|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Evaluation of Highly Thermally Mature Shale-Gas Reservoirs in Complex Structural Parts of the Sichuan Basin显示文摘Successful exploration and development of shale-gas in the United States and Canada suggest a new solution to the energy problem in China.The Longmaxi(龙马溪)Formation in the Sichuan(四川)Basin is regarded as a strong potential play for shale-gas with the following significant features:(1)complex structural types caused by multiphase tectonic superposition and reconstruction;(2)varied slippage processes that enhance porosity and permeability;(3)high thermal maturation of organic matter(Ro>2.5%);(4)high brittle mineral contents;(5)high and constant thicknesses of shale horizons within the formation.Evaluation of shale-gas prospects in this area should consider not only hydrocarbon parameters,but also preservation conditions and structural stability.Data from several new exploration wells in the Sichuan Basin indicate that tectonically induced net-shaped fractures effectively enhance shale reservoir properties.Structural types providing favorable storage conditions for shale-gas are described and evaluated.The high-yielding shale gas reservoir shares the same characteristics of conventional gas reservoirs except for its consubstantial source rock and reservoir in South China. | 郭彤楼 | 2013 | Journal of Earth Science2013，24，6： | 52 |
| 2 | The Grid Search Algorithm of Tectonic Stress Tensor Based on Focal Mechanism Data and Its Application in the Boundary Zone of China, Vietnam and Laos显示文摘Stress field plays a key role in geodynamics. In this study, an algorithm to determine the stress tensor and its confidence range from focal mechanism data by using grid search method was proposed. The experiment uses artificial focal mechanism data which were generated by extensional, compression and strike-slip stress regime and different level of noise, shows that the precision of the estimated stress tensor based on this algorithm is greatly improved compared with traditional algorithms. This algorithm has three advantages:(1) The global optimal solution of the stress tensor is determined by fine grid search of 1o×1o×1o×0.01 and local minimum value is avoided;(2) precision of focal mechanism data can be considered, i.e., different weight of the focal mechanism data contributes differently to the process of determining stress tensor;(3) the confidence range of the determined stress tensor can be obtained by using F-test. We apply this algorithm in the boundary zone of China, Vietnam and Laos, and obtain the stress field with SSE-NNW compressive stress direction and NEE-SWW extensional stress direction. The stress ratio is 0.6, which shows that the eigen values of the stress tensor are nearly in arithmetic sequence. The stress field in this region is consistent with the left-lateral strike slip of the Dienbien-Lauangphrabang arc fault. The result will be helpful in studying the geological dynamic process in this region. | Yongge Wan Shuzhong Sheng Jichao Huang Xiang Li Xin Chen | 2016 | Journal of Earth Science2016，27，5： | 48 |
| 3 | Landslide Hazard Mapping Using GIS and Weight of Evidence Model in Qingshui River Watershed of 2008 Wenchuan Earthquake Struck Region显示文摘Tens of thousands of landslides were triggered by May 12,2008 earthquake over a broad area.The main purpose of this article is to apply and verify earthquake-triggered landslide hazard analysis techniques by using weight of evidence modeling in Qingshui(清水) River watershed,Deyang(德阳) City,Sichuan(四川) Province,China.Two thousand three hundred and twenty-one landslides were interpreted in the study area from aerial photographs and multi-source remote sensing imageries post-earthquake,verified by field surveys.The landslide inventory in the study area was established.A spatial database,including landslides and associated controlling parameters that may have influence on the occurrence of landslides,was constructed from topographic maps,geological maps,and enhanced thematic mapper(ETM+) remote sensing imageries.The factors that influence landslide occurrence,such as slope angle,aspect,curvature,elevation,flow accumulation,distance from drainages,and distance from roads were calculated from the