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| 1 | Strongly peraluminous granites of Mesozoic in Eastern Nanling Range, southern China: Petrogenesis and implications for tectonics显示文摘The strongly peraluminous granites (SPGs) of Eastern Nanling Range (ENR) are a characteristic of all bearing highly aluminous minerals, such as muscovite±Al-rich biotite±tourmaline±garnet, and lack of cordierite. In respect of petrography, geochemistry, Nd isotope, and single grain zircon U-Pb dating, the representative granite bodies of them are studied. The research shows that these granites were emplaced in two stages, namely 228-225 Ma BP and J2-3 159-156 Ma BP, belonging to Indosinian and early Yanshanian periods, respectively, and they have low εNd(t) values (-10.6--11.1), high A/CNK, Rb/Sr ratios and tDM values (1887-1817 Ma), and REE's tetrad effect (TE1, 3=1.13-1.34). In comparison with related geology, petrology and chronology of granites in adjacent regions, it is suggested that Indosinian SPGs of ENR formed in the circumstance of post-collisional extension 20 Ma after the major collision of Indosinian Movement (258-243 Ma BP) in Indo-China Peninsula, and early Yanshanian SPGs formed in the background of back-arc extension setting controlled by paleo-Pacific tectonic domain, and J1, the interval of two stages, is the interim from Tethyan to Pacific tectonic domains in South China. These SPGs have similar geological and geochemical characteristics, because they all crystallized from the magma of partial melting of early Proterozoic metasedimentary rocks when the thickened crust (≤50 km) became thinning, decompression, and transmitting of water. | SUN Tao, ZHOU Xinmin, CHEN Peirong, LI Huimin, ZHOU Hongying, WANG Zhicheng & SHEN Weizhou Department of Earth Sciences, Nanjing University, Nanjing 210093, China Tianjin Institute of Geology and Mineral Resources, China Geological Survey, Tianjin 300170, China | 2005 | Science China Earth Sciences2005,48,2: | 78 |
| 2 | Re-Os isotopes and PGE geochemistry of black shales and intercalated Ni-Mo polymetallic sulfide bed from the Lower Cambrian Niutitang Formation, South China显示文摘The Lower Cambrian Niutitang Formation consists of a thick black shale sequence with a regionally distributed conformable Ni Mo polymetallic sulfide horizon and a chert bed at its basal strata on theYangtze Platform, South China. In this paper, we discuss all available data on Re Os isotopes and Platinum Group Element (PGE) distribution pattern of the Ni Mo polymetallic sulfide ore and its host rocks (black shales, cherts, and phosphorites) from Guizhou and Hunan provinces. Our results show that the black shales and the Ni Mo sulfide ore have a high initial 187 Os/ 188 Os ratio of 0.78~0.86, indicating that the Early Cambrian ocean across the Yangtze Platform had a highly radiogenic Os value. This ratio is slightly lower than but still similar to present day seawater, possibly as a result of high continental weathering at that time. The Ni Mo sulfide ore yields a Re Os isochron of 537±10 Ma (MSWD=11.9), possibly representing the depositional age of the Niutitang Formation. The chondrite normalized PGE pattern, Pt anomaly (Pt/Pt *), Pt/Pd, Ir/Pd, Au/Ir and Re/Mo ratios of the Ni Mo sulfide ore and its host rocks from South China indicate a varying source contribution of the PGE and other metals for different rocks. It is suggested that the cherts and Ni Mo sulfide ore may have a significant proportion of PGE and probably other metals deriving from submarine hydrothermal fluids with a mantle signature. | JIANG Shaoyong*, YANG Jinghong, LING Hongfei, FENG Hongzhen, CHEN Yongquan and CHEN Jianhua(State Key Laboratory for Mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China) | 2003 | Progress in Natural Science:Materials International2003,13,10: | 78 |
