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Geological setting of some classical selenium-bearing formations in China

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Chinese Science Bulletin 1999年第S2期44卷 185-186页

作者： WEN Hanjie and qiu yuzhuo institute of geochemistry, Chinese academy of {2., Guiyang 550002. China institute of geochemistry Chinese Academy of Sciences Guiyang 550002 China

SELENIUM is a highly dispersed element with a lower Clarke of 0.05×10-6 and rarely forms its own independent deposits in the crust. In recent years by the discovery of a series of selenium-bearing deposits（such as Laerma selenium-gold deposit and Yutangba selenium deposit） and selenium-rich strata （westHubei, Laerma, Ziyang, Langao, northwest Hunan, etc.）, the character and genesis of the seleniumbearing formation （SBF） have been noted by many researchers. 1 Some classical SBF in China In China the classical SBFs include: （i） The Lower Cambrian SBF in Laerma, west Qinling: Thebackground value of selenium is 5.47×10-6, and the selenium content of the sillcalite and slate （mainrock type） averages 8.70×10-6 and 3.05×10-6 respectively. （ii） The Lower Cambrian SBF inZiyang and Langao, east Qinling: Selenium is present in relatively high abundance in the SBF, averaging3.89×10-6 in the slate, 2.86×10-6 in the sillcalite. （iii） The Lower Cambrian SBF in northwest Hu-

关键词： selenium selenium-bearing formation geological setting.

Research on the dynamics of the South China Sea opening:Evidence from analogue modeling

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Science China Earth sciences 2006年第10期49卷 1053-1069页

作者： SUN Zhen1,2. ZHOU Di1, ZHONG Zhihong3. XIA Bin2. qiu Xuelin1, ZENG Zuoxun4 & JIANG Jianqun5 1. CAS Key Laboratory of Marginal Sea Geology, South China Sea {3. of Oceanology, Chinese {2. of sciences, Guangzhou 5103.1, China 2. CAS Key Laboratory of Marginal Sea Geology, Guangzhou {3. of geochemistry, Chinese {2. of sciences, Guangzhou 510640, China 3. Department of Technology, Shenzhen Branch of CNOOC, Guangzhou 5102.0, China 4. Faculty of Earth sciences, China University of Geosciences, Wuhan 43.074, China 5. Hainan Oil & Gas Exploration Company, Liaohe Oilfield PetroChina, Panjin 12.010, China 1. CAS Key Laboratory of Marginal Sea Geology South China Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China 2. CAS Key Laboratory of Marginal Sea Geology Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China 3. Department of Technology Shenzhen Branch of CNOOC Guangzhou 510240 China 4. Faculty of Earth sciences China University of Geosciences Wuhan 430074 China 5. Hainan Oil & Gas Exploration Company Liaohe Oilfield PetroChina Panjin 124010 China

Independent of Indochina extrusion, the South China Sea experienced a process from passive continental rifting to marginal sea drifting. According to the fault patterns in the Beibu Gulf basin and the Pearl River Mouth basin, the continental rifting and early spreading stage from 3.0}to 2. Ma were controlled by extensional stress field, which shifted clockwise from southeastward to south southeastward. From 2. Ma on, the sea spread in NW-SE direction and ceased spreading at around 15.5 Ma. Integrated geological information with the assumption that the South China Sea developed along a pre-Cenozoic weakness zone, we did analogue experiments on the South China Sea evolu- tion. Experiments revealed that the pre-existing weakness zone goes roughly along the uplift zone between the present Zhu-1 and Zhu-2.depression. The pre-existing weakness zone is composed of three segments trending NNE, roughly EW and NEE, respectively. The early opening of the South China Sea is accompanied with roughly 15° clockwise rotation, while the SE sub-sea basin opened with SE extension. Tinjar fault was the western boundary of the Nansha block (Dangerous Ground), while Lupar fault was the eastern boundary of the Indochina, NW-trending rift belt known as Zengmu basin developed between above two faults due to block divergent of Indochina from Nansha. In the experiment, transtensional flower structures along NW-trending faults are seen, and slight inversion occurs along some NE-dipping faults. The existence of rigid massifs changed the orientations of some faults and rift belt, and also led to deformation concentrate around the massifs. The rifting and drifting of the South China Sea might be caused by slab pull from the proto South China Sea subducting toward Borneo and/or mantle flow caused by India-Asia collision.

