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Risk-based evaluation on geological environment carrying capacity of mountain city - A case study in Suide County, Shaanxi Province, China

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Journal of Mountain Science 2018年第12期15卷 2730-2740页

作者： WANGYao ZHANG Mao-sheng XUE Qiang WU Si-duo Development Research center of China geological survey Beijing 100037China xi'an center of geological survey China Geological SurveyXi'an jiooooChina East China Normal University Shanghai 200062China

With the rapid development and expansion of the cities in China, the carrying capacity of resource and environment has become a huge concern for local governments. From the perspective of geological environment, geological disasters are the main restraining factor of the development in mountain cities. This study was conducted in Suide County of Shaanxi Province with a risk-based approach as followed: a hazard analysis on geological disasters based on a slope geological survey at a scale of 1:10,000; a consequence analysis based on unmanned aerial vehicle(UAV) aerial survey data; integrating the results of hazard analysis and consequence analysis, a risk zonation and analysis of geological disasters in urban areas were completed considering urban planning, land use planning and the safety of infrastructure and major engineering. Subsequently, taking the acceptable levels of human life and property risks incurred by landslides as the criteria of the evaluation of geological environment carrying capacity, a comprehensive assessment of current and future urban carrying capacity was conducted based on the results of the risk analyses. Accordingly, the prior development zone, the restricted development zone and the prohibited zone were delineated, with corresponding suggestions for future urban development. The technological and methodological system used in the study can be applied to geological environment carrying capacity evaluation of other important mountain cities, which can provide scientific basis for the optimization of land and space.

关键词： Mountain cities Risks geological environment Carrying capacity Evaluation

Grenvillian and early Paleozoic polyphase metamorphism recorded by eclogite and host garnet mica schist in the North Qaidam orogenic belt

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Geoscience Frontiers 2021年第4期12卷 244-259页

作者： Yunfei Ren Danling Chen Haijie Wang xiaohui Zhu Bowen Bai State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi'an 710069China xi'an center of geological survey China Geological SurveyXi'an 710054China

The North Qaidam orogenic belt(NQOB) is generally considered to be an early Paleozoic ultrahigh pressure metamorphic belt,but increasing reports of the Neoproterozoic magmatic and metamorphic events indicate that the NQOB probably also experienced the assembly of the ***,the Neoproterozoic evolution of the NQOB is not well constrained due to the sparse records and ambiguous nature of the Neoproterozoic *** order to reveal the multi-orogenic history of the NQOB,an integrated study of petrology,phase equilibrium modelling and geochronology was conducted on an epidote eclogite and host garnet mica schist from the Yuka–Luofengpo *** zircon and monazite U–Pb ages show that the protolith of the garnet mica schist was deposited during 994–920 Ma and experienced Neoproterozoic(920–915 Ma) and early Paleozoic(451–447 Ma) polyphase metamorphism together with the enclosed *** omphacite inclusions were first identified in garnet and early Paleozoic zircon domains from the garnet mica schist,which provide solid evidence for the early Paleozoic eclogite facies metamorphism of the mica *** early Paleozoic peak P–T conditions of >27.4 kbar/613–670 ℃ and 30.2–30.8 kbar/646–655 ℃ were obtained for the garnet mica schist and enclosed eclogite,respectively,indicating that eclogites and their host paragneisses in this region underwent continental deep subduction as a coherent metamorphic terrane in early *** peak P–T conditions of the Neoproterozoic metamorphism were roughly constrained at 7.7–12.0 kbar and 634–680 ℃ for the garnet mica schist,based on stability field of mineral inclusions in Neoproterozoic zircons domains in P–T pseudosection,the relic garnet core composition and Ti-in-zircon *** high thermal gradients(16–37 ℃/km) defined by presently our and previously reported P–T conditions indicate that the Neoproterozoic metamorphism likely occurred in continental collision setting at >945–890 *** the

关键词： Grenvillian metamorphism Two orogenic cycles Pseudosection North Qaidam Rodinia

Cretaceous-Neogene Exhumation of the Daqing Shan,North China Constrained by Apatite Fission Track Thermochronology

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Journal of Earth Science 2024年第1期35卷 99-111页