| 3 | 恶意的腹水: 预示的因素, pathophysiology 和治疗学的措施的评论显示文摘 Malignant ascites indicates the presence of malignant cells in the peritoneal cavity and is a grave prognostic sign. While survival in this patient population is poor, averaging about 20 wk from time of diagnosis, quality of life can be improved through palliative procedures. Selecting the appropriate treatment modality remains a careful process, which should take into account potential risks and benefits and the life expectancy of the patient. Traditional therapies, including paracentesis, peritoneovenous shunt placement and diuretics, are successful and effective in varying degrees. After careful review of the patient’s primary tumor origin, tumor biology, tumor stage, patient performance status and comorbidities, surgical debulking and intraperitoneal chemotherapy should be considered if the benefit of therapy outweighs the risk of operation because survival curves can be extended and palliation of symptomatic malignant ascites can be achieved in select patients. In patients with peritoneal carcinomatosis who do not qualify for surgical cytoreduction but suffer from the effects of malignant ascites, intraperitoneal chemotherapy can be safely and effectively administered via laparoscopic techniques. Short operative times, short hospital stays, low complication rates and ultimately symptomatic relief are the advantages of laparoscopically administering heated intraperitoneal chemotherapy, making it not only a valuable treatment modality but also the most successful treatment modality for achieving palliative cure of malignant ascites. | Suma L Sangisetty Thomas J Miner | 2012 | World Journal of Gastrointestinal Surgery2012,4,4: | 45 |
| 4 | Carboniferous Post-collisional Rift Volcanism of the Tianshan Mountains, Northwestern China显示文摘The Tianshan Carboniferous post-collisional rift volcanic rocks occur in northwestern China as a large igneous province. Based on petrogeochemical data, the Tianshan Carboniferous post-collisional rift basic lavas can be classified into two major magma types: (1) the low-Ti/Y type situated in the eastern-central Tianshan area, which exhibits low Ti/Y (<500), Ce/Yb (<15) and SiO2 (43-55%), and relatively high Fe2O3T (6.4-11.5%); (2) the high-Ti/Y type situated in the western Tianshan area, which has high Ti/Y (>500), Ce/Yb (>11) and SiO2 (49-55%), and relatively low Fe2O3T (5.8-7.8%). Elemental data suggest that chemical variations of the low-Ti/Y and high-Ti/Y lavas cannot be explained by fractional crystallization from a common parental magma. The Tianshan Carboniferous basic lavas originated most likely from an OIB-like asthenospheric mantle source (87Sr/86Sr(t) ≈ 0.703-0.705, εNd(t) ≈ +4 to +7). The crustal contamination and continental lithospheric mantle have also contributed significantly to the formation of the basic lavas of the Tianshan Carboniferous post-collisional rift. The silicic lavas were probably generated by partial melting of the crust. The data of this study show that spatial petrogeochemical variations exist in the Carboniferous post-collisional rift volcanics province in the Tianshan region. Occurrence of the thickest volcanics dominated by tholeiitic lavas may imply that the center of the mantle-melting anomaly (mantle plume) was in the eastern Tianshan area at that time. The basic volcanic magmas in the eastern Tianshan area were generated by a relatively high degree of partial melting of the mantle source around the spinel-garnet transition zone, whereas the alkaline basaltic lavas are of the dominant magma type in the western Tianshan area, which were generated by a low degree of partial melting of the mantle source within the stable garnet region, thus the basic lavas of the western Tianshan area might have resulted from relatively thick lithosphere and low geothermal gradient. | XIA Linqi, XU Xueyi, XIA Zuchun, LI Xiangmin, MA Zhongping and WANG Lishe Xi’an Institute of Geology and Mineral Resources, China Geological Survey, Xi’an, Shaanxi 710054 E-mail: geologyx@pub.xaonline.com. Liu Shuchun and Liu Xinzhu | 2003 | Acta Geologica Sinica(English Edition)2003,77,3: | 49 |
