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| 1 | Role of mantle-derived magma in genesis of early Yanshanian granites in the Nanling Range, South China: in situ zircon Hf-O isotopic constraints显示文摘Although a number of petrographic observations and isotopic data suggest that magma mixing is common in genesis of many granite plutons, it is still controversial whether the mantle-derived magmas were involved in granites. We carried out in this study a systematic analysis of in situ zircon Hf-O isotopes for three early Yanshanian intrusions dated at ca. 160 Ma from the Nanling Range of Southeast China. The Qinghu monzonite has very homogeneous zircon Hf-O isotopic compositions, εHf(t) =11.6±0.3 and δ18O=5.4‰±0.3‰. In combination with whole-rock geochemical and Sr-Nd isotopic data, the parental magma of the Qinghu monzonite were likely derived from the partial melting of recently-metasomatized, phlogopite-bearing lithospheric mantle without appreciable crustal contamination. The Lisong and Fogang granites and the mafic microgranular enclaves (MME) within the Lisong granites have a wide range of zircon Hf-O isotopic compositions, with Hf and O isotopes being negatively correlated within each pluton. The Lisong MMEs were crystallized from a mantle-derived magma, similar to the parental magma of the Qinghu monzonite, with small amount of crustal assimilation. The Lisong and Fogang granites were formed by reworking of meta-sedimentary materials by mantle-derived magmas and mixing of the mantle-and sediment-derived melts to varying degrees. It is thus concluded that these two Yanshanian granites in the Nanling Range were formed associated with growth and differentiation of continental crust. | LI XianHua LI WuXian WANG XuanCe LI QiuLi LIU Yu TANG GuoQiang | 2009 | Science China Earth Sciences2009，52，9： | 101 |
| 2 | North Qinling Paleozoic granite associations and their variation in space and time: Implications for orogenic processes in the orogens of central China显示文摘Integrated zircon U-Pb dating and whole rock geochemical analyses have been carried out for two typical S-and I-type granitoids in the north Qinling. Zircon dating by SIMS of the Piaochi S-type grani- toids yields an emplacement age of 495±6 Ma. The granitoids show whole-rock εNd(t)=-8.2--8.8, zircon εHf(t)=-6―-39. The Huichizi I-type granitoids have emplacement ages of 421±27 Ma and 434±7 Ma es- tablished by LA-ICP-MS and SIMS methods, respectively. Their whole-rock εNd(t)=-0.9-0.9 and zircon εHf(t)=-11-8.4. Combined with statistical analyses of 28 zircon ages of granitoid plutons collected from the literature, Paleozoic magmatism in the north Qinling can be divided into three stages. The first-stage magmatism (~505-470 Ma) mainly occurred in the east part of the north Qinling and has features of an I-type arc, associated with which are S-type granitoids such as Piaochi pluton. The early granitoids (~505-490 Ma) have close spatio-temporal relations to ultra-high-pressure (UHP) rocks, and thus are interpreted as an oceanic subduction system along a continental margin. The second-stage magmatism (~450-422 Ma) occured through the whole north Qinling, and is characterized by I-type granitoids represented by the Huichizi pluton. The magma is interpreted as partial melting of lower crust mixed by mantle-derived magma in a collisional setting with the uplift of terranes. The third-stage magmatism (~415-400 Ma) is dominated by I-type granitoids and only took place in the middle part of the north Qinling, and is regarded as a late-stage collision. The spatial and temporal variations of the Qinling Paleozoic magmatism reveal protracted subduction/collision. The subduction was initiated from the east part of the north Qinling, earlier than that in the Qilian-northern Qaidam, Kunlun, and northern Dabie regions. This demonstrates variations in time of subduction, accretion and collision of separate blocks or terranes in the orogenic systems in central China. | WANG Tao WANG XiaoXia TIAN Wei ZHANG ChengLi LI WuPing LI Shan | 2009 | Science China Earth Sciences2009，52，9： | 79 |
