Abstract:Graphite is widely used in such fields as metallurgy, machinery, aviation, aerospace, electronic information, and new energy vehicles, and has become an important raw material in the high technology. In recent years, Chahanmuhulu deposit in Inner Mongolia, Nanjiang deposit in Sichuan and and some other large-sized metamorphic graphite ore deposits have been found, especially the discovery of the Huangyangshan magmatic type crystalline graphite deposit in Xinjing has indicated a new direction for the study of the metallogenic regularity of graphite deposits. Based on the extensive collection and study of the past graphite achievements, combined with field research and latest graphite exploration results, the authors systematically summed up temporal and spatial distribution regularity and metallogenic factors of graphite deposits, and divided the metallogenic zone of graphite deposits. In China, the graphite ore deposits are dominated by regional metamorphic type, and the main metallogenic period is Precambrian; the deposits formed in this period have large graphite scale, high crystallinity and great economic significance. The host rock of magmatic rock type graphite deposit is Hercynian alkaline granite, whose metallogenic age is the same as the age of magma invasion; the contact metamorphic graphite ore deposits are mainly concentrated in the Permian Jurassic period, and their mineralization was closely related to the intermediate acid magmatism of the Hercynian period. The large fold structure and the transitional end of the large fold structure in the stable uplift area are favorable structural units for the formation of graphite. The authors preliminarily divided the country into 21 graphite metallogenic zone, and pointed out that Jiamusi-Xingkai (massif) graphite metallogenic belt, middle northern margin of North China block graphite metallogenic belt, Jiabei uplift metallogenic belt, Junggar massif metallogenic belt, southern margin of the North China continental block, Qinling and some other graphite metallogenic belts are especially important. The summary of the metallogenic regularity of the graphite deposits and the preliminary division of metallogenic belts are of significance for guiding the prospecting and exploration of graphite deposits.

Abstract:The Wulagen superlarge lead-zinc deposit in Xinjiang is a red bed lead-zinc deposit discovered for the first in continental basin in China. There exists controversy concerning its mineralization and genesis, and different researchers have classified it as different existing types of deposits, such as SEDEX type and sandstone type. Nevertheless, these classifications can not reflect its specific metallogenic environment and mineralization. Therefore, based on collected and studied the geological data of the continental red bed basin and its mineralization through comparison and analysis of regional geological structure background, ore-forming material sources, characteristics of ore-controlling factors, ore-forming fluid and some other phenomena, the author holds that the Wulagen lead-zinc deposit is very similar to many red bed copper deposits in China's continental basins in such aspects as the deposit characteristics, ore-controlling conditions and deposit genesis, and hence they are the same type of deposits.The red bed deposit is a specific mineral resource in diwa (geodepression) region and a new type deposit in diwa epoch, and red bed basin's hot brine action is a fully independent metallogenic system. The red bed deposit is a unique deposit type which has important theoretical significance and practical significance. A new direction and field are therefore opened for the prospecting of lead-zinc deposits.

Abstract:The Longjiang Formation in Longjiang basin is composed of intermediate-acidic volcanic rocks, pyroclastic rocks and tuffaceous sedimentary rocks. The petrochemical compositions of most volcanic rocks belong to the calc-alkaline island arc series. These volcanic rocks are characterized by high SiO₂, Na₂O, Al₂O₃ and Sr content, low MgO, Y and Yb content and clear depletion of high field strength elements (Ta, Nb), similar to the characteristics of the classical adakite. These Sr values and Sr/Y ratios are also similar or close to features of most subduction-type adakites. Geochemical characteristics indicate that the magma experienced crust contamination and fractional crystallization of clinipyroxene, plagioclase, Ti-Fe-oxides and apatite during the early evolution process. The zircon LA-ICP-MS U-Pb age is 125.9±1.5Ma, consistent with the fossils data, representing volcanics formation age. Combined with the spatial variation of ages of the Mesozoic volcanic rocks in Northeast China, the authors hold that the formation of the volcanic rocks was related to the Circum-Pacific tectonic system as well as the Mongolia-Okhotsk structural belt.