| 5 | Recovery of Iron From High-Iron Red Mud by Reduction Roasting With Adding Sodium Salt显示文摘Red mud is the waste generated during aluminum production from bauxite, containing lots of iron and other valuable metals. In order to recover iron from red mud, the technology of adding sodium carbonate-reduction roasting-magnetic separation to treat high-iron red mud was developed. The effects of sodium carbonate dosage, reduction temperature and reduction time on the qualities of final product and the phase transformations in reduction process were discussed in detail. The results showed that the final product (mass percent), assaying Fe of 90.87% and Al2O3 of 0.95% and metallization degree of 94.28% was obtained at an overall iron recovery of 95.76% under the following conditions of adding 8% sodium carbonate, reduction roasting at 1 050 ℃ for 80 min and finally magnetic separation of the reduced pellets by grinding up to 90% passing 0.074 mm at magnetic field intensity of 0.08 T. The XRD (X-ray diffraction) results indicated that the iron oxides were transformed into metallic iron. Most of aluminum mineral and silica mineral reacted with sodium carbonate during the reduction roasting and formed nonmagnetic materials. | ZHU De-qing, CHUN Tie-jun, PAN Jian, HE Zhen (School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, Hunan, China) | 2012 | Journal of Iron and Steel Research(International)2012,19,8: | 38 |
| 6 | Potash-rich volcanic rocks and lamprophyres in western Shandong Province:^(40)Ar-^(39)Ar dating and source tracing显示文摘Highly precise 40Ar-39Ar dating results demon-strate that the ages of potash-rich volcanic rocks in western Shandong Province are 114.7-124.3 Ma, and that of the lamprophyres is 119.6 Ma. The potash-rich volcanic rocks have relatively high (87Sr/86Sr)i ratios ( 0.708715-0.711418) and distinctly negative εNd values ( -11.47--17.54), and are enriched in radiogenic lead (206Pb/204Pb=17.341-17.622, 207Pb/204Pb=15.525-15.538, 208Pb/204Pb=37.563-37.684). Similarly, the lamprophyres also have quite low εNd values (-11.57 - -19.64). Based on the fact that the Sr, Nd and Pb isotopic compositions of potash-rich volcanic rocks are very consistent with that of the clinopyroxene separates, and by integrating comprehensive analyses of their tectonic settings, and extensive comparisons of the Sr, Nd isotopic composi-tions with that of the related simultaneous rocks, it is con-cluded that the potash-rich volcanic rocks and lamprophyres in western Shandong Province were most possibly derived from the partial melting | QIU Jiansheng, XU Xisheng & LO Ching-HuaState Key Laboratory of Mineral Deposit Research of Nanjing University, Nanjing 210093, China Department of Earth Sciences, Nanjing University, Nanjing 210093, China Department of Geology, Taiwan Unive | 2002 | Chinese Science Bulletin2002,47,2: | 39 |
| 7 | ^(40)Ar-^(39)Ar dating and geological implication of auriferous altered rocks from the middle-deep section of Q875 gold-quartz vein in Xiaoqinling area, Henan,China显示文摘The 40Ar-39Ar age method is employed in this work to analyze the auriferous altered rocks from the middle-deep section of the Q875 gold-quartz vein in the Xiao-qinling area, and the results show that the main gold deposition of the Q875 occurred in ca. 128-126 Ma. As a typical gold-bearing quartz vein in this gold-rich area, the age data obtained from the Q875 also constrain on the metallogenic time of the lode gold deposits developed in the same geological settings. This geochronological study supplies new evidence for further understanding the timing of gold mineralization, the genesis of gold deposits and the geodynamic settings in Xiaoqinling area. | WANG Yitian, MAO Jingwen, LU Xinxiang & YE AnwangInstitute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China Institute of Geological Sciences, Henan Province, Zhengzhou 450053, China Lingbao Bureau of Geology and Mineral | 2002 | Chinese Science Bulletin2002,47,20: | 36 |
| 8 | Permian Alkaline Granites in Central Inner Mongolia and Their Geodynamic Significance显示文摘Alkaline granites (Rb-Sr ages 276-286 Ma)occurring in the Bayan Ul-East Ujimqin belt at the southern margin of the Siberian plate originated in a tensional tectonic environment about 60 Ma earlier than the Late Devonian to Early Carboniferous collision between the Siberian and Sino-Korean plates. They belong to post-orogenic A-type granites and may be used as an indicator of the end of the orogeny. At the northern margin of the Sino-Korean plate, however, only late-orogenic calc-alkaline granites occurred during the late Caboniferous-Permian, and alkaline syenites did not appear until the Late Triassic. The asymmetric magmatism at the margins of the two neighbouring plates might be controlled by the differences in size and mass of the two plates. | Hong Dawei, Huang Huaizeng, Lithosphere Research Center, Chinese Academy of Geological Sciences, BeijingXiao Yijun, Institute of Geology, Chinese Academy of Geological Sciences, BeijingXu Haiming,Institute of Mineral Deposits, Chinese Academy of Geological Sciences, Beijingand Jin M anyuanTianjin Geological Academy, Ministry of Metallurgical Industry, Tianjin Fei Zhenbi | 1995 | Acta Geologica Sinica(English Edition)1995,69,1: | 40 |