| 3 | Sr and O isotopic characteristics of porphyries in the Qinling molybdenum deposit belt and their implication to genetic mechanism and type显示文摘A great deal of Mesozoic hypobatholithic granites and hypabyssal porphyries develop in the Qinling Mountains. The former has long been regarded as transformation type (or S-type), and the latter associated with Mo-mineralization regarded as syntexis type (or l-type) granitoids. Statistics show that Sr, andδ18O of hypabyssal porphyries respectively range from 0.705 to 0.714, and from 7.2‰ to 12.1‰, agreeing with those of hypobatholithes (Sr1=0.705-0.710, δ18O = 6.1‰-10.4‰), which indicates that they share similar material sources and petrogenic mechanism. Based on analysis of lithological, mineralogical and geochemical characteristics of these granitoids and on study of their petrogenic tectonic background and regional geophysical data, we argue that both the shallow-seated porphyries and deep-seated batholithes were the products of Mesozoic collision between South China and North China paleocontinents. Subsequently, all these granti-toids should be attributed to collision type. | 陈衍景 李超 张静 李震 王海华 | 2000 | Science China Earth Sciences2000，43，S1： | 70 |
| 4 | Geology and isotopic composition of helium,neon,xenon and metallogenic age of the Jinding and Baiyangping ore deposits,northwest Yunnan,China显示文摘Both the Jinding and Baiyangping ore deposits developed in the Lanping basin, which is a Mesozoic-Cenozoic terrestrial clastic sedimentary basin. Their occurrences can easily lead many people to compare them with the Pb-Zn deposit hosted in sedimentary rocks, such as Mississippian Valley-, Sedex- and sandstone-type Pb-Zn deposits. However, the Lanping basin developed in the settings of strong tectonic activity of the continental crust, which could cause an effective material exchange between the lower crust and the upper mantle. The orebodies are clearly tectonically controlled without syngenetic features, which probably represents a new type of the sedimentary rock-hosted Pb-Zn deposit. The isotopic compositions of noble gases in ore-forming fluids indicate that 2%32% of helium (3He/4He = 0.19 Ra1.97 Ra) is derived from the mantle, 50.1% of neon (20Ne/22Ne = 10.4510.83; 21Ne/22Ne = 0.03) from the mantle, and considerable amount of xenon (129Xe/130Xe = 5.846.86; 134Xe/130Xe = 2.262.71) from the mantle, which show that mantle fluids played an important role in the ore formation. The ore-forming age of 6760 Ma obtained by Re-Os and 40Ar-39Ar dating methods is later than the host rock, which is coeval with the Himalayan alkali magmatism of the mantle source and mantle-crust source. In this paper, the mineralization of the Jinding and Baiyangping ore deposits is considered to be related to the mantle fluids which move upward with the magma or along the deep faults, and mix with the meteoritic brine in the crust to result in large-scale deposition. | 薛春纪 陈毓川 王登红 杨建民 杨伟光 曾荣 | 2003 | Science China Earth Sciences2003，46，8： | 42 |
| 5 | Geochemical and Pb-Sr-Nd isotopic compositions of Indosinian granitoids from the Bikou block,northwest of the Yangtze plate:Constraints on petrogenesis,nature of deep crust and geodynamics显示文摘This paper reports geochemical and Pb-Sr-Nd isotopic compositions of the Indosinian Yangba (215 Ma),Nanyili (225 Ma) and Mopi granitoids from the Bikou block of the northwestern margin of the Yangtze plate. These granitoids are enriched in Al (Al2O3:14.56%―16.48%) and Sr (352 μg/g―1047 μg/g),and depleted in Y (<16 μg/g) and HREE (e.g. Yb<1.61 μg/g),resulting in high Sr/Y (36.3―150) and (La/Yb)N (7.8―36.3) ratios and strongly fractionationed REE patterns. The Indosinian granotoids show initial Sr isotopic ratios (ISr) from 0.70419 to 70752,εNd(t) values from-3.1 to -8.5,and initial Pb isotopic ratios 206Pb/204Pb=17.891-18.250,207Pb/204Pb=15.494-15.575,and 208Pb/204Pb=37.788-38.335. Their geochemi-cal signatures indicate that the granitoids are adakitic. However,they are distinct from some adakites,generated by partial melting of subducted oceanic slab and/or underplated basaltic lower crust,be-cause they have high K (K2O: 1.49%―3.84%) and evolved Nd isotopic compositions,with older Nd iso-topic model ages (TDM=1.06―1.83 Ga). Geochemical and Sr-Nd isotopic compositions suggest that the magmas of the Insoninian adakitic rocks in the Bikou block were derived from partial melting of thick-ened basaltic lower crust. Combined with regional analyses,a lithospheric delamination model after collision between the North China and South China plates can account for the Indosinian adakitic magma generation. On the other hand,based on the Pb-Sr-Nd isotopic probing to the magma sources of the adakitic rocks,it is suggested that there is an unexposed continent-type basement under the exposed Bikou Group volcanic rocks. This can constrain on the Bikou Group volcanic rocks not to be MORB-or OIB-type. | ZHANG HongFei XIAO Long ZHANG Li YUAN HongLin JIN LanLan | 2007 | Science China Earth Sciences2007，50，7： | 38 |
