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Genesis Process of the Cretaceous Daqushan Pluton in Zhejiang Province: Crystal-Melt Separation and Magmatic Recharge HE Chen, XIA Yan, XU Xisheng, QIU Jiansheng, XU Hang, ZHANG Zhi, ZHAO Sidi Geological Journal of China Universities    2023, 29 (5): 657-678.   DOI: 10.16108/j.issn1006-7493.2022018 Abstract （1240）      PDF （11167KB）（1080）       Knowledge map    Save The models of trans-crustal magmatic system and crystal mush provide new insights into the study of Cretaceous magmatism in northeast China. The Daqushan pluton is located in the northeast of coastal Zhejiang and Fujian. It is mainly composed of K-feldspar granite with abundant melanocratic microgranular enclaves (MME) and is locally traversed by several mafic-intermediate dikes. A small outcrop of monzonite is exposed near the Chaotoumen. MME have a fine-grained texture with acicular apatites. Zircon U-Pb dating results show that the rock samples in the Daqushan pluton (including the K-feldspar granite, MME, monzonite, and mafic-intermediate dikes) crystallized at ~100 Ma. The K-feldspar granite are highly silicic (SiO2=68.45%-73.82%). While the miarolitic granite (DQS-7) without MME has the higher silica (76.27%), and its whole-rock geochemical and Sr-Nd isotope compositions are similar to those of coeval high silica granites (SiO2>75%) exposed around the Daqushan pluton. Daqushan K-feldspar granite bearing aggregates of plagioclase and K-feldspar exhibit“complementary”trace element geochemical characteristics with Daqushan miarolite and surrounding high silica granites. Further researches show that the Daqushan K-feldspar granite and miarolite were formed by felsic magma which originated from the partial melting of the ancient crustal basement and was recharged by mantle-derived magma. Such felsic magma underwent fractional crystallization and the extraction of high silica melt. Then, the residual silicic cumulate of the crystal mush and high silica melt crystallized and formed the Daqushan K-feldspar granite, miarolite and the surrounding coeval high silica granites. The mafic dikes of Daqushan are enriched in LILEs and depleted in HFSEs and are derived from the partial melting of the enriched mantle metasomatized by subducted dehydration fluids. The results of EPMA analyses indicate that the plagioclase in the K-feldspar granite and MME has a core-mantle-rim texture with low- An in the core (27-36, 25-41) and rim (17-32, 18-26) and relatively high-An in the mantle (28-57, 27-65). Integration of the element geochemical characteristics and Sr-Nd-Hf isotopic results, monzonite and intermediate dikes should be the product of magma mixing of mantle-derived mafic magma and felsic magma, while MME are the product of magma mingling of the two endmembers. The results of the Al-in-hornblende geobarometer show that the crystallization depth of MME is 1.8- 3.0 km, hornblende in monzonite develops core-mantle-rim texture, the crystallization depth of hornblende core and mantle is 17.0-21.2 km, and the depth of hornblende rim is 1.9-4.5 km. Based on the study of the origin and genetic relationships of K-feldspar granite, MME, miarolite, monzonite and mafic-intermediate dikes, and compared with the surrounding coeval high silica granites, this study establishes a model of trans-crustal magmatic systems for Daqushan pluton. The rollback of the subducting paleo-Pacific plate, the back-arc extension in the coastal area and the upwelling of the asthenosphere led to the underplating of the mantle-derived mafic magma, and further induced the partial melting of basement rocks in the lower crust to produce felsic magma. The continuous recharge and heating of mantle-derived magma favor the existence of long-lived melt-bearing regions in magma chambers, promoting magma differentiation and crystal-melt separation and thus forming two magma chambers with depths of 17-21 km and 2-3 km, respectively. K-feldspar granite, high silica granites, monzonite, MME and intermediate-mafic dikes were formed by magma mingling/mixing and crystal-melt separation in two connected magma chambers at different depths. Related Articles | Metrics

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The Petrogenesis of Baishuizhai Granitic Pluton and Its Significance to Uranium Mineralization in the Xiazhuang Area, Guangdong Province LI Kun, CHEN Weifeng, GAO Shuang, SHEN Weizhou, HUANG Guolong, LIU Wenquan, FU Shuncheng, LING Hongfei Geological Journal of China Universities    2023, 29 (4): 497-513.   DOI: 10.16108/j.issn1006-7493.2021117 Abstract （370）      PDF （2375KB）（678）       Knowledge map    Save The Baishuizhai pluton is one of the main ore-bearing wall rocks of the Zutongjian uranium deposit in the northwestern part of the Xiazhuang granite-related uranium ore filed, yet its petrogenetic mechanisms and its relationship with uranium mineralization are still unclear. Thus, in this study, we present zircon SHRIMP U-Pb ages, whole-rocks and mineral geochemical data for the Baishuizhai granite. Field and petrographic investigations show that the Baishuizhai granitic pluton was emplaced into the Xiazhuang granitic batholith, mainly composed of fine-grained two-mica granite and muscovite granite, and the zircon SHRIMP U-Pb dating reveals that both granites were formed during the Indochina period with ages of 229.4 Ma and 231.8 Ma, respectively. They show typical peraluminous S-type granitic geochemical characteristics that are high SiO 2 contents, total alkalis contents and ACNK values ( ≥ 1.1), low FeOt+MgO+TiO 2 contents and P 2O 5 contents, enriched in Rb, Th and U, depleted in Ba, Sr, P and Ti, and enriched in aluminum-rich minerals. Compared with the Xiazhuang granite, both types of granites in the Baishuizhai pluton show enriched in inherited zircon, higher SiO 2 contents and Rb/Sr ratios, but lower FeOt+MgO+TiO 2 contents, P 2O 5 contents, Zr/Hf ratios, and Fe 2+/(Fe 2++Mg) ratios of biotites, indicating that they were derived from low partial melting of reducing material-rich feldspathic meta-pelites, and are not formed by the differentiation evolution of the parent magma of the mafic meta-pelites-derived Xiazhuang granite. Furthermore, compared with the two-mica granite, the muscovite granite display significant tetrad REE patterns, lower REE, Zr/Hf ratios and Eu/Eu* values, indicating that an interaction of F-rich fluids with the magma occurred in the formation of the muscovite granite. Both types of granites in the Baishuizhai granitic pluton are enriched in uranium and can be important uranium-bearing granites in the region. Relative to the 2-mica granite in the Baishuizhai pluton, the muscovite granite is more enriched in uranium and more favorable to be uranium source rocks for hydrothermal uranium mineralization. Related Articles | Metrics