| 9 | Sr-Nd isotopic compositions of the Changjiang sediments: Implications for tracing sediment sources显示文摘The suspended particulate and fine-grained floodplain sediments were collected from the main stream and tributaries of the Changjiang River for Sr-Nd isotopic measurements. The εNd(0) values gradually decrease downstream from -10.8 on average in the upper reaches to -12.3 in the lower reaches, whereas the 87Sr/86Sr ratios increase correspondingly, averaging 0.721899 and 0.725826 respectively in the upper and middle-lower reaches. The compositional variations primarily reflect the complex con- trols of provenance rocks, chemical weathering, and sediment characters between different catchments, among which the abnormal Sr-Nd isotopic compositions of the Yalong, Fujiang, Tuojiang and Yuanjiang rivers indicate the sediment provenance contributions from the Emeishan Basalt in the upper reaches and the old metamorphic and siliceous rocks in the middle-lower reaches. The Sr-Nd isotopic ratios of the Changjiang sediments can better reflect the average composition of weathered continental crust compared to other major rivers in the world because of the unique source rock types in the Changjiang drainage basin. The recognition of the Sr-Nd isotopic systematics of the Changjiang sediments will contribute to our understanding of the Changjiang evolution history and continental weathering processes during the Cenozoic, and also to reconstructing the paleoenvironmental changes in East China and the marginal seas. | YANG ShouYe1?, JIANG ShaoYong2, LING HongFei2, XIA XiaoPing3, SUN Min3 & WANG DeJie4 1 State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China 2 State Key Laboratory for Mineral Deposit Research, Nanjing University, Nanjing 210093, China 3 Departmen of Earth Sciences, The University of Hong Kong, Hong Kong SAR, China 4 Development Research Center, China Geological Survey, Beijing 100083, China | 2007 | Science China Earth Sciences2007,50,10: | 32 |
| 10 | Chronological and geochemical studies of granite and enclave in Baimashan pluton, Hunan, South China显示文摘Zircon LA-ICP-MS U-Pb dating reveals that the Baimashan Pluton is composed mainly of late Indosinian (204.5±2.8 Ma-209.2±3.8 Ma) biotite granodiorites/monzonitic granites (LIGs) and early Yanshanian (176.7±1.7 Ma) two-micas monzonitic granites (EYGs), and the coeval (203.2±4.5 Ma-205.1±3.9 Ma) mafic microgranular enclaves (MMEs) are generally found in the former. In addition, the ages of cores within zircons from LIGs and MMEs ranging from 221.4±4.0 Ma to 226.5±4.1Ma provide evidence of multistage magma intrusion during Indosinian in the study area. Measured 3010±20.6 Ma of inherited zircon age suggests that there may be recycling Archaean curstal material in existence in this area. LIGs and EYGs share some similar geochemical features: subalkaline and peraluminous granites, enrichment of Th, U, K, Ta, Zr, Hf and LREE but depletion of Ba, Nb, P, Ti and Eu, low εNd(t) values but high (87Sr/86Sr)i ratios, and old T2DM (ca. 1.9-2.0 Ga). The behaviors of incompatible elements and REE are mainly dominated by fractional crystallization of plagioclase, K-feldspar, ilmenite and apatite, but that of Sr isotope mainly controlled by EC-AFC. They are crust-sourced and derived from partial melting of paleo-Proterozoic metagreywackes and related to biotite dehydration melting. LIGs are formed in post-collisional tectonic setting as crustal local extension and thinning during late Indosinian. But EYGs may be evolved products of congeneric granitic magma with LIGs formed in late Indoinian, which were emplaced again when crust underwent extensive thinning and extension in post-orogenic tectonic setting during Yanshanian in SC after undergoing EC-AFC. MMEs should be cognate enclaves and derived from liquid immiscibility of host magma. | CHEN WeiFeng1, CHEN PeiRong1, HUANG HongYe2, DING Xing1,3 & SUN Tao1 1 State Key Laboratory of Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China 2 Research Institute No.230, CNNC, Changsha 410011, China 3 Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China | 2007 | Science China Earth Sciences2007,50,11: | 33 |
