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    Overview of the Application and Prospect of Common Chemical Weathering Indices
    LI Xulong, ZHANG Xia, LIN Chunming, HUANG Shuya, LI Xin
    Geological Journal of China Universities    2022, 28 (1): 51-63.   DOI: 10.16108/j.issn1006-7493.2020118
    Abstract3437)      PDF (1109KB)(4417)       Save
    Common chemical weathering indices such as the Weathering Index of Parker (WIP), the Chemical Index of Alteration (CIA), the Index of Compositional Variability (ICV), CIX index and αAlE are often used to evaluate the chemical weathering intensity of source areas. But the factors which controlling the above chemical weathering indices should be considered, otherwise the results of the weathering evaluation will be distorted. This paper argues that the geological survey of source area should be known when chemical weathering indices are used to study the chemical weathering process. The selection of fine sediments or suspended matter can weaken the influence of grain size on chemical weathering indices. The impurities in the sediments are removed by acid treatment. Then, the Sc/Th-CIA diagram was used to reflect the material source information, Th/SC-Zr/Sc diagram was used to further distinguish the control effect of sedimentary differentiation and sedimentary recirculation, and then the samples with ICV value less than 1 were selected to eliminate the interference of recirculation. The A-CN-K diagram or the formula proposed by Panahi (2000) were used to correct the potassium metasomatism, and the strength of chemical weathering of source rocks was evaluated by CIA eventually. To ensure that the calculation of chemical weathering indices can accurately reflect the weathering situation of the source area, SPSS software can be used to analyze the proportion of some factors which affecting the CIA to construct characteristic weathering index of the study area.
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    Paleogeographic Reconstruction Driven by Big Data: Challenges and Prospects
    ZHANG Lei, ZHONG Hanting, CHEN Anqing, ZHAO Yingquan, HUANG Keke, LI Fengjie, HUANG Hu, LIU Yu, CAO Haiyang, ZHU Shengxian, MU Caineng, HOU Mingcai, JAMES G. Ogg
    Geological Journal of China Universities    2020, 26 (1): 73-.   DOI: 10.16108/j.issn1006-7493.2019091
    Abstract546)      PDF (1094KB)(864)       Save
    Paleogeography is a typical data-reliable subject. Paleogeographic reconstruction focuses on the characteristics of geographic, life, and climate changes on the Earth's surface through geological history. In the new era of big data, the continuous accumulation of massive paleogeographic data and the rapid development of computer science technology make it possible to reconstruct the paleogeographic history using more standard and intelligent tools and software. The current paper reviews the major databases and research groups related to paleogeography, and proposes the following key components of big data-driven paleogeographic reconstruction: (1) A standard paleogeographic knowledge system; (2) An open and interactive paleogeographic data platform with new technologies such as natural-language understanding to expand data sources; (3) Paleogeographic data quality control mechanisms; (4) Various types of paleogeographic reconstruction models contructed with artificial intelligence technology; (5) Visual outputs as time-sliced maps or animations.
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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
    Abstract190)      PDF (1237KB)(549)       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.
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    Active Source Seismic First-arrival Pickup Method Based on Small Sample Convolutional Neural Network
    YU Zhihan, WANG Tao, SUN Pengyuan, WANG Wenchuang, GUO Zhenbo
    Geological Journal of China Universities    2022, 28 (3): 414-423.   DOI: 10.16108/j.issn1006-7493.2021060
    Abstract356)      PDF (3646KB)(521)       Save
    The interpretation of seismic travel-time imaging depends on the accuracy of picking up first arrivals, and it is low efficiency and high cost to pick up arrivals manually. Previous studies showed that deep learning can be applied for automatically picking, but the methods often need a large number of arrivals as the training set. In this study, we trained the U-Net with multichannel images and found that the root mean square error (RMSE) of first P arrivals decreases with the increase in the number of training sets. The errors of 35 and 597 shots are 11.4 and 6.5 ms, respectively. Referring to data augmentation methods in semisupervised
    learning, we selected methods (Random Crop, Random Erase, etc.) suitable for seismic data and applied them to the training set. After random erase of the training sets of 35 shots, the RMSE is less than 5.5 ms (about 3 sampling points), which is 51% less than the error with the original training set. Compared with previous deep learning methods, the augmentation methods can be implemented to pick up the first arrivals with higher precision in the case of small samples.
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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
    Abstract100)      PDF (1310KB)(306)       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.