Abstract:There is a suite of volcanic-sedimentary strata comprising Dongxileke Formation in Kanasi area; nevertheless, there is no accurate ages and geochemical study for these rocks. The genesis and geodynamical background are in controversy for a long time. To tackle these problems, the authors chose a layered mylonitic dacite in this area as the study object. LA-ICP-MS zircon U-Pb ages of(445.4±3.1)Ma and(445.7±3.7)Ma from two mylonitic dacite samples suggest that these volcanic rocks erupted in late Ordovician and that Dongxileke Formation was formed in late Ordovician. The mylonitic dacite is characterized by SiO₂ content from 53.99% to 71.04%, high Al₂O₃ (13.83%-16.27%) and low MgO (1.09%-3.53%), with K₂O between 1.11% and 3.83%, 2.84% on average, suggesting high alkline volcanic rock series. The mylonitic dacite forms a LREE-enriched distribution pattern with the existence of negative Eu anomaly (δEu=0.65-0.82). Geochemical characteristics of mylonitic dacite suggest island-arc volcanic features characterized by enrichment of LILE such as Rb, Th and Ce and depletion of HFSE such as K, Nb and Ta. Combined with regional data and the results obtained by this study, the authors consider that the volcanic rocks were generated during syn-collision of the late stage subduction in an active continental margin arc. The background was the conversion from the northward subduction of Paleo-Asia Ocean under the Siberia plate to Altay micro landmass land, which resulted in the formation of late Ordovician volcanic rocks in an active continental margin arc of Kanasi area.

Abstract:Located in the Yamansu-Hongshishan-Heiyingshan Late Paleozoic rift of Xingxingxia-Mingshui-Hanshan microplate in Kazakhstan plate, the Sunjialing scandium mineralized intrusion emplaced in the Early Carboniferous Baishan Formation and consists of plagioclase amphiboles and amphiboles, with scandium mainly occurring in the amphibole. Scandium mineralized intrusion belongs to iron-rich ultrabasic intrusion, whose components are characterized by high alkali and alumina. The content of rare earth is high, and the light rare earth is slightly enriched, with obvious negative δ (Eu) anomaly. LILE elements Rb, Ba, Sr and U are enriched whereas HFSE elements Nb, Zr, Hf, Th, and P, Ti are depleted. LA-MC-ICP-MS zircon U-Pb dating of the hornblende yielded an age of (339.5 ±2.6)Ma, which suggests that both the intrusion of the ore-bearing complex and the mineralization occurred in early Carboniferous in a rift environment.

Abstract:Transverse faults are widespread in the thrust belt, and the study of these faults is significant and valuable. Having experienced multi-episodic tectonic changes, the Kuqa thrust belt has had the structural foundation of developing transverse faults. In combination with the remote sensing image, deep geophysical data and seismic section analysis, the authors studied the tectonic characteristics and genetic types of transverse faults in the Kuqa thrust belt. Some conclusions have been reached:(1) There are 16 transverse faults in the Kuqa thrust belt, with structure and properties of nine faults being confirmed. These transverse faults are mainly distributed in northern monocline tectonic zone, Kelasu tectonic zone and Qiulitag tectonic zone; (2) Transverse faults can be divided into three genetic types, i.e., basement activation transverse fault, cover-tear fault and tensional transverse fault; (3) Transverse faults have some geological significance in adjusting the thrust displacement difference between segments, developing transverse rivers, enriching structural styles and controlling oil and gas migration.