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Grain-size Characteristics and Environmental Implication of Neogene Red Clays in the Chinese Loess Plateau LU Keke, CHEN Zhong, YANG Yanpeng, ZHANG Jialin, ZHAO Zhongqiang, XIA Dinghong, NI Chunzhong, SONG Yinxian, ZHANG Shitao Geological Journal of China Universities    2023, 29 (5): 713-725.   DOI: 10.16108/j.issn1006-7493.2022020 Abstract （242）      PDF （1237KB）（649）       Knowledge map    Save The aeolian origin of red clays in the Loess Plateau has been unanimously recognized. The earliest red clay was found in the late Oligocene and early Miocene, indicating that the arid environment had been formed in the inland northwest of China at the end of Paleogene. The grain size characteristics of red clay in the loess plateau show that the average grain size gradually decreases from the north to the south, indicatin g that the initial monsoon system has been established, and the winter wind played an important role in the transport of aeolian dust. The grain size distribution of red clay indiactes that it is composed of two components. The coarse grain (>20 μm) represents those transported by the near surface wind (winter wind), while the fine grain (<5 μm) represents those transported by the upper westerly wind. The grain size composition characteristics of red clays well record the development and change of atmospheric circulation. Since the end of Oligocene, the average grain size and sedimentation rate of red clays in the west of Liupanshan Mountain increased at 21.3-20.2 Ma, 16.0-13.3 Ma and 8.7-6.9 Ma, which may be related to global cooling and the Qinghai-Tibet Plateau uplift, and the 8.7- 6.9 Ma increase was mainly controlled by global cooling. In the red clay section to the east of Liupanshan, the grain size of variation characteristics shows that the grains deposited during 7.6 Ma to 6.2 Ma or to 5.4 Ma is coarse, indicating that the winter monsoon was strong. After that, the average particle size was fine up to 3.6 Ma, and the deposition rate was low, indicating that the winter monsoon was weak climate environment. From 3.6 Ma to 2.6 Ma, most profiles show an increase in mean grain size, an increase in sedimentation rates, and an increase in both winter and summer monsoon, which indicates to the transition to Quaternary glacial period. The development of the Arctic ice sheet and the uplift of the Qinghai-Tibet Plateau may have contributed to these changes. Related Articles | Metrics

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Research on the Control of CBM Well Reservoir Geological Engineering Characteristics on Productivity LI Quanzhong, SHEN Jian, HU Haiyang, JI Xiaofeng Geological Journal of China Universities    2023, 29 (4): 644-656.   DOI: 10.16108/j.issn1006-7493.2021118 Abstract （167）      PDF （711KB）（591）       Knowledge map    Save In order to improve the single well gas production of CBM well，the influencing factors of CBM well gas production are studied from the geological static parameters and engineering dynamic parameters of CBM development. Based on a block of Shanxi Qinshui Basin 12 reservoir parameters and geological characteristics of typical CBM Wells and development data， starting from the geological control factors, engineering control, detailed analysis of seven aspects of 24 kinds of factors, including coal bed methane resource characteristics，coal reservoir seepage characteristics，structures，energy，drilling，fracturing，drainage，we study the degree to which these factors control the CBM gas production. The results show that the gas production of CBM Wells in the same block is different, which is affected by both geological factors and engineering factors; Also, coalbed methane resources and coalbed methane reservoir seepage, structures and energy characteristics clearly influence coalbed methane production, and when the permeability of coalbed methane reservoir is more than 0.7 mD，it is favorable for coalbed methane well to yield increased gas production. In addition, faults affect the gas content of coal reservoir and fluid migration in the process of drainage and production. In the development of CBM, faults should be avoided and a safe distance of 400 m should be maintained. Furthermore, the higher the casing pressure and gas release pressure of CBM well，the more conducive to expanding the desorption radius of coal reservoir, which results in high and stable production of a CBM well. The scale of fracturing operation in coal reservoir also has great influence on gas production, and the scale of fluid injection is more significant than that of sand injection in the study area. The pressure drop rate and gas production rising rate should be reasonably controlled in each stage of CBM well, and the pressure drop rate should be controlled within 10 kPa/d in the pressure control and production raising stage. These will allow to enlarge the pressure drop funnel radius of Coal Reservoir. The analysis of the geological and engineering factors of CBM Wells in the study area provides a theoretical basis for the geological selection and geological selection of CBM. It may also serve as technical guidance for the development of other CBM projects.  Related Articles | Metrics

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Types and Characteristics of Geoheritage Resources in the Shungeng Mountain, Huainan, Anhui Province ZHANG Zikang, GU Chengchuan, WU Jiwen, ZHAO Ming, ZHAN Run, SHAO Qingqing, ZHANG Yuanyuan Geological Journal of China Universities    2024, 30 (01): 89-99.   DOI: 10.16108/j.issn1006-7493.2022063 Abstract （144）      PDF （4598KB）（487）       Knowledge map    Save The Shungeng Mountain in Huainan, Anhui Province, is tectonically located in the southern thrust-napped belt of the Huainan Coalfield within the North China Craton (NCC) and hosts many natural and artificial exhumed geoheritages. According to the field geological survey, 62 major geoheritage sites have been identified in the Shungeng Mountain, which can be divided into 3 major categories, 8 categories and 14 subcategories. Among them, typical Cambrian-Ordovician sections of the NCC, karst topography, fault structures and mining heritages are well developed and are of high scientific research and ornamental value. Based on the previous studies, the genesis and regional geological background of these geoheritages in the Shungeng Mountain are discussed, which provide a theoretical basis for the proper exploitation of the geoheritage resources. In light of the problems existing in the protection and exploitation of geoheritage resources in the Shungeng Mountain, this paper puts forward suggestions for long -term planning. Related Articles | Metrics

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Structural Characteristics and Deformation Mechanisms of Multipledetachments in Luzhou area, Southeastern Sichuan Basin ZHAO Shengxian, XU Wenqiao, YANG Xuefeng, YIN Hongwei, LI Bo, WANG Wei, ZHANG Chenglin, JIA Dong, LIU Yongyang, XIE Wei, ZHANG Dongjun, LI Changsheng Geological Journal of China Universities    2023, 29 (5): 726-734.   DOI: 10.16108/j.issn1006-7493.2022029 Abstract （1012）      PDF （7113KB）（435）       Knowledge map    Save In recent years, shale gas exploration and development in southeastern Sichuan has gradually expanded to the deep areas. The Luzhou area shows great potential of shale gas exploration and development with the depth over 3500 m. In order to further clarify the characteristics and evolution mechanism of various structural deformation in Luzhou area, the main controlling factors of fold belt were explored by using discrete element numerical simulation based on structural analysis of seismic data, and the evolution process of Mesozoic and Cenozoic was restored. And the following research results show that multiple detachment layers and regional tectonic compression are the main controlling factors of structural deformation in Luzhou area. Influenced by multiple detachment layers, Luzhou area has developed low steep thin-skinned structure and obvious vertical stratification, forming complex structure such as fault-propagation folds, detachment folds, buried folds and duplex structures between detachment layers. Among them, the lower Cambrian gypsum rock plays a major role in controlling the deformation, and the gypsum rock and shale slippage coordinate and accumulate towards the core of the anticlines. Since the late Yanshanian, the multi-detachment allochthonous succession with regional compression in Luzhou area were developed the thin-skinned comb-shaped folds. The fold belt rose again in Himalayan, the displacement of the original fault sand shear zones increased, and a series of secondary faults and buried folds formed between the detachment layers. The reservoirs are easy to be destroyed at anticline zones, while the syncline areas are a favorable area for shale gas exploration. The relatively simple deformation for syncline composed of ramp thrusts results in comparable stable internal stress distribution. Related Articles | Metrics