| 11 | Carbon isotope composition of the Lower Triassic marine carbonates, Lower Yangtze Region, South China显示文摘Studies on three Lower Triassic sections located on the shallow water platform, the deep water slope and in the deep water basin in the Lower Yangtze Region, South China, show the similar trend of carbon isotope evolution. Biostratigraphic correlations among the Lower Triassic sections on the basis of standard conodont zones indicate that three negative shifts occurred in the Griesbachian, the Smithian and the late Spathian stages respectively, and one distinctly positive shift occurred in the early Spathian stage. Trend of carbon isotope evolution of the Lower Triassic reflects some significant changes in the global carbon cycle. Moreover, δ 13C background values are intensively controlled by palaeogeographic environment. In general, δ 13C values from deep-water slope carbonates are lighter than those from carbonate platform and heavier than those from deep-water basin carbonates. The positive carbon isotope excursion may be induced by a significant amount of organic carbon burial in marine sediments and increase in primary productivity. The large negative carbon isotope excursions during the Early Triassic in Lower Yangtze Region are interpreted to relate to volcano eruptions based on tuffaceous claystone interlayers observed near the Permian-Triassic boundary, the Induan- Olenekian boundary and the Lower Triassic-Middle Triassic boundary. | ZUO Jingxun1,2, TONG Jinnan3, QIU Haiou4 & ZHAO Laishi3 1. Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China 2. Henan Institute of Geological Survey, Zhengzhou 450007, China 3. State Key Laboratory of Geological Processes and Mineral Resources at China University of Geosciences, Wuhan 430074, China 4. Faculty of Material Sciences and Chemical Engineering, China University of Geosciences, Wuhan 430074, China | 2006 | Science China Earth Sciences2006,49,3: | 32 |
| 12 | SHRIMP U-Pb dating and Hf isotopic analyses of Middle Ordovician meta-cumulate gabbro in central Qiangtang, northern Tibetan Plateau显示文摘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. | 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 | 2010 | Science China Earth Sciences2010,53,5: | 31 |
| 13 | Early J_2 basalts in SE China:Incipience of large-scale late Mesozoic magmatism显示文摘Magmatism in SE China was dormant during 204―180 Ma, but was reactivated in 180― 170 Ma (early J2), and then became more and more intensive towards the end of early Cretaceous. The small-scale early J2 magmatism is the incipience to long-term and large-scale magmatism in this region. A near east-west (EW) trend volcanic belt was distributed across south Hunan, south Jiangxi and southwest Fujian was formed during early J2 time. Along this belt from the inland toward the coast, the lithology of basalts changes from alkali into tholeiite, and the amount of erupted volcanic rocks and the proportions of rhyolites coexisting with the basalts increase. On the basis of geochemical char- acteristics of these basalts, we infer that the melting degree of source rocks and the extent of frac- tional crystallization and crustal contamination all increased whereas the depth of mantle source de- creased from the inland to the coast, which led to the variations of geological characteristics of the volcanic belt. In early J2, the western spreading Pacific plate began to subduct underneath SE China continental block, reactivating near EW trend deep fault that was originally formed during the Indos- inian event. The stress of the western spreading Pacific plate and the extent of asthenosphere up- welling increased from the inland to the coast, which is consistent with the generation and evolution of early J2 basalts. | XIE Xin1, XU Xisheng1, ZOU Haibo2, JIANG Shaoyong1, ZHANG Ming3 & QIU Jiansheng1 1. State Key Laboratory of Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China 2. Department of Earth and Space Sciences, University of California at Los Angeles, Los Angeles, CA90095-1567, USA. 3. GEMOC ARC National Key Centre, Department of Earth and Planetary Sciences, Macquarie University, Sydney, N.S.W. 2109, Australia | 2006 | Science China Earth Sciences2006,49,8: | 30 |