Abstract:The Hutouya mining area in Qiman Tage of Qinghai Province owns the characteristics of inner-and exo-contact belt skarn subtype mineralization. The magmatic intrusive activities are strong in this area. The carbonatite formation of different ages is exposed extensively. The combination of metal metallogenic elements is complex. The potential for the ore prospecting is great. This study is based on the thermochronology theory for rock bodies. The total energy of rock bodies is proportional to its scale. The thermal energy is larger as the scale of rock bodies is larger, the thermal effect is larger as the thermal energy is larger, and the cooling rate is larger as the thermal effect is larger. The cooling rate is calculated via the closure temperature of different minerals. The authors studied Ar-Ar ages of biotite and plagioclase from the Hutouya mining area. The ⁴⁰Ar-³⁹Ar plateau ages of biotite and plagioclase from the HTY002 monzonitic granite sample related to mineralization are 2(33.6 ±2.2) Ma and (231.5 ±1.3) Ma, respectively. The ⁴⁰Ar-³⁹Ar plateau ages from the HTY016 sample are (229.6±2.3) Ma and (219.3±1.8) Ma, respectively. The ⁴⁰Ar-³⁹Ar plateau ages of the HTY019 sample are (224.7±2.6) Ma and (222.2±2.2) Ma, respectively. The calculated cooling rates are 57.14℃/Ma, 11.65℃/Ma, and 48.00℃/Ma. Where the compositions of the intrusive rocks are similar, the differences of the unit thermal energies of their emplacement are very small. Because the total energy of rock bodies is proportional to its scale, the total energies of rock bodies of different scales are different. The thermal energy of large rock bodies is large, the time of balance with the surrounding rock is long, the thermal effect is large, and the cooling rate is low. The cooling rates of different minerals from the Hutouya mining area are similar. The values of the cooling rates are high, varying from 11 to 57℃/Ma, so the thermal effect is large. It is thus concluded that the potential for the ore prospecting is great in the Hutouya mining area.

Abstract:The Huangtian Pb-Zn deposit occurs along the contact zone between the carbonate rocks of lower Permian and Emeishan basalt of upper Permian. Orebodies are mainly bedded and lenticular in form. The ore minerals are mainly sphalerite and galena, whereas the gangue minerals are quartz, calcite and dolomite primarily. The composition of C and O isotopes of the hydrothermal calcite indicates that the carbon of CO₂ in the ore-forming fluid is pluralistic, mainly from the mixed carbon of the mantle source and the marine carbonate rocks. The sulfur isotope composition of sulfide indicates that the sulfur in the lead-zinc deposit is dominated by magmatic sulfur and may be mixed with other sulfur sources (possibly including formation sulfate). The lead isotopes indicate that the metallogenic material mainly came from the surrounding rock. The lead isotopes indicate that the metallogenic material mainly came from the surrounding rock, basalt and Yanshanian granite, which is the product of multisource mixing. Isochron age of Rb-Sr isotope is (83.2±3.4) Ma, indicating the formation of the lead-zinc deposit in the late Yanshanian period. The metallogenic dynamic background of the Huangtian Pb-Zn deposit might have been related to the large-scale lithospheric extension of the Youjiang fold belt at the end of Mesozoic. The Late Permian marine eruption volcanic rocks played an important role in the formation of lead and zinc deposits in the aspect of cover and ore-bearing layer and mineralization. All the geochemical information suggests that the source of ore-forming metals and fluids of the Huangtian Pb-Zn deposit was mixed product. The type of the deposit is sedimentary and reformed deposit.