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Advance in Laser Raman Spectroscopy Carbon Geothermometer and Its Application in Earth Sciences CHEN Yiyi, WANG Bo, LIU Jiashuo, LU Shenghua, COCHELIN Bryan Geological Journal of China Universities    2023, 29 (6): 908-923.   DOI: 10.16108/j.issn1006-7493.2021116 Abstract （131）      PDF （1310KB）（409）       Knowledge map    Save Organic matter is usually enriched in sediments, and will be transformed from disordered carbonaceous material to fully-ordered crystalline graphite, after being buried and heated to some high temperature during metamorphism. The crystalline order is closely corresponding to the certain temperature condition of metamorphism. The Raman spectroscopy (RS) can reflect the vibrational modes of molecules of carbonaceous material (CM), and to reveal the crystalline degrees of graphite, and thus the metamorphic conditions. The RSCM method is an empirical geothermometer by obtaining and analyzing the Raman parameters like band position, peak intensity, band area and FWHM (full width at half maximum) of carbon or graphite grains from a series of metamorphic samples, whose metamorphic temperatures are already known or can be calculated by other methods. A close correlation between the RSCM and peak metamorphic temperature is very well defined, so as to quantitively calculate the peak temperature of the unknown samples during regional or contact metamorphism. Based on the comparisons with the traditional geothermometers, it is suggested that the RSCM is practicable and reliable, and it shows several advantages such as high efficiency, in situ and nondestructive measurements, wide range of temperature detection, high sensitivity to CM inner structures, being free from later retrograde metamorphism, and wide fields of application. Thus, this method is significant for the reconstruction of regional tectonic and thermal evolution, and crustal thermal state. This paper reviews the study history of the RSCM, introduces the theory on CM Raman spectrum band distribution and its relationship with metamorphic temperature, summarizes some representative studies of natural graphitic carbons by Raman spectroscopy in recent years, and its applications in different fields of Earth Sciences. The research foreground of RSCM is finally prospected. Related Articles | Metrics

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Mechanisms of Ce(III) Oxidation and Fixation by Coexisting Iron and Manganese Oxides ZHAO Hanyue, ZHOU Yuefei, LI Xiaosong, XIE Qiaoqin, CHEN Tianhu Geological Journal of China Universities    2023, 29 (5): 705-712.   DOI: 10.16108/j.issn1006-7493.2022031 Abstract （162）      PDF （887KB）（370）       Knowledge map    Save In this study, we conducted bulk and dynamic experiments to investigate the efficiency of Ce (III) oxidation and fixation by Mn-contained limonite and goethite. Based on experimental results, the mechanism of Ce oxidation and fixation by coexisting iron and manganese, and its geological significance, are discussed. Results of bulk experiments show that Mn-contained limonite has a high performance on the oxidation and fixation of Ce; Ce was totally removed after 48 hours under solution with Ce concentration of 6000 μg/L and limonite concentration of 1 g/L. For experiments with initial Ce concentrations of 300 to 4500 μg/L, Ce removal is positively correlated with Mn content for limonite experiments. As for goethite, it decreased Ce removal when comparing to the control experiments. Results of dynamic adsorption experiments show that for high-Mn limonite, the distribution of Ce is constrained not by Mn minerals, but by iron oxides. The results of this study indicates that: (1) the process of Ce oxidation and precipitation is adsorption of Ce (III) -oxidation of Ce(III) to Ce(IV)-precipitation of Ce(IV) minerals-autocatalytic oxidation of Ce(III) to Ce(IV) by CeO 2, and (2) the contributions of coexisted Mn and Fe oxides to Ce oxidation and fixation are Mn oxides promoting the oxidation of Ce(III) and Fe oxides promoting the precipitation of CeO 2 through electrostatic attraction. This study is significant in explaining the geological phenomenon that although Mn oxides have higher Ce(III) oxidation ability than that of Fe oxides, under Fe- and Mn-oxides coexisting conditions, Ce tends to be fixed by Fe oxides. Related Articles | Metrics

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Sr-Nd-Pb Isotopic Composition of the Chinese National Standard Igneous Rock Powders Measured by the Thermal Ionization Mass Spectrometry WANG Zhiyi, CHENG Hong, ZHAO Jingxin, YE Risheng, LI Weiyong, HE Jianfeng, CHEN Fukun Geological Journal of China Universities    2023, 29 (5): 679-692.   DOI: 10.16108/j.issn1006-7493.2022017 Abstract （174）      PDF （1003KB）（368）       Knowledge map    Save In this study, Sr-Nd-Pb isotopic compositions of three Chinese national igneous rock standard materials, GSR-1 granite, GSR-2 andesite, and GSR-3 basalt, were measured by means of the techniques of the isotopic dilution and the thermal ionization mass spectrometry, to investigate the homogeneity of their isotopic compositions and the suitability for the usage as rock standard materials. Three international rock standard materials, BCR-2 basalt, BHVO-2 basalt, and AGV-2 andesite, produced by the US Geological Survey, were simultaneously analyzed as reference materials to check the reliability of the analytical procedures. The analytical results show that three national standard materials of igneous rocks have homogeneous Sr and Nd isotopic compositions. Compared to the GSR-1 granite, the GSR-2 andesite and GSR-3 basalt yield homogeneous Pb isotopic compositions. Relatively large variation in Pb isotopic composition of the GSR-1 granite might be caused by the addition of radiogenic Pb isotopes from those minerals having high U and Th contents. On the basis of the analytical results reported in this study, it is suggested that the three national standard materials of igneous rock powders are suitable as the reference materials for the Sr and Nd isotopic measurements and, the GSR-2 andesite and GSR-3 basalt are also the ideal candidates as reference materials f or the Pb isotopic analysis. Related Articles | Metrics

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Discrete Element Numerical Simulation of the Sspin Evolution Process of Rubble Pile Asteroids ZHANG Chenwei, LIU Chun, GENG Huan, LIU Hui Geological Journal of China Universities    2023, 29 (5): 743-755.   DOI: 10.16108/j.issn1006-7493.2022022 Abstract （113）      PDF （6890KB）（366）       Knowledge map    Save In recent years, exploration research has shown that the rubble pile structure formed by gravity and cohesion may be an important method of asteroid formation. To explore the evolution mechanism of this kind of asteroid, this paper makes secondary developments based on the discrete element software MatDEM and realizes the calculation of the element’s gravitational force. A numerical model of a “rubble mound” asteroid with a diameter of 1.2 km is established, and the rotational remodelling and failure processes of spherical aggregates under different adhesion strength and bulk densities are analysed by numerical simulation. The results show that spherical aggregates are affected by the initial increment of angular velocity to start the remodelling process of aggregates, leading to deformation or failure. With the decrease in the adhesion strength, the model will be destroyed more easily. Before destruction, the asteroid will maintain the stability of its configuration by deforming into an oblate ellipsoid. The increase in bulk density effectively increases the structural stability of the asteroid model with a certain adhesion strength, can delay the occurrence of asteroid destruction, and the number of particles falling off decreases with the increase of density. Discrete element analysis can better simulate the spin evolution process of asteroids. Combined with real asteroid data, it is beneficial to explore the mechanism of asteroid spin evolution and destruction deeply and comprehensively.  Related Articles | Metrics

