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The hydrogen, oxygen, sulfur, and lead isotopes of Yinshan copper-lead-zinc polymetallic deposit were studied to determine the sources of ore-forming materials.The research results indicate that the δD values range from-78.9 ‰ to-28.5 ‰, with an average value of-56.5 ‰;the δ18OV-SMOW values range from 12.10 ‰ to 18.70 ‰, with an average value of 16.06 ‰;the δ18OH2O values range from 0.18 ‰ to 11.26 ‰, with an average of 8.24 ‰, indicating a mixture of magmatic water and atmospheric precipitation as the ore-forming fluids.The δ34S values range from-1.04 ‰ to 2.71 ‰, with an average value of 1.35 ‰, which is significantly different from the sulfur isotopes of the ore-bearing strata of Zhangcun Formation in the mining area, suggesting that the ore-forming materials do not directly come from the strata but have a clear mantle sulfur (-3 ‰ to 3 ‰) signature, closely related to volcanic-subvolcanic activities in the mining area.The lead isotopes(206Pb/204Pb = 17.890 0-18.319 0, 207Pb/204Pb=15.528 0-15.602 5, 208Pb/204Pb=38.025 2-38.445 0) indicate a mixed source of crust and mantle, and the ores have an affinity with the magmatic rocks. [ABSTRACT FROM AUTHOR]

LA-ICP-MS zircon U-Pb age of the Middle Jurassic granodiorite is 172. 7±1. 1 Ma in Gaxiangou area, northern Great Xing'an Range. The whole-rock SiO2 content ranges from 62. 81% to 68. 78% with higher whole-alkali (ALK) and Al2O3 and lower FeOT, MgO and TiO2 tontents. Rittman index (σ) is from 2. 27 to 5. 33, Na2O/K2O = 1. 19-3. 57, Mg# values from 38. 0 to 49. 0, aluminum saturation index (A/CNK) = 0. 91-0. 97, illustrating the granodiorite belongs to medium-high potassium calc-alkaline series and metaluminous rocks. The ∑REE = (117. 70-146. 32) × 10-6, and (La/Yb)N = 11. 70-18. 10, show a right-leaning distribution pattern with enrichment in light rare earth elements and relative depletion in heavy rare earth elements. Slightly Eu negative anomaly (δEu = 0. 86 - 0. 98) suggests that there is no significant plagioclase remains or fractional crystallization in the source region. The high Zr/Hf, Nb/Ta and Sr/Y ratios, low Y and Yb contents, enrichment of the large ionic lithophilic elements Rb, Sr and Ba, and depletion of the high-field-strength elements Nb, Ta and Ti indicate that the source rocks are crust-derived. P2O5 decreases with increasing SiO2 content and TZr values range from 700. 50 to 781. 20 °C. These indicate that the diagenetic type of this granodiorite is an I-type granite with C-type edakite characteristics. Combined with the regional data, the Middle Jurassic granodiorites were formed in the transition from collision to post-collision, and the Mongolian-Okhotsk Ocean tectonic system in the Middle Jurassic was characterized by a tectonic regime shift from extrusion to extension, and from crustal thickening to thinning, which is corresponding to the significant decrease of magmatic activity in the Middle Jurassic. [ABSTRACT FROM AUTHOR]

The Kangdian iron-copper metallogenic belt on the western margin of the Yangtze landmass is one of the important copper rich and iron rich ore producing areas in China. However, the metallogenic epoch and genesis of many of its deposits are still controversial. Many orebodies of Youheimu iron-copper polymetallic ore deposit located in Mianning, Sichuan, have reached a certain scale. There are few previous studies and reports on this, and its genesis and mineralization age are still unclear. In this paper, the wall rock and ore of the ironcopper orebody of the deposit are analyzed by geochemistry, and the ore is dated with LA-ICP-MS monazite U-Pb. The protolith of wall rock(biotite quartz schist) of the Heheimu iron-copper orebody is argillaceous rock mainly composed of clay minerals formed by volcanic deposition, with the addition of ancient sediment components. The LA-ICP-MS monazite U-Pb dating in Youheimu iron-copper orebody has two groups: one group is 812. 8±4. 6 Ma, representing the formation age of Lengzhuguan formation of Kangding Group; the other group is 698. 5±5. 0 Ma, representing the mineralization age of iron-copper orebody. The hydrothermal fluid brought by acid magma in the east of the study area flows in to the interlayer fracture zone of the wall rock, undergoes metasomatism and skarnization with the surrounding rock, and forms iron-copper orebody. The genesis of the deposit is magmatic hydrothermal skarn. [ABSTRACT FROM AUTHOR]

Suoluogou Gold Deposit is the largest gold deposit identified in the Ganzi - Litang gold belt. Stibnite is one of the associated minerals of the deposit, and no relevant research work has been carried out. Based on a detailed investigation of the field geological characteristics of the stibnite, this study conducted a gold content test and in-situ LA - MC-ICP-MS analysis of the single mineral of stibnite in the Suoluogou Gold Deposit and Rila Gold Deposit through petrographic and mineralogical observations. It was found that with similar ore section grades, the gold content of Suoluogou Gold Deposit is higher than that of Rila Gold Deposit, and pyrite is still the main gold-bearing mineral. The ore-forming materials are derived from highly homogeneous crust-derived metamorphic hydrothermal fluids. Based on the sulfur isotope characteristics of other deposits in the region, it is believed that most ore-forming hydrothermal fluids in the Ganzi - Litang gold belt mainly come from metamorphic hydrothermal fluids. The element correlation analy- sis found that As, Cu, Hg, Ag, Pb, Zn, Cr, and other elements has a positive correlation with Au. In addition to Au, As, and Sb elements, Cu can also be used as a feature element for geochemical prospecting in the region. [ABSTRACT FROM AUTHOR]

Kongquegou rock body is situated in Kumishi area of Southern Tianshan, and the lithology is mainly syenogranite.Its geochronology and petrogenesis type bear significance in defining the time of Southern Tianshan Ocean Basin closure.Zircon U-Pb isotope and whole-rock analysis were carried out to study Kongquegou rock body.Zircon U-Pb dating indicates that Kongquegou rock was formed during Early Permian（295.1-296.5 Ma） magmatism.The petrology and element composition indicate that Kongquegou rock body is characterized by high fractionated I-type granite, specifically:（1） low w（Zr）/w（Hf） value（19-26）;（2） fairly low Zr saturation temperature（749 ℃-802 ℃）;（3） development of hornblende minerals.In this study, comprehensive analysis believed that Southern Tianshan Ocean had closed before Early Permian, and Kongquegou rock body was formed in a post-collision tectonic setting.In addition, Kongquegou rock body has a similar geochemical feature with the coeval skarn W mineralization ore-forming rock body, indicating W prospecting potential. [ABSTRACT FROM AUTHOR]

In order to clarify the Neoproterozoic tectonic setting of the western segment of Jiangnan orogenic belt, the petrography, zircon U-Pb chronology, characteristics of Hf isotope, major and trace elements geochemistry of Qingmingshan granite in northern Guangxi are studied. LA-ICP-MS zircon U-Pb dating results show that the diagenetic age of Qingmingshan granite is 823. 8± 1. 8 Ma. Geochemical study shows that the potassium-rich magmatic rocks are S-type granites with strong peraluminite, moderate to weak fractionation between light and heavy rare earth elements, moderate negative Eu anomalies, enrichment of Rb, Th, U, Pb, and depletion of Ba, Nb, Sr, Ti. Zircon εHf(t) values mainly range from -5. 8 to -2. 6, corresponding to the two-stage model ages (TDM2) from 1 863 to 2 060 Ma. It indicates that Qingmingshan granite was mainly formed by melting of Paleoproterozoic continental crust material. According to the geochemical characteristics and regional research data of the Neoproterozoic Qingmingshan granite in northern Guangxi, it is concluded that it is the product of post-collisional tectonic environment. [ABSTRACT FROM AUTHOR]