Abstract:The Xiaoxinancha Au-rich Cu deposit is an important hydrothermal deposit in eastern China. The deposit includes two mines, known as the North mine (veinlet-dissemination type) and the South mine (vein type), which show different ore grades and orebody characteristics. The total homogenization temperatures (T_h,total) range from 120 to 470 ° C, and the salinities in the Ⅰ mineralization stage and Ⅱ-Ⅲ mineralization stage are 10.1%-20.0% NaCl eqv and 0.4%-45.5% NaCl eqv, respectively, with the gas composition consisting mainly of H₂O, CO₂, CH₄ and N₂ in the North mine. The South mine fluids yield T_h,total of 150 to 450℃, salinities of 4.0%-11.1% NaCl eqv in the Ⅰmineralization stage, and the salinities in theⅡ-Ⅲ mineralization stage decrease with the decreasing temperatures, and the main gas composition consists of H₂O, CO₂, and CH₄. The quartz-hosted fluid inclusions in the hornblende-granodiorite have homogenization temperatures of 150 to 510℃, and salinities of 4.9%-11.5% NaCl eqv, being similar to those in the North and South mine. The authors hold that the North mine was formed by replacement of fluids which experienced mixing with crustal fluids in the Wudaogou Group after the boiling, whereas the South mine was mainly formed through fillingcrystallization of the initial ore-forming fluids with the decreasing temperatures and pressures, and the ore-forming fluids that involved the meteoric water in the mid-late stage produced melnikovite-quartz veins in the North mine and pure sulfide veins in the South mine. The fluid inclusions in the hornblende-granodiorite possibly reveal initial ore-forming fluid signatures characterized by low-moderate salinity and mantle-derived magmatic fluids.

Abstract:The Tangjiazhai Pb-Zn deposit is located in the middle of the Longshan-Luota mining field in western Hunan Province, China, and is an important lead and zinc reserve base for Hunan Province. Sr isotope compositions measured for sphalerite were agecorrected by 372 Ma. As a result, the (⁸⁷Sr/⁸⁶Sr)_i values range from 0.70904 to 0.71143 with an average value of 0.70998(n=10) which is higher than that of the seawaterin the mineralized age (372 Ma),and lower than that of Lower Cambrian Shipai Formation shale enriched in organic matter. Speculation can be made is that Sr in ore-forming fluids is sourced from seawater (372 Ma) with relatively lower Sr contaminated high Sr Lower Cambrian Shipai Formation shale. Sphalerite and galena are measured for sulfur isotope composition. The δ³⁴S_V-CDT values of them have a range from 14.78‰ to 7.21‰ with a mean of 15.84‰ (n=9) which is lower 13.66‰ than that of the Early Ordovician seawater sulfate. This variation conforms to sulfur isotope fractionation of 10‰-20‰ when the mineralized temperature is from 100℃ to 200℃.These evidences indicate that the reduced sulfur in the sulfides probably derive from the Thermochemical Sulfate Reduction (TSR) of seawater sulfate within the ore-bearing strata.

Abstract:The lower part of the first member of Zhiluo Formation of Middle Jurassic is the main uranium ore-bearing layer of the Nalinggou uranium deposit. Because of the formation has braided river sedimentary system features such as good sand body connectivity and permeability, rich reducing substances (charcoal and pyrite), it has good conditions for uranium mineralization. Using multiple testing means such as microscope microscopy, X-ray diffraction analysis, scanning electron microscopy analysis, the authors studied sandstone rock characteristics. Alteration phenomena and altered mineral characteristics of the uranium target strata was observed. the conversion relationship in clay minerals, biotite and other minerals was explored. Component analysis was conducted, and existing forms of uranium mineral in the Nalinggou uranium deposit were investigated using α track etching, electron microprobe analysis and tensile test. By discussing the relationship between petrologic features and existing form of uranium minerals in the ore-hosting horizon, it is found that the enrichment of U, occurrence of U and component type of U were closely related to the exchange of material in the mineral alteration transformation, and uranium mineralization in Nalinggou area was controlled by paleo-interlamination oxidized zone and was affected by the later hydrothermal fluid.