| 14 | Microcosmic analysis of ductile shearing zones of coal seams of brittle deformation domain in superficial lithosphere显示文摘The ductile shearing zones of coal seams in a brittle deformation domain in super-ficial lithosphere are put forward based on the study on bedding shearing and ductile rheology of coal seams. The macrocosmic and microcosmic characteristics include wrinkle fold, mymonitized zones and ductile planar structure of coal seams, etc., while the microcosmic characteristics may also include different optic-axis fabrics and the anisotropy of vitrinite reflectance as well as the change of chemical structure and organic geochemistry components. The forming mechanism is analyzed and the strain environment of ductile shearing zones of coal seams discussed. The result indicates that, in the superficial brittle deformation domain, the coal seams are easy to be deformed, resulting in not only brittle deformation but also ductile shearing deformation under the action of force. Because of simple shearing stress, the interlayer gliding or ductile rheology may take place between coal seams and wall rocks. Therefore, many ductile shearing zones come into being in superficial lithosphere (<5 km). The research on ductile shearing zone of brittle de-formation domain in superficial lithosphere is significant not only theoretically for the study of ductile shearing and ductile rheology of the lithosphere but also practically for the structural movement of coal seams, the formation and accumulation of coal-bed methane, and the preven-tion and harness of gas burst in coal mine. | JU Yiwen1,2, WANG Guiliang2, JIANG Bo2 & HOU Quanlin1 1. Graduate School, Chinese Academy of Sciences, Beijing 100039, China 2. College of Mineral Resources and Geosciences, China University of Mining & Technology, Xuzhou 221008, China | 2004 | Science China Earth Sciences2004,47,5: | 28 |
| 15 | Edge Effect Correction in the S-A Method for Geochemical Anomaly Separation显示文摘Anomaly separation using geochemical data often involves operations in the frequency domain, such as filtering and reducing noise/signal ratios. Unfortunately, the abrupt edge truncation of an image along edges and holes (with missing data) often causes frequency distribution distortion in the frequency domain. For example, bright strips are commonly seen in frequency distribution when using a Fourier transform. Such edge effect distortion may affect information extraction results; sometimes severely, depending on the edge abruptness of the image. Traditionally, edge effects are reduced by smoothing the image boundary prior to applying a Fourier transform. Zero-padding is one of the most commonly used smoothing methods. This simple method can reduce the edge effect to some degree but still distorts the image in some cases. Moreover, due to the complexity of geoscience images, which can include irregular shapes and holes with missing data, zero-padding does not always give satisfactory results. This paper proposes the use of decay functions to handle edge effects when extracting information from geoscience images. As an application, this method has been used in a newly developed multifractal method (S-A) for separating geochemical anomalies from background patterns. A geochemical dataset chosen from a mineral district in Nova Scotia, Canada was used to validate the method. | Ge Yong Department of Earth and Atmospheric Science, York University, Toronto, ON, M3J 1P3, Canada State Key Laboratory of Resources and Environmental Information System, Institute of Geographic Sciences & Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Cheng Qiuming Department of Earth and Atmospheric Science, York University, Toronto, ON, M3J 1P3, Canada Earth Systems and Mineral Resource Engineering Lab, China University of Geosciences, Wuhan 430074, China Zhang Shenyuan Department of Earth and Atmospheric Science, York University, Toronto, ON, M3J 1P3, Canada Department of Resource and Earth Science, China University of Mining & Technology, Beijing 100083, China | 2004 | Journal of China University of Geosciences2004,15,4: | 28 |