Coal and its fly ash after combustion can be rich in critical metals, and the content can reach or even exceed the traditional deposit, which is expected to become the main source of critical metals in the future. Xintian coal mine in the western Pingle depression was taken as the research object, and the technical methods such as SEM-EDS analysis, TIMA system, XRF, and ICP-MS were used to carry out coal petrology and whole-rock geochemistry research, aiming at finding out the enrichment types and causes of critical metals in Xintian coal mine. The results show that the coal in Xintian coal mine is mainly composed of organic matter and kaolinite, followed by quartz, feldspar and illite, with slight magnetite, tremolite, rutile, and apatite. Compared with the contents of critical metals in global coal and global sedimentary rocks, Cs is considered as the main critical metal that is enriched in Xintian coal mine and can be enriched in the coal seams and floor surrounding rocks. The occurrence mode of critical metal Cs may be that isomorphism replaces K and Rb in the feldspar lattice, isomorphism replaces K in illite, exists in lattice of clay minerals or is adsorbed by clay minerals together with Li. Combined with the study on Al2O3/TiO2 ratios and the characteristics of rare earth elements with coal seam and surrounding rock in Xintian coal mine with the evolution history of regional tectonic-magmatic activity, it is considered that the enrichment of critical metal Cs in coal may be the terrigenous source formed by weathering of Paleozoic granite in the southern margin of Pingxiang coal-bearing basin, and the superimposition by later Cs-rich magmatic hydrothermal fluid in Yanshanian is beneficial to the further enrichment of critical metal Cs in coal. [ABSTRACT FROM AUTHOR]

The central region of Inner Mongolia that straddles across the Central Asian Orogenic Belt(CAOB)and the northern margin of the North China Block, widely develops magmatic Cu-Ni sulfide deposits(or occurrences). The Ebutu Cu-Ni sulfide deposit is one of the large scales and high-grade magmatic Cu-Ni sulfide deposits within this region. The plagioclase-bearing olivine pyroxenite of Ebutu Cu-Ni sulfide deposit was selected as the main research object by systematic mineralogy, petrography, mineralography, zircon U-Pb geochronology, petrogeochemistry and Sr-Nd isotopes to discuss the diagenetic and metallogenic age and petrogenesis of Ebutu mafic-ultramafic intrusions; based on the integration of regional geological data, the metallogenic potential of Ebutu Cu-Ni sulfide deposit was also briefly discussed, in order to provide suggestions for further breakthrough in Cu-Ni prospecting. The results show that the plagioclase-bearing olivine pyroxenite of Ebutu mafic-ultramafic intrusions yields a LA-ICP-MS zircon U-Pb weighted mean age of(326.0±2.1)Ma, belonging to the Early Carboniferous, indicating that it forms in an island arc setting during the Paleo-Asian ocean subducted to the North China Block. The plagioclase-bearing olivine pyroxenite showes SiO2 contents of 44.62%-55.81% with the average of 51.60%, MgO contents of 27.45%-33.10% with the average of 30.32%, and CaO contents of 1.15%-2.22% with the average of 1.61%. They are enrichment in light rare earth elements(LREE), depletion in heavy rare earth elements(HREE)and slightly negative Eu anomalies on the right-leaning chondrite-normalized REE pattern.(87Sr/86Sr)i,(143Nd/144Nd)i and εNd(t)values vary from 0.708 5 to 0.712 3 with the average of 0.710 6, from 0.511 7 to 0.511 8 with the average of 0.511 8 and from -10.57 to -8.07 with the average of -8.91, respectively. Based on the above studies, it is concluded that the parent magma of Ebutu mafic-ultramafic intrusion probably derives from the partial melting for the enriched lithospheric mantle interacted by the subducted slab-derived fluids. The primary magma is mainly high magnesium basaltic magma, which undergoes strong crustal contamination during the ascending emplacement process. Since the addition of the crustal sulfur and the contamination of silicon-rich crust, it results in sulfide segregation and mineralization. Combined with the regional geological data and the latest prospecting finding, it is considered that the deep and marginal part of Ebutu mafic-ultramafic intrusion has high exploration potential, and the next focus of mineral prospecting should be to clarify the direction of magma flow and to find the hidden intrusions and deep magma channel. [ABSTRACT FROM AUTHOR]

In order to enhance the understanding of Archean continental crust formation and evolution history of Liaonan block in North China Craton, the Neoarchean TTG(tonalite-trondhjemite-granodiorite)gneisses in Shijianfang area of Liaonan block were focused on, and the detailed field investigation, zircon U-Pb dating and Lu-Hf isotope analysis, and whole-rock geochemical analysis were intergrated. The results show that TTG gneiss in Shijianfang area crystallizes at(2 499.7±5.4)Ma. The TTG gneiss samples have high contents of SiO2(66.1%-69.1%)and Al2O3(14.6%-15.6%), are enriched in Na and depleted in K(K2O/Na2O is 0.41-0.51)with weakly positive Eu anomalies(1.06-1.59); the samples are relatively enriched in large ion lithophile elements(Ba, Rb, K, etc.)and high field strength elements(Zr, Hf, etc.), featured by high Sr/Y(44.3-69.5)and(La/Yb)N(11.8-24.0), and depleted zircon Hf isotopic composition with two-stage model ages of 2 903-2 687 Ma. Compared with TTG rocks derived from partial melting of the thickened lower crust, TTG gneisses in Shijianfang area have relatively higher contents of MgO, Cr and Ni. The above geochemical characteristics reveal TTG gneisses in Shijianfang area are typical medium-pressure TTG rocks, which is the product of partial melting of Meso-Neoarchean basaltic crust. The source area is rich in garnet and amphibolite, but short of rutile and plagioclase. Combined with previous studies, TTG gneisses in Shijianfang area are likely formed by the partial melting of subduction slabs, indicating the warm subduction tectonic system of the ancient continental margin. The North China Craton might be controlled by both plate tectonics and mantle plume tectonics during Late Neoarchean. [ABSTRACT FROM AUTHOR]

The Middle Triassic Pingtai pluton, which occurs in the southeastern part of Wulonggou gold orefield, East Kunlun orogen, provides new insights into the subduction history of the Paleo-Tethyan ocean. The detailed petrology, whole-rock geochemistry, zircon U-Pb age and Hf isotopic data of granodiorite from Pingtai pluton were conducted. The results show that the granodiorite of Pingtai pluton mainly comprises plagioclase(the volume fraction is 45%-50%), quartz(20%-25%), K-feldspar(20%-25%), hornblende(5%), and biotite(5%), and it yields a zircon U-Pb weighted mean age of(247±1)Ma, suggesting an emplacement age of Middle Triassic; whole-rock geochemistry characteristics show that SiO2 content varies from 64.88% to 65.90%, average ratios of FeOT/MgO and Fe2O3/FeO are 3.70 and 1.48, respectively, and average saturation temperature for zircon is calculated to be 770 ℃. Therefore, it is suggested that the granodiorite belongs to strong peraluminous and high-potassium calcium alkaline series, which is similar to typical I-type granite. Chondrite-normalized REE pattern shows that the granodiorite is enriched in LREEs and depleted in HREEs with weak negative Eu anomaly. The εHf(t)values range from -4.51 to 0.64, and the Hf model age is 1.54-1.22 Ga. In combination with regional geological data, it is suggested that the granodiorite of Pingtai pluton is generated in a continental magmatic arc setting, which is related to the northward subduction of the Paleo-Tethyan ocean, and its parental magma is derived from meta-sandstone of continental crust. It is further indicated that the subduction of the Paleo-Tethyan ocean might have lasted until the late Middle Triassic. [ABSTRACT FROM AUTHOR]

Heilangou gold deposit is located in the east of Jiaobei area, and the proven gold reserves currently account for more than 70 % of that of Penglai area. The intrusive rocks related to mineralization in this area are rich in silicon, and alkali while lacking magnesium, with TFeO (1.22 %-12.36 %,with an average of 3.38 %),and the Rb mass fraction is less than 270×10-6. The REE chondrite-normalized distribution curve has an obvious right-leaning distribution model and weak positive Eu anomaly, and the w (Rb)/w (Nb) value is 7.8-36.0,which is A-type granite, with the characteristic of low-Mg adakites. The crystal ages of intrusive rocks measured by the LA-ICP-MS zircon U-Pb method are respectively (172.8±0.3)Ma, (172.8±0.4)Ma, and (174.0±0.4)Ma, which are all related to magmatic activity in the early Middle Jurassic. Heilangou gold area is mainly controlled by the lower crust and lithospheric mantle, and the source of ore-forming material is related to the partial melting of the crust and upwelling of lithospheric mantle and asthenosphere mantle, which belongs to the mixed material source of crust and mantle. [ABSTRACT FROM AUTHOR]