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Overview of New Taxa on Global Vertebrate Fossil during 2017-2021 WANG Haohan, ZHU Min, SHI Xiaodong, PAN Zhaohui Geological Journal of China Universities    2023, 29 (5): 788-794.   DOI: 10.16108/j.issn1006-7493.2022026 Abstract （1159）      PDF （2181KB）（365）       Knowledge map    Save Biodiversity data of vertebrate fossils is important information source for studying earth history and life evolution. The species list of vertebrate fossils is an essential basis for studying the diversity of global vertebrate fossils. Reviewing new taxa and literature on vertebrate fossils can reveal the research hotspots of vertebrate fossils diversity and grasp disciplinary development directions on a time scale. Based on the DeepBone Database, this study reviews the annual variation characteristics of taxa and literature, distribution countries of the holotype, published journals, and significant contributing institutions of new taxa on the different categories of global vertebrate fossils during 2017-2021 using bibliometrics analysis. The result shows that 2662 new taxa emerged, and 1946 literature were published on global vertebrate fossils during 2017-2021. New taxa and literature on vertebrate fossils have decreased since the outbreak of COVID-19 at the end of 2019. Countries with a high distribution of the holotype of new taxa for global vertebrate fossils during 2017-2021 and are rich in vertebrate fossil resources, are strong in the economic and scientific research, mainly including the United States, China, New Zealand, Argentina, and Germany. Journal of Vertebrate Paleontology, Cretaceous Research, Historical Biology, PeerJ, and Journal of Systematic Palaeontology are the prominent journals on new taxa of vertebrate fossils. The institutions with a high contribution to the new taxa for vertebrate fossils are the Chinese Acad Sci, Russian Acad Sci, Consejo Nacl Invest Cient & Tecn, Nat Hist Museum, and the research cooperations of various institutions are very close. The study of taxonomy on vertebrate fossils in China has reached a high level in the world. We should continue to strengthen the accumulation of primary data on vertebrate fossils diversity to provide the DeepBone database for exploring the origin and evolution of bio diversity in the future.  Related Articles | Metrics

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Influence of Fuel Pollution on Hydrogeological Parameters of Porous Media YANG Pengfei, CHEN Yudao, JIANG Yaping, YAN Jianing, ZHENG Gao, ZOU Zhikun, LIU Quan, QIN Jiaxiao Geological Journal of China Universities    2023, 29 (4): 608-616.   DOI: 10.16108/j.issn1006-7493.2021108 Abstract （1748）      PDF （1695KB）（364）       Knowledge map    Save Influence of fuel pollution on groundwater environment is an important subject. Investigating the hydrogeological parameters of contaminated sites will be helpful to understand the changes of hydrogeological parameters before and after pollution, as well as changes of the migration behavior of contaminants in groundwater. To compare the differences of parameters before and after gasoline contamination and evaluate the impacts of gasoline contamination on hydrogeological parameters, three stages of quantitative tracer experiments in sand-tank were performed. The results show that: (1) the accumulation of gasoline contamination leads to the occurrence of bioclogging, and the degree of bioclogging tends to slow down with the increasing percolation distance; there exist differences in solute dispersion in different regions of porous media, and increased solute flux in the dominant flow on the central line and the mass recovery rate ; the solute Breakthrough Curves show a lean-high pattern and a clear trailing. (2) by monitoring the gasoline contamination for 6 years, it is found that the permeability coefficients of traditional gasoline tank (TG-tank) and ethanol gasoline tank (EG-tank) were 25.4 and 20.5 m/d, respectively, which decreased to 61% and 49% of the initial permeability coefficient KII before the sand tank was contaminated; the effective porosity of TG-tank and EGtank was reduced from the initial value of 0.30 to 0.28 and 0.26, respectively. Hydrodynamic dispersion coefficient also tended to decrease. The permeability of porous media is reduced more significantly by ethanol gasoline pollution. The accumulation of organic contamination will change the hydrogeological parameters of the contaminated site, and strengthening studies of hydrogeological parameters after contamination can provide a reasonable basis for evaluating the contamination risk. Related Articles | Metrics

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Analysis of Deformation Characteristics and Parameters of Clay Layers in South Subsidence Area of Beijing YOU Binhao, YE Shujun, TIAN Fang, LUO Yong Geological Journal of China Universities    2023, 29 (4): 590-599.   DOI: 10.16108/j.issn1006-7493.2021083 Abstract （3020）      PDF （2292KB）（360）       Knowledge map    Save The land subsidence in Beijing is divided into north and south areas, and the southern area mainly includes Lixian-Yufa subsidence zone. The subsidence rate in this area has accelerated in recent years and reached 50-75 mm/a during 2017-2019, showing new subsidence characteristics. Based on the subsidence and water level observation data of 7-year time series from 2011 to 2017 at Yufa Subsidence Monitoring Station, the only subsidence observation station in the south subsidence area. The deformation characteristics of soil layers, especially clay layers, are systematically analyzed. Then the elastic and inelastic specific storage, vertical hydraulic conductivities and deformation lag time of the clay layers are estimated by the stress-strain diagram method and the type curve method. The results show that there are both elastic deformation and plastic deformation in each soil layer, and the plastic deformation is the main deformation with obvious deformation hysteresis. However, the deformation rate of each soil layer presents different characteristics. The results of the stress-strain diagram method show that the inelastic specific storage of the first and second clay layers is between 1.49×10 -5 and 2.10×10 -5, the elastic specific storage is between 3.93×10 -5 and 8.38×10 -5, the inelastic specific storage is 2-4 times of the elastic specific storage, the vertical hydraulic conductivity is between 6.20×10 -6~4.39×10 -5 m/d, and the soil deformation lag time is 2.1-12.8 years. The specific storage of the shallow layers in the study area estimated by the type curve method is about 4.8×10 -4, and that of the deep layer is between 1.08×10 -4 and 2.05×10 -4. The specific storage of shallow layer is 2-4 times of that of deep layer, and the vertical hydraulic conductivities are 1-2 orders of magnitude larger than that of the deep layers. Related Articles | Metrics

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Meso-Cenozoic Uplift and Transformation of Tectonic Extension Mode in the Eastern Margin of Qinghai-Tibet Plateau JIN Wenzheng, BAI Wankui, YE Zhixu Geological Journal of China Universities    2023, 29 (6): 872-885.   DOI: 10.16108/j.issn1006-7493.2022057 Abstract （638）      PDF （1532KB）（290）       Knowledge map    Save In order to analyze changes in of tectonic deformation and extension mode during the process of eastward compression of Qinghai-Tibet Plateau, the eastern edge of Qinghai-Tibet Plateau is selected as the study area, and apatite/zircon fission track studies were carried out. The results show that many differences between the Zoige Basin and the Longmenshan Block in the aspect of low-temperature geochronology and tectonic uplift: the cooling rates of several samples in the Zoige basin are relatively stable, ranging from 1.257 ℃ to 1.285 ℃ /Myr, while the cooling rates of several samples in the Longmenshan Block changes greatly, ranging from 1.243 ℃ to 2.875 ℃ /Myr; Zoige Basin has experienced two obvious tectonic thermal events since 100 Ma with the first in 100-80 Ma (cooling rate is 4.40±0.395 ℃ /Myr) and the second in 21-12 Ma (cooling rate is 2.89±0.597 ℃ /Myr). The eastern edge of Longmenshan Block has generally shown a gradual increase in the degree of tectonic uplift since 70 Ma, and the uplift has continued to increase since 8 Ma with the cooling rate of 5.75±0.238 ℃ /Myr; The tectonic deformation of Zoige Basin can be classified as forward expansion, while the Longmenshan Block has backward expansion (especially since 8 Ma). The process mentioned above is summarized a“s reflection and refraction of tectonic expansion”, the“ reflection tectonic stress”reached current location of Longriba fault in Pliocene (about 4.48 Ma), with the result of the Longriba fault zone with the features of both thrust and dextral strike slip. Related Articles | Metrics