| 16 | Petrogenesis and significance of early Yanshanian syenite-granite complex in eastern Nanling Range显示文摘In the eastern Nanling Range there exists the early Yanshanian syenite-granite assemblage. A representative example is the Pitou-Tabei complex composed of the Tabei syenite pluton and the Pitou syenogranite pluton in southern Jiangxi Province. U-Pb zircon dating yields ages of 188.6±2.2 Ma for the Tabei pluton and 186.3±1.1 Ma for the Pitou pluton. The Tabei syenite is characterized by relatively low SiO2 content (62.40% - 68.75%), high alkalis (K2O+Na2O = 10.56%-11.96%), low percent K2O/Na2O ratios (0.56-0.93), metaluminous fea- ture (A/CNK = 0.80-1.00), enrichment in LILE (Rb, Ba, K) and HFSE (Th, U, Nb, Ta, Zr, and so on), weakly negative to positive Eu anomalies (δ Eu = 0.63-1.82), relatively low (87Sr/86Sr)i (0.70412-0.70543), and relatively high ε Nd(t) (3.14-3.52). The Pitou syenogranite is charac- terized by high silicon content (SiO2 = 71.06%-76.28%), relatively low alkalis (K2O+Na2O = 8.10%-9.80%), high percent K2O/Na2O ratios (1.22-1.94), metaluminous feature (A/CNK = 0.94-1.07), enrichment in Rb, Th (U), K, depletion in Ba, Nb, Ta, Sr, P , Zr, Ti, high ΣREE (av- eraging 451.03 μg/g), strong negative Eu anomalies (δ Eu = 0.27-0.33), relatively high (87Sr/86Sr)i (0.70805-0.70912), and relatively low ε Nd( t ) (?5.35-?6.29). The Tabei syenite and Pitou syenogranite both have the characteristics of A-type granites. The former is considered to be from the asthenosphere mantle, and the latter was the product of the crust-mantle mixture. They both were probably formed in a rifting setting. | CHEN Peirong1, ZHOU Xinmin1, ZHANG Wenlan1, LI Huimin2, FAN Chunfang1, SUN Tao1, CHEN Weifeng1 & ZHANG Min1 1. State Key Laboratory of Mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China 2. Tianjin Institute of Geology and Mineral Resources, China Geological Survey, Tianjin 300170, China | 2005 | Science China Earth Sciences2005,48,7: | 26 |
| 17 | Origin of ore-forming fluid in the Piaotang tungsten deposit in Jiangxi Province:Evidence from helium and argon isotopes显示文摘The Piaotang tungsten deposit in Jiangxi Province is one of the most important tungsten deposits in the South China Tungsten Metallogenic Province.In this study,we selected wolframite and chalcopyrite from the main mineralizing stage of the Piaotang tungsten deposit,and analyzed the helium and argon isotopic compositions in fluid inclusions of these minerals.The results show a 3He/4He ratio of 0.17 to 0.86 R/Ra,which fall within the range between continental crust(0.01―0.05 R/Ra) and air-saturated water(1 R/Ra) ,but are significantly lower than those of the normal mantle(6―9 R/Ra) .Their 40 Ar/36 Ar ratios are between 354.5 and 590.7,which are slightly higher than the air-saturated water(295.5) .Along with the other geochemical observation such as the lithium enrichments in the ore bodies and the ore-related granites,we suggest that the ore-forming fluid in the Piaotang tungsten deposit was mainly derived from crustal fluid.It may have mixed with some amounts of air-saturated water,but there was no considerable involvement of mantle-derived fluid. | WANG XuDong 1,2,3,NI Pei 1,2,3,JIANG ShaoYong 1,3,ZHAO KuiDong 1,3 & WANG TianGang 1,2,3 1State Key Laboratory for Mineral Deposits Research,Nanjing University,Nanjing 210093,China 2Institute of Geo-Fluids,Nanjing University,Nanjing 210093,China 3 School of Earth Sciences and Engineering,Nanjing University,Nanjing 210093,China | 2010 | Chinese Science Bulletin2010,55,7: | 26 |
| 18 | Underplating in the middle-lower Yangtze Valley and model of geodynamic evolution:Constraints from geophysical data显示文摘The lower crust and Moho are the most active boundary layers in the process of continental evolution, in which marks left by tectonic and magmatic activities during the process are preserved. The evolutionary process of the continental lithosphere may be reconstructed by exploring the structures of the lower crust and Moho. According to a study of the deep seismic reflection data obtained from the middle-lower Yangtze Valley, the authors find bright layered reflections ubiquitous in the lower crust and think that the bright reflections are caused by un-derplating of basic or ultrabasic magmas, which