and reversible photoinduced bending and unbending at ambient temperature as well as high mechanical strength and good solvent/heating stability, but also could be easily recycled into processable azo polymers in the presence of a reducing agent that can cleave the disulfide bond into thiol groups (i.e., tributylphosphine). In particular, the occurrence of the post-crosslinking reaction only on the thin surface layers of the azo polymer fibers afforded recycled polymers with large amounts of NHS carboxylate-substituted azo mesogens (together with a small amount of oxygen/heating-sensitive thiol-substituted ones) in the first several (at least 5) recycling processes, thus allowing highly efficient reconstruction of photodeformable fibers with excellent photomobile properties by applying melt spinning and post-crosslinking (by using cystamine) methods. The strategy presented here opens the new possibility to the facile and efficient development of various advanced chemically crosslinked recyclable photodriven actuators.

Sulfide melt inclusions enclosed in silicate minerals have been observed in many oxidized Cu-bearing porphyries. The origin of such sulfide melt inclusions could bear critical information of metal enrichment or depletion during magma evolution of porphyry systems. The giant Yulong porphyry Cu-Mo deposit in eastern Tibetan Plateau consists of a series of felsic intrusions, among which the mineralized Yulong intrusion emplaced at a late stage of the magmatic activity. This study reports detailed texture and composition of sulfide melt inclusions from barren and mineralized intrusions, as well as platinum-group elements of these intrusions, to evaluate potential role of early sulfide saturation in the porphyry mineralization system. These sulfide melt inclusions, occurring as globules or droplets, are preserved in zircon, amphibole and quartz grains. Most of them are composed of a major phase of pyrrhotite and minor pyrite, chalcopyrite and pentlandite. Smooth boundaries between these phases suggest the origin of fractionation from sulfide melt upon cooling. Small amounts of Cu and Ni are heterogeneously distributed in the pyrrhotite. The sulfide melt inclusions could be observed in both the pre- and syn-mineralization intrusions at Yulong, indicating that sulfide saturation had commonly occurred during magma evolution. Magnetite mineral inclusions could be observed in zircon and amphibole grains as well. The mineral assemblage of magnetite + pyrrhotite + pyrite of the mineral inclusions constrains the Yulong magmatic system to redox conditions near the magnetite-pyrite/pyrrhotite buffer and above the fayalite/ magnetite-quartz buffer (FMQ). High Eu/Eu* values (0.56–0.78) of the hosting zircons and high calculated ΔNNO values (>0.5) of the hosting amphibole indicate highly oxidized nature of the parental magma. Both pre- and syn-mineralization intrusions have low PGE contents (Pt = 0.04 to 0.17 ppb, Pd = 0.19–0.60 ppb) with compositions plotting in the Au-poor porphyry Cu fields in discriminating diagrams. Early sulfide saturation may have been reached and small amounts of sulfides have been segregated from magma. Most PGEs and Au but little Cu have been removed from the evolved magma because the partition coefficient of Cu between sulfide and silicate melt is about two orders of magnitude lower than PGE or Au. As a consequence, the evolved magma would have high Cu but very low PGE and Au, resulting in the Au-poor porphyry Cu mineralization at Yulong.