The potential of river Mg isotope systems to trace continental chemical weathering processes has been emphasized in recent years. The geochemical behavior of Mg isotopes in the surface process of the watershed was summarized. The results show that river Mg is mainly derived from mineral chemical weathering, atmospheric precipitation, groundwater and plant debris. Mg isotopic composition of the world's major runoff shows great variability, which is difficult to fully explain by the conservative mixing of Mg reservoirs in the basin alone, because the differential weathering of bedrock and Mg isotope fractionation during continental chemical weathering is important influencing factor of Mg isotopic composition in river water. The main fractionation processes affecting Mg isotopic composition in river water include primary mineral decomposition, secondary mineral formation, adsorption-desorption of exchangeable states, plant uptake and debris release. At present, the primary control process of river Mg isotope system is still not well understood. On a global scale, Mg isotopic composition of large rivers correlates well with the chemical weathering strength of carbonate minerals. In addition, multi-isotopic systems such as Mg-Sr, Mg-Li, Mg-Ca and Mg-O also provide powerful tracing tools for the study of surface environment evolution. In the future, the discussion on Mg isotope fractionation factors, special chemical weathering types, multi-isotope coupling combination and quantitative tracing of Mg isotopes in key processes in river basins should be strengthened, and the application of river Mg isotopes in chemical weathering in river basins should be promoted. [ABSTRACT FROM AUTHOR]

The Erge Region is located on the Wuerqihan volcanic passive continental margin on the accretion zone of the southeast margin of the Siberian plate, the middle section of the northwest side of the Derbugan fault. Regionally, the region is located in the northeast section of the NE metallogenic belt of Central Mongolia - Erguna, and the ore-forming geological conditions are similar to those of the adjacent Jiawula Silver Lead Zinc Deposit and Erentaolegai Silver Deposit. Based on the comprehensive study of the metallogenic geological background, mineralized alteration, and geo- chemical anomalous characteristics in this region, 1: 10 000 soil geochemical survey and trenching are used to verify the 1:50 000 comprehensive AS8, resulting in prospecting breakthrough, including mineralization belt and ore body find. The comprehensive analysis takes that acidic volcanic rocks are favorable spots for further prospecting of silver polymetallic deposits, and that Erge Region possesses the potential of the formation of medium - low temperature hydrothermal, vein type silver polymetallic deposits related to Mesozoic acidic volcanic rocks and late-phase dikes. [ABSTRACT FROM AUTHOR]

The Jiaodong Region has always been a hot spot for gold deposit research, but most of the research focuses on Northwest Jiaodong and Muping — Rushan metallogenic zone, while the Penglai — Qixia metallogenic zone is basically undeveloped. The Hushan Gold Deposit is located in the southern part of the Penglai — Qixia metallogenic zone and is controlled by the NE-trending Taigian — Douya fault. The main gold-bearing mineral in the Hushan Gold Deposit is pyrite. According to the structural and morphological characteristics of the pyrite, it can be divided into two stages: early metallogenic stage and late metallogenic stage. In this study, the in-situ microzone component analysis of the pyrite from different metallogenic stages of the Hushan Gold Deposit is carried out by LA — ICP — MS. The results show that the maximum value of w( Co) in pyrite is 502.57 x 10-6, and the average value is 137.56 x 10-6, which indicates that it belongs to medium-low temperature type pyrite. The w( Co) /w( Ni) in the early metallogenic stage is higher than in the late stage, indicating the temperature gradually decreased during the metallogenic process. The gold element in the Hushan Gold Deposit mainly exists in the form of visible gold, and a large number of visible gold parti-cles can be observed under the microscope. According to the element content relation diagram, all the gold contents are below the maximum solubility curve of Au, indicating that the invisible gold in the pyrite mainly exists in the form of lattice gold. The data shows that there is a positive correlation between Au and As, suggesting that the enrichment of Au is affected by As. The substitution of As for S in the unit cell of pyrite in the early metallogenic stage facilitates the enrichment of Au. In the late metallogenic stage, the ore-forming hydrothermal fluid transited from the relatively reduced state to the relatively oxidized state. The pressure decrease in the ore-forming fluids precipitated the gold in the ore-forming hydrothermal fluids, which eventually formed visible gold particles. [ABSTRACT FROM AUTHOR]

The marine-continent transitional mud shale in Upper Carboniferous Benxi Formation is a potential shale gas exploration target in the eastern Ordos Basin. Based on the systematic observation and sampling analysis of representative profiles and key well, the influencing factors and development pattern of organic-rich mud shale in Benxi Formation of Liulin-Zizhou area, the eastern Ordos Basin were studied, and the development pattern “slow subsidence, terrigenous organic matter supply, and enclosed preservation” of marine-continent transitional organic-rich mud shale was established. The results show that the organic-rich mud shale in Benxi Formation of Liulin-Zizhou area, the eastern Ordos Basin mainly belongs to Jinci and Pangou members, and the lithofacies is mainly clay mud shale with a small amount of siliceous mud shale; the abundance of organic matter is high, and the type is mainly humic; the coal-forming plants flourish in the region because of the hot and humid climate in Benxi depositional period, and result in an abundant supply of organic matter for the sedimentary water; the transgression occurs in the eastern Ordos Basin under the tectonic background of slow subsidence; the high salinity of anoxic water at the bottom maintains reduction environment in the barrier island-lagoon-neritic muddy shelf sedimentary system, which provides a favorable zone for the preservation and enrichment of sedimentary organic matter. [ABSTRACT FROM AUTHOR]

The sedimentary sequences and geochemistry characteristics of mudstone contain much geological information and are widely used in sedimentology and provenance analysis. The Upper Carboniferous Benxi Formation in Gongyi area, the western Henan is rich in lithium resources. However, the source rocks, deposition conditions, and other controlling factors of lithium resouces and the occurrence minerals are not clear. Based on the field outcrop and the characteristics of major, trace and rare earth elements, the comprehensive analysis of Upper Carboniferous Benxi Formation in the western Henan were carried out. The lithium enrichment characteristics of Benxi Formation was illustrated, the source rocks, weathering degree, sediment sorting and recycling, paleoenvironment of Benxi Formation were discussed, and then the controlling factors of lithium enrichment were analyzed. The results show that lithium is mainly concentrated in mudstone with the average content of 1487×10-6, and the content of lithium in bauxite is low; Benxi Formation is mainly composed of fine-grained sediments, and the sedimentary sequences indicate that the sediments are deposited in lagoon; B/Ga ratio indicates that the sea water is brackish during the sedimentation; Sr/Cu ratio and other parameters show that the sediments are deposited in a warm humid-dry hot climate under anoxic conditions; the different diagrams of trace and rare earth elements in Benxi Formation indicate that the source rocks are mainly felsic igneous rock, and secondary limestones and mudstones; the chemical index of alteration and weathering index of parker parameters and related diagrams show that the source rocks have undergone strong weathering and sedimentary recycling. Lithium enrichment in Benxi Formation is closely related to the content of clay minerals (such as kaolinite and chlorite). Source rocks provide materials for lithium enrichment, and sedimentary characteristics such as sedimentary recycling processes and sedimentary environment, affect the enrichment of lithium resources. [ABSTRACT FROM AUTHOR]

The occurrence and compositional diversity of granitic pluton is determined by properties of source rocks and conditions of partial melting, and can be further modified by magmatic processes such as magma mixing, crystal fractionation and assimilation during the transfer. However, the role and relative importance of each process during pluton construction are still elusive. Several representative Early Mesozoic granitic plutons in the West Qinling orogen were chosen to illustrate how the magmatic processes control the compositional variation of granitic plutons. The S-type granites in the West Qinling orogen were derived from partial melting of metapelite and can be classified into two categories based on geochemical features, i.e., high Sr content, and low Rb/Sr ratio and REE content (Group A), and low Sr content, and high Rb/Sr ratio and REE content (Group B). Groups A and B might have been produced through fluid-present and fluid-absent incongruent melting of muscovite, respectively, which can well explain respective contrasting major and trace elemental characteristics, and zircon and monazite saturation temperatures. Three types of zircon were identified in the microgranular mafic enclaves(MMEs)from Mishuling pluton based on the morphology. They have consistent zircon U-Pb age but different trace elemental and Hf isotopic compositions. Type-3 zircon develops {100} prisms and has εHf(t)similar to these of zircon in the host granite. Hence type-3 zircon is interpreted as xenocryst captured from the host granitic magma. Type-1 and type-2 zircons are characterized by {100}+{110} and {110} prisms, respectively. They have relatively higher Th/U ratio and εHf(t)values than type-1 zircon, and may have crystallized from hybridized magmas with varying degrees of the mixing. The mafic endmember of the hybridized magma likely has mantle-derived affinity. Thus, the MMEs in Mishuling pluton record crust-mantle interaction. Zhongchuan pluton is comprised of five rock units from the periphery to the center, which mostly have indistinguishable zircon U-Pb ages. The peripheric porphyritic granodiorite is intruded by phenocryst-bearing (K-feldspar and quartz) medium-grained biotite monzogranite; medium-grained biotite monzogranite is crosscut by medium-grained two-mica tourmaline granite, which is inversely invaded by fine-grained biotite monzogranite in the center. Moreover, the correlations between contents of Rb and Ba, and contents of Rb and Sr for these rock units are not observed. Therefore, Zhongchuan pluton might have been formed by incremental assembly of at least five magma batches. [ABSTRACT FROM AUTHOR]