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    Petrogenesis of Ophiolite-type Chromite Deposits in China and Some New Perspectives
    HU Zhenxing, NIU Yaoling, LIU Yi, ZHANG Guorui, SUN Wenli, MA Yuxin
    J4    2014, 20 (1): 9-.  
    Abstract931)      PDF (1391KB)(1979)       Save
    Ophiolites of varying ages are widespread in China, some of which contain chromite deposites of industrial value. However, compared with some of the world’s large ophiolite chromite deposites (e.g., Kempirsai, Bulquiza, Guleman), the Chinese chromite deposits are small (e.g., Sartohay, Dongqiao, Luobusa). Recent research recognizes that most ophiolites with significant chromite reserves are all formed in a surpasubduction zone environment. Melt-rock interaction is a popular interpretation for the origin of podiform chromite deposits, but the actual mechanism in this model for chromite enrichment remains unclear. It remains the primary task to understand process or processes of chromium enrichment towards the formation of chromite deposits. Is the formation of chromium-rich melts necessary? If so, when, where, how, and under what conditions could this take place? These are additional processes beyond the well-understood aspects of the petrogenesis that need to research towards an effective chromite mineralization model.
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    Cited: Baidu(3)
    SedimentaryEnvironmentandMineralizationMechanismofthe StromatoliticPhosphoriteintheEdiacaranDengyingFormation, Weng′anCountyofGuizhouProvince,China
    ZHANG Wei, YANG Ruidong*, MAO Tie, REN Haili, GAO Junbo, CHEN Jiyan
    J4    2015, 21 (2): 186-.   DOI: 10.16108/j.issn1006-7493.2
    Abstract1335)      PDF (3299KB)(1733)       Save

     Stromatolitic phosphorite in the Ediacaran Dengying Formation was initially discovered in Weng′an-Fuquan area of SouthwesternGuizhouProvince,Chinawherephosphateoresarewidelydistributed.Asanewphosphorousstratumofphosphorite,itis characterizeddominantlybytypicalstromatoliticstructures.ThephosphoriteofstromatoliteislocatedatthetopoftheEdiacaran DengyingFormationthatiscomposedoflenticularorganicreef(algalreefofstromatolite).Themajormineralcomponentsofthe stromatoliticphosphoritearephosphatesandcarbonates.Thewhitelaminatedbedsareenrichedinphosphatemineralswhilethedark laminatedbedshavelowercontentsofphosphatemineralsandcontainmainlycarbonateminerals.Analysisofthemineralogicaland geochemicalcharacteristicsindicatesthatstromatoliticphosphoriteintheEdiacaranDengyingFormationisalgalreefofstromatolite thatwasformedinasemi-restrictedsubtidalenvironment.Accordingly,itcouldbeinferredthatthephosphoriccolumnarstromatolitic reefswereformedbyenrichmentinandprecipitationofphosphorusfromtheseawaterwithrichphosphorusduetocomplexbiological orbio-chemicalactionsofalgae.Inaddition,theresultsshowthatthemineralizationofphosphaticmineralsoccurredmainlyatthe sediment-waterinterfaceinweaklyalkalineandsuboxicenvironmentwherealgaehadplayedasignificantrole.