topographic maps.Lithology,distance from seismogenic fault,distance from all faults,and distance from stratigraphic boundaries were de-rived from the geological maps.Normalized dif-ference vegetation index(NDVI) was extracted from ETM+ images.Seismic intensity zoning was collected from Wenchuan(汶川) Ms8.0 Earthquake Intensity Distribution Map pub-lished by the China Earthquake Administration.Landslide hazard indices were calculated using the weight of evidence model,and landslide hazard maps were calculated from using different controlling parameters cases.The hazard map was com-pared with known landslide locations and verified.The success accuracy percentage of using all 13 con-trolling parameters was 71.82%.The resulting landslide hazard map showed five classes of landslide hazard,i.e.,very high,high,moderate,low,and very low.The validation results showed satisfactory agreement between the hazard map and the existing landslides distribution data.The landslide hazard map can be used to identify and delineate unstable hazard-prone areas.It can also help planners to choose favorable locations for development schemes,such as infrastructural,buildings,road construc-tions,and environmental protection. | 许冲 徐锡伟 戴福初 肖建章 谭锡斌 袁仁茂 | 2012 | Journal of Earth Science2012，23，1： | 35 |
| 4 | Mechanisms and Simulation of Accelerated Shrinkage of Continental Glaciers: A Case Study of Urumqi Glacier No. 1 in Eastern Tianshan, Central Asia显示文摘Similar to most mountain glaciers in the world, Urumqi Glacier No. 1 (UG1), the best observed glacier in China with continued glaciological and climatological monitoring records of longer than 50 years has experienced an accelerated recession during the past several decades. The purpose of this study is to investigate the acceleration of recession. By taking UG1 as an example, we analyze the generic mechanisms of acceleration of shrinkage of continental mountain glaciers. The results indicate that the acceleration of mass loss of UG1 commenced first in 1985 and second in 1996 and that the lat-ter was more vigorous. The air temperature rises during melting season, the ice temperature augment of the glacier and the albedo reduction on the glacier surface are considered responsible for the accel-erated recession. In addition, the simulations of the accelerated shrinkage of UG1 are introduced in this article. | 李忠勤 李慧林 陈亚宁 | 2011 | Journal of Earth Science2011，22，4： | 31 |
| 5 | Age,Association and Provenance of the “Neoproterozoic” Fengshuigouhe Group in the Northwestern Lesser Xing'an Range,NE China:Constraints from Zircon U-Pb Geochronology显示文摘The formation time of the Fengshuigouhe (风水沟河) Group in the northwestern Lesser Xing'an Range (小兴安岭),NE China,remains controversial owing to the lake of the precise dating data.This article reports zircon U-Pb ages for the leptynite and gneissic granitoids from the Fengshuigouhe Group in the northwestern Lesser Xing'an Range.The aim is to constrain the formation time and provenance of Fengshuigouhe Group.Field observation indicates that the Fengshuigouhe Group consists of a suit of metamorphic rocks (leptynite) and gneissic granitoids intruding the leptynite,and that both of them are cut by late granitic pegmatite.Zircons from two leptynites are euhedral-subhedral in shape and display oscillatory zoning in CL (cathodeluminescence) images.These detrital zircons give weighted mean ages of 255,291,321,361,469,and 520 Ma.The youngest age of them is interpreted to maximum depositional age of the protoliths of these leptynites.Zircons from gneissic granites are euhedral and subhedral in shape and exhibit typical oscillatory zoning in CL images.The dating results indicate that the gneissic granites were formed in the Early Jurassic (185±2 Ma).Zircons from the late granitic pegmatite are subhedral in shape and exhibit two types in CL images:structureless and oscillatory zoning.The former gives a weighted mean age of 143±1 Ma,considered to represent the timing of crystallization of the pegmatite,the latter yield several groups of ages:178,273,319,482,611,and 788 Ma,representing the crystallization age of inherited or captured zircons entrained by the pegmatite.Taken together,we conclude that the Fengshuigouhe Group in the northwestern Lesser Xing'an Range formed between Late Paleozoic (255 Ma) to Early Mesozoic (185 Ma),rather than Neoproterozoic as previously believed,and that the sediments in the Fengshuigouhe Group were sourced directly from geological bodies in the study area and adjacent regions. | 徐美君 许文良 王枫 高福红 | 2012 | Journal of Earth Science2012，23，6： | 26 |
