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Dissolved rare earth elements estimation of ion-absorption rare earth ores using reflectance spectroscopy in south Jiangxi province,China

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Journal of Rare Earths 2021年第10期39卷 1300-1310,I0005页

作者： Jingjing Dai Denghong Wang Zhenghui Chen Institute of Mineral Resources Chinese Academy of Geological SciencesBeijing 100037China Ministry of Natural Resources.Key Laboratory of Metallogeny and Mineral Assessment Beijing 100037China

Ion-absorption rare earth ores are an important mineral resource in ***,the unauthorized mining has become a serious problem,resulting in severe water pollution and the wastage of rare earth elements(REEs).Being able to estimate the concentration of dissolved REEs in water bodies near mines is essential for tackling this environmental ***,quantitative analyses of the contents of dissolved REEs are performed using laboratory-based techniques,which can be time consuming and *** reflectance is a rapid and cost-effective means of characterizing the chemical compositions of light-absorbing *** this study,reflectance spectroscopy was performed on dissolved REEs,and the correlation between their reflectance characteristics and REE content was determined.A total of 50 aqueous media samples collected in south Jiangxi Province and 25 laboratory-produced aqueous media samples were tested,and their reflectance spectra and REE contents were measured using reflectance spectroscopy and inductively coupled plasma mass spectrometry,***,the reflectance,differential reflectance,and absorption depth were analysed based on the REE *** diagnostic absorption features related to REEs are recognised in the visible and near-infrared wavelength regions,along with several smaller *** indicates that the results of the absorption depth analysis are in accordance with the absorption spectra characteristics of the REEs,with the R2 value being higher than *** intensity of each of the six absorption bands exhibits a linear correlation to the total REE ***,linear regressio n models can be derived for estimating the total concentration of REEs in aqueous media ***’s more,the detection limit for REEs is determined to be about 30μg/***,it can be concluded that reflectance spectroscopy is a suitable technique for estimating the concentration of dissolved REEs.

关键词： Rare earth elements Ion-absorption rare earth ores Spectroscopy Concentration Correlation analysis

Reconstruction of the thermal evolution since the late paleozoic in the Ounan Sag, Eastern Qaidam Basin, NW China: New constraints from vitrinite reflectance data and(U-Th)/He thermochronology

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Petroleum Science 2024年第5期21卷 2984-3000页

作者： Chang Zhong Hui Shi Xiao-Yin Tang Hao Zhang Yuan-Yuan Yang Jun-Jie Hu Xiao-Jie Wei Jia-Qi Wang Institute of Geomechanics Chinese Academy of Geological SciencesBeijing100081China Key Laboratory of Paleomagnetism and Tectonic Reconstruction Ministry of Natural ResourcesBeijing100081China Key Laboratory of Petroleum Geomechanics China Geological SurveyBeijing100081China SinoProbe Center Chinese Academy of Geological SciencesBeijing100037China

Reconstructing the thermal evolution of the eastern Qaidam Basin is important for gaining a deeper understanding of its lithospheric geodynamics and for more accurate hydrocarbon evaluation and prediction. This article presents a set of new apatite and zircon(U-Th)/He thermochronological *** with 336 vitrinite reflectance(R_(o)) data, the thermal history of the Ouanan Sag in the eastern Qaidam Basin has been reconstructed using inversion models. Three detrital samples from the Ounan Sag shows that the apatite(U-Th)/He ages are primarily concentrated in the range of 17.0 Ma to 76.5 Ma and that the zircon(U-Th)/He ages range from 200 Ma to 289.3 Ma. The time-temperature models demonstrate that the Ounan Sag experienced rapid subsidence and heating from the Carboniferous to late Permian, and exhumation/cooling events from the end of Permian to the Triassic. This thermal evolution was influenced by the widespread intrusion of plutons, and the collision and orogenesis caused by asthenosphere upwelling below the Qaidam arc, and slab rollback of the Southern Kunlun oceanic lithosphere, respectively. Additionally, our models depict the main exhumation/cooling stages since the Paleogene and a reheating event in the Miocene as a result of the intensifying growth of the Qinghai-Tibet Plateau and local sedimentary loading, followed by the initial India-Eurasia collision. Furthermore, the eastern Qaidam Basin experienced consistent heating during the late Paleozoic, reaching the maximum paleotemperature and geothermal gradient in the late Permian, with values of ~230℃ and~43-44℃/km, respectively. This study suggests that the source rocks in the most upper member of upper Carboniferous Keluke(C_(2)k) Formations in the Ounan Sag reached the gas generation stage in the late Permian.