| 6 | Oxygen and carbon isotopic characteristics of rainwater,drip water and present speleothems in a cave in Guilin area,and their environmental meanings显示文摘The studies of the oxgen and carbon isotopes of the rainwater in Guilin area, the drip water and the present carbonate deposit in Panlong cave of Guilin show that: (i) as to the general characteristics of the oxygen isotopes of the rainwater within a year and between years, the δ18O values decrease with an increase of air temperature and the rainfall, and the correlation betweenδ18O values and the mean monthly air temperature is much better than that between δ18O values and the rainfall, and the δ18O values of the rainwater during the summer monsoon are much smaller than those during winter monsoon; (ii) δ18O values of the drip water have a quite good correlation with the δ18O values of the rainwater in the same period; (iii) when the conditions are appropriate, δ13C can be used as an environmental proxy, that is, the smaller δ13C of speleothems is, the larger the proportion of C3 plants is and the more plentiful the rainfall is. On the contrary, C4 plants may be prevailing or the environment | 李彬 袁道先 覃嘉铭 林玉石 张美良 | 2000 | Science China Earth Sciences2000，43，3： | 31 |
| 7 | Geochronology of Ailaoshan-Jinshajiang alkali- rich intrusive rocks and their Sr and Nd isotopic characteristics显示文摘Twenty-nine isotopic ages, ranging from 41 to 27 Ma, are presented for the alkali-rich intrusive rocks and their coexisting alkaline volcanic rocks, lamprophyres and acidic porphyries, indicating that they are Tertiary in age. The alkali-rich intrusive rocks have 143Nd/144Nd ratios from 0. 512 415 to 0. 512 544, and 87Sr/86Sr ratios from 0.705 4 to 0.706 8, suggesting that their material originates from an enriched mantle source. | 张玉泉 谢应雯 | 1997 | Science China Earth Sciences1997，40，5： | 29 |
| 8 | Origin of ore-forming fluids of the Dachang Sn-polymetallic ore deposit: Evidence from helium isotopes显示文摘The ore genesis model for the Dachang Sn-polymetallic ore deposit has long been in dispute, and the major debate focuses on whether the stratiform and massive orebodies formed during the Yanshanian magmatic-hydro-thermal event or they were products of Devonian syn-sedi-mentary exhalative-hydrothermal event. This note presents new helium isotope data from fluid inclusions of four pyrites and one fluorite. The pyrites were collected from the stratiform and massive orebodies in the deposit, and their 3He/4He ratios are significantly higher than 1, ranging from 1.7 to 2.5 Ra, which indicates a mantle component in the responsible hydrothermal fluids. It is suggested that the ore-forming fluids were a mixture of deep circulating seawater and a mantle-derived fluid, which are similar to many of those modern submarine hydrothermal fluids. In contrast, the fluorite, collected from a granite-related hydrothermal vein in the deposit, shows a low 3He/4He ratio of 0.7 Ra, which indicates no mantle component | Kuidong Zhao Shaoyong Jiang Hongquan Xiao Pei Ni | 2002 | Chinese Science Bulletin2002，47，12： | 28 |