| 6 | Sources and Thermo-Chemical Sulfate Reduction for Reduced Sulfur in the Hydrothermal Fluids, Southeastern SYG Pb-Zn Metallogenic Province, SW China显示文摘Located on the western Yangtze Block, the Sichuan(四川)-Yunnan(云南)-Guizhou(贵州)(SYG) Pb-Zn metallogenic province has been a major source of base metals for China. In the southeastern SYG province, structures are well developed and strictly control about 100 Pb-Zn deposits. Almost all the deposits are hosted in Devonian to Permian carbonate rocks. Lead-zinc ores occur either as veinlets or disseminations in dolomitic rocks with massive and disseminated textures. Ore minerals are composed of pyrite, sphalerite and galena, and gangue minerals are calcite and dolomite. Sulfide minerals from four typical Pb-Zn deposits are analyzed for sulfur isotope compositions to trace the origin and evolution of hydrothermal fluids. The results show that δ34S values of sulfide minerals range from+3.50‰ to +20.26‰, with a broad peak in +10‰ to +16‰, unlike mantle-derived sulfur(0±3‰). However, the mean δ34Ssulfide and δ34S∑S-fluids values are similar to that of sulfate-bearing evaporites in the host rocks(gypsum: ^+15‰ and barite: +22‰ to +28‰) and Cambrian to Permian seawater sulfate(+15‰ to +35‰). This suggests that reduced sulfur in hydrothermal fluids was likely derived from evaporates in the host rocks by thermo-chemical sulfate reduction(TSR). Calculated δ34S∑S-fluids values of the Shanshulin(杉树林), Qingshan(青山), Shaojiwan(筲箕湾) and Tianqiao(天桥) Pb-Zn deposits are +21.59‰, +18.33‰, +11.43‰ and +10.62‰, respectively, indicating sulfur-bearing hydrothermal fluids may be evolved from the Shanshulin to Qingshan and then the Shaojiwan to Tianqiao deposition sites along the Yadu(垭都)-Ziyun(紫云) lithospheric fracture in the southeastern SYG province. | 周家喜 黄智龙 包广萍 高建国 | 2013 | Journal of Earth Science2013，24，5： | 25 |
| 7 | Tectonic Evolution of the Palaeo——Tethys in Changning——Menglian Belt and Adjacent Regions,Western Yunnan显示文摘The Changning-Menglian belt,located between theBaoshan-Gengma massif and the Simao-Lincangmassif in Western Yunnan,preserves the complete recordof a suture zone and the most continuous record of deepwater sedimentation,representing the main branch of thePalaeo-Tethys polyisland ocean in the Hercynian-Indo-sinian stage.This belt could be further subdivided into threetectono-lithofacies zones.In the east zone,terrigenouselastics,argillaceous,marl-argillaceous and silicate sediments lie on the metamorphosed Early Palaeozoic basement in concealed unconformity,representing deep watersediments on a passive continental margin.The centralzone,although the basement rocks are absent fromoutcropping here,includes a contemporary complexof various sedimentary types,among them one type is ofdeep ocean sediments represented by radiolarian beddedchert,appearing from at least early Early Devonian tothe Middle Triassic.Another type includes purecarbonates of the Early Carboniferous to the LatePermian,a type of shallow | Liu Benpei Feng Qinglai Fang NianqiaoChina University of Geosciences , Beijing 100083 | 1991 | Journal of Earth Science1991，10，1： | 22 |
| 8 | Geochemical Features of Ophiolite in Mianxian Lueyang Suture Zone,Qinling Orogenic Belt显示文摘GeochemicalFeaturesofOphioliteinMianxianLueyangSutureZone,QinlingOrogenicBeltLaiShaocong;ZhangGuowei(DepartmentofGeology,Nort... | Lai Shaocong Zhang Guowei(Department of Geology, Northwest University, Xi’an 710069) | 1996 | Journal of Earth Science1996，15，2： | 22 |