The Dabalang pluton, located in Huanan uplift area of the central Jiamusi block, is lithologically medium-to-fine-grained biotite granodiorites, which intrude into Late Permian muscovite monzogranites. LA-ICP-MS zircon U-Pb age is (234±1) Ma, the biotite granodiorites are in early Late Triassic. The Dabalang pluton has high SiO2 content (62.04%-64.30%), Al2O3 content (15.68%-16.95%), Sr/Y ratio (23.38-36.15) and (La/Yb) N ratio (18.57-33.04), containing low MgO content (0.91%-1.20%), moderate Mg# value(34.03-37.27), as well as low Yb content((1.18-1.52)×10-6 with an average of 1.30×10-6)and Y content((15.43-20.50)×10-6 with an average of 16.94×10-6), Na2O/K2O is 0.77-1.06 with an average of 0.94. The above geochemical characteristics are similar to the C-type adakites. Considering the active continental margin arc setting of Permian in the eastern margin of Jiamusi block and the distribution characteristics of Late Triassic peripheral accretionary complexes, it is found that the Dabalang pluton may be a product of partial melting of crust below Jiamusi block, which is continuously shortened and thickened due to the subduction of Paleo-Pacific plate towards the lower part of Jiamusi block in Late Triassic. [ABSTRACT FROM AUTHOR]

In order to understand the tectono-magma events in the southern margin of Altun in Early Neoproterozoic, the Yaganbuyang granitic gneiss in Mantelike area was selected for detailed studies of petrology, isotope chronology and petrochemistry. The results show that Yaganbuyang granitic gneiss is formed in Neoproterozoic Qingbaikou period, and the zircon U-Pb age is(880.3±3.4) Ma; the rock with obvious fractional distillation of LREE and HREE and the loss of HFSEs such as Nb,Ta,Zr and Hf, is magnesian granite in the peraluminous and calc-alkaline series, and has the characteristics of crustal remelting granite, which originates from the partial melting of base rock in the amphibolite facies of the lower crust and forms in the syn-collisional granite zone. It is suggested that the tectono-magma events in the southern margin of Altun has the possiblity of matching to the assemblage events of Rodinia supercontinent in Neoproterozoic, indicating that assemblage collision occurs between Tarim and Qaidam plates at the early time. [ABSTRACT FROM AUTHOR]

The Liujiang Basin records a wide range of important geological events and phenomena from the Archaeozoic to the Cenozoic in the North China Plateau and even the Globe, including crustal movements, magmatic activity, sedimentary environments, climatic evolution and biological evolution and development, making it an excellent choice for the study of palaeoenvironmental recovery in different periods. Based on the fieldwork of the Upper Cambrian Mountains Formation in Liujiang Basin of Qinhuangdao and the determination of full elements of rocks in different layers, the abundance of each element enrichment is analyzed. Using the index system of trace element geochemical indicators, paleosalinity, paleoclimate and redox environment are studied. The analysis shows that the values of Sr/ Ba and Th / U indicate that the study area is a freshwater-semisaline environment, and the salinity decreases from bottom to top. Sr/ Cu and Rb / Sr data indicate that the study area is a warm and humid climate. δU, U/ Th, V/ Cr, Ni / Co and Ce / Ce ∗ values indicate that the study area is an oxidizing environment. [ABSTRACT FROM AUTHOR]

Matigou-Wangjiatai area is located on the Pb-Zn-Ag-Au-Hg-Cu metallogenic belt, South Qinling. Based on the 1 ∶25 000 stream sediment survey, element variation coefficient, relevance analysis, and cluster analysis methods are used, delineating 7 Au-Ag-As-Sb element composite anomalies, 7 Cu-Pb-Zn element composite anomalies, and 3 prospecting targets. Verified by engineering practices, mineralized altered belts and ore bodies are discovered and delineated, indicating good prospecting potential in the area. [ABSTRACT FROM AUTHOR]

The tectonic setting of Jiangda-Weixi magmatic belt is still controversy. Two different interpretations include the eastward subduction of Longmucuo-Shuanghu-Changning-Menglian Paleo-Tethys main ocean basin, and the westward subduction and subsequent collision of Jinshajiang Paleo-Tethys main ocean basin. These controversies concern different models for tectonic evolution of Paleo-Tethys. A new set of intrusive complex has been discovered in Pantiange area, the southern part of Jiangda-Weixi magmatic belt. The main components include dioritic, granodioritic and granitic rocks, which have been mylonitized. The zircons from granitic rocks have U-Pb mean age of (243.0±4.8) Ma. The age is considered as crystallization age of granitic rocks. Dioritic rocks have high contents of Na2O and Al2O3, and moderate content of K2O, suggesting they belong to metaluminous and calc-alkaline series. Granodioritic rocks has high contents of K2O and Al2O3, but low content of Na2O, suggesting they belong to peraluminous and shoshonite, high potassium calc-alkaline series. Granitic rocks have moderate content of Na2O and low content of K2O, and belong to metaluminous-peraluminous and low-potassium series. All three types of rocks are enriched in LILEs (such as Rb, Th, U), depleted in HFSEs (such as Nb, Ta, P, Ti) and LILEs (such as Ba, Sr), with high values of LREE/HREE ratio. The dioritic rocks have no obvious Eu anomaly, whereas granodioritic and granitic rocks show weak negative Eu anomaly. The granitic rocks have zircon εHf(t) values of-11.92--8.54, whole rocks initial 87Sr/86Sr ratio of 0.717 229-0.725 994, and εNd(t) values of-14.2--7.8. These characteristics show that dioritic magmatism is formed by partial melting of Paleoproterozoic basaltic lower crust; granodioritic magmatism is formed by partial melting of metamorphic mudstones of Paleoproterozoic upper crust with the addition of mantle material; granitic magmatism originates from partial melting of metamorphic graywacke in Paleoproterozoic upper crust, and then underground crystallization fractionation with the addition of mantle material. Combined with regional tectonic setting and petrogeochemical characteristics, it is proposed that Jiangda-Weixi magmatic belt is formed by the eastwards subduction of Paleo-Tethys. [ABSTRACT FROM AUTHOR]

The Carboniferous Yanghugou Formation in the western margin of the Ordos Basin is found to have good source rocks with high organic matter content and good prospects for exploitation. The original stratigraphic division is controversial, and it is difficult to meet the growing demand for exploration. Taking the Xiaheyan section in Beishan area of Weining as an example, through field measurement, geochemical element detection, paleontological detection, the Yanghugou Formation was finely divided to determine the stratigraphic division marker bed in the southern section of the western margin of the basin. The boundary between the Yanghugou Formation and the Taiyuan Formation was redefined, and the boundary between the Carboniferous and the Permian was taken as the boundary between the Yanghugou Formation and Taiyuanzu. According to the sporopollen distribution characteristics, the Yanghugou Formation was divided into three sporopollen belts from bottom to top:Lycospora noctuina-Cyclogranisporites aureus combination,Dictyotriletes bireticulatus-Ahrensisporites guerickei-Torispora securis combination,Crassispora kosankei-Densosporites anulatus combination. The geochemical characteristics show that the Mn/ Fe value increases and the - δ13 C value decreases during the Yanghugou Formation period, and the sea level rose during this period. In the Taiyuan Formation, the Mn/ Fe value decreases and the - δ13 C value increases, and the sea level decreases during this period. Based on this, the Yanghugou Formation was divided into three segments: Yang 3, Yang 2 and Yang 1 from bottom to top. Through the combination of geochemical characteristics and sedimentary characteristics, the division of third-order cycles was determined to further verify the lithospheric division. . By establishing regional stratigraphic comparison sections, the depositional characteristics of large stratigraphic thickness in the western part of the work area and small in the eastern part were demonstrated, and there were obvious differences in the distribution and development of the stratigraphy of the Yanghugou Formation and each small layer within its group in different areas. [ABSTRACT FROM AUTHOR]