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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
    Abstract143)      PDF (4319KB)(245)       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.
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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
    Abstract131)      PDF (711KB)(481)       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. 
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    Chloritization Sequences in Mudstone during Diagenesis and Its Geological Significance
    FU Yu, DING Qingfeng*, WU Changzhi
    Acta Metallurgica Sinica   
    Feasibility Analysis of the Longyan Geopark in Fujian Province for Applying UNESCO Global Geopark
    JIA Zhenjie, WU Fadong, WANG Yawei, QIANG Xiaoxiao, ZHANG Lihua, XU Lei
    Geological Journal of China Universities    2021, 27 (1): 111-119.   DOI: 10.16108/j.issn1006-7493.2019103
    Abstract459)      PDF (4426KB)(739)       Save
    Longyan Geopark is located in western Fujian Province. The geopark recorded transitional processes of the South China Block from the Indosinian intracontinental orogenic tectonic system to the subduction tectonic system of the paleo-Pacific plate during the Mesozoic. Hence, it is a key area for studying the Mesozoic tectonic evolution in Southeast China. This article analyzes and contrasts the geoheritage, natural and cultural heritages of the geopark to confirm and highlight its uniqueness and important values in geology, aesthetics, education, and tourism. According to the Unite Nations Educational, Science and Cultural Organization (UNESCO) Global Geopark guidelines, there are still some room for improvement for Longyan Geopark to bid for the UNESCO Global Geopark and the suggested improvement has been proposed.
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    Research Progress and Prospect of the Tectonic Evolution of Okinawa Trough and Its Relationship with Magmatism, Hydrothermal Activities and Sedimentation
    LIU Wei,SUN Yujie,ZHENG Hanyue,XIN Mengran,HE Wei,WEI Tong,GUO Shiyue,CHEN Sifang,LIU Wenwen,FENG Yuge
    Acta Metallurgica Sinica    2020, 26 (6): 680-690.   DOI: 10.16108/j.issn1006-7493.2019084
    Abstract638)      PDF (2313KB)(1001)       Save
    The Okinawa Trough is a typical back-arc basin in the western Pacific Trench Arc Back-Arc system. Its unique tectonic location, magmatism, hydrothermal activities and sedimentary records have been a focus of academic research. Based on previous research, we review the controls of magmatic, hydrothermal and sedimentary activities by tectonic evolution of the Okinawa Trough. The subduction of the Philippine Sea plate led to the formation of the Okinawa Trough and the occurrence of arc volcanism, back-arc volcanism and cross-back arc volcanism. These three types of volcanism resulted in three different zones of hydrothermal activity. The magmatism and fault system caused by subduction of Philippine Sea plate provide heat sources and channels for the development of hydrothermal fluid in the Okinawa Trough. The subsidence of Zhe -Min Uplift at ~416 ka brought about the sediments in the northern Okinawa Trough to change from coarse-to fine-grained. Finally, we also provide the outlook of further research based on the current research status of the Okinawa Trough.
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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
    Abstract77)      PDF (4598KB)(199)       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.
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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
    Abstract341)      PDF (2375KB)(535)       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.