Abstract:Kuruktag region of Tarim Basin is one of the most important strategic replacement areas of oil and gas resources, and is an effective entry point based on special structural setting for studying basin-mountain coupling and evolution of regional structures. Events deposited products from glacial event, volcanic event, storm event and turbidity event are developed widely in the Sinian-Ordovician sedimentary strata of Kuruktag region on the northeastern margin of Tarim Basin. The formation time of these events has obvious coupling relationship with tectonic evolution of Kuruktag region. The breakup of Rodinia supercontinent was a inducing factors for global glacial deposition of Neoproterozoic, which caused the formation of glacialfacies in the Kuruktag region. In addition, volcanic event in Early Cambrian was also a reflection of the breakup of Rodinia. Continuous tension caused by cracking continued until the end of Early Ordovician. However,shorter-period reversed structures occurred during the late Cambrian, which led to the shallowing of south and north facies and caused the formation of tempestuous deposits. The rapid uplift of Kuruktag Mountain under the pressing structural surroundings during the Middle-Late Ordovician caused the increase of material source, which offered advantage conditions for turbidity event. In addition, changing of regional tectonics was a decisive factor for the development of source rocks and reservoirs. Early and Middle Cambrian as well as Early Ordovician constitute a main stage for the development of source rocks under the extension condition. High-quality reservoirar of pore type comprised bonatite and clastic rocks, and the pores were intracrystalline pores, dissolved pores and cracks mainly distributed in Late Sinian, Late Cambrian and Middle-Late Ordovician strata. These source rocks and reservoirs with mudstone formed multiple source-reservoircaprock association in the vertical direction.

Abstract:The Chunzhe area is located in the south of the Qingdu-Zexue iron-copper polymetallic secondary metallogenic belt in the Gangdise-Nyainqentanggula metallogenic belt, and has a good ore-searching prospect. 1:50000 stream sediment survey results show that Chunzhe area should be conducive to enrichment and mineralization of lead, zinc, silver, tungsten, molybdenum. On the basis of the correlation of elements, spatial distribution characteristics of various element anomalies and main indicator elements of inferred deposit types, the authors hold that there exist three types of element anomaly associations i.e., Pb, Zn, Cd, Ag association, W, Mo, Bi association and As Sb association. The authors also pointed out the minerals or deposit types reflected by these associations of anomalies, i.e., skarn type iron-copper polymetallic deposits and tectonic hydrothermal type lead-zinc deposits. Based on follow-up anomaly investigation, the authors obtained remarkable achievements as shown be the discovery of two medium-sized deposits (Qiawo iron-tungsten polymetallic deposit and Leweng iron polymetallic deposit) and many ore spots. In addition, the Qiawo deposit with iron-tungsten association is a new mineralization type in this area, so it has good guiding significance for prospecting and also shows that this area has good prospecting potential.

Abstract:Determination of chemical elements was performed in urban and suburban areas of Zibo City. For this purpose, the statistical principles, univariate and multivariate Nemerow comprehensive index, Hakanson potential ecological risk methods were applied in order to assess the geochemical characteristics of these elements, soil environment quality, potential ecological risks, and their impact on environment and crops. The investigation reveals that the values of Hg, Cd, S, Pb, Se, OrgC and some other components at the surface soil are significantly higher than those in deep soil, that there exists poor correlation of elements and index between surface and deep soil, and surface soil samples, affected by different degrees of human activities, are obviously alkaline. Furthermore, single pollutant evaluation shows various degrees of contamination of Cd, Cu, Hg, Ni, and Zn in soil, in which the pollution area of Cd is the biggest, accounting for 5.11% of the whole city, and the comprehensive pollutant evaluation of overall soil is effective, which reveals that 9.84% of the soil samples have been contaminated, and its formation may be associated with industrial production and human activities. Heavy metals Hg, Cd seem to be the highest potential ecological risk elements, and local area has reached strong or extreme potential ecological risk level, whereas the comprehensive potential ecological risk evaluation is overall medium, with the mild, moderate, strong and extreme harm area accounting for 29.32%, 55.02%, 12.85%, 2.81%, respectively. From the spatial distribution, strong and extreme potential ecological risk areas coincide types of industrial space layout; furthermore, the values of Cd, Pb, Zn, Hg and other heavy metals of the crop samples exceed the standard limits in different degrees, which suggests that the soil and agricultural products should be monitored and evaluated cooperatively to prevent heavy metal pollution and aggravate human health.

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