The Yinan area is located in the southeastern margin of North China Craton. There are lots of Late Mesozoic magmatic rocks in the area, which is an important case to study the North China Craton destruction and the intense crust-mantle interaction. Petrography, zircon U-Pb dating, geochemical and Sr-Nd-Pb-Hf isotope characteristics of the typical intrusive rocks in the area were carried out. The zircon U-Pb ages of quartz diorite and monzonite granite porphyry are（130.4±0.7）Ma and（129.5±0.6）Ma, respectively, indicating that the rocks form in Early Cretaceous. Geochemical characteristics show that the dioritic rocks are Na-rich but K-poor, belonging to cal-alkaline metaluminous series. The dioritic rocks are geochemically similar to high magnesian andesite/diorite and adakites. The rocks are enriched in LILEs and depleted in HFSEs. The chondrite-normalized REE patterns are right-inclined, LREE is steeper and HREE is gentler, there is no negative or weak Eu positive anomalies. The monzonitic granite porphyries are peraluminous and show high contents of Si and alkalis, low abundances of TFe2O3, MgO and CaO. The rocks are evidently depleted in Eu, belonging to highly differentiated I-type granite. Isotopic geochemical characteristics show that the εHf（t） values of the monzonitic granite porphyries are obviously lower than those of dioritic rocks. The dioritic rocks are more enriched in Pb isotopes than the monzonitic granite porphyries. Combined with the regional geological data, it is considered that Early Cretaceous intrusion in the area likely forms in the extensional background of the rotation of paleo-Pacific plate. The upwelling of the asthenosphere promotes partial melting of the overlying EM1+EM2 enriched mantles. The basaltic magma intrudes into the lower crust and mixes with the felsic magma in varying degrees in the lower crust to form dioritic magma. Felsic magma absorbs a small amount of mantle-derived basic magma, and experiences strong differentiation and evolution to form the monzonitic granite porphyries. [ABSTRACT FROM AUTHOR]

The Lower Devonian Lianhuashan Formation is unconformly unlained by Cambrian strata due to Early Paleozoic Yunan orogeny and Kwangsian orogeny in Dayaoshan area of Guangxi. The new petrology and whole-rock geochemical data of Lower Devonian Lianhuashan Formation in Dayaoshan area were presented in order to constrain their provenance and sedimentary tectonic setting. The sandstones are composed of the predominated moderately sorted and rounded quartz and sedimentary lithic fragments, indicating a close detrital provenance. These samples have obviously high SiO2 contents ( 7 4. 19 % - 95. 35 % with an average of 85. 72%), low Al2 O3 contents 0. 23%-14. 73% with an average of 6. 48%), TiO2 contents (0. 09% -1. 05% with an average of 0. 38%) and Al2 O3 /SiO2 (0. 01- 0. 20). The sandstones have low REE contents ( (12. 48- 281. 10) X 10- 6 ) and are characterized by depletion in LILE, enrichments in HFSE and LREE ((La/ Yb)N is 3. 70- 29. 40) coupled with slightly negnative Eu anomaly (0. 66-1. 14 with an average of 0. 88). The high SiO2 /AlzO3 (5. 04-77. 28 with an average of 22. 30) implies the high grade of maturity. The wide ranges of ICV (0. 61- 2. 13 with an average of 1. 21) and high CIA ( 82. 13 - 91. 68) indicate that the source rocks contain recycled ancient sediments and first-cycle materials, which have experienced high degree of chemical weathering and alteration in the heat and humid climate environment of tropical or subtropical zone. Integrated with geochemistry, elastic zircon U-Pb geochronology, paleogeography and tectonic evolution, it is suggested that Lower Devonian Lianhuashan Formation is deposited in passive margin, and its provenance may be Dayaoshan-Damingshan area in the north, and Yunkai area in the south. The source rocks of Lower Devonian Lianhuashan Formation mainly comprise Cambrian Huangdongkou Formation, and minor Neoproterozoic sedimentary rocks of Cathaysia block and the granitoids formed in Kwangsian orogeny (470-435 Ma). [ABSTRACT FROM AUTHOR]

By analyzing the cycling mechanism of nitrogen and the conversion pathway between different forms, new ideas and inspirations are provided for the research of new technologies of nitrogen removaL Nitrogen forms are diverse, and the conversion between them is complex and its cycle path profoundly affects the evolution of geochemistry. Due to the continuous advancement of human production activities and the continuous exploitation and utilization of natural resources, nitrogen accumulates in the environment in a certain form and causes environmental pollution. Natural river water is the acceptor of sewage discharge, and excessive nitrogen enrichment is one of the important factors of water pollution. The research on wastewater denitrification technology has always been the focus of attention, and the characteristics and current research progress of wastewater denitrification technology are highlighted. [ABSTRACT FROM AUTHOR]

[Objective]The purpose of this stndy was to identify the distribution characteristics of nutrient elements in the soil of Yuanmou county, to grasp the nutrient problem of the soil in this area, to come up with reasonable suggestions for land use and improvement, to improve the technical level of land management and design in the area, to use the land scientifically and promote the healthy development of the agricultural economy. [ Method] A total of 2368 topsoil samples were collected at a density of 1. 2 s amples/km² throughout Yuanmou county, using the method combining traditional geochemistry, geology, and ecology, which were combined into 513 analysis samples, and 510 components were remained after screening and processing. The characteristic parameters of the data were analyzed using Excel, SPSS, etc., and the mathematical models of abnormal el ements were established. Finally, with reference to the rel evant specifications, GeolPAS and ArcGIS were used to create the maps and integrate the results. [Result] The distribution of organic carbon (Corg), nitrogen (N), phosphorus (P), potassium oxide (K2 0), magnesium oxide (MgO), manganese (Mn), molybdenum (Mo), zinc (Zn), total iron (TFe2O3), copper (Cu), and boron (B) in the topsoil of Yuanmou county was balanced. Among them, the main element Corg and N content were low overall, and their correlation coefficient was significantly positive (R² ~ 0 . 66). The balance of sulfur (S) and cal cium oxide (CaO) was lower than other el ements, which showed abnormalities, and there were no abnormalities in trace el ements. The results of comprehensive grade evaluation of nutrient elements showed that the rich area were mainly distributed in the northwest of Jiangyi town, the line of Wumao villageJiangbian town-Huangguayuan town-Pingtian towns, Laocheng town and the southeast of Y angjie town, which was consistent with the distribution of the main agricultural areas in Yuanmou county. [ Conclusion] There were two causes of the low contents of Corg and N were mainly two: (i) the sandy content of the soil was generally high, and its ability of water and fertilizer conservation was not strong; (ii) The biological carbon and N fixation capacity was weak in most of the areas with low vegetation shade, except for the concentrated area of cultivated land. The CaO ratio of cultivated land in the study area was relatively high, and the CaO content in the soil was low in equilibrium affected by human, which did not caused soil pollution and soil deterioration. The high level of S deficiency was related to the lack of organic sulfur in the soil due to the fragile ecosystem in the dry hot valley. [ABSTRACT FROM AUTHOR]