| 9 | Primary Intergranular Pores in Oolitic Shoal Reservoir of Lower Triassic Feixianguan Formation,Sichuan Basin,Southwest China:Fundamental for Reservoir Formation and Retention Diagenesis显示文摘The Lower Triassic Feixianguan (飞仙关) Formation oolitic shoal reservoir in the Sichuan (四川) basin (Southwest China) is currently an exploration and research highlight in China. The reservoir is widely believed to be formed mainly by burial dissolution and/or dolomitization on the basis of primary intergranular pores. In this study, through a comprehensive geological study on the whole basin, the dissolution and dolomitization are suggested not to be the fundamental factor of reservoir formation and there thus may be a possible new fundamental mechanism-the preservation of primary intergranular pores, i.e., the retention diagenesis. Based on this, a complex and multi-stage reservoir evolution and formation model is proposed. In the model, the depositional environment is the basis of reservoir initial formation. Subsequently, early compaction and shallow burial cementation result in the primary reservoir differentiation. Then, multi-stage burial dissolution alters and adjusts the reservoir. Because the last stage gaseous hydrocarbons have little diagenetic impact, the reservoir is formed finally. Therefore, this study presents a possible new fundamental mechanism and evolution model for the reservoir formation. The results can be applied in the regional reservoir predication and shaping exploration strategies, and provide reference for the study of shoal reservoirs in other areas. | 谭秀成 刘宏 李凌 罗冰 刘晓光 牟晓慧 聂勇 席文艳 | 2011 | Journal of Earth Science2011，22，1： | 21 |
| 10 | Timing of Uranium Mineralization and Geological Implications of Shazijiang Granite-Hosted Uranium Deposit in Guangxi, South China: New Constraint from Chemical U-Pb Age显示文摘Miaoershan (MES ) 铀矿石地是在中国的最重要的铀来源,之一和许多另外的招待花岗石的铀存款在华南招待最大的 Chanziping carbonaceous-siliceous-pelitic 岩石类型铀存款。Shazijiang (SZJ ) 铀存款是 MES 铀矿石地里的代表性的招待花岗石的铀存款之一,位于 Ziyuan, Guangxi 省,华南。在 SZJ 存款的铀矿化作用主要与空间地在这个区域与 mafic 女同性恋被联系的石英和方解石静脉作为沥青铀矿发生。热水的改变包括 silicification,碳酸饱和和 hematitization。新沥青铀矿化学药品 U-Pb 地球年代学和 petrographic 证据提供预定限制和新卓见进 SZJ 铀存款的形成。第一铀矿化作用上演的结果表演在 97.5 湯漠 ? 桴 ? 敚慤杮愠摮 ? 潵畢慳瀠牥摩瑯瑩獥椠 ? 潣獮獩整瑮眠瑩 ? 潢桴愠祢獳污愠摮猠'T 畤瑣潩 ? | Jincheng Luo Ruizhong Hu Shaohua Shi | 2015 | Journal of Earth Science2015，26，6： | 21 |
| 11 | Permian–Triassic Conodonts from Dajiang(Guizhou, South China) and Their Implication for the Age of Microbialite Deposition in the Aftermath of the End-Permian Mass Extinction显示文摘The widespread microbialites deposition that followed the End-Permian mass extinction in the Tethyan realm have been intensively studied because of the evidence they provide on the nature of this crisis and its aftermath. However, the age of the microbialite event remains controversial. New conodont collection across the Permian–Triassic(P–T) transition from Dajiang(Guizhou Province, South China) in this study enable us to discriminate four conodont zones, in ascending order, they are: Hindeodus parvus zone, Isarcicella lobata zone, Isarcicella isarcica zone and Hindeodus sosioensis zone. The age of microbialite in the P–T transition at the Dajiang Section is considered to be within the Hindeodus parvus zone and thus to clearly post-date the main extinction crisis. Reviewing the age of onset of microbialites throughout the Tethyan regions reveals two different ages: a Hindeodus changxingensis zone age is dominant in south-western and westernmost Tethys, whilst most other regions show microbialite deposition began in the Hindeodus parvus zone. Our investigation also indicates that two conodont changes occur at this time: an increase of hindeodid species immediately following a sequence boundary and the mass extinction, and a phase of extinction losses in the earliest Triassic Isarcicella isarcica zone during highstand development. | Haishui Jiang Xulong Lai Yadong Sun Paul B Wignall Jianbo Liu Chunbo Yan | 2014 | Journal of Earth Science2014，25，3： | 20 |
| 12 | The Origin and Tectonic Significance of the Volcanic Rocks of the Yeba Formation in the Gangdese Magmatic Belt, South Tibet显示文摘Zircon U-Pb geochronology, Hf isotope and whole-rock geochemistry were performed on the tuffs of the Yeba Formation in the Gangdese magmatic belt, South Tibet. The results are used to detail the age, source nature and tectonic processes that led to the formation of the Gangdese belt. Dating results indicate that the rhyolitic-andesitic tuffs were formed at 174–170 Ma. Positive and variable zircon ε_(Hf)(t) values of the rhyolitic tuffs reveal that the source was dominated by juvenile material, however, experienced crustal