| 9 | U-Pb zircon geochronology and Hf isotope study of metamorphosed basic-ultrabasic rocks from metamorphic basement in southwestern Zhejiang:The response of the Cathaysia Block to Indosinian orogenic event显示文摘A combined study using LA-ICP-MS U-Pb dating, Hf isotopes, trace elements and the Ti-in-zircon geo-thermometer was carried out on zircons from the metamorphosed basic-ultrabasic rocks in the meta-morphic basement of the Cathaysia Block, southwestern Zhejiang Province. The formation and meta-morphic ages of the rocks from the metamorphic basement of the Cathaysia Block were determined based on zircon U-Pb geochronology. The age for the magmatic crystalline zircons from the protolith is about 1.85 Ga. The εHf(t) values of the older zircons were from ?7 to ?3, with two-stage model Hf ages (TDM2LC) of about 2.9 to 3.4 Ga, indicating that the source material was derived from anatexis and recy-cling of the Archean crust. The newly formed metamorphic zircons yielded U-Pb ages of 260―230 Ma. The metamorphic temperature calculated using the Ti-in-zircon geothermometer ranged from 610 to 720℃, consistent with the results from petrographic observations, indicating that the Cathaysia Block experienced an amphibolite facies metamorphism during the Indosinian. Results from this study pro-vided an important timeframe for the tectonic evolution in South China and the Southeast Asia during the Late Permian and Early Triassic times. | XIANG Hua ZHANG Li ZHOU HanWen ZHONG ZengQiu ZENG Wen LIU Rui JIN Song | 2008 | Science China Earth Sciences2008，51，6： | 24 |
| 10 | Evolution and variation of the Tsushima warm current during the late Quaternary: Evidence from planktonic foraminifera, oxygen and carbon isotopes显示文摘The evolution and variation history of the Tsushima warm current during the late Quaternary was reconstructed based on the quantitative census data of planktonic foraminiferal fauna, together with oxygen and carbon isotope records of mixed layer dweller G. ruber and thermocline dweller N. dutertrei in piston core CSH1 and core DGKS9603 collected separately from the Tsushima warm current and the Kuroshio dominated area. The result showed that the Tsushima warm current vanished in the lowstand period during 40―24 cal ka BP, while the Kuroshio still flowed across the Okinawa Trough, arousing strong upwelling in the northern Trough. Meanwhile, the influence of freshwater greatly increased in the northern Okinawa Trough, as the broad East China Sea continental shelf emerged. The freshwater reached its maximum during the last glacial maximum (LGM), when the upwelling obviously weakened for the lowest sea-level and the depression of the Kuroshio. The modern Tsushima warm current began its development since 16 cal ka BP, and the impact of the Kuroshio increased in the middle and north- ern Okinawa Trough synchronously during the deglaciation and gradually evolved as the main water source of the Tsushima current. The modern Tsushima current finally formed at about 8.5 cal ka BP, since then the circulation structure has been relatively stable. The water of the modern Tsushima cur- rent primarily came from the Kuroshio axis. A short-term wiggle of the current occurred at about 3 cal ka BP, probably for the influences from the enhancement of the winter monsoon and the depression of the Kuroshio. The cold water masses greatly strengthened during the wiggle. | LI TieGang SUN RongTao ZHANG DeYu LIU ZhenXia LI Qing JIANG Bo | 2007 | Science China Earth Sciences2007，50，5： | 15 |
| 11 | Chemocline instability and isotope variations of the Ediacaran Doushantuo basin in South China显示文摘Stable isotope analyses in sections across a shelf to basinal transect of the Ediacaran Doushantuo basin show substantial isotope variabilities. In Songlin section where sediments were deposited in an intrashelf basin, δ 13C values are persistently negative (_3‰ to _5‰, VPDB) through the entire Doushantuo Formation, similar to those obtained from the slope section in Wuhe (_5‰ to _10‰, VPDB). Shallow water sections in Weng'an and Duoding show two broad δ 13C anomalies overprinted with significant meter-scale variations, but none of the curves has similar absolute δ 13C values compared to the Yangtze Gorges areas in South China and other sections globally. Such isotope variations, if partially recording ancient seawater signature, imply spatial and temporal chemocline instability in the Doushantuo basin. In combination with available δ 13C records from other Ediacaran successions globally, the data from the Doushantuo basin are consistent, in first order, with the existence and oxidation of a large dissolved organic carbon (DOC) reservoir in Ediacaran oceans, but imply local environmental controls on Neoproterozoic isotope values and call attentions for using δ 13C anomalies as time lines in stratigraphic correlation. | JIANG GanQing ZHANG ShiHong SHI XiaoYing WANG XinQiang | 2008 | Science China Earth Sciences2008，51，11： | 15 |