关键词： Thermal evolution Eastern Qaidam Basin Late Paleozoic Apatite and zircon(U-Th)/He thermochronology Vitrinite reflectance

Petrology and PGE Abundances of High-Cr and High-Al Podiform Chromitites and Peridotites from the Bulqiza Ultramafic Massif, Eastern Mirdita Ophiolite, Albania

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Acta Geologica Sinica(English Edition) 2018年第3期92卷 1063-1081页

作者： QIU Tian YANG Jingsui MILUSHI Ibrahim WU Weiwei MEKSHIQI Nezir XIONG Fahui ZHANG Cong SHEN Tingting Center for Advanced research on the Mantle (CARMA) Key Laboratory of Deep Earth Dynamics of Ministry of Land and Resources Institute of Geology Chinese Academy of Geological Sciences Institute of Geosciences Energy Water and Environment Polytechnic University of TIRANA Faculty of Earth sciences China University of Geoscience Institute of geological Science and Engineering Shandong University of Science and Technology

The Bulqiza ultramafic massif, which is part of the eastern Mirdita ophiolite of northern Albania, is world renowned for its high-Cr chromitite deposits. High-Cr chromitites hosted in the mantle section are the crystallized products of boninitic melts in a supra-subduction zone(SSZ). However,economically important high-Al chromitites are also present in massive dunite of the mantle-crust transition zone(MTZ). Chromian-spinel in the high-Al chromitites and dunites of the MTZ have much lower Cr~# values(100 Cr/(Cr+Al))(47.7-55.1 and 46.5-51.7, respectively) than those in the high-Cr chromitites(78.2-80.4), harzburgites(72.6-77.9) and mantle dunites(79.4-84.3). The chemical differences in these two types of chromitites are reflected in the behaviors of their platinum-group elements(PGE).The high-Cr chromitites are rich in IPGE relative to PPGE with 0.10-0.45 PPGE/IPGE ratios, whereas the high-Al chromitites have relatively higher PPGE/IPGE ratios between 1.20 and 7.80. The calculated melts in equilibrium with the high-Cr chromitites are boninitic-like, and those associated with the high-Al chromitites are MORB-like but with hydrous, oxidized and TiO-poor features. We propose that the coexistence of both types of chromitites in the Bulqiza ultramafic massif may indicates a change in magma composition from MORB-like to boninitic-like in a proto-forearc setting during subduction initiation.

关键词： chromian-spinel platinum-group elements high-Cr and high-Al chromitite Mirdita ophiolite Albania

Surface Rupture of the 1515 Yongsheng Earthquake in Northwest Yunnan, and Its Seismogeological Implications

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Acta Geologica Sinica(English Edition) 2018年第4期92卷 1324-1333页

作者： HUANG Xiaolong WU Zhonghai WU Kungang Key Laboratory of Neotectonic Movement & Geohazard Ministry of Natural Resources Institute of Geomechanics Chinese academy of geological sciences School of Earth and Space sciences Peking University

The 1515 M7/4 Yongsheng earthquake is the strongest earthquake historically in northwest Yunnan. However, its time, magnitude and the seismogenic fault have long been a topic of dispute. In order to accurately define those problems, a 1：50000 active tectonic mapping was carried out along the northern segment of the Chenghai-Binchuan fault zone. The result shows that there is an at least 25 km- long surface rupture and a series of seismic landslides distributed along the Jinguan fault and the Chenghai fault. Radiocarbon dating of the 14C samples indicates that the surface rupture should be a part of the deformation zone caused by the Yongsheng earthquake in the year 1515. The distribution characteristics of this surface rupture indicate that the macroscopic epicenter of the 1515 Yongsheng earthquake may be located near Hongshiya, and the seismogenic fault of this earthquake is the Jinguan- Chenghai fault, the northern part of the Chenghai-Binchuan fault zone. Striations on the surface rupture show that the latest motion of the fault is normal faulting. The maximum co-seismic vertical displacement can be 3.8 m, according to the empirical formula for the fault displacement and moment magnitude relationship, the moment magnitude of the Yongsheng earthquake was Mw 7.3-7.4. Furthermore, combining published age data with the 14C data in this paper reveals that at least four large earthquakes of similar size to the 1515 Yongsheng earthquake, have taken place across the northern segment of the Chenghai-Binchuan fault zone since 17190~50 yr. BP. The in-situ recurrence interval of Mw 7.3-7.4 characteristic earthquakes in Yongsheng along this fault zone is possibly on the order of 6 ka.