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Early Cretaceous Large-scale Reworking of the Juvenile Crust in North Qinling: Geochemical Composition and Genesis of the Huanghuaman Pluton QI Zeqiu, YU Yang, ZHAO Jingxin, GE Dongli, HE Jun, CHEN Fukun Geological Journal of China Universities    2023, 29 (6): 831-846.   DOI: 10.16108/j.issn1006-7493.2022046 Abstract （168）      PDF （4319KB）（289）       Knowledge map    Save The eastern Qinling orogen documents two magmatic episodes of granitoids in the Late Jurassic and Early Cretaceous. Their geochemical characteristics, being a petrologic probe for the composition and structure of the deep crust, are distinctly different, pointing to the complex magma sources. In this study, we report zircon U-Pb isotopic ages and whole-rock major and trace element contents and Sr-Nd-Pb isotopic compositions of the Huanghuaman pluton exposed in the eastern section of the North Qinling block. Zircon U-Pb ages indicate that the large-volume biotite monzogranite of the Huanghuaman pluton was emplaced during the 119 Ma to 117 Ma interval. The biotite monzogranites are enriched in large ion lithophile elements and light rare earth elements, but depleted in high field-strength elements and heavy rare earth elements, with significantly negative Eu anomalies and belong to the weakly peraluminous high-K calc-alkaline series. They are characterized by high radiogenic Pb isotopic compositions and relatively depleted Nd isotopic composition with initial εNd values of -5.7 to -4.1. These geochemical characteristics are remarkably different from those of the Late Jurassic granitoids within the North Qinling block and L ate Mesozoic granitoids within the southern margin of the North China block. The relatively depleted Nd isotopic composition of the Huanghuaman pluton is similar to those of the coeval Laojunshan in the eastern section and the Early Cretaceous Taibai granite in the western section of the North Qinling block, s uggesting that this block underwent large-scale reworking of the juvenile crust during the Early Cretaceous. The juvenile crustal materials might be derived from the mafic rocks within the North Qinling block or the subducted Neoproterozoic crustal rocks of the Yangtze and/or South Qinling blocks. These Early Cretaceous granitoids have different Nd isotopic compositions from those of the Late Jurassic Mangling and Muhuguan plutons in the North Qinling block, reflecting the compositional diversity of the granitoids that were derived from the deeply underlying, co mplex crustal materials. Related Articles | Metrics

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Origin and Genetic Mechanism of the Early Cretaceous Metabasite from the Ramba Area, Tethyan Himalaya YU Youzhi, LIU Zhichao Geological Journal of China Universities    2023, 29 (4): 527-542.   DOI: 10.16108/j.issn1006-7493.2022007 Abstract （163）      PDF （4128KB）（275）       Knowledge map    Save A large number of Early Cretaceous mafic rocks are widely exposed in the Tethyan Himalaya, southern Tibet, China. These rocks provide an important record of the tectonic-magmatic evolution of the north margin of the Indian continent before the Cenozoic Indian-Eurasian collision. Their genesis is critical for reconstructing the evolution history of the Indian passive margin. This paper presents systematical petrographic and geochemical data of the Early Cretaceous metabasites from the Ramba area, eastern Tethyan Himalaya. The Ramba metabasites include amphibolitie-amphibolitic gneisses, which occurred as dikes and lenses in the low-medium grade metasedimentary rocks of the Ramba dome. These Ramba metabasites display tholeiitic affinity and low contents of SiO 2 (44.78-47.42 wt%), relatively high contents of MgO (7.31-9.60 wt%) and FeOt (9.68-15.87 wt%) with variable TiO 2 contents (0.73-2.16 wt%) and medium to high Mg# values (46.4-63.9). The radiogenic Nd isotopic compositions of the Ramba metabasites (ε Nd(t) values range from 5.7 to 6.5) are comparable with that of the Indian Oceanic MORB. However, the REEs distribution patterns of the Ramba metabasites are similar to that of the E-MORB, indicating involvement of enriched components in their origin. It is worth noting that the Ramba metabasites do not show depletion in high-field-strength elements (HFSE), and their Nb/U ratios are similar to that of the mantle-derived rocks. Therefore, it can be inferred that the continental crust contamination is not significant in the formation of Ramba metabasites and their enrichment components should be mainly attributed to an enriched mantle source. Consequently, it is speculated that the Ramba metabasites were products of the interaction between magma derived from a depleted asthenospheric mantle and an enriched continental lithospheric mantle. They were generated during the early stage of the breakup of eastern Gondwana (~140 Ma) and were originated from the asthenosphere upwelling that was triggered by early activity of the Kerguelen mantle plume. Related Articles | Metrics

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Predicting Permeability of Porous Media from Pore Structure Features of Slices by Machine Learning MENG Yinquan, JIANG Jianguo, WU Jichun Geological Journal of China Universities    2024, 30 (01): 1-11.   DOI: 10.16108/j.issn1006-7493.2022088 Abstract （161）      PDF （3148KB）（272）       Knowledge map    Save Using machine learning models to predict the permeability of porous media is one of the key research directions of current pore-scale models. Since three-dimensional porous media data cannot be directly applied to classical machine learning models, it is necessary to perform feature extraction on the pore s pace structure. Deep learning, as the advancement of classical machine learning models, has achieved many successes in predicting permeability from three-dimensional digital images of porous media, but the computational cost is quite high. This study extracted pore structure features of slices of porous media, converting digital images into multidimensional vectors and serving as input to machine learning models. While reducing the amount of input data and greatly improving the training efficiency, the models maintained excellent prediction performance, where the long short -term memory (LSTM) neural network achieved the best results. Related Articles | Metrics

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Petrogenesis and Geologic Implication of the Late Paleoproterozoic A-type Xiaohe Pluton along the Southern Margin of the North China Craton WANG Meixuan, WANG Zhiyi, ZHAO Jingxin, QI Zeqiu, HE Jun, CHEN Fukun Geological Journal of China Universities    2023, 29 (6): 809-830.   DOI: 10.16108/j.issn1006-7493.2022053 Abstract （153）      PDF （3050KB）（265）       Knowledge map    Save Paleoproterozoic granitoids in the southern margin of the North China Craton are important carriers for studying the crustal evolution in Precambrian. In this study, we report zircon U-Pb ages and whole-rock geochemical compositions of the Xiaohe pluton exposed along the southern margin of the North China Craton in order to discuss its petrogenesis and significance for Precambrian crustal evolution. The Xiaohe pluton is composed of biotite-bearing monzogranite, geochemically, which can be divided into two categories according to its rare earth element characteristics. Type I shows the right dip distribution mode of light rare earth elements enrichment and heavy rare earth elements depletion, which has the characteristics of medium differentiation. Type II has a distribution pattern of rare earth elements with low total rare earth elements, insignificant fractionation of light and heavy rare earth elements, and depletion of middle rare earth elements, which has the characteristics of high differentiation. The zircon U-Pb dating on these two types of granite yielded ~1.80 Ga ages for the emplacement time of the magmas, indicating both of them emplaced in single magmatic period. All the analyzed rocks are rich in silica and alkaline and weakly peraluminous, having high-K alkali-calcareous and calc-alkaline characteristics. They are enriched in Rb, Th, U, K, etc., but depleted in Ba, Sr, P, and Ti. Both types granites have similar Nd-Hf isotopic compositions and their magmas should originate from partial melting of the Late Archean basement rocks along the southern margin of the North China Craton. The magmatism of A-type granite probably represents the tectonicsthermal event closely related to extension, implying a post-collisional/post-orogenic extensional setting along the southern margin of the North China Craton at ca. 1.80 Ga.  Related Articles | Metrics