| 12 | Paleoproterozoic volcanic rocks in the southern margin of the North China Craton, central China:Implications for the Columbia supercontinent显示文摘The volcanic rocks of the Xiong’er Group are situated in the southern margin of the North China Craton(NCC).Research on the Xiong er Group is important to understand the tectonic evolution of the NCC and the Columbia supercontinent during the Paleoproterozoic.In this study,to constrain the age of the Xiong’er volcanic rocks and identify its tectonic environment,we report zircon LA-ICP-MS data with Hf isotope,whole-rock major and trace element compositions and Sr-Nd-Pb-Hf isotopes of the volcanic rocks of the Xiong’er Group.The Xiong’er volcanic rocks mainly consist of basaltic andesite,andesite.dacite and rhyolite,with minor basalt.Our new sets of data combined with those from previous studies indicate that Xiong’er volcanism should have lasted from 1827 Ma to 1746 Ma as the major phase of the volcanism.These volcanics have extremely low MgO.Cr and Ni contents,are enriched in LREEs and LILEs but depleted in HFSEs(Nb,Ta,and Ti),similar to arc-related volcanic rocks.They are characterized by negative zirconεHft values of-17.4 to 8.8,whole-rock initial 87Sr/86Sr values of 0.7023 to 0.7177 andεNd(t)values of-10.9 to 6.4.and Pb isotopes(206Pb/204Pb=14.366-16.431,207Pb/204Pb=15.106-15.371,208Pb/204Pb=32.455-37.422).The available elemental and Sr-Nd-Pb-Hf isotope data suggest that the Xiong’er volcanic rocks were sourced from a mantle contaminated by continental crust.The volcanic rocks of the Xiong’er Group might have been generated by high-degree partial melting of a lithospheric mantle that was originally modified by oceanic subduction in the Archean.Thus,we suggest that the subduction-modified lithospheric mantle occurred in an extensional setting during the breakup of the Columbia supercontinent in the Late Paleoproterozoic,rather than in an arc setting. | Changming Wang Xinyu He Emmanuel John M. Carranza Chengmin Cui | 2019 | Geoscience Frontiers2019，10，4： | 14 |
| 13 | Geochemical Studies on Organic Carbon Isotope of the Huanghe River(Yellow River)Estuary显示文摘The concentrations of the particulate organic carbon (POC) and its isotopic compositions inthe freshwater in the lower reaches of the Huanghe River were observed for one year period.The annualfluxes of the POC and total carbon of the Huanghe River entering seas were estimated,in combination withthe available data on carbon in the dissolved state in literature.For this study 295 water samples and 115sediment ones from 118 stations were collected on three separate cruises to the Huanghe Estuary and morethan 400 organic carbon isotope data were obtained.After the comprehensive study a new model was con-structed on the dispersion of fine-grained suspended matter entering seas from the Huanghe River in combi-nation with contents of suspended matter,concentrations of POC in water samples and grain size parame-ters,contents of organic carbon in sediment samples. | 蔡德陵 | 1994 | Science China Chemistry1994，37，8： | 13 |
| 14 | Petrogenesis of mafic enclaves from the north Taihang Yanshanian intermediate to felsic plutons: Evidence from petrological, geochemical, and zircon Hf-O isotopic data显示文摘We report the zircon Hf-O isotopic data for mafic enclaves from the Taihang Yanshanian intermediate to felsic plutons, and use them, along with the petrological, whole-rock chemical and Nd-Sr isotopic data, to reveal the petrogenesis of mafic enclaves. Mafic enclaves show magmatic textures and are finer-grained than host rocks. In places they are highly elongated due to stretching within the partially crystallized, convective felsic magma, but show no solid-state deformation. These data suggest that mafic enclaves and host rocks were co-existing, but compositionally distinct magmas. The mafic enclaves contain abundant hydrous minerals such as hornblende and biotite, with pyroxene relict being surrounded by hornblende reaction rim. Plagioclase xenocrysts from mafic enclaves show a complicated compositional and textural disequilibrium. Comparison