关键词： South China Sea, rifting and drifting, clockwise rotation, analogue modeling, rigid massifs.

Unexpected Diversity in Ecosystem Nutrient Responses to Experimental Drought in Temperate Grasslands

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Phyton-International Journal of Experimental Botany 2024年第4期93卷 831-841页

作者： Biying qiu Niwu Te Lin Song Yuan Shi Chuan qiu Xiaoan Zuo Qiang Yu Jianqiang Qian Zhengwen Wang Honghui Wu Wentao Luo School of Life sciences Hebei UniversityBaoding071002China Liaoning Northwest Grassland Ecosystem National Observation and Research Station Erguna Forest-Steppe Ecotone Research StationInstitute of Applied EcologyChinese Academy of SciencesShenyang110164China Northwest institute of Eco-Environment and Resources Chinese Academy of SciencesLanzhou730030China School of Grassland Science Beijing Forestry UniversityBeijing100083China College of Forestry Henan Agricultural UniversityZhengzhou450002China State Key Laboratory of Efficient Utilization of Arid and Semi-Arid Arable Land in Northern China Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing100081China Key Laboratory of Arable Land Quality Monitoring and Evaluation Ministry of Agriculture and Rural AffairsInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing100081China

The responses of ecosystem nitrogen (N) and phosphorus (P) to drought are an important component of globalchange studies. However, previous studies were more often based on site-specific experiments, introducing a significantuncertainty to synthesis and site comparisons. We investigated the responses of vegetation and soil nutrientsto drought using a network experiment of temperate grasslands in Northern China. Drought treatment (66%reduction in growing season precipitation) was imposed by erecting rainout shelters, respectively, at the driest,intermediate, and wettest sites. We found that vegetation nutrient concentrations increased but soil nutrient concentrationsdecreased along the aridity gradient. Differential responses were observed under experimentaldrought among the three grassland sites. Specifically, the experimental drought did not change vegetation andsoil nutrient status at the driest site, while strongly reduced vegetation but increased soil nutrient concentrationsat the site with intermediate precipitation. On the contrary, experimental drought increased vegetation N concentrationsbut did not change vegetation P and soil nutrient concentrations at the wettest site. In general, the differentialeffects of drought on ecosystem nutrients were observed between manipulative and observationalexperiments as well as between sites. Our research findings suggest that conducting large-scale, consistent, andcontrolled network experiments is essential to accurately evaluate the effects of global climate change on terrestrialecosystem bio-geochemistry.

关键词： Climate change drought experiment precipitation nutrient cycles

Dating Kimberlite Using Apatite U-Pb Geochronology: A Case Study from Diamond-Bearing Dikes in South China

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Journal of Earth Science 2024年第3期35卷 1059-1062页

作者： Jiawei Zhang Huan Wang Defeng He Yuhua Zhu Kun Wang Yuan qiu Guizhou Geological Survey Bureau of Geology and Mineral Exploration and Development of Guizhou ProvinceGuiyang 550081China College of Resources and Environmental Engineering Guizhou UniversityGuiyang 550025China Yanduzhongshi Geological Analysis Laboratory Ltd. Beijing 100080China State Key Laboratory of Ore Deposit geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

Kimberlite,one of the deepest known magmatic rocks on Earth,offers valuable glimpses into the deep mantle composition(Woodhead et al.,2.19),craton structure(Gardiner et al.,2.2.),global geodynamic variation(Tappe et al.,2.18),and diamond formation(Giuliani et al.,2.2.).The accurate determination of the emplacement of this special rock is crucial for revealing such ***,dating kimberlite is challenging due to its silica-poor,volatile-rich,strongly altered,and hybrid nature(Mitchell et al.,2.19).Zircon is unsuitable for dating kimberlite and related rocks due to its preference for crystallizing in intermediate to felsic melts(Gervasoni et al.,2.16)rather than silica-poor *** if present,zircon is prone to Pb loss through hydrothermal alteration(Zi et al.,2.2.)in a volatile-rich system like kimberlitic magmas.