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Petrogenesis of Granite Porphyry in the Yangchuling Tungsten Ore District, Northern Jiangxi HUANG Yu, HUANG Xudong, LU Jianjun, ZHANG Rongqing, WU Jinwei, YAN Jichi Geological Journal of China Universities    2023, 29 (6): 795-808.   DOI: 10.16108/j.issn1006-7493.2022049 Abstract （186）      PDF （2668KB）（262）       Knowledge map    Save Granodiorite, monzogranite porphyry, and granite porphyry are exposed in the Yangchuling tungsten ore district, northern Jiangxi. The granodiorite and monzogranite porphyry were formed in Late Jurassic and derived from the same source and the latter is more evolved than the former. Tungsten mineralization dominantly occurs as veinlet-disseminated within the monzogranite porphyry which is cut by the granite porphyry dykes. In this contribution, zircon U-Pb chronological, petrochemical, and Sr-Nd-Hf isotope geochemical studies are carried out on the Yangchuling granite porphyry, aiming to reveal the petrogenetic differences between the granite porphyry and the monzogranite porphyry and granodiorite in combination with other published data and provide new constraints for tungsten ore genesis. LA-ICP-MS zircon U-Pb dating manifests that the granite porphyry was formed at 144.6±1.8 Ma which is consistent with those of the granodiorite and monzogranite porphyry. The granite porphyry is high-Si, K-enriched, and weakly peraluminous, shows distinctly Ba-, Nb-, Sr-, P-, and Ti-depleted trace element patterns and rightward-sloping REE patterns with negative Eu anomalies, indicating fractional crystallization of feldspar, biotite, apatite, and Ti-Fe oxide minerals, etc. The granite porphyry has whole-rock (87Sr/86Sr)i , εNd(t), εHf(t), and zircon εHf(t) values of 0.711329-0.711726, -5.3 to -4.9, -4.6 to -4.2, and mainly -6.0 to -3.0, respectively, suggesting that its source is dominated by ancient crustal materials. Compared with the granodiorite and monzogranite porphyry, the granite porphyry exhibits higher HFSE, ΣREE contents, AMF values, Sr/V ratios and lower Mg# values, Ti/Zr ratios, whole-rock εHf(t) values, implying that it was derived from a more felsic source and is the product of partial melting of ancient metasediments. Compared with the monzogranite porphyry, the granite porphyry displays higher SiO2 contents, (Na2O+K2O)/CaO, Na2O/CaO, Ba/Sr, Rb/Sr ratios and lower CaO, MgO, TiO2, P2O5 contents, δEu values, manifesting that it has experienced stronger magmatic fractionation. The barren granite porphyry is reflective of a W-poor source, while the source of the granodiorite and monzogranite porphyry is relatively W-rich. Both the W-rich source and magmatic fractionation facilitate the formation of t he Yangchuling tungsten deposit. Related Articles | Metrics

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Comparison of Gravel Layers along the Yangtze River between Yichang and Wuhan WANG Heyuan, WANG Zekun, GU Siying, YANG Shuoxuan, ZHAO Ziyao, CHEN Xu Geological Journal of China Universities    2024, 30 (01): 47-55.   DOI: 10.16108/j.issn1006-7493.2022091 Abstract （125）      PDF （2101KB）（261）       Knowledge map    Save Several thick gravel layers are widely distributed in the middle reaches of the Yangtze River, providing useful clues for tracking the evolution of the Yangtze River. Previous studies mainly focused on the chronologies and sedimentary characteristics of gravel layers in local sites, while comparison of gravel layers among different regions has not been extensively investigated. In this study, eleven profiles of gravel layers in Yichang and Wuhan were explored, the morphology and lithology of 1616 gravels were analyzed. Furthermore, geochemical composition of silty sediments intermixed in gravel layers were measured in order to explore the provenance of the sediments, in combination with regional geological conditions. The results show that the dominant inclinations of gravels in the gravel layers of Yichang and Wuhan are different. Gravels in the Yichang gravel layers mainly consist of granite, sandstone, conglomerate and some siliceous rocks. Gravels in Wuhan are dominated by quartzite, with a small amount of flint. Silty sediments in the gravel layers of Yichang are relatively enriched in Ca and Sr, while those in Wuhan are relatively enriched in Fe and Al. Comparison of gravels and silty sediments in the two regions shows that the provenances of gravel layers in the two regions are different. Detritus from the upper reaches of the Yangtze River are important sources of the gravel layers in Yichang, while the gravel layers in Wuhan are sourced from the Dabie Mountains. The results of this study provide new evidence for improving our understanding of the provenances of gravel layers in the middle reaches of the Yangtze River. Related Articles | Metrics

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Columbite-group Minerals from the Pegmatite in the Lalong Pluton, Eastern Himalaya and the Two-staged Nb-Ta Mineralization LI Xuejiao Geological Journal of China Universities    2023, 29 (6): 847-861.   DOI: 10.16108/j.issn1006-7493.2022006 Abstract （131）      PDF （8863KB）（260）       Knowledge map    Save Leucogranites are widely distributed in the Himalayan orogenic belt and are closely related to rare-metal mineralization. This study focuses on the Nb and Ta mineralization and columbite-group minerals (CGMs) from the granitic pegmatite in the Lalong pluton, eastern Himalayas. Three zones (i.e., wall zone, intermediate zone, and core zone) can be identified from the Lalong pegmatite based on their lithology. The CGMs mainly exist in the intermediate zone (quartzfeldspar- muscovite zone). Major element, trace element, and U-Pb isotopic compositions of CGMs were systemically analyzed. Two types of CGMs are distinguished by occurrences and chemical compositions. Type I CGMs have euhedral occurence and uniform chemical compositions with low Ta # [Ta/(Nb+Ta)] ranging from 0.08 to 0.34. Type II CGMs mainly distribute around crystals of the type I CGMs or as tiny veins cutting through the type I CGMs with higher Ta # ranging from 0.45 to 0.60. Several structures (i.e., oscillatory structure, metasomatic structure, fissure-filling, and porous) are well developed in the type II CGMs. The normalized REE patterns of these CGMs are similar, showing a strong negative Eu anomaly with δEu ranging from 0.001 to 0.020. The LREE/HREE ratio of CGMs ranges from 0.016 to 0.044. Our results indicate a two-staged Nb-Ta mineralization in the Lalong pluton. The first-staged mineralization is related to the magmatic process with the crystallization of the type I CGMs, while the second-staged process is late-staged hydrothermal fluidrich magmatism with the formation of the type II CGMs. The REE pattern of the type II CGMs, however, is not convincing enough to indicate the magmatic-hydrothermal mineralization. The CGMs U-Pb isotopic analysis reveals the age of Nb- Ta mineralization at 22.3±0.3Ma, implying a rare-metal resource potential of the leucogranites formed in the Neohimalayan period (25-14 Ma). Related Articles | Metrics