contamination. The basaltic tuffs have low HREEs, high contents of compatible elements(V and Cr) and no Eu anomaly. In contrast, the rhyolitic-andesitic tuffs show low compatible trace elements, depletion in Eu but enrichment in incompatible elements(Rb, Zr and Hf). According to the discrimination diagrams of P_2O_5-SiO_2 and Th-Rb, the rhyolitic-andesitic tuffs show a close affinity to Ⅰ-type granitoids. Moreover, these tuffs are marked by significant depletion in Nb, Ta and Ti, plotted in calc-alkaline field, and with the andesitic-rhyolitic tuffs falling into an active continental margin setting. We suggest that these tuffs of the Yeba Formation were probably generated in an active continental margin above the northward subduction of the Neo-Tethyan oceanic lithosphere. | Xuxuan Ma Zhiqin Xu Xijie Chen Joseph G.Meert Zhenyu He Fenghua Liang Yuanku Meng Shiwei Ma | 2017 | Journal of Earth Science2017，28，2： | 20 |
| 13 | Geological Evidence for the Operation of Plate Tectonics throughout the Archean:Records from Archean Paleo-Plate Boundaries显示文摘Plate tectonics describes the horizontal motion of rigid lithospheric plates away from midoceanic ridges and parallel to transforms, towards deep-sea trenches, where the oceanic lithosphere is subducted into the mantle. This process is the surface expression of modern-day heat loss from Earth. One of the biggest questions in Geosciences today is 'when did plate tectonics begin on Earth' with a wide range of theories based on an equally diverse set of constraints from geology, geochemistry, numerical modeling, or pure speculation. In this contribution, we turn the coin over and ask 'when was the last appearance in the geological record for which there is proof that plate tectonics did not operate on the planet as it does today'. We apply the laws of uniformitarianism to the rock record to ask how far back in time is the geologic record consistent with presently-operating kinematics of plate motion, before which some other mechanisms of planetary heat loss may have been in operation. Some have suggested that evidence shows that there was no plate tectonics before 800 Ma ago, others sometime before 1.8–2.7 Ga, or before 2.7 Ga. Still others recognize evidence for plate tectonics as early as 3.0 Ga, 3.3–3.5 Ga, the age of the oldest rocks, or in the Hadean before 4.3 Ga. A key undiscussed question is: why is there such a diversity of opinion about the age at which plate tectonics can be shown to not have operated, and what criteria are the different research groups using to define plate tectonics, and to recognize evidence of plate tectonics in very old rocks? Here, we present and evaluate data from the rock record, constrained by relevant geochemical-isotopic data, and conclude that the evidence shows indubitably that plate tectonics has been operating at least since the formation of the oldest rocks, albeit with some differences in processes, compositions, and products in earlier times of higher heat generation and mantle temperature, weaker oceanic lithosphere, hotter subduction zones caused by more slab-melt generation, and under different biological and atmospheric conditions. | Timothy M.Kusky Brian F.Windley Ali Polat | 2018 | Journal of Earth Science2018，29，6： | 20 |
| 14 | Measurement of Joint Roughness Coefficient by Using Profilograph and Roughness Ruler显示文摘Joint roughness coefficient(JRC) is the key parameter for the empirical estimation of joint shear strength by using the JRC-JCS(joint wall compressive strength) model.Because JRC has such characteristics as nonuniformity,anisotropy,and unhomogeneity,directional statistical measurement of JRC is the precondition for ensuring the reliability of the empirical estimation method.However,the directional statistical measurement of JRC is time-consuming.In order to present an ideal measurement method of JRC,new profilographs and roughness rulers were developed according to the properties of rock joint undulating shape based on the review of measurement methods of JRC.Operation methods of the profilographs and roughness rulers were also introduced.A case study shows that the instruments and operation methods produce an effective means for the statistical measurement of JRC. | 杜时贵 胡云进 胡晓飞 | 2009 | Journal of Earth Science2009，20，5： | 19 |