作者： Junlin Zhou Yuhong Li Wei Han Yunpeng Zhang Gaochao Chen Qiao Zhang Jianshe Wei Yazhuo Niu xi'an center of China geological survey Xi an 710054China Northwest China center for center Geoscience Innovation Xi'an 710054China

The Daqing Shan(DQS)located in the Yinshan-Yanshan Orogenic Belt plays an important role in the Mesozoic to Cenozoic evolution of the North China ***,the cooling and exhumation history since the Cretaceous is still *** the apatite fission track(AFT)data in both this study and previous works,a three-stage exhumation history from Cretaceous to Neogene of the DQS is proposed.(1)The first stage is composed of the early exhumation during Early Cretaceous driven by the collision between the North China and Siberia cratons(ca.148-132 Ma)and the far-field effect of the subduction of the Pacific Plate(ca.132-114 Ma).(2)Due to the subsidence of the Hetao Basin and the subsequent compensation between the DQS and the Hetao Basin,the DQS experienced the second rapid exhumation from Early Eocene to Early Oligocene(ca.54-29 Ma).(3)Since the Late Miocene(ca.13.5 Ma),the third rapid cooling and exhumation of the DQS occurred due to the far-field effect of the uplift of the Tibetan Plateau and the subduction of the Pacific Plate.

关键词： Daqing Shan Hetao Basin Cretaceous-Neogene apatite geochronology apatite fission track cooling and exhumation

Genesis of the Wulong gold deposit,Liaoning Province,NE China:Constrains from noble gases,radiogenic and stable isotope studies

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Geoscience Frontiers 2020年第2期11卷 547-563页

作者： Peng Zhang Linlin Kou Yan Zhao Zhongwei Bi Deming Sha Renping Han Zhumin Li Shenyang geological survey center China geological survey

The Wulong lode deposit contains over 80 tonnes of gold with an average grade of 5.35 g/*** is one of the largest deposits in Dandong City,Liaoning Province in northeast *** studies on the deposit focused on its geological characteristics,geochemistry,fluid inclusions,and the timing of gold ***,controversy remains regarding the origin of the ore-forming fluids and metals,and the genesis of the gold *** paper presents zircon U-Pb and pyrite Rb-Sr ages and S,Pb,He,and Ar isotopic results along with quartz H and O isotopic data for all litho-units associated with the *** ablation inductively coupled mass spectrometry measurements yielded zircon U-Pb dates for samples of pre-mineralization rocks like granite porphyry dike,the Sanguliu granodiorite,fine-grained diorite,and syn-mineralization diorite,as well as post-mineralization dolerite,and lamprophyre;their emplacement ages are 126±1 Ma,124±1 Ma,123±1 Ma,120±1 Ma,119±2 Ma,and 115±2 Ma,*** pyrite Rb-Sr isochron age is 119±1 Ma,indicating that both magmatism and mineralization occurred during the Early *** δ18OH2 O values of ore-forming hydrothermal fluids from the quartz-polymetallic sulfide vein stage vary from 4.8‰to 6.5‰,and the δDv-SMOW values are between-67.7‰and-75.9‰,indicating that the ore-forming fluids were primarily *** noble gas isotope compositions of fluid inclusions hosted in pyrite suggest that the ore-forming fluids were dominantly derived from crustal sources with minor mantle *** isotopic values of pyrite vary between 0.2‰and 3.5‰,suggesting that S was derived from a homogeneous magmatic source or possibly from fluids derived from the *** Pb isotopic compositions of sulfides（207 Pb/204 Pb=15.51-15.71,206 Pb/204 Pb=17.35-18.75,208 Pb/204 Pb=38.27-40.03） indicate that the Pb of the Wulong gold deposit is a mixture of crust and mantle *** and geochemical data,together with the region

关键词： The Wulong gold deposit Zircon U-Pb Pyrite Rb-Sr H-He-O-Ar-S-Pb isotopes Liaodong Peninsula

A New Discovery of ~2.7 Ga Granitic Magmatism in Southeastern Jilin Province, China

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Acta Geologica Sinica(English Edition) 2017年第5期91卷 1919-1923页

作者： WANG Chaoyang MENG En LI Yanguang CAI Jia YANG Hong LI Zhuang Institute of Geology Chinese Academy of Geological Sciences xi'an center of geological survey China Geological Survey College of Geosciences China University of Petroleum