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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
    Abstract613)      PDF (1532KB)(215)       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.
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    Enzyme-induced Calcium Carbonate Precipitation (EICP) and Its Application in Geotechnical Engineering
    CAO Guanghui, LIU Shiyu, YU Jin, CAI Yanyan, HU Zhou, MAO Kunhai
    Geological Journal of China Universities    2021, 27 (6): 754-768.   DOI: 10.16108/j.issn1006-7493.2020200
    Abstract1977)      PDF (4975KB)(1450)       Save
    The technique of improving soil by enzyme-induced calcium carbonate precipitation is called EICP, which has attracted more and more attention over the past decade due to its wide application. The article describes the mechanism of EICP and summarizes the extraction methods of plant urease and bacterial urease. In addition, the influence of factors such as urease, calcium source, urea, skimmed milk powder, temperature and pH on the cementing effects of EICP is explored. Furthermore, methods for testing the strength, calcium carbonate content, microstructure and composition of EICP reinforced samples are summarized, and the application of EICP in geotechnical engineering is evaluated. The purpose of this article is to summarize the current status of EICP research and potential problems that need to be overcome in future research.
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    Geochemistry of Huheengeer Complex, Bayan Obo Region, Inner Mongolia and It,s Tectonic Implications
    ZHAO Lei
    J4   
    Abstract1475)      PDF (868KB)(1990)       Save
    Huheengeer mafic-ultramafic complex is found in Bayan Obo region, Inner Mongolia. Petrographically, the complex shows a concentric zoning in rock distribution: hornblende-peridotite, hornblende-gabbro and diorite from core to margin successively. Characteristics of structure and chemistry of the pluton suggest that the rocks were derived from a gabbroicdioritic magma by crystal differentiation. The hornblende-peridotite and hornblende-gabbro were formed by cumulation of early crystallized mafic minerals, and the other rocks crystallized from a magma formed after cumulative process by eutectic crystallization. The parental magmas were compositionaeey similar to high-Al basalt and (or) basaltic andesite. The K-Ar apparent ages of the rocks are between 242-287 Ma. The major rock-forming minerals in the Huheengeer Complex are olivine, pyroxene,plagioclase and hornblende. Based on electron microprobe analysis (EMPA), pyroxene is diopside, and plagioclase is bytownite (An90.6) in amphibole gabbros. The complex also shows geochemical characteristics of enrichment in LREE, LILE (K,Rb,Sr,Ba), and depletion in HREE, HFSE (Nb,Ta,Zr,Hf). According to the AlZ-TiO2, An-Mg,, Hf/3-Th-Ta and Hf/3-Th-Nb/16 diagrams, the Huheengeer complex is suggested to be generated at an active continental margin. All the combined information indicates that these plutons are mafic-ultramafic complex of peritotite-diorite type and they should be a record of Paleoasian Ocean plate subduction to the northern side of North China plate in the Permian.
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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
    Abstract133)      PDF (1003KB)(290)       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.
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    Construction and Application of Lithofacies Paleogeography Knowledge Graphs
    ZHANG Jiajia, ZHANG Lei, ZHONG Hanting, WANG Han, CHEN Anqing, LI Fengjie, REN Qiang, ZHENG Dongyu, ZHAO Hongyi, HOU Mingcai
    Geological Journal of China Universities    2023, 29 (3): 345-358.   DOI: 10.16108/j.issn1006-7493.2023027
    Abstract876)      PDF (2348KB)(377)       Save
    Big data has brought new ideas and challenges to lithofacies paleogeography research. However, due to the problems of complex data types, rich semantic relationships and unclear sharing mechanisms, it is difficult to conduct in-depth data mining, analysis, and effective utilization of lithofacies paleogeographic data, which makes making many advantages of big data not fully exploited in this field. The powerful semantic processing and open interconnection capabilities of knowledge graphs, make it plays an important role in solving the problems of big data text analysis and image understanding, which and haves broad application prospects. This paper summarizes the research background of lithofacies paleogeography knowledge graphs from the perspective of construction and application; by systematically investigates investigating the construction ideas, technologies and processes of lithofacies paleogeography knowledge graphs., and The paper also lists outlines the relevant applications of knowledge graphs in lithofacies paleogeography; and points out the main problems of lithofacies paleogeography knowledge graphs, prospects for future research directions.
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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
    Abstract89)      PDF (6890KB)(309)       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. 
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    Mechanism of Poly-phosphates Sorption by Boehmite: A 31P Solid-state NMR Study
    LI Yongfang, REN Chao, ZHOU Qiang, LI Wei
    Geological Journal of China Universities    2021, 27 (4): 385-393.   DOI: 10.16108/j.issn1006-7493.2020012
    Abstract504)      PDF (2121KB)(650)       Save
    Poly-Phosphate (Poly-P) is a group of very important inorganic phosphates, which exists widely in natural systems. Studying of the transport and transformation of Poly-P is critically essential to understand the biogeochemical cycling of phosphorus. Sorption reactions at mineral-solution interface control the transport and transformation of elements. In this research, the widely distributed hydrated alumina, Boehmite, was selected as the adsorbent to explore the behavior and mechanism of Poly-P sorption, as a function of initial P concentration and pH. Under the experimental conditions, the amounts of the sorbed Poly-P increase with P
    concentration, whereas decrease with increasing pH. To further understand the mechanisms, we adopted several technologies, such as XRD, SEM and 31P solid-state NMR to characterize our samples. The results of 31P solid-state NMR indicate the occurrence of both adsorption and hydrolysis. The P-O-P bond in the middle of the long chain was randomly broken, generating short-chain Poly-P and orthophosphate, both of which were adsorbed as inner-sphere complexes on the surface of Boehmite.