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Study on Optical Fiber Temperature Measurements and Ground Temperature Changes in Pumping and Irrigation Wells of Carbonate Thermal Storage SHI Qipeng, TAN Xianfeng, MENG Jia, ZHENG Huiming, ZHANG Xi, LIU Xiao, SONG Shuailiang, DU Ying Geological Journal of China Universities    2023, 29 (5): 756-765.   DOI: 10.16108/j.issn1006-7493.2022013 Abstract （848）      PDF （1505KB）（253）       Knowledge map    Save Carbonate thermal reservoirs have the characteristics of rich geothermal resources, good mining conditions and large water inflow of single wells, and represent one type of the main thermal reservoirs for the development and utilization of middle and deep geothermal resources. In the process of long-term geothermal exploitation and tail water reinjection, it is necessary to maintain the hydraulic connection between pumping and irrigation wells to avoid thermal breakthrough, The long-term monitoring of thermal reservoir temperature, analysis, and calculation of heat sources in pumping and irrigation wells are important topics for sustainable development and utilization of geothermal resources. This paper introduces the distributed optical fiber temperature measurement technology of pumping and irrigation wells, monitors the influence of pumping and reinjection of carbonate thermal storage on ground temperature, and analyzes the heat sources and quantity of heat storage temperature recovery using the monitoring data. The results show that (1) the heat storage temperature of the pumping well decreased significantly on the sixth day after heating with an average decrease of 1.6 ℃、 which was affected by the small spacing of pumping and irrigation wells and the dominant channel of carbonate heat reservoir, and the pumping and irrigation well produced a thermal breakthrough； the heat storage temperature of the reinjection well failed to recover to the initial temperature before the second heating season due to a large amount of low-temperature tail water reinjection for a long time, and the temperature of pumping well basically recovered. Analysis reveals that the main source of reservoir heat recovery is geothermal water convection and heat accumulation, followed by high-temperature reservoir and geothermal water conduction and heat accumulation. The results of this study show that under the condition of large-scale reinjection, the temperature of reinjection well decreases and the thermal breakthrough of pumping and irrigation well is an inevitable development trend. In order to promote the sustainable development and utilization of geothermal resources, it is very necessary to study the appropriate well spacing of pumping and irrigation wells to prevent thermal breakthrough in a short timescale. Related Articles | Metrics

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Reactive Transport Numerical Modeling for Deep Geological Sequestration of Brine Wastewater DU Zhuoran, DU Song, YANG Yun, SONG Jian, WU Jianfeng, WU Jichun Geological Journal of China Universities    2023, 29 (4): 571-579.   DOI: 10.16108/j.issn1006-7493.2021110 Abstract （1879）      PDF （2212KB）（253）       Knowledge map    Save Brine wastewater deep well injection in China is still at the stage of access demonstration. The transport of liquid waste in deep reservoirs involves variable density drive, water-rock chemical reactions and variable-parameter synergistic physical-chemical interactions. How to quantitatively characterize these processes is one of the key scientific and technological challenges to be solved in deep well injection. Consequently, this paper selected a certain injection zone in Ordos Basin as prototype, used PFLOTRAN to construct a variable-density and variable-parameter reactive solute transport model to predict and evaluate the migration, transformation and evolution of reservoir minerals, as well as the change of reservoir properties after the brine wastewater injection to the deep geological body. As the simulation results showed, the injection of brine wastewater into the injection zone contributes to secondary minerals precipitation, such as anhydrite, calcite and fluorite; the geological storage capacity decreases by 1.51% approximately in the simulated 100 years; and the contamination area is around 2.57 km 2. This model provides a simulation tool to quantitatively characterize the migration and transformation process of brine wastewater components after the deep well injection. Related Articles | Metrics

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Petrogenesis and Tectonic Implications of the Indosinian Fengxian Pluton, Western Qinling Orogeny NI Chunyu, JIANG Yaohui Geological Journal of China Universities    2023, 29 (4): 559-570.   DOI: 10.16108/j.issn1006-7493.2021121 Abstract （186）      PDF （1868KB）（245）       Knowledge map    Save This paper reports systematically petrological and SHRIMP zircon U-Pb dating, whole-rock geochemical and Sr-Nd-Hf isotopic research for the Fengxian Pluton. We discussed the magmatic evolution, source characteristics, tectonic and geodynamic settings of these plutons. Our study shows that: 1. The Fengxian pluton is composed of granodiorite and quartz monzonite, invaded in the Middle Triassic (~237.5 Ma). The SiO 2 content of the rock is 61.7~66.7 wt %, belonging to the high potassium calc-alkaline series, with relatively high MgO content (1.49-2.43 wt%) and Mg# value (0.53-0.58), belonging to the high-K calc-alkaline series. They are enriched in light rare earth elements (LREE) and lack marked negative Eu anomalies. They are also enriched in LILE and depleted in HFSE. Their high Sr (474×10-6-629×10-6) low Y (6.85×10-6-7.60×10-6) and Yb (0.57×10-6- 0.72×10-6) value are similar to those of adakites. They show εNd(t) values of -4.2 to -5.8, initial 87Sr/ 86Sr ratios of 0.7072-0.7077 and ε Hf(t) values of -1.1 to -4.3. We believe that the Fengxian pluton is mainly derived from subducted sediments in the continental margin environment of the northward subduction of the Paleo-Tethys oceanic slab. The origin of the Fengxian pluton suggests that the Animaqing-Mianlue oceanic crust had subducted under the West Qinling before 237.5 Ma, and the eastern segment of the West Qinling remains a continental arc till the Middle Triassic. Related Articles | Metrics

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Stagnant Lid Tectonics in the Early Earth and Its Transition to Plate Tectonics YANG Haokun, LI Jianghai Geological Journal of China Universities    2023, 29 (6): 862-871.   DOI: 10.16108/j.issn1006-7493.2022052 Abstract （910）      PDF （958KB）（237）       Knowledge map    Save Plate tectonics has been regarded as the dominant tectonic regime on the earth today, but what was earth’s tectonic regime before the present plate tectonics began and when the present plate tectonics began are still controversial. To understand the evolution of earth and predict its future, we are required to clarify this question. Previously, researchers generally reached a consensus on an uniformitarian view that the early earth’s tectonics was similar to the present plate tectonics. However, with the accumulation of geological data and the progress of research technology, the idea of the transition from stagnant lid tectonics to modern plate tectonics was increasingly accepted. The so called “stagnant lid” refers to single plate around earth surface. In this paper, firstly we review the hypothesis of possible tectonic regime models in the early Earth under the background of stagnant lid tectonics, including heat pipe tectonics, plutonic-squishy lid model, mantle overturn and lid-and-plate tectonics. Then we review the latest research of the transition from stagnant lid tectonics to plate tectonics in early Earth. We believe that the mainstream researchers have reached a roughly consistent framework, that is, the transition from stagnant lid tectonics to plate tectonics occurred in the Meso-Neoarchean, and the modern plate tectonics may have formed in the Neoproterozoic. Related Articles | Metrics

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Trace Element Characteristics and Geological Significance of Sphalerite in Xiwan Lead-Zinc Deposit, Luzong Basin, Anhui Province ZHANG Hongqiu, HAN Shanchu, ZHANG Yong, PAN Jiayong, ZHANG Yanqun, ZHAO Bibo, DING Yong, JIANG Yao, HU Shengping Geological Journal of China Universities    2023, 29 (5): 693-704.   DOI: 10.16108/j.issn1006-7493.2022028 Abstract （210）      PDF （2751KB）（222）       Knowledge map    Save The Luzong volcanic basin is an important part of the metallogenic belt in the middle and lower reaches of the Yangtze River. In recent years, a large-scale Xiwan lead-zinc deposit has been discovered in the East Ma’anshan Formation on its northern margin. Previous studies have shown that sphalerite in this deposit is enriched in certain dispersed elements, but there are few in-depth studies on its content and distribution characteristics and comprehensive evaluation of dispersed elements is lacking. Therefore, in this paper, the LA-ICP-MS analytical method was used to study the characteristics of trace elements in sphalerite of No. Ⅳ and Ⅴ ore bodies in the Xiwan lead-zinc deposit and discuss its geological significance. The results show that (1) Sphalerite is rich in Fe, Mn, Cd, Pb elements, and depleted in In, Tl, Se, Te, Sn elements, among which dispersed Cd element has certain comprehensive utilization values; (2) The substitution mechanisms of trace elements in sphalerite mainly include single element and multi-element coupling. Among them, the substitution mechanism of single element mainly includes Fe 2+ instead of Zn 2+, Cd 2+ instead of Zn 2+, etc. The multi-element coupling substitution mechanism mainly includes (Cu ++Ge 3+) instead of 2Zn 2+, (2Cu ++Ge 4+) instead of 3Zn 2+, etc.; (3) The composition characteristics of Fe, Mn, Cd, In and other trace elements (dispersed elements) in sphalerite show that the metallogenic temperature of the Xiwan lead -zinc deposit is medium to low temperatures, which belong to the epithermal deposit.  Related Articles | Metrics