Objective The North China Craton（NCC）is characterized by widespread tectono-thermal events at ca.2.5 Ga,which differs from many other older cratons on Earth,which usually record tectono-thermal events at-2.7 ***,the... 详细信息

关键词： A New Discovery of Th NCC China

Fractal analysis of small-micro pores and estimation of permeability of loess using mercury intrusion porosimetry

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第7期24卷 584-595页

作者： Tuo LU Yaming TANG Yongbo TIE Bo HONG Wei FENG Chinese Academy of geological Sciences Beijing 100037China School of Water Resources and Environment China University of GeosciencesBeijing 100083China xi'an center of China geological survey Xi'an 710054China Chengdu center of China geological survey Chengdu 610081China

Many popular models have been proposed to study the fractal properties of the pores of porous materials based on mercury intrusion porosimetry(MIP).However,most of these models do not directly apply to the small-micro pores of loess,which have a significant impact on the throat pores and tunnels for fluid ***,in this study we used a combination of techniques,including routine physical examination,MIP analysis,and scanning electron microscope(SEM)image analysis,to study these small-micro pores and their saturated water permeability *** techniques were used to determine whether the fractal dimensions of six MIP fractal models could be used to evaluate the microstructure types and permeability properties of *** results showed that the Neimark model is suitable for analysis of small-micro *** applied to saturated water permeability,the results from this model satisfied the correlation significance test and were consistent with those from SEM analysis.A high clay content and density cause an increase in the number of small-micro pores,leading to more roughness and heterogeneity of the pore structure,and an increase in the fractal *** process further leads to a decrease in the content of macro-meso pores and saturated water ***,we propose new parameters:the*Ellipse and its area ratios(*EAR).These parameters,coupled with 2D-SEM and 3D-MIP fractal dimensions,can effectively and quantitatively be used to evaluate the types of loess microstructures(from typeⅠto typeⅢ)and the saturated water permeability(magnitude from 1×10^(-4)cm/s to 1×10^(-5)cm/s).

关键词： Malan loess Fractal models Small-micro pores Mercury intrusion porosimetry(MIP) Microstructure Saturated waterpermeability

Seismic interpretation and hydrocarbon accumulations implication of the Miocene Meishan Formation reefs in southern Qiongdongnan Basin, northern South China Sea

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Journal of Palaeogeography 2017年第3期6卷 206-218页

作者： Yang-Wei Feng Hong-Jun Qu Gong-Cheng Zhang Ren-Hai Pu xi'an center of geological survey China Geological Survey Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits MLR geological Research center of Orogenic Belt China Geological Survey Department of Geology Northwest University Research center of CNOOC (China)

Numerous moundy reflections were found at the Upper Meishan Formation in southern Qiongdongnan Basin, South China Sea which are suspected reefs. However, no common understanding on the seismic and geologic interpretation was acquired. Based on seismic reflection identification, geometrical configuration description, wave impedance inversion, forward simulation, analysis of reef-building sedimentary environments and pseudomorph identification, these suspected-reef moundy reflections were studied in *** types of reefs were recognized, i.e., patch reef, platform-edge reef, and pinnacle reef. They have some typical characteristics of reefs, including moundy or lenticular shape, clear outline with crest and canal, internal foreset bedding, bidirectional uplap between limbs, and strong reflection at top and bottom. The patch reefs are of moundy seismic facies, with moderateestrong amplitude and moderate frequency, and distribute at the higher part of southern slope belt. Fore-reef and back-reef of patch reefs are slightly asymmetrical being perpendicular to palaeo-bathymetric orientation; while symmetrical to slightly asymmetrical being parallel to the palaeo-bathymetric orientation, and the wave impedance value is about 7 kg/m^3×m/***-edge reefs are of flat-moundy seismic facies with strong amplitude and moderate frequency, which develop at the carbonate platform edge of higher part of southern slope belt, and the wave impedance value is about 7.5 kg/m^3×m/s. Pinnacle reefs grow up on volcanic cones, forming the complex of pinnacle reef and volcanic cone. The Miocene Meishan Formation reefs in southern Qiongdongnan Basin, northern South China Sea, with high quality sourceereservoireseal assemblages, have good petroleum exploration prospects.