关键词： dating magma alteration

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常见稀土氧化物矿物中氧同位素分馏研究

中国稀土学报 1997年第2期15卷 178-181页

作者：方涛裘愉卓中国科学院地球化学研究所

通过加和增量模式，对主要稀土氧化物矿物的氧同位素分馏方程进行了计算，并对矿物中稀土成份的变化，Ｔｉ４＋、Ｎｂ５＋、Ｔａ５＋、Ｔｈ４＋等类质同象替换，非晶质化作用对矿物氧同位素分馏的影响进行了讨论。由于稀土氧化物矿物的... 详细信息

通过加和增量模式，对主要稀土氧化物矿物的氧同位素分馏方程进行了计算，并对矿物中稀土成份的变化，Ｔｉ４＋、Ｎｂ５＋、Ｔａ５＋、Ｔｈ４＋等类质同象替换，非晶质化作用对矿物氧同位素分馏的影响进行了讨论。由于稀土氧化物矿物的氧同位素分馏曲线变化较大，不宜用作地质温度计。

关键词：氧同位素稀土氧化物矿物分馏系数

Texture and geochemistry of Multi-stage Hydrothermal Scheelite in the Mamupu Cu-Au-Mo(-W)Deposit,Eastern Tibet:Implications for Tungsten Mineralization in the Yulong Belt

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Acta Geologica Sinica(English Edition) 2024年第3期98卷 701-716页

作者： ZHANG Xiaoxu TANG Juxing LIN Bin WANG Qin HE Liang YAN Gang SHAO Rui WU Qiang DU qiu ZHAXI Pingcuo Chengdu Center China Geological Survey(Geosciences Innovation Center of Southwest China)Chengdu 610081China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing 100037China SinoProbe Laboratory Chinese Academy of Geological SciencesBeijing 100094China Earth sciences College Chengdu University of TechnologyChengdu 610059China No.6 Geological Party Tibetan Bureau of Geology and Mineral Exploration and DevelopmentLhasa 851400China Tibet Shengyuan Mining Group Co. Ltd.Lhasa 851400China

Multistage tungsten mineralization was recently discovered in the Mamupu copper-polymetallic deposit in the southern Yulong porphyry copper belt(YPCB),*** study reports the results of cathodoluminescence,trace element and Sr isotope analyses of Mamupu scheelite samples,undertaken in order to better constrain the mechanism of W mineralization and the sources of the ore-forming *** different types of scheelite are identified in the Mamupu deposit:scheelite A(Sch A)mainly occurs in breccias during the prograde stage,scheelite B(Sch B)forms in the chlorite-epidote alteration zone in the retrograde stage,while scheelite C(Sch C)occurs in distal quartz sulfide *** extremely high Mo content and negative Eu anomaly in Sch A represent high oxygen fugacity in the prograde *** with ore-related porphyries,Sch A has a similar REE pattern,but with higher ΣREE,more depleted HREE and slightly lower(^(87)Sr/^(86)Sr)i *** features suggest that Sch A is genetically related to ore-related porphyries,but extensive interaction with carbonate surrounding rocks affects the final REE and Sr isotopic *** B shows dark(Sch B-I)and light(Sch B-II)domains under CL *** Sch B-I to Sch B-II,LREEs are gradually depleted,with MREEs being gradually *** C has the highest LREE/HREE ratio,which indicates that it inherited the geochemical characteristics of fluids after the precipitation of HREE-rich minerals,such as diopside and garnet,in the early prograde *** Mo content in Sch B and Sch C gradually decreased,indicating that the oxygen fugacity of the fluids changed from oxidative in the early stages to reductive in the later,the turbulent Eu anomaly in Sch B and Sch C indicating that the Eu anomaly in the Mamupu scheelite is not solely controlled by oxygen *** extensive interaction of magmatic-hydrothermal fluids and carbonate provides the necessary Ca^(2.)for the precipitation of scheelite in the Mamupu deposit.

关键词： scheelite geochemistry Mamupu Cu deposit Yulong porphyry copper belt eastern Tibet

Single grain Rb-Sr isotopic analysis of GA-1550 biotite,LP-6 biotite and Bern-4M muscovite 40Ar-3.Ar dating standards

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Single grain Rb-Sr isotopic analysis of GA-1550 biotite,LP-6...