might be related to delamination of the lithosphere. On the basis of an integrated analysis of the geophysical and geological data of the region, the authors propose a model for geodynamic evolution of the middle-lower Yangtze Valley. This model suggests that the middle-lower Yangtze Valley had undergone such geodynamic processes as collision-compression, delamination-extension and underplating-melting since the end of the Permian, finally forming the gigantic middle-lower Yangtze Valley metallogenic belt. | Lü Qingtian, HOU Zengqian, YANG Zhusen & SHI Danian Institute of Mineral Resources,Chinese Academy of Geological Sciences,Beijing 100037,China | 2005 | Science China Earth Sciences2005,48,7: | 24 |
| 19 | ^(40)Ar-^(39)Ar thermochronology of two ductile shear zones from Yiwulüshan,West Liaoning Region: Age constraints on the Mesozoic tectonic events显示文摘Two ductile shear zones trending EW and NNE respectively not only controlled the tectonic framework of the northern North China, but also constrained the geody-namic background for gold mineralization in this region. Field observations and microstructural analyses reveal that the EW trending ductile shear zones are mainly contributed to dextral compressional deformation resulting from top-to-the-southeast oblique thrust shearing, whereas the NNE trending ones are genetically related to sinistral strike-slip and extensional faulting. One sample from the former yielded an 40Ar-39Ar plateau age of (219±4) Ma (Bi) and two samples from the latter gave 40Ar-39Ar plateau ages of (116± 2) Ma (Bi) and (127±3) Ma (Bi). These ages provide constraints on the top-to-the-southeast oblique thrusting event occurring in Late Triassic and the sinistral extensional and strike-slip faulting event which occurred in Early Cretaceous. | ZHANG Xiaohui, LI Tiesheng & PU ZhipingResearch Center of Mineral Resources Exploration, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100101, China Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 51 | 2002 | Chinese Science Bulletin2002,47,13: | 24 |
| 20 | Indian Ocean-MORB-type isotopic signature of Yushigou ophiolite in North Qilian Mountains and its implications显示文摘In order to explore the disputed issue concerning the tectonic affinity of the ancient ocean mantle of North Qilian Mountains (NQM), geochemical and Sr, Nd, Pb isotopic compositions of pillow basalts of the Yushigou Ophiolite (YSGO) suite from NQM have been analyzed systematically. The pillow basalts exhibit tholeiitic characteristics, with flat chondrite-normalized REE patterns ((La/Yb)N = 0.98―1.27). They display no Nb, Ta, Zr, Hf negative anomalies, and show MORB features in 2Nb-Zr/4-Y and Ti/100-Zr-Y×3 tectonic discrimination diagrams. These results indicate that the Yushigou ophiolite is most likely to be formed in a mid-ocean ridge or mature back-arc basin. Their isotopic data show a relatively broad and enriched 87Sr/86Sr (0.70509 ― 0.70700), restricted 143Nd/144Nd (0.512955―0.512978). Pb isotopes are in the range of 206Pb/204Pb (18.054―20.562), 207Pb/204Pb (15.537―15.743) and 208Pb/204Pb (38.068―38.530). These isotopic data imply that the basalts originated from the depleted mantle (DMM), with the involvement of enriched mantle compo-nents (mainly EMII). Geochemical comparisons between the basalts in YSGO and the MORB-type basalts of ophiolite suites occurring in the known ancient Tethyan tectonic domain indicate that the ancient oceanic mantle represented by YSGO suite forming in early Paleozoic in the North Qilian Moutains is very similar to the Tethyan mantle in both trace elements and isotopic compositions. The North Qilian Mountains should be a part of the Tethyan tectonic domain in early Paleozoic. This further implies that the Tethyan tectonic domain can be deduced to early Paleozoic in the study area, which will be helpful to discussing the tectonic affinity and evolution of the North Qilian Mountains. | HOU Qingye1,2, ZHAO Zhidan1,2, ZHANG Hongfei3, ZHANG Benren3 & CHEN Yuelong2 1. State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China 2. School of Earth Science and Mineral Resources, China University of Geosciences, Beijing 100083, China 3. Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, China | 2006 | Science China Earth Sciences2006,49,6: | 21 |