关键词： historical earthquake earthquake surface rupture normal fault Chenghai-Binchuan fault zone Southeastern margin of the Tibetan Plateau

Numerical study on the deformation of soil stratum and vertical wells with gas hydrate dissociation

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Acta Mechanica Sinica 2016年第5期32卷 905-914页

作者： Xudong Chen Xuhui Zhang Xiaobing Lu Wei Wei Yaohong Shi Institute of Mechanics Chinese Academy of Sciences research Institute of Petroleum Exploration and Development-Langfang Marine Environmental and Engineering geological Survey Guangzhou Marine Geological Survey

Gas hydrate（GH） dissociates owing to thermal injection or pressure reduction from the well in gas/oil or GH exploitation. GH dissociation leads to, for example, decreases in soil strength, engineering failures such as wellbore instabilities, and marine landslides. The FLAC3 D software was used to analyze the deformation of the soil stratum and vertical wells with GH dissociation. The effects of Young＇s modulus, internal friction angle, cohesion of the GH layer after dissociation, and the thickness of the GH layer on the deformation of soils were studied. It is shown that the maximum displacement in the whole soil stratum occurs at the interface between the GH layer and the overlayer. The deformation of the soil stratum and wells increases with decreases in the modulus, internal friction angle, and cohesion after GH dissociation. The increase in thickness of the GH layer enlarges the deformation of the soil stratum and wells with GH dissociation. The hydrostatic pressure increases the settlement of the soil stratum, while constraining horizontal displacement. The interaction between two wells becomes significant when the affected zone around each well exceeds half the length of the GH dissociation zone.

关键词： Gas hydrate Dissociation FLAC3D Soil stratum Well

Ordovician Granitoids and Silurian Mafic Dikes in the Western Kunlun Orogen, Northwest China:Implications for Evolution of the Proto-Tethys

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Acta Geologica Sinica(English Edition) 2019年第1期93卷 30-49页

作者： ZHANG Qichao WU Zhenhan LI Shan LI Kan LIU Zhiwei ZHOU Qing chinese academy of geological sciences Key Laboratory of Deep-Earth Dynamics Ministry of Natural Resources Institute of Geology Chinese Academy of Geological Sciences Xi'an Institute of Geology and Mineral Resources Chinese Geological Survey Chengdu Institute of Geology and Mineral Resources Chinese Geological Survey

The western Kunlun orogen in the northwest Tibet Plateau is related to subduction and collision of Proto-and Paleo-Tethys from early Paleozoic to early Mesozoic. This paper presents new LA-ICPMS zircon U-Pb ages and Lu-Hf isotopes, whole-rock major and trace elements, and Sr–Nd isotopes of two Ordovician granitoid plutons(466–455 Ma) and their Silurian mafic dikes(～436 Ma) in the western Kunlun orogen. These granitoids show peraluminous high-K calcalkaline characteristics, with(^(87)Sr/^(86)Sr)_i value of 0.7129–0.7224, ε_(Nd)(t) values of -9.3 to -7.0 and zircon ε_(Hf)(t) values of -17.3 to -0.2, indicating that they were formed by partial melting of ancient lower-crust(metaigneous rocks mixed with metasedimentary rocks) with some mantle materials in response to subduction of the Proto-Tethyan Ocean and following collision. The Silurian mafic dikes were considered to have been derived from a low degree of partial melting of primary mafic magma. These mafic dikes show initial ^(87)Sr/^(86)Sr ratios of 0.7101–0.7152 and ε_(Nd)(t) values of -3.8 to -3.4 and zircon ε_(Hf)(t) values of -8.8 to -4.9, indicating that they were derived from enriched mantle in response to post-collisional slab break-off. Combined with regional geology, our new data provide valuable insight into late evolution of the Proto-Tethys.

关键词： High-K calc-alkaline granitoids mafic dikes Western Kunlun Orogen Proto-Tethys

Numerical Simulation on Unsteady Flow Mechanism of a 1.5-Stage Axial Transonic Compressor

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Journal of Thermal Science 2024年第5期33卷 1851-1866页

作者： PENG Shuxuan ZHANG Xiaoyu WANG Wentao ZHANG Hongwu LI Xinlong High Efficiency and Low Carbon Gas Turbine Digitalization research Centre Nanjing Institute of Future Energy SystemNanjing 211135China Advanced Gas Turbine Laboratory Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China Key Laboratory of Advanced Energy and Power Chinese Academy of SciencesBeijing 100190China Innovation academy for Light-Duty Gas Turbine Chinese Academy of SciencesBeijing 100190China University of chinese academy of sciences Beijing 100049China BYD Auto Industry Company Limited Shenzhen 518116China