| 15 | Re-Os Geochronology of Porphyry Molybdenum Deposit in South Segment of Da Hinggan Mountains,Northeast China显示文摘The ages for porphyry Mo deposits in south segment of Da Hinggan Mountains,Northeast China,are not well known.Five molybdenite samples from the Aolunhua(奥伦花) porphyry Mo deposit,five molybdenite samples from the Yangchang(羊场) porphyry-quartz vein Mo deposit and two molybdenite samples from the Banlashan(半拉山) porphyry Mo deposit were selected for Re-Os dating.Three deposits are spatial-temporally associated with the granite porphyry stock.Re-Os isochron age of 131.2±1.9 Ma was obtained for the Aolunhua porphyry Mo deposit.The Yangchang Mo deposit provides isochron age of 138.5±4.5 Ma for two groups of molybdenite(within porphyry ore and within quartz vein).The Banlashan porphyry Mo deposit provides model ages of 140.5±2.4 and 143±2.2 Ma.All of these Re-Os ages are consistent presumed Yanshanian ages for granite intrusions,formed in crust thinning setting in Cretaceous in North China. | 曾庆栋 刘建明 张作伦 | 2010 | Journal of Earth Science2010，21，4： | 19 |
| 16 | Study on Estimation Method of Rock Mass Discontinuity Shear Strength Based on Three-Dimensional Laser Scanning and Image Technique显示文摘The estimation of shear strength of rock mass discontinuity is always a focal,but difficult,problem in the field of geotechnical engineering.Considering the disadvantages and limitation of existing estimation methods,a new approach based on the shadow area percentage (SAP) that can be used to quantify surface roughness is proposed in this article.Firstly,by the help of laser scanning technique,the three-dimensional model of the surface of rock discontinuity was established.Secondly,a light source was simulated,and there would be some shadows produced on the model surface.Thirdly,to obtain the value of SAP of each specimen,the shadow detection technique was introduced for use.Fourthly,compared with the result from direct shear testing and based on statistics,an empirical formula was found among SAP,normal stress,and shear strength.Data of Yujian (鱼简) River were used as an example,and the following conclusions have been made.(1) In the case of equal normal stress,the peak shear stress is positively proportional to the SAP.(2) The formula for estimating was derived,and the predictions of peak-shear strength made with this equation well agreed with the experimental results obtained in laboratory tests. | 唐辉明 葛云峰 王亮清 苑谊 黄磊 孙淼军 | 2012 | Journal of Earth Science2012，23，6： | 19 |
| 17 | Geochemistry of Rare Earth Elements(REE) in the Weathered Crusts from the Granitic Rocks in Sulawesi Island, Indonesia显示文摘We report for the first time the geochemistry of rare earth elements(REE) in the weathered crusts of I-type and calc-alkaline to high-K(shoshonitic) granitic rocks at Mamasa and Palu region, Sulawesi Island, Indonesia. The weathered crusts can be divided into horizon A(lateritic profile) and B(weathered horizon). Quartz, albite, kaolinite, halloysite and montmorrilonite prevail in the weathered crust. Both weathered profiles show that the total REE increased from the parent rocks to the horizon B but significantly decrease toward the upper part(horizon A). LREE are enriched toward the upper part of the profile as shown by La/YbN value. However, HREE concentrations are high in horizon B1 in Palu profile. The total REE content of the weathered crust are relatively elevated compared to the parent rocks, particularly in the lower part of horizon B in Mamasa profile and in horizon B2 in Palu profile. This suggests that REE-bearing accessory minerals may be resistant against weathering and may remain as residual phase in the weathered crusts. The normalized isocon diagram shows that the mass balance of major and REE components between each horizon in Mamasa and Palu weathering profile are different. The positive Ce anomaly in the horizon A of Mamasa profile indicated that Ce is rapidly precipitated during weathering and retain at the upper soil horizon. | Adi Maulana Kotaro Yonezu Koichiro Watanabe | 2014 | Journal of Earth Science2014，25，3： | 18 |