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    High Precision Analysis of Chemical Composition of SPI Monazite Standard on Large Spectrometer of 140 mm Rowland Circle
    HU Huan, WANG Rucheng, XIE Lei, ZHANG Wenlan, TIAN Enrong, XU Yating, FAN Hongrui
    Geological Journal of China Universities    2021, 27 (3): 317-326.   DOI: 10.16108/j.issn1006-7493.2021036
    Abstract367)      PDF (1551KB)(620)       Save
    Monazite is the bearing-LREE (light rare earth elements) phosphate mineral that occurs all types of rocks. It is an essential mineral for understanding the formation processes and U-Pb dating, thus high precision analysis of monazite chemical composition has an important geological significance, and also provides reliable parameters for follow-up studies, such as EMPA CHIME dating and in-situ isotopic microanalysis. EMPA is an in-situ and non-destructive technique with an excellent spatial resolution (~1 μm). Due to that, based on the detailed wavelength scanning for SPI Monazite standard, we focus on discussing the important issues in analytical procedure of monazite chemical composition: accelerate voltage, beam current, time, spectrometer, analysis lines, detected limits, interference factor and standards, and obtain the chemical composition data that are finely consistent with the recommended values of the SPI monazite standard under the optimal analysis conditions. This paper presents the best analytical set-up of JEOL JXA-8530F Plus electron microprobe facility at State key laboratory for mineral deposits research, Nanjing University, particularly establishes the high precision analysis of the trace rare earth elements on large spectrometer of 140 mm Rowland circle. The relative standard deviations (RSD) of all element contents are less than 20% (0.05%-17.75%)and meet the accuracy requirement of integration analysis of monazite composition and geochronology.

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    Application of the Weighted Logistic Regression Model in Prediction of Volcanic Rock-Hosted Copper Deposits-Taking the Middle Part of Ning-Wu Basin as an Example
    ZHAO Zengyu, CHEN Huogen, PAN Mao, JIA Gen, LI Xiangqian, XU Shiyin,GUO Gang, ZH
    J4    2016, 22 (1): 105-.  
    Abstract1048)      PDF (1967KB)(1279)       Save

    Application of the Weighted Logistic Regression model in prediction of volcanic rock type Copper deposits in the Middle
    part of Ning-Wu Basin is studied. First, the geological setting of ore-forming processes is analyzed. Three kinds of factors including
    geological body, structure and wall rock alteration are extracted based on the spatial distribution of copper deposits from the geologic
    map. Then, the spatial relationships between Copper mineral occurrence and each evidence factor are analyzed. It is suggested that
    Niangniangshan and Gushan volcanic edifice play an important role in spatial distributions of volcanic rock-hosted Copper deposits.
    The ten evidence raster layers including Longwangshan Formation, Gushan Formation, trachyte porphyry of Gushan volcanic edifice,
    monzonite porphyry of Niangniangshan volcanic edifice, buffers of the structure lines with NE, NW and EW trending, and the alteration
    areas of chalcopyrite, silicide and Limonite are selected. Finally, metallogenic probabilities are calculated using the Weighted Logistic
    Regression model. Four ore-forming prospects, including P1, P2, P3 and P4, are indicated based on the geological conditions of

    metallogenesis and model results. Among these prospecting areas, P1, P2 and P3, which are controlled by Niangniangshan and Gushan
    volcanic edifice, are spread in the northeast direction. P4 extends in the west-east direction and is controlled by Longwangshan volcanic
    edifice. The copper ore bodies are already found in these prospecting areas, suggesting that the results should be generally reliable.