Earlier Cambrian banded iron construction (BIF) type iron ore is the most important source of iron in China, accounting for more than 60% of the country's iron reserves, of which the BiF type iron ore in the late Neo-Archean period in North China is the most typical. Detailed petrology, geochemistry and isotopic studies were carried out on the Bif and surrounding rocks of the Xiaolai River in the Qingyuan region of Liaoning Province, northeast of Craton, North China, aiming to provide constraints on the source area and tectonic environment. Xiaolaihe BIF is mainly composed of magnetite, quartz and silicates (such as iron perilla pyroxene, etc.), and the SiO and all-iron (FeO) content of the samples varies widely. The AlO content (mass fraction, the same below) in a small number of Xiaolai River BIF samples was higher (>1%), indicating the presence of an input of land-based clastic material during the sedimentation process. The BIF samples, which were not contaminated with clastic substances, showed typical seawater characteristics, including low alO, high field strength elements and transition metal elements, relative loss of light rare earth elements, and enrichment of heavy rare earth elements and Eu positive anomalies. The simulation results showed that the sample matched the PAAS standardized rare earth element dispensing pattern of the seabed high temperature hydrothermal and seawater 1:100 mixed solution, indicating that the hydrothermal activity on the seabed provided heat and substances to the BIF. The mineralization of the Bif of the Xiaolai River comes from the base-super-bedrock rock at the bottom of the Qingyuan greenstone belt leached with high temperature hydrothermal fluid. The surrounding rocks of the Xiaolai River BIF are mainly metamorphic volcanic rocks of the Stone Shed Subgroup and a small amount of metamorphic clastic sedimentary rocks. The geochemical characteristics of clastic sedimentary rocks are controlled by the composition of complex source regions with medium-low degree of weathering under the island arc system (such as Aochang granite, Yingyun diorite and a small amount of bedrock), which is similar to the source area of the Xiaolai River BIF. Based on the geological, geochemical, isotopic, chronological and other characteristics of the deposit, it is believed that the Xiaolai River BIF system was formed in the Post-Arc Basin of the Algoma-type BIF [ABSTRACT FROM AUTHOR]

Carbonate rocks, as one of the magmatic rocks with little but significant geological significance in nature, are generally considered to be mantle-derived causes, and shell-derived causes are rarely reported. The exposed dioprosene carbonate in the Annamba area of the southeast edge of the Tarim Basin is irregular and vein-like intrusive into the surrounding rock, and the surrounding rock trapper body can be seen inside the rock, and has a dense block structure and fine grain structure, indicating that it is an igneous carbonate rather than a sedimentary carbonate rock. The geochemical characteristics of rocks show that the carbonate-rich CaO (content (mass fraction, the same below) is 24.63%-33.20%), SiO (33.11%-40.07%), poor MgO (2.25%-3.21%), FeO (1.38%-2.03%), the total rare earth element content ((45.44-91.47) ×10) and the total light rare earth element content ((42.83-86.06)×10) are significantly lower, and the relative enrichment Rb is significantly lower Large ionic lithophilic elements such as Ba, Th, Sr, etc., with losses of Nb, Ta, Zr, Hf and other high field strength elements, are obviously different from mantle-derived carbonate rocks, and similar to shell-derived carbonate rocks. Zircon in the dioprose carbonate develops oscillating ring band structure, with obvious Ce positive anomaly, weak Eu negative anomaly and low Th/U value (average value 0.24), indicating that it is metamorphic deep molten zircon. The study of the U-Pb-Lu-Hf isotope of zircon zircon showed that the age of the zircon Hf isotope pattern had an age peak of about 2.59 Ga, and the age of lithogenesis was (1 910±13) Ma, which was consistent with the formation era of the Milan rock group and the era of hemp grain phase metamorphism, respectively. Combined with the comprehensive analysis of the previous research results, it is believed that the dipyrene carbonate in the Annamba area may be the product of the deep melting action of the Diopline Dali rock of the Milan rock group under the condition of hemp granular phase metamorphism, which is the response of the Columbia supercontinent aggregation event in the southeast edge of the Tarim Basin [ABSTRACT FROM AUTHOR]

The Central Orogenic Belt of New Guinea is the youngest orogenic belt in the world and the most important porphyry-type copper-gold mineralization belt in the world. A set of high-magnesium diorite mass developments has been found in the Nabire region of Indonesia, located in the central-northwestern part of the Central Orogenic Belt of New Guinea, providing a good record for detailed study of magmatic processes and mineralization environments associated with ocean subduction. Through field observations and studies of petrology and geochemical characteristics, it was found that the high magnesium diorite was dominated by fine-grained hornblende and plagiobolite, and no olivine traps or trap crystals were found; Rocks have high MgO content (mass fraction, the same below) (4.51%~10.88%), Yb content ((1.16~2.69)×10) and Y content ((11.68~25.09)×10), high Mg value (50.07~72.50), enrichment of large ionite elements, loss of high field strength elements, relatively low Sr/Y and La/Yb values; Combined with the more consistent Nb/La, U/Nb, Th/La and U/Th values, it is suggested that it may have evolved from the interaction of subduction sediment melt with the overlying mantle peridotite and undergoing separation crystallization, which is accompanied by the release of a large number of HO and fluids, increasing oxygen escape; The formation environment of high magnesium andes/diorites is similar to that of porphyry copper-gold deposits, and has a close affinity with porphyry copper-gold deposits, which is a prospecting marker for large porphyry deposits, while the high-magnesium diorites in the Nabire area have been found to have the development of copper-gold mineralization, indicating that the area has the potential to find large copper-gold deposits [ABSTRACT FROM AUTHOR]

The southern structure of the Yining Plot brings out a large area of Late Devonian-Early Carboniferous magmatic rocks, and its formation is closely related to the evolution of the Southern Tianshan Ocean, and there are still disputes in terms of rock genesis and production environment. In the area of the Coksu Forest Farm in the southern tectonic belt of the Yining Plot, high-magnesium andesite rocks endowed in the volcanic rocks of the Lower Carboniferous Great halajunshan Formation were newly discovered, and detailed field geological surveys and indoor analysis work were carried out, and the tectonic background of the period was explored. The results show that the rock types of the Great Hara Junshan Formation in the area are mainly Andesan rocks, containing a small amount of basalt and volcaniclastic rocks. The andesan samples had high MgO, TiO, AlO content, low PO content, and Bitman index, showing the characteristics of medium-high potassium calcium alkaline series rocks, combined with their high Sr, Y content and low Ni and Co content, and low Sr/Y, La/Yb values, showing the geochemical characteristics of Sanqi high magnesium andesite rocks; The total content of rare earth elements in the samples varied widely, with high (La/Yb), (La/Sm) and (Gd/Yb) values, showing significant enrichment of light rare earth elements; The samples enriched large ionic lithophilic elements such as K, Ba, Th, U, and Pb, and the relative loss of high field strength elements such as Nb, Ta, Ti, and P, and negative Eu anomalies. Combined with regional data, it is believed that these Zamgi high magnesium andes rocks originate from the equilibrium reaction of mantle wedges and subduction zone materials, and are the products of the late Devonian-Early Carboniferous Southern Tianshan Ocean subducting northward under the southern tectonic belt of the Yining Massif. The discovery of high-magnesium andesites not only enriches the rock types in the area, but also provides an important reference for solving the problem of regional tectonic evolution [ABSTRACT FROM AUTHOR]

Zhihe Copper Mine is located in the Lenglongling volcanic rock belt in the middle section of the North Qilian Tectonic Belt, and the copper mineralization is mainly endowed with basal volcanic rock (fine turquoise), accompanied by jet rock (jasper rock), and the ore type is mainly block copper ore, which belongs to the Cyprus type block sulphide deposit. LA-ICP-MS zircon U-Pb was given a fine bluestone age of (457.1±2.8) Ma at the fixed year, indicating that the diagenetic age was late Ordovician. Fine turquoise TiO2The content (mass fraction, the same below) is 1.12% to 1.37%, between the island arc porphyry basalt and the ocean ridge basalt, strongly enriched with large ionic lithic elements, loss of Nb, Ta and other high field strength elements, similar to the island arc volcanic rock characteristics, while the rare earth element distribution pattern is flat light rare earth element loss characteristics, similar to the ridge basalt (N-MORB), its geochemical characteristics are between the island arc and the ridge basalt, indicating that its output is in the post-arc basin environment. The Ore-bearing volcanic rocks of the Zhihe Copper Mine are more natrified (Na2The O content is greater than 4%), indicating that the water-rock exchange reaction is strong, and the circulating convective hydrothermal system can be leached from the submarine volcanic rock to dissolve more metal into minerals, showing good mineralization potential. The Zhihe Cyprus type copper mine, together with the Yincan Black Ore type copper zinc lead mine, the Langlik sub-volcanic type copper mine, and the Maozang temple porphyry type copper molybdenum ore, which are also located in the Lenglongling volcanic rock belt, constitute the Ordovician arc-basin mineralization system [ABSTRACT FROM AUTHOR]