关键词： Meishan Formation Patch reef Platform-edge reef Pinnacle reef Hydrocarbon accumulations implication Qiongdongnan Basin South China Sea

Tectonic Nature of the Northern Segment of the Jiao-Liao-Ji Belt:A Rift or Continental Collision Belt?

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Acta Geologica Sinica(English Edition) 2017年第3期91卷 1159-1160页

作者： MENG En WANG Chaoyang LI Yanguang CAI Jia YANG Hong LI Zhuang Institute of Geology Chinese Academy of Geological Sciences xi'an center of geological survey China Geological Survey School of Earth and Space Sciences Peking University

Objective The tectonic characteristics and evolution of the Paleoproterozoic Jiao-Liao-Ji belt have been extensively studied in recent decades （Fig. 1 a）. Two main models have been proposed for the formation of this belt： a continental-or arc-continent collisional belt, and the opening and closure of an intra-continental rift. The main reasons for these ongoing debates are own to the complex composition, including metamorphosed volcano-sedimentary rocks, multiple pulses of granitic magmatism, meta-mafic intrusions, and tectono- metamorphic history. In addition, earlier work focused on the geochronology and metamorphic evolution, whereas the source properties, petrogenesis, and tectonic setting of the metamorphosed volcano-sedimentary sequence and meta- mafic intrusions are poorly understood.

关键词： of in as with Ga Tectonic Nature of the Northern Segment of the Jiao-Liao-Ji Belt:A Rift or Continental Collision Belt were meta or

Origin of the Newly Discovered Zhunuo Porphyry Cu-Mo-Au Deposit in the Western Part of the Gangdese Porphyry Copper Belt in the Southern Tibetan Plateau,SW China

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Acta Geologica Sinica(English Edition) 2017年第1期91卷 109-134页

作者： HUANG Yong LI Guangming DING Jun DAI Jie YAN Guoqiang DONG Suiliang HUANG Hanxiao Chengdu center China Geological Survey Tianjin center China Geological Survey

The newly discovered Zhunuo porphyry Cu-Mo-Au deposit is located in the western part of the Gangdese porphyry copper belt in southern Tibet, SW China. The granitoid plutons in the Zhunuo region are composed of quartz diorite porphyry, diorite porphyry, granodiorite porphyry, biotite monzogranite and quartz porphyry. The quartz diorite porphyry yielded zircon U-Pb ages of 51.9±0.7 Ma（Eocene） using LA-ICP-MS, whereas the diorite porphyry, granodiorite porphyry, biotite monzogranite and quartz porphyry yielded ages ranging from 16.2±0.2 to 14.0±0.2 Ma（Miocene）. CuMo-Au mineralization is mainly hosted in the Miocene granodiorite porphyry. Samples from all granitoid plutons have geochemical compositions consistent with high-K calc-alkaline series magmatism. The samples display highly fractionated light rare-earth element（REE） distributions and heavy REE distributions with weakly negative Eu anomalies on chondrite-normalized REE patterns. The trace element distributions exhibit positive anomalies for large-ion lithophile elements（Rb, K, U, Th and Pb） and negative anomalies for high-field-strength elements（Nb and Ti） relative to primitive mantlenormalized values. The Eocene quartz diorite porphyry yielded εNd（t） values ranging from-3.6 to-5.2,（-（87）Sr/-（86）Sr）i values in the range 0.7046–0.7063 and initial radiogenic Pb isotopic compositions with ranges of 18.599–18.657 -（206）Pb/-（204）Pb, 15.642–15.673 -（207）Pb/-（204）Pb and 38.956–39.199 -（208）Pb/-（204）Pb. In contrast, the Miocene granitoid plutons yielded ε（Nd）（t） values ranging from-6.1 to-7.3 and（87Sr/86Sr）i values in the range 0.7071–0.7078 with similar Pb isotopic compositions to the Eocene quart diorite. The Sr-Nd-Pb isotopic compositions of the rocks are consistent with formation from magma containing a component of remelted ancient crust. Zircon grains from the Eocene quartz diorite have ε（Hf）（t） values ranging from-5.2 to ＋0.9 and two-stage Hf model ages ranging from 1.07 to 1.46 Ga, while zircon grains from the M

关键词： Zircon U-Pb dating Sr-Nd-Pb-Hf isotope Zhunuo porphyry Cu-Mo-Au deposit Gangdese porphyry copper belt