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    Advances in the Study of Biogeochemical Cycles of Phosphorus
    ZHOU Qiang, JIANG Yunbin, HAO Jihua, JI Junfeng, LI Wei
    Geological Journal of China Universities    2021, 27 (2): 183-199.   DOI: 10.16108/j.issn1006-7493.2020002
    Abstract1940)      PDF (2398KB)(1894)       Save
    Phosphorus is an essential element for life and an important limiting factor for food production. The biogeochemical cycles of phosphorus not only regulate marine primary production, but also has an impact on the global climate system; it also determines the formation and distribution of phosphate resources and affects the continuity of life on earth. The current theory of “earth system science” integrates the subsystems of atmosphere, hydrosphere, lithosphere (crust and upper mantle) and biosphere, providing a broader view for studying the global phosphorus cycles. Based on the existing research and combined with the theory of “earth system science”, the following important understandings of the biogeochemical cycles of phosphorus has been obtained: The evolution of phosphorus in geological history determines the current cycle pattern of phosphorus on a global scale (terrestrial ecosystems and marine ecosystems); Human industrial and agricultural activities, as an important geological agent, has changed the biogeochemical cycles of phosphorus, resulted in resource crisis of phosphate depletion and environmental problem of eutrophication of water bodies; The key to solve the resource crisis problem of phosphorus shortage and environmental pollution problem of phosphorus surplus lies in regulating the biogeochemical cycle process that cause these problems. 
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    Performance of Thermally Activated Colloidal Pyrite in Removal of Cadmiun(Ⅱ) in Acid Solution
    ZHU Yuke, LI Ping, LIU Haibo, YANG Yan, CHEN Tianhu*
    J4    2016, 22 (4): 638-.  
    Abstract465)      PDF (1162KB)(844)       Save

    The thermally activated colloidal pyrite was characterized by XRD and SEM. The effect of solution pH, dissolved oxygen,
    and thermal activation temperatures on the performance of thermally activated colloidal pyrite on removal of Cd(Ⅱ) from aqueous solution were systematically studied. The reactive kinetics and the mechanism of the adsorption of Cd(Ⅱ) on thermally activated colloidal pyrite were also discussed. Colloidal pyrite was decomposed into Porous Monoclinic Pyrrhotite (PMPyr) after thermal activation at 650℃ for 5 minutes in a muffle furnace (nitrogen atmosphere). The removal efficiency of Cd(Ⅱ) by PMPyr in the solution of no dissolved oxy gen was above 88% at pH 2~6, suggesting that the removal efficiency of Cd(II) was less affected by pH. Moreover, surface oxidation of PMPyr could restrain the interaction between PMPyr and Cd( Ⅱ). The kinetic adsorption process was well described by pseudo-second-order model with high correlation coefficient (R2> 0.9992). The influence of pH and change of concentration of Fe (Ⅱ) and SO42- showed that the adsorption of Cd(Ⅱ) on PMPyr was mainly dominated by ion exchange and surface complexation.

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    Influence of Subducting Plate Dynamic Properties to Flat-slab Subduction by Numerical Modeling
    ZHU Zhiyuan, WU Benjun
    Geological Journal of China Universities    2021, 27 (2): 240-248.   DOI: 10.16108/j.issn1006-7493.2019110
    Abstract476)      PDF (1886KB)(767)       Save
    This particular phenomenon of flat-slab subduction mainly occurs in South American, which is closely related to the structural geological phenomena such as earthquakes and volcanoes in this area. However, mechanics of flat-slab subduction is not yet
    well understood. By numerical modeling, we investigate influences of subducting plate dynamic properties to the geometry of flat-slab subduction. The model results show that subducting plate thickness and density contrast between slab and mantle have great impacts to flat-slab formation. The appropriate slab thickness (around 70 km) facilitate slab flattening, while thicker slab is difficult to bend and hesitates to flatten. The smaller the density anomaly of subducting plate, the easier slab flattens and the longer flab-slab length. When density anomaly is very large, no flat-slab is predicted. In addition, strong plate promotes flat-slab formation. Flat-slab length increases with plate viscosity increasing. We also find that trench rollback velocity decreases during the slab flattening episode. Our reference model REF_MODEL has comparable flat-slab geometry with central Chile subduction, which provides the insight of flat subduction formation in this area.
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    LA-ICP-MS Zircon U-Pb Dating and Hf Isotopic Composition of Dacite in Hezhou, Northeastern Guangxi
    WANG Yongqiang, SHI Yu, LI Xiang, LIU Xijun, TANG Yuanlan, SUN Yirong
    Geological Journal of China Universities    2022, 28 (2): 141-152.   DOI: 10.16108/j.issn1006-7493.2021027
    Abstract517)      PDF (3932KB)(627)       Save
    The study area is located at the junction of Hunan and Guangxi in the western part of Nanling metallogenic belt, where Mesozoic magmatic activity is frequent and the diagenesis and mineralization are remarkable, especially during Yanshanian. In order to determine the formation age of kongzimiao dacite in Kaishan Town, Hezhou, northeastern Guangxi, and to discuss its source property, LA-ICP-MS zircon U-Pb dating and Lu-Hf isotope are obtained. zircon U-Pb age of 157.1±0.9 Ma displayed the formation age of the dacite. Zircons grains have a wide range of isotopic composition (εHf(t) values rang from -5.68 to -0.97), with corresponding two-stage Hf isotope model age (TDM2) varying from 1.26~1.54 Ga, suggesting that the protolith was predominantly derived from the crystalline basement crust in Mesoproterozoic, and may be accompanied by a small amount of mantle-derived materials. Combined with the previous studies on the Yanshanian diagenesis and mineralization in South China, it is considered that the dacite in the study area and the early Yanshanian rocks and deposits in Northeast Guangxi are the products of the first large-scale magmatic activity in the Yanshanian in South China, and the formation of dacite may be related to the intraplate extension thinning of the Yanshanian lithosphere in South China.