Pingxiang area located in the eastern part of the Dian-Qiong suture zone, is important to address the history of closure of the Paleo-Tethys Ocean. The petrology, geochemistry, chronology, Nd and zircon Hf isotopic analysis of the Pingxiang Fuboshan granite are studied. LA-ICP-MS zircon U-Pb dating shows that the 206Pb / 238U weighted average age of zircon from the Pingxiang Fuboshan granite is 244. 7 ± 0. 9 Ma (MSWD = 0. 45), indicating that it belongs to the early Middle Triassic granite. The Pingxiang granits have high SiO2 content(73. 88% -75. 88%), medium Al2O3 content (11.61% -12.03%) and medium alkalinity (Na2O+K2O = 6. 89%-7. 25%) with A/ CNK ratios (1.08-1.39), belonging to peraluminous A2-type granite. The granites, belonging to a typical high-K calc-alkaline series, are characterized by relative enrichment in LILEs ( e. g., Rb, Th) and pronounced depletion HFSEs (e. g., Nb, Ta and Ti), with low εNd(t) ( -10. 9--10. 2). Such signatures display geochemical characteristics of typical subduction-related arc magmatic rock. The εHf(t) values(-12. 9--7. 2) have crustal characteristics, indicating that the magma source area is crustal material. The A2-type alkali-feldspar granites in Pingxiang area may have been formed by decompression and ancient felicitic crustal materials melting by local extension of South China plate under subduction tectonic background, which provides new evidence for the tectonic-magmatic evolution of South China plate in the early Middle Triassic. [ABSTRACT FROM AUTHOR]

The discriminant indexes, petrogenesis and tectonic significance of unfractionated A-type granites have been widely recognized, while there has not been a universal consensus on the discriminant criterion of highly fractionated A-type granites. LA-ICP-MS zircon U-Pb dating shows that Dajin granites form at Early Paleozoic(～440 Ma), and have high Rb contents(>400×10-6), Rb/Sr and Rb/Ba values, and relatively low Zr/Hf values, illustrating that they are highly fractionated. According to the high zircon saturation temperature(819 ℃-863 ℃), and high Ga/Al(2.6-3.1), Zr+Nb+Ce+Y contents and the evolution trend of specific geochemical indexes, Dajin granites are comprehensively determined as highly fractionated A-type granites. Combining with geochemical and Nd-Hf isotopic compositions, it is suggested that Dajin granites are mostly likely generated by partial melting of the mafic lower crustal rocks, and experienced high degree fractional crystallization and contamination of a samall amount of the wall rock materials. As consequence to post-orogenic lithospheric delamination, the forming time of Dajin A-type granites represent the timing of geodynamic transition of Kwangsian orogeny from orogenic compression to post-orogenic extension in the northeastern Guangxi. [ABSTRACT FROM AUTHOR]

Based on the regional geochemical results obtained from the multi-purpose regional geochemical survey project in the offshore marine areas of Shanghai in 2007, according to the basic concepts and requirements of element geochemical reference values, the geochemical baseline of sediments of the whole region, different sediment types and different sedimentary units are calculated respectively, and compared with the geochemical baselines of shallow sea sediments in China, the China soil geochemical baselines, the geochemical baselines of soil of the Yangtze river basin and the Yangtze river delta. The establishment of geochemical baseline of sediments in the Yangtze Estuary and offshore marine areas provides an important geochemical basis for the comparison of sediment environment in large estuaries, the formulation of regional sediment environmental quality standards, and the evaluation of coastal environmental pollution. [ABSTRACT FROM AUTHOR]

T he petrogenesis and geodynamic mechanism of Late Cretaceous magmatic rocks in southern Lhasa terrane, Tibet, are still controversial. T he hornblende gabbros and quartz diorites in the west of Chabala area, Qushui county of southern Lhasa terrane were selected as the research object, and based on field geological surveys, the petrography, geochemistry and Ll\- ICP-MS zircon U-Pb geochronology were analyzed to identify the formation ages and petrogenesis of hornblende gabbros and quartz diorites, and further constrain the tectonic evolution of southern Lhasa terrane during Late Cretaceous. T he results show that the hornblende gabbros emplace at 91-87 Ma, and the quartz diorites emplace at 81 Ma. T he hornblende gabbros have low contents of SiO2 (48. 16% - 51. 05%), high contents of MgO (4. 54%- 11. 13 %), Co ((31. 2-46. 8) X 10-6 ) and Ni ((1. 79-82. 70) X 10-6 ), and ( 87 Sr/86 Sr); value is 0. 703 925- 0. 704 380, €Nd (t) value is 2. 50 - 3.96, indicating that the hornblende gab bros are generated by partial melting of a depleted mantle wedge that have been metasomatized by slab-derived fluid, and suffer from no obvious crustal contamination. T he quartz diorites are generally high Si02 ( 62.45 % - 62.90 %), AI2O3 05.94 % -16.22%), K2O+Na2O (6.36%-6.46%) and Mg# value (43. 77 - 44. 65 ), thus can be grouped into quasi aluminous I-type granite. T he quartz diorites are generated by partial melting of the lower crust and mix with a little mantle-derived magma. Both rocks show the characteristics of arc magma with enrichment of LREEs and LILEs (such as Rb, Th, U and Sr), and depletion of HREEs and HFSEs (such as Nb, Ta and Ti). Integrating regional data, the "flare-up" event in southern Lhasa terrane during the early Late Cretaceous Cl 00-80 Ma) is likely the result of the northwards subduction of an oceanic ridge of Neo-Tethys. T he ridge subduction would have resulted asthenosphere material upwelling through a slab window and decompression melting to form a basic magma, which provides heat to cause partial melting of the mantle wedge and lower crustal rocks, resulting in the magma eruption during the early Late Cretaceous of southern Lhasa terrane. [ABSTRACT FROM AUTHOR]

Phosphorus is an essential nutrient element for all living things in the wetland ecosystem, the growth and development of plants are mostly related to phosphorus. The critical zone of wetland is a complex open system and an important place for material exchange and energy transmission. There are multiple subsystems such as nitrogen, carbon and phosphorus cycles, which constantly interact and influence each other. Phosphorus has the function of source and sink in the critical zone of wetland, and it is constantly undergoing complex physical, chemical and biological effects. The process includes organophosphorus mineralization, soil phosphorus adsorption and desorption, biological assimilation, and so on. Based on the basic characteristics of the biogeochemical cycle of phosphorus in the critical zone of wetland, the existence form of phosphorus in the critical zone of wetland was analyzed, the effective process of soil phosphorus, the migration and transformation of phosphorus between sediments and water bodies, and phosphorus transport process of organisms in critical zone of wetland were explained. On the basis of the microbial-mediated process, the synergistic mechanism and quantitative relationship between phosphorus and nitrogen, carbon cycles were discussed separately, and the linkage and coupling mode between phosphorus and nitrogen, carbon cycles were analyzed in depth, and future research directions were proposed. The focus of attention should be to strengthen the discussion of the biogeochemical mechanism of phosphorus on the time and space scales from testing means, research methods to theoretical analysis, and incorporate phosphorus cycle into the global ecosystem model from qualitative description to quantitative evaluation, and build a hydrological- biological-geochemical theoretical system of phosphorus, nitrogen and carbon cycles so as to better strengthen protection of wetland ecological environment and water resources, as well as pollution prevention and control. [ABSTRACT FROM AUTHOR]

Large-scale granitoid bodies including alkali-feldspathic granites, and few quartz diorite and diorite granites, are distributed in Kalamaili area, the northeastern margin of Junggar Basin. Zircon U-Pb chronology, Hf isotope and petrological geochemistry were carried out on these granitic bodies. Isotope data and geochemical features indicate that the granites have Late Carboniferous emplacement age and belong to quasi-aluminous to peraluminous high-K calcalkaline series with the characteristics of high Si, alkali-rich, K-rich, and Al-rich. The alkalifeldspathic granite is A-type, while the quartz diorite and diorite granite are I-type. The Late Carboniferous granite bodies in Kalamaili should be under the tectonic setting which transforms from compression to extension. Provenance analysis indicates that the uranium source of sandstone-type uranium deposit is derived from granodiorite bodies in Kalamaili area. The average U content of these granodiorite exceeds 3 X 10-6 with the mean Th/ U value of 7.18, showing the characteristic of U-rich geological body. T he transported uranium amount (Δ U) can be as high as 8. 26 X10 -6 and the average paleo U content (Uo ) is 5. 46 X 10-6. K2 O/Na2O and FeO/ MgO values show high continental crustal maturity, indicating that this region has a high potential for uranium mineralization. [ABSTRACT FROM AUTHOR]