In this paper,a numerical simulation method is used to calculate a 1.5-stage axial transonic compressor to explore its unsteady flow *** performance curve is compared with the experimental data to verify the calculation method with a high numerical accuracy,which shows that the unsteady calculation has good *** to the analysis of the data from the monitoring points under the near-stall condition,the unsteady disturbances originate from the tip region of blade and perform the strongest at the blade pressure surface with a broadband *** analysis is conducted by combining with the characteristics of the transient flow field at the tip of *** results show that the unsteady pressure fluctuations are caused by the migration of the new vortex *** new vortex cores are generated by the breakdown of leakage vortex in the downstream,which is induced by the leakage vortex and shock wave ***,the relationship between the unsteady flow characteristics and the working conditions is also *** leakage vortex intensity and the shock wave strength gradually increase with the decrease of flow *** the combination of the leakage vortex intensity and shock wave strength reaches the first threshold,a single frequency of unsteady disturbances appears at the blade *** the combination of the leakage vortex intensity and shock wave strength reaches the second threshold,the frequency of unsteady disturbances changes to a broadband.

关键词： numerical simulation axial transonic compressor unsteady flow vortex breakdown

Identifying the Hydrochemical Characteristics,Genetic Mechanisms and Potential Human Health Risks of Fluoride and Nitrate Enriched Groundwater in the Tongzhou District,Beijing,North China

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 468-476页

作者： ZHANG Shouchuan LIU Kai MA Yan WANG Luyao SUN Junliang chinese academy of geological sciences Beijing 100037China School of Water Resources and Environment China University of Geosciences(Beijing)Beijing 100083China

Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas and economic *** study focuses on the high F^(−)and NO_(3)^(−)concentration groundwater in Tongzhou District,Beijing,North China.A total of 36 groundwater samples were collected to analyze the hydrochemical characteristics,elucidate genetic mechanisms and evaluate the potential human health *** results of the analysis indicate:Firstly,most of the groundwater samples are characterized by Mg-HCO_(3) and Na-HCO_(3) with the pH ranging from 7.19 to 8.28 and TDS with a large variation across the range 471-2337 mg/*** NO_(3)^(−)concentration in 38.89%groundwater samples and the F^(−)concentration in 66.67%groundwater samples exceed the permissible limited ***,F^(−)in groundwater originates predominantly from water-rock interactions and the fluorite dissolution,which is also regulated by cation exchange,competitive adsorption of HCO_(3)−and an alkaline ***,the effect of sewage disposal and agricultural activities have a significant effect on high NO3-concentration,while the high F^(−)concentration is less influenced by anthropogenic *** alkaline environment favors nitrification,thus being conducive to the production of NO_(3)^(−).Finally,the health risk assessment is evaluated for different population *** results indicate that high NO_(3)^(−)and F^(−)concentration in groundwater would have the largest threat to children’s *** findings of this study could contribute to the provision of a scientific basis for groundwater supply policy formulation relating to public health in Tongzhou District.

关键词： fluoride concentration nitrate pollution genetic mechanism health risk assessment Tongzhou District

SHRIMP U-Pb dating and Hf isotopic analyses of Middle Ordovician meta-cumulate gabbro in central Qiangtang, northern Tibetan Plateau

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Science China Earth sciences 2010年第5期53卷 657-664页

作者： ZHAI QingGuo1 WANG Jun1, LI Cai2 & SU Li3 1 Institute of Geology, chinese academy of geological sciences, Beijing 100037, China 2 College of Earth sciences, Jilin University, Changchun 130061, China 3 The geological Laboratory Center and State Key Laboratory of geological Processes and Mineral Resources, China University of Geo- sciences, Beijing 100083, China Institute of Geology Chinese Academy of Geological Sciences Beijing China College of Earth sciences Jilin University Changchun China The geological Laboratory Center and State Key Laboratory of geological Processes and Mineral Resources China University of Geosciences Beijing China

Metabasites consisting of metamorphic ultra-mafic rocks, cumulate gabbro, gabbro (diabase), basalt, and plagiogranite are exposed at the Taoxinghu area in central Qiangtang, northern Tibetan Plateau. Zircon SHRIMP U-Pb dating for the cumulate gabbro yields a weighted mean age of 467±4 Ma, which is the oldest and most reliable magmatic age in this area. Zircon 176Hf/177Hf ratios range from 0.282615 to 0.282657, with εHf(t) values of 5.02±0.28, indicating that the cumulate gabbro was mainly derived from the depleted mantle. In addition, geochemical data of metabasites suggest that they have similar characteristics to those in the mid-ocean ridge basalts (MORB). The Taoxinghu metabasites may represent the fragment of Early Paleozoic ophiolite in the "Central Uplift" of the Qiangtang, northern Tibetan Plateau.

关键词： Qiangtang cumulate gabbro SHRIMP dating Hf isotope