between mafic enclaves and the immediate host rocks suggests that the two rock units are compositionally correlated. The εNd values of mafic enclaves are generally higher than the host rocks, though the Sr isotopic ratios of the two rock units are indistinguishable. Zircons from a single enclave sample show a significant variation in Hf isotopic compositions, with εHf = -10―-22, suggesting an origin through magma mixing between mafic and felsic magmas. This is supported by the relatively large variation of zircon O isotopic ratios (δ 18O = 5.5‰- 7.8‰) of the mafic enclaves. The petrogenesis of mafic enclaves could be described as below. Evolved basaltic magma (via fractionation of olivine and pyroxene) first mixed with crustally derived granitic melts in depths, forming a hybrid magma; then the hybrid magma broke up into discrete lumps upon entering the above felsic magma. Subsequently, the enclave-forming magma experienced a double mechanical transfer of plagioclase, and inward chemical transfer of fluid and Na, P, Y, Nb and Pb at the contacts with host felsic magmas. | CHEN Bin HE JingBo MA XingHua | 2009 | Science China Earth Sciences2009，52，9： | 12 |
| 15 | Formation and evolution of the Archean continental crust of China:A review显示文摘The mainland of China is composed of the North China Craton,the South China Craton,the Tarim Craton and other young orogehie belts.Amongst the three cratons,the North China Craton has been studied most and noted for its widely-distributed Archean basement rocks.In this paper,we assess and compare the geology,rock types,formation age and geochemical composition features of the Archean basements of the three cratons.They have some common characteristics,including the fact that the crustal rocks prior to the Paleoarchean and the supracrustal rocks of the Neoarehean were preserved,and Tonalite-Trondhjemtite- Granodiorite (TTG)magmatism and tectono-magmatism occurred at about 2.7 Ga and about 2.5 Ga respectively.The Tarim Craton and the North China Craton show more similarities in their early Precambrian crustal evolution.Significant findings on the Archean basement of the North China Craton are coneluded to be:(1)the tectonic regime in the early stage (>3.1 Ga)is distinct from modem plate tectonics;(2)the continental crust accretion occurred mostly from the late Mesoarchean to the early Neoarehean period;(3)a huge linear tectonic belt already existed in the late Neoarchean period,suggesting the beginning of plate tectonics;and (4)the preliminary cratonization had already been completed by about 2.5 Ga. Hadean detrital zircons were found at a total of nine locations within China.Most of them show clear oscillatory zoning,sharing similar textures with magmatic zircons from interrnediate-felsic magmatic rocks. This indicates that a fair quantity of continental material had already developed on Earth at that time. | Yu-sheng Wan Shou-jie Liu Hang-qiang Xie Chun-yan Dong Yuan Li Wen-qian Bai Dun-yi Liu | 2018 | China Geology2018，1，1： | 12 |
| 16 | Geodynamic Background of Intracontinental Cenozoic Alkaline Volcanic Rocks in Laojiezi, Western Yangtze Craton: Constraints from Sr-Nd-Hf-O Isotopes显示文摘The Laojiezi alkaline volcanic rocks, which are located in the intraplate region of the Yangtze craton, coincide with the formation of the Jinshajiang-Ailaoshan-Red River alkaline rock belt. Although this belt has been widely studied by geologists because of its porphyry-related Pb-Ag-Au polymetallic deposit and geotectonic location, the material sources of this belt are still debate. Whole-rock analyses show that these rocks have high total alkali contents(3.73–11.08 wt%), and their aluminum saturation index(ASI) values widely vary from 0.82 to 3.07, which comprise a metaluminous-peraluminous magma series. These rocks are characterized by high K(K2 O/Na2 O>1) and low Ti and Mg contents; enrichment in large-ion lithophile elements, such as Rb, Ba, K and light rare earth elements; and depletion in high field strength elements, such as Ta, Nb, P, and Ti. These rocks exhibit moderate Eu(Eu/Eu*=0.86–1.04) and Ce(Ce/Ce*=0.63–0.96) anomalies. Their(87 Sr/86 Sr)i, εNd(t), zircon εHf(t) and δ18 O values range from 0.70839 to 0.71013, from-10.16 to-12.45, from-19.6 