The Fule deposit is one of the carbonate-hosted Pb-Zn deposits in southeastern part of the Sichuan-Yunnan-Guizhou (SYG) metallogenic province, SW China. This deposit is hosted by dolomitic limestone and dolomite of the Yangxin Formation with Zn-Pb ore reserves of more than 20 million tons (Mt). Ore minerals mainly include sphalerite, galena and pyrite. According to the occurrence of orebodies, ore textures, and mineral assemblages, the hydrothermal Zn-Pb mineralization stage could be subdivided into three generations: (1) light brown sphalerite associated with minor galena in dolomite breccias; (2) dark brown to brown sphalerite associated with galena, dolomite and minor gypsum; (3) disseminated reddish-brown to light yellow sphalerite in calcite vein. Sulfides from three stages have similar major, trace elements, Re-Os and S isotopic compositions. Rhenium and Os in sphalerite are 7–58 ppb and 3–56 ppt, respectively, and in galena of 13–30 ppb and 1-5ppt, respectively. 187Re/188Os and 187Os/188Os ratios in sphalerite are 387–16193 and 1.29–12.0, respectively, and in galena of 5449–27180 and 0.35–5.0, respectively. Pyrite, galena, and sphalerite have δ34S values of +14.69‰ to +20.64‰, +6.26‰ to +12.39‰, and +12.01‰ to +16.03‰, respectively. Re-Os isotopic compositions of sphalerite and galena have Os model ages from 1 Ma to 500 Ma, indicating an unclosed Re-Os system. Different sulfides from the same sample follow the trend of (δ34Spyrite ≥ ) δ34Ssphalterite > δ34Sgalena, indicating that sulfur isotopes between different sulfides have attached equilibrium. Fluid inclusions in sphalerite have homogenization temperatures ranging from 135 ℃ to 235 ℃ with two peaks of 220–235 ℃ and 135–160 ℃, which agree well with calculated temperatures of sphalerite-galena pairs (99 ℃–202 ℃). A relatively high sulfur isotope composition (+6.3‰ to + 16.6‰) in sulfides, indicating that sulfur was mainly derived from the reduction of gypsum in Carboniferous strata. Sphalerite and galena in sulfide ores of carbonate-hosted deposits in SYG metallogenic province have experienced post-ore hydrothermal alteration by oxidizing fluids, forming oxidized minerals including gypsum, smithsonite, and anglesite. The activity of such oxidized fluids might last for a long time. Rhenium in sulfides is more mobile than Os in such an oxidizing environment and thus Re-Os isotope system remains open until the interaction between sulfide and fluids stops. Therefore, redox condition of hosting carbonates can highly influence the closure of Re-Os isotope system of sulfide in carbonate-hosted Pb-Zn deposits. Sulfide in oxidizing mineral bearing carbonate-hosted Pb-Zn deposits is not suitable for Re-Os dating. In contrast, Re-Os isotope system is possible to be used for dating the age of Pb-Zn mineralization within reduced carbonates.

The Lengshuikeng Ag-(Pb-Zn) deposit (LSKD) is one of the largest independent porphyry silver deposits in China. Its silver mineralization is related to the Late Mesozoic granite porphyry, but the oxidizing hydrous conditions of the associated magma are still unclear. This study focuses on the associated granite porphyry (GP) and barren K-feldspar granite porphyry (KFGP) to constrain their oxidizing hydrous conditions. New zircon U-Pb dating shows the GP emplaced at 155.8 ± 1.9 Ma and 158.5 ± 2.3 Ma for GP, and the KFGP emplaced at 136.6 ± 1.9 Ma. Both granites are peraluminous with A/CNK ratios of 1.09–3.01 (mean = 1.48), similar to that of typical S-type granites. They are enriched in light rare earth elements (LREE), with large (La/Yb)N (7.0–19.1 for the GP and 1.8–34.3 for the KFGP) and negative Eu anomalies (0.29–0.67 for the GP and 0.02–0.05 for the KFGP). The GP has eNd(t) values ranging from − 10.0 to − 9.7 with TDM2 ages of 1688–1915 Ma, while the KFGP has higher eNd(t) values ranging from − 7.5 to − 7.6 with younger TDM2 ages of 1538–1548 Ma. The initial Pb isotopic ratios for (206Pb/204Pb)i, (207Pb/204Pb)i and (208Pb/204Pb)i are 17.647–17.952, 15.555–15.604 and 37.851–38.541, respectively. Our new chemical and isotopic data suggest that both granites were dominantly derived from dehydration melting of the Proterozoic meta-sedimentary rocks, with more dehydration fluids for the GP and relatively more mantle contribution to the KFGP. Both granites underwent fractional crystallization of plagioclase, K-feldspar and ilmenite/magnetite followed by minor assimilation of the upper crust. Comparative study on the relative water content, oxidation state and melting temperature of magma have shown relatively moderate oxidation state and water content in the associated magma probably played more important roles in porphyry silver mineralization than other factors in porphyry Cu deposit. This study helps deepen the understanding of silver mineralization.

The purpose of this study was to explore the effects of different concentrations of calcitonin gene-related peptide (CGRP) on long-term potentiation (LTP) in the hippocampus of mice. C57BL/6J mice (30 days old) were randomly divided into control group, three CGRP groups, and CGRP + CGRP

Digestion with aqua regia in a Carius tube and separation of Re with anion exchange resin is commonly employed for Re–Os dating of molybdenite and pyrite. However, the recovery of Re is extremely low when this routine anion exchange method is applied to galena, causing difficulty in Re–Os dating of galena. In this study, we investigated the mechanism of Re loss during sample preparation and tested a revised procedure for Re–Os dating of galena and sphalerite.