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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
    Abstract104)      PDF (8863KB)(201)       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).
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    Zircon U-Pb Age and Geochemistry of the Granitic Porphyry from the Baibuxie River of the West Junggar, Xinjiang, and Its Tectonic Significance
    YU Zhiquan, LIU Bo, HONG Yangbaihe
    Geological Journal of China Universities    2021, 27 (1): 80-93.   DOI: 10.16108/j.issn1006-7493.2020013
    Abstract525)      PDF (4202KB)(588)       Save
    The Late Carboniferous-Late Permian intrusive rocks are widely distributed in the central West Junggar, and the tectonic settings in which these rocks were formed are of great significance to reveal the tectonic evolution of the West Junggar during the Late Paleozoic. In this paper, the granitic porphyry from the Baibuxie-River that intruded into the Upper Carboniferous Molaoba Formation in the northern Barleik Mountains is studied to provide further constrains for the tectonic evolution of central West Junggar. We present the results of petrology, U-Pb dating of zircons, whole-rock major and trace elements and Sr-Nd isotopes of the granitic porphyry to investigate the petrogenesis and tectonic setting. The LA-ICP-MS zircon U-Pb age of the granite porphyry from the Baibuxi 4

    e River is 276±5 Ma, indicating that it was formed in the Early Permian. The granitic porphyry is characterized by high SiO2 (76.72%~79.25%), total alkali (Na2O+K2O=5.53%~7.06%) contents, and low magnesium values (Mg#=8~14). Its A/CNK values range from 1.07 to 1.40,which belong to peraluminous and subalkaline granite series. The chondrite-normalized REE distribution patterns exhibit a right-inclined “seagull” shape ((La/Yb) N =3.22~4.34), with a significant negative Eu anomaly (δEu=0.09~0.10). It is enriched in LILEs such as Rb and K, strongly depleted in Sr, P and Ti, moderately depleted in Ba, Nb and Ta elements, and has high FeOT/MgO (10.65~19.32) and 10000Ga/Al (3.61~4.41) values and Zr+Nb+Ce+Y concentrations (859.7×10-6~1054.8×10-6), typical of aluminum A2 type granite. The granite porphyry exhibits low initial 87Sr/86Sr ratios of 0.70482~0.70535 and high positive εNd(t) values of +6.3~+7.3. Based on the above-mentioned geochemical characteristics, we suggest that it was likely formed by partial melting of juvenile crust, followed by high degrees of fractional crystallization and minor crustal contamination under a post-collisional extension regime. Based on the comprehensive analysis of the regional data of coeval intrusive rocks, volcanic rocks, and sedimentary rocks and the fact that there are no post-Early Carboniferous ophiolitic mélange and subduction-related metamorphic rocks in the whole West Junggar, it can be inferred that there was no subduction of oceanic crust since the Early Carboniferous and the Junggar Ocean might have been closed at the early Late Carboniferous.

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