to-5.8, and from 5.69‰ to 8.54‰, respectively, and their Nd and Hf two-stage model ages(TDM2) are 1.67–1.86 Ga and 1.27–2.02 Ga, respectively. These data reflect the primary partial melting of Paleoproterozoic to Mesoproterozoic lower crust with minor residual continental lithospheric mantle and supracrustal metasediments. The lithosphere was likely thickened along the southeastern margin of the Tibetan Plateau following the Indian-Asian continentcontinent collision(65–41 Ma). During the post-collision phase(36–16 Ma), the transition from a compressional to extensional setting triggered the convective removal of the over-thickened CLM beneath the Yangtze craton, which led to the upwelling of asthenospheric materials. This process created alkali-rich and high-K magma through the partial melting of the thickened lower crust. Magma that carried Cu-Au-Pb-Ag minerals was emplaced by strike-slip motion along the E-to W-or ENE-to WSWtrending tectonically weak zone, finally forming an alkaline porphyry Cu-Au-Pb-Ag polymetallic deposit. | YAN Qinggao JIANG Xiaojun LI Chao ZHOU Limin WANG Zhongqiang Sultan Baig SHER QU Wenjun DU ANDao | 2018 | Acta Geologica Sinica(English Edition)2018，92，6： | 12 |
| 17 | Carbon and Strontium Isotopes of Late Palaeozoic Marine Carbonates in the Upper Yangtze Platform,Southwest China显示文摘238 marine carbonate samples were collected from seven sedimentary sections ofthe entire late Palaeozoic (Permian, Carboniferous and Devonian) in the Upper Yangtze Plat-form, southwest China. Based on the absence of cathodoluminescence and very low Mn (gener-ally<50 ppm) contents of the samples, it is thought that they contain information on the orig-inal sea water geochemistry. The results of isotopic analyses of these samples are presented interms of δ13C and 87Sr/86Sr ratios versus geological time. The strontium data, consistent withother similar data based on samples from North America, Europe, Africa and other areas inAsia, support the notion of a global consistency in strontium isotope composition of marinecarbonates. The strontium data exhibit three intervals of relatively low 87Sr/86Sr ratios in thelate Middle Devonian to early Late Devonian, Early Carboniferous and Early Permian, corre-sponding to global eustatic high sea level stands. The lowest 87Sr/86Sr ratio recorded in theLate Permian was probably caused by substantial basalt eruptions in the Upper Yangtze Plat-form at the time. Three corresponding periods of relatively high δ13C values at roughly the samethe intervals were caused by a relatively high rate of accumulation of organic carbon duringsea level rises at these times. The deposition of coal was probably responsible for the increaseof sea water δ13C at other times. The δ13C values drop dramatically near theDevonian/Carboniferous, Carboniferous/Permian and Permian/Triassic boundaries, con-sistent with other similar data, which further support the notion that geological time boundariesare associated with mass extinction and subsequent rejuvenation. | Huang Sijing and Zhou Shaohua State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology, Chengdu, 610059, Sichuan, China Geological Institute, University of Copenhagen, Oster Voldgade 10,DK-1350 Copenhagen K,Denmark | 1997 | Acta Geologica Sinica(English Edition)1997，71，3： | 11 |
| 18 | Fluid Inclusion and H-O Isotope Geochemistry of the Phapon Gold Deposit, NW Laos: Implications for Fluid Source and Ore Genesis显示文摘The Phapon gold deposit, located in northern Laos, is a unique large-scale gold deposit in Luang Prabang-Loei metallogenic belt. It is hosted in the Lower Permian limestone and controlled by a NE-trending ductile-brittle fault system. There are three types of primary ore including auriferous calcite vein type, disseminated type, and breccia type, and the first two are important in the Phapon gold deposit. Based on fluid inclusion petrography and microthermometry, three types of primary fluid inclusions including type 1 liquid-rich aqueous, type 2 vapor-rich aqueous and type 3 daughter mineralbearing aqueous were identified in hydrothermal calcite grains. The ore-forming fluids are normally homogeneous, as indicated by the widespread type 1 inclusions with identical composition. The coexistence of type 1 and type 2 inclusions, showing similar final homogenization temperature but different compositions, indicate that fluid immiscibility did locally take place in both two types of ores. The results of microthermometry and H-O isotopes geochemistry indicate that there are little differences on ore-fluid geochemistry between the auriferous calcite vein-type and disseminated type ores. The oreforming fluids are characterized by medium-low temperatures(157–268 oC) and low salinity(1.6 wt.