Nowadays, more than 160 granitic plutons have been confirmed to form in Caledonian ( including Ordovician, Silurian, and Devonian), since Longhui and Shangyou plutons in Jiangxi were firstly found in the 1950s. Among them, only 14 plutons are genetically related to the polymetallic mineralizations (major W with minor Mo, Cu, Sn, and Au), and 11 plutons are related to the REE mineralizations. Previous studies on Caledonian granites were mainly concentrated on the characteristics of petrology, geochemistry, and tectonic dynamics, but hardly on the mineralization. Based on 800 mineralization and crystallization ages, the data of wholerock elements of 1 248 samples, the whole-rock Sr-Nd isotopes of 428 samples, and the zircon Lu-Hf isotopes of 2 352 analytical spots, which were collected from 280 papers and theses, four main conclusions about metallogenic characteristics of Caledonian granites were summarized as follows: CD 440- 420 Ma is the peak of magmatic activity and metal mineralization; @ Metallogenic granites are mainly focused in Dayaoshan and north-northeast areas of Guangxi, and their source materials and differentiation degrees are all different with each other; @ REE forming granites are primarily concentrated in Wuyi and Nanling areas, and most of the former experienced the metamorphism, but the latter did not; © Compared with Ordovician and Devonian granites, Silurian granites have the largest distribution area, the broadest lithologies, and the complicated source materials. [ABSTRACT FROM AUTHOR]

Gejiu area in Yunnan is located at a faulted depression basin in the southwestern of Youjiang continental margin rift basin, which is the transitional zone between Yangtze platform and South China Caledonian geosyncline, and the tectonic location is in the southwestern South China. The geology, geochemistry of Late Ladinian-Norian meta-basalt in Tabai area of Gejiu, Yunnan indicate that these basalts have undergone strong metamorphism because of regional dynamic tectonics. The meta-basalts are characterized by low contents of silica, calcium, magnesium, and enrichment of incompatible elements(Ti, P, K, etc.). They can be classified as high-Ti alkaline basalts. The trace elements are characterized by extremely low contents of Rb and Ba, severely depletion in Sr and enrichment in Ta, Ti, Zr, Hf, Th, which is similar to the weak crustal contamination of the Emeishan high-Ti basalt. The chondrite-normalized REE pattern shows LREE enrichment and weak positive Eu anomaly. The Sr-Nd isotopes suggest that meta-basalts in Tabai area of Gejiu are mainly from the primitive mantle and fall in the oceanic island basalts(OIB), which are of the same origin as Emeishan high-Ti basalts. Emeishan mantle plume activity has ended in Late Permian. Therefore, the stretching of Yangtze massif in Triassic and the subduction of Simao massif to Yangtze massif induce Emeishan mantle plume stigma to a low degree of partial melting. Because the influence of mantle plume activity lasts for a long time, the energy of mantle plume activity is low in some areas, the basaltic magma does not erupt to the surface and forms magma chamber. Meta-basalts in Tabai area of Gejiu are formed in the relatively weak stage of the center of mantle plume magma activity, especially in the edge zone of mantle plume activity center, the relatively thick lithosphere, and low melting degree. The magma chamber activity in Late Triassic re-erupts and forms basalt. [ABSTRACT FROM AUTHOR]

Based on geological survey of volcanic rock in Manketouebo Formation of Huyuan area, the main ridge of the northern part of the Great Xing'an Mountains, zircon LA-ICP-MS U-Pb geochronology and petrogeochemical studies were used to determine the age of its formation and reveal its geological structure background. The lower part of Manketouebo Formation is mainly composed of dacite breccia tuff and dacite tuff, and the upper part is of dacite and rhyolite. The zircon dating results show that the age of the Manketouebo Formation is 150-159 Ma, and belongs to the Late Jurassic. The rock geochemistry results show that the mass fraction of SiO2 is 69. 59%-80. 54%, the mass fraction of Al2O3 is 10. 32% -14. 93%, the total alkali Na2O+K2O is 7. 29%-9. 89%, and the rock belongs to the high potassium calcium-alkaline series. A/ CNK is 1. 02-1. 53, and A/ NK is 1. 05~1. 56. It belongs to peraluminous rock and shows the characteristics of crust source. The total amounts of rare earth in the rocks are 127. 22×10-6-191. 26×10-6. The light and heavy rare earth fractionation is obvious((La / Yb) N = 11. 57-16. 53). δEu = 0. 27-0. 50. The trace elements are depleted of Nb, Ta, Sr, etc. The enrichment of Rb, U, Th large ion lithophile elements, etc. indicates that the original magma of the Manketouebo Formation volcanic rock is a partial melting product of crustal rocks, which may be formed in the lithospheric extension and collapse tectonic environment after the Mongolia-Okhotsk collision closed. [ABSTRACT FROM AUTHOR]

The Bikou micro-block in the northwestern margin of Yangtze plate develops more Neoproterozoic basic and intermediate-acid intrusions. The petrology, geochemistry, zircon U-Pb dating and Hf isotope of Neoproterozoic Erliba granodiorites in Mianxian-Lueyang-Ningqiang area of Bikou micro-block were systematic studied. The results show that Erliba granodiorites are mainly in Early Neoproterozoic with 206 Pb/238 U weighted mean ages of (821. 3 ± 5. 5) Ma and (822. 6 ± 5. 8) Ma; Erliba granodiorites belong to metaluminous to weak peraluminous and calcalkaline series, and are enriched in LREEs and LILEs, depleted in HFSEs ( e. g. Ti, Nb, and Ta), indicating I-type granite affinity; the total contents of REE are (81. 5-147. 3) X 10- 6, and the chondrite-normalized REE pattern shows right-sloping type with weak positive Eu anomalies (0. 92-1. 26); the values of zircon cm(t) range from -14. 06 to -7. 38 with the corresponding two-stage Hf model age of 2. 25 - 1. 90 Ga. The above features indicate that the source rocks probably derive from the ancient crust. Combined with regional geological data, it is suggested that Er lib a granodiorites are formed by partial melting of meta basic rocks in the lower crust, and the products under Neoproterozoic continental arc environment related to subduction. [ABSTRACT FROM AUTHOR]

In order to unde rstand the diagenetic sequence, petrogenesis and prospe cting prospect of Tangshe complex pluton in the northeastern margin of Jiangnan orogenic belt, the regional geological mapping, LA-ICP-MS zircon U-Pb age, and all-rock geochemical a nalysis were studied. According to the geological contact r elationship, the diagenetic sequence of Tangs he complex pluton from early to late is determined as medium grained monzonitic granite, medium- coarse grained syenogranite, coarse-medium grained porphyritic syenogranite and fine grained syenogranite, respectively, and the diagenetic ages are (140. 4±3. 3), (131. 7 ±3. 2), (132. 2± 1. 6), and 025. 0±2. 0)Ma. The rocks have the characteristics of high Si and alkali, low P and Ti, being metaluminum-weak peraluminous and high-K calc-alkaline series, which belong to I- type granites. In addition, the light and heavy rare earth elements are highly differentiated, and the chrondrite-normalized REE pattern leans to right with the enrichment of Rb, Th, U, and K, the depletion of Ba, Nb, Ta, Sr, P, and Ti, and the medium-strong negative Eu anomaly. Generally, the magmatic evolution from early to late shows that the contents of SiO2 and K2O, the ratio of K2O/ Na2O, and A/CNK gradually increase, the contents of TiO2, Al2O3, TFeO, MgO, CaO, P2O5 gradually decrease, negative Eu anomaly gradually increases, and the degree of differentiation gradually increases. Tangshe complex pluton is the product of anticline tectonic emplacement after crystal-separation of the remelting of lower crustal material in the inland tension environment after the subduction-collision orogenic of paleo-Pacific plate. Types of mineralization and minerals in the contact zone of Tangshe complex pluton are characterized by W---+Ag-Pb-Zn---+Sb/fluorite zoning from inside to outside, which form a skarn-hydrothermal vein- type mineralization system with a good prospecting prospect. [ABSTRACT FROM AUTHOR]