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Synthesis Technology and Application of Red Mud Based Layered Double Hydroxide JIANG Yimei, SHEN Zhengtao Geological Journal of China Universities    2024, 30 (01): 12-21.   DOI: 10.16108/j.issn1006-7493.2022065 Abstract （138）      PDF （1410KB）（221）       Knowledge map    Save Red mud is a highly alkaline waste produced in the process of refining alumina from bauxite. Due to the rapid development of the aluminum industry, the annual discharge of red mud in the world has seriously exceeded the environmental load, resulting in huge disposal pressure and pollution risks. Therefore, the efficient utilization of red mud as a resource is imminent. The preparation of layered double hydroxide (LDH) from red mud is a circulating route, and has the potential for large-scale industrialization. This paper reviews the research progress of red mud based LDH synthesis technology and application. It is found that the main synthesis processes include co-precipitation, calcination-hydration and mechanochemical methods. The synthesized red mud-based LDH type is affected by bauxite composition and smelting technology. Significant impact. Red mud based LDH is typically used as an absorbent to remove inorganic pollutants and capture CO2, and it is also a new environmentally friendly halogen-free flame retardant additive. Red mud based LDH is also an excellent photocatalyst, and the introduction of impurities(Fe2O3) in red mud leads to the local construction of heterostructures, which is beneficial to the separation and transfer of photosensitive electrons and holes. Finally, this paper puts forward the following prospects: (1) In the context of carbon neutral targets, the preparation of red mud based LDH meets the sustainable development goals such as “circular economy” and has practical potential for large-scale application, and the synthesis and application research should be vigorously promoted; (2) It should focus on how to further optimize the synthesis process, improve yield, enhance sustainability (such as introducing other wastes as divalent metal sources), improve synthesis specificity, and reduce the environmental risk of red mud-based LDH in the application process; (3) Understand the relationship between LDH properties and its performance, and exploit the advantages of the heterostructure of red mud based LDH achieve a more efficient a pplication. Related Articles | Metrics

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Sedimentary Characteristics of the Triassic Karamay Formation in the North Hongshanzui Area, Junggar Basin WANG Jin, YU Xinghe, LU Fenghao, NIU Xiaojun, YE Zhaorui, YANG xintao Geological Journal of China Universities    2023, 29 (5): 776-787.   DOI: 10.16108/j.issn1006-7493.2022024 Abstract （158）      PDF （6278KB）（213）       Knowledge map    Save The obvious sedimentary differences can be found between the upper and lower parts of the Karamay Formation in the north of Hongshanzui. To determine the sedimentary characteristics of the Karamay Formation, the seismic, core logging, and analytical data were used to analyze the rock and mineral characteristics, typical lithofacies, and sedimentary facies of the Karamay Formation. The results show that the lower Karamay Formation is characterized by the braided river deposits with obvious traction-current deposition, which is mainly composed of braided channel (Gi → St → Sp → (Sh) → Md), braided bar (St→Sp↔Sm), and alluvial plain (Mr↔Md → Fr). The channel sand-bodies are banded and mostly isolated from thick mudstone. The upper Karamay Formation is dominated by fan-delta with debris flow, density flow and tractioncurrent deposits. The braided channel (Gmm→Gcm→Gi→Sh), braided distributary channel (Gcm→Gi↔Gt) and braided bar (Gp↔Gi→Gcm) are developed in the fan-delta plain. The underwater distributary channel (Gi→Gt→Gp→St), mouth bar (Md→Sp↔Sw) and interdistributary bay (Md↔Sc) are developed in the fan-delta front. The thick stacked sandy conglomerate bodies are scours and overlap with each other and also characterized by good connectivity and broad distribution. The transformation from the braided river to fan-delta in the Karamay Formation is mainly controlled by the forwarded provenance system and increased supply capacity, the transition of the paleoclimate from arid and semi-arid to sub-humid and humid, and the lake level rise.  Related Articles | Metrics

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Advances on the Analogue Modeling of the Emplacement of Granitic Magma LI Yingying, WANG Bo, CAO Tingting Geological Journal of China Universities    2023, 29 (4): 543-558.   DOI: 10.16108/j.issn1006-7493.2022055 Abstract （219）      PDF （7635KB）（210）       Knowledge map    Save Regional tectonics not only facilitate the ascent and emplacement of the granitic intrusions but also control the final shapes of the intrusions. Analogue modeling is a critical method to study the magma emplacement. This paper reviewed the experimental set-up, materials and scaling used in previous analogue models related to magma emplacement, and summarized the influence of various parameters on the geometry of the intrusions in various tectonic settings. We suggested that: (1) the intrusion geometry is controlled by the characteristics of the country rocks in pre-kinematic static settings during tectonic quiescent stage. (2) In syn-kinematic settings during tectonic active stage, the intrusion geometry and deformation patterns of plutons are influenced by several parameters, including the thickness and rheological layering of the country rocks, velocity and total distance of displacement, velocity and total volume of magma injection, position of the injection inlet (magma channel), relative timing of tectonic activity and magma emplacement. Deformation can in turn control the shape of intrusions. (3) The parameters, such as displacement velocity and injection velocity in different settings, have similar impact on the intrusion geometry. In addition, some limitations of analogue modeling method are also discussed. The CT technique and numerical modeling methods are suggested to be profitable supplementation of analogue modeling for the study in magma emplacement.  Related Articles | Metrics

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Research on Ecological Restoration Mode of Abandoned Open Pit Mines along the Yangtze River WAN Jiajun, XIA Yinfeng, SHAO Yong, ZHOU Qigang Geological Journal of China Universities    2024, 30 (01): 110-117.   DOI: 10.16108/j.issn1006-7493.2023036 Abstract （144）      PDF （2142KB）（208）       Knowledge map    Save The ecological restoration of the Yangtze River Basin has been an important part of China’s environmental protection work in recent years. This paper proposes ecological engineering mode, land reclamation mode, landscape reconstruction mode, and natural restoration mode of ecological restoration, based on the current situation of abandoned open-pit mines in the Yangtze River Basin (within Jiangsu province) and a large number of practical restoration experiences. The characteristics and applicability of these four Modes are elaborated, providing a reference for the ecological restoration of abandoned mines. An abandoned open-pit mine ecological restoration project along the coast of the Yangtze River in Jiangsu Province was introduced in detail as an example. The main issues in the development of geological disaster risks, the destruction of ecological environment and landscape, and the waste of land resource are identified through the analysis of ecological environmental problems. The ecological restoration of the abandoned mine was carried out successfully following the ecological engineering mode, resulting in good ec ological, social, and economic benefits. Related Articles | Metrics