%–9.9 wt.% NaCl eq.). It is likely to have a metamorphic-dominant mixed source, which could be associated with dehydration and decarbonisation of Lower Permian limestone and Middle–Upper Triassic sandstones during the dynamic metamorphism. The fluid-wallrock interaction played a major role, and the locally occurred fluid-immiscible processes played a subordinate role in gold precipitation. Combined with the regional and ore deposit geology, and ore-fluid geochemistry, we suggest that the Phapon gold deposit is best considered to be a member of the epizonal orogenic deposit class. | Linnan Guo Shusheng Liu Lin Hou Jieting Wang Meifeng Shi Qiming Zhang Fei Nie Yongfei Yang Zhimin Peng | 2019 | Journal of Earth Science2019，30，1： | 11 |
| 19 | Sources of Cretaceous Bimodal Volcanic Rocks in the Coastal Region of Southeastern China -- Constrains of the Sr content and its isotopes显示文摘Cretaceous volcanism in the coastal region of southeastern China was characteristized by occurrenceof bimodal volcanics consisting of basalts and rhyolites, the geneses of which are still controversial. Based on the factthat their isotopic compositions are similar but the Sr content of the former is much higher than that of the latter, thispaper discusses the respective sources of the two end-member rocks, and concludes that basalts were derived fromthe subduction-related enriched upper mantle wedge and their isotopic compositions had not been affected by crustalassimilation, whereas rhyolites were formed by remelting of the old metamorphic basement, but they were mixed upwith the underplating basaltic magmas to various degrees so that their Sr isotopic compositions varied significantlyfrom the sources and tended to be homogeneous to the latter. | XING Guanfu YANG Zhuliang and TAO Kuiyuan Nanjing Institute of Geology and Mineral Resources, Chinese Academy of Geological Sciences,534 East Zhongshan Road, Nanjing 210016 | 1999 | Acta Geologica Sinica(English Edition)1999，73，1： | 11 |
| 20 | Carbon and oxygen isotopic constraints on paleoclimate and paleoelevation of the southwestern Qaidam basin, northern Tibetan Plateau显示文摘We investigate the growth of the northern Tibetan Plateau and associated climate change by applying oxygen and carbon isotopic compositions in Cenozoic strata in the southwestern Qaidam basin. The X-ray diffraction and isotopic studies reveal that the carbonate minerals are mainly authigenic and they do not preserve any evidence for detrital carbonate and diagenesis. The isotope data show large fluctuations in the δ^(18)O and δ^(13)C values in the middle-late Eocene, indicating relatively warm and seasonal dry climate.The positive correlation of the δ^(18)O and δ^(13)C values in the Oligocene and the positive shift of the δ^(13)C values from the Eocene to Oligocene suggest that the climate changed to arid in the Oligocene. However,the δ^(18) values show negative shift, which is closely related to the global cooling event. During the Miocene, the δ^(13)C values vary between-2‰ and-4‰, whereas the δ^(18)O values show continuous negative shift. The mean δ^(18) values decrease from-8.5‰, in the early Miocene to-10.0‰, in the late Miocene. The stable isotope-based paleoaltimetry results suggest that the elevation of the southwestern Qaidam basin was approximately 1500 m in the middle-late Eocene and Oligocene. Subsequently, during Miocene the crustal uplift process started and the elevation reached approximately 2000 m in the early Miocene and 2500 m in the late Miocene, which suggests large-scale growth of the northern Tibet Plateau during the Miocene. | Lin-Lin Li Chao-Dong Wu Chang-Fu Fan Ji-Jun Li Chang-Hao Zhang | 2017 | Geoscience Frontiers2017，8，5： | 11 |
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