| 18 | Hydrogeochemical and Isotopic Evidence for Flow Paths of Karst Waters Collected in the Heshang Cave,Central China显示文摘Understanding of hydrological processes in caves is important to help us interpret paleoclimate records from speleothems. In this study,we integrated hydrogeological and hydrogeochemical properties to characterize the hydraulic behavior of karst waters in the Heshang Cave,Central China. Using geological and topographical analyses,we identified regional watershed boundaries and hydrogeological connections that were controlled by anticlinal geometry and faults. Water samples were collected from the Heshang Cave and potential recharge sites. Geochemical data of c(Sr2+)/c(Ca2+) and c(Mg2+)/c(Ca2+) ratios suggest that the drainage system in Heshang Cave consists of two flow paths. For vadose waters,including drip water and rimstone pool water,c(Sr2+)/c(Ca2+) ratio ranges from 0.000 6 to 0.001 1,and c(Mg2+)/c(Ca2+) ratio ranges from 0.97 to 1.1,indicating that recharge was mainly from rainfall infiltration through the overlying Cambrian dolomite stratum. In contrast,slope current and underground river waters have higher c(Sr2+)/c(Ca2+) ratios(values from 0.002 2 to 0.002 8),and lower c(Mg2+)/c(Ca2+) ratios(values from 0.50 to 0.64). These waters show homogeneous isotopic composition(δ18O:-7.15‰–-6.95‰; δD:-52.73‰–-51.31‰),implying recharge of allogeneic water from the Xiaoer River via karst conduits that pass through Ordovician limestone and Cambrian dolomite stratum. | Xiang Long Ziyong Sun Aiguo Zhou Deliang Liu | 2015 | Journal of Earth Science2015，26，1： | 18 |
| 19 | Proto-South China Sea Plate Tectonics Using Subducted Slab Constraints from Tomography显示文摘The past size and location of the hypothesized proto-South China Sea vanished ocean basin has important plate-tectonic implications for Southeast Asia since the Mesozoic. Here we present new details on proto-South China Sea paleogeography using mapped and unfolded slabs from tomography. Mapped slabs included: the Eurasia-South China Sea slab subducting at the Manila trench; the northern Philippine Sea Plate slab subducting at the Ryukyu trench; and, a swath of detached, subhorizontal, slab-like tomographic anomalies directly under the South China Sea at 450 to 700 km depths that we show is subducted ‘northern proto-South China Sea' lithosphere. Slab unfolding revealed that the South China Sea lay directly above the ‘northern Proto-South China Sea' with both extending 400 to 500 km to the east of the present Manila trench prior to subduction. Our slab-based plate reconstruction indicated the proto-South China Sea was consumed by double-sided subduction, as follows:(1) The ‘northern proto-South China Sea' subducted in the Oligo–Miocene under the Dangerous Grounds and southward expanding South China Sea by in-place ‘self subduction' similar to the western Mediterranean basins;(2) limited southward subduction of the proto-South China Sea under Borneo occurred pre-Oligocene, represented by the 800–900 km deep ‘southern proto-South China Sea' slab. | Jonny Wu John Suppe | 2018 | Journal of Earth Science2018，29，6： | 18 |
| 20 | Rapid Shrinking of Glaciers in the Middle Qilian Mountain Region of Northwest China during the Last ~50 Years显示文摘During the past five decades, fluctuations of glaciers were reconstructed from historical documents, aerial photographs, and remote sensing data. From 1956 to 2003, 910 glaciers investigated had reduced in area by 21.7% of the 1956 value, with a mean reduction for the individual glacier of 0.10 km2. The relative area reductions of small glaciers were usually higher than those of large ones, which exhibited larger absolute loss, indicating that the small glaciers were more sensitive to climate change than large ones. Over the past ~50 years, glacier area decreased by 29.6% in the Heihe (黑河) River basin and 18.7% in the Beidahe (北大河) River basin, which were the two regions investigated in the Middle Qilian (祁连) Mountain region. Compared with other areas of the Qilian Mountain region, the most dramatic glacier shrinkage had occurred in the Middle Qilian Mountain region, mainly re-sulting from rapid rising temperatures. Regional differences in glacier area changes are related to local climate conditions, the relative proportion of glaciers in different size classes, and other factors. | 王璞玉 李忠勤 高闻宇 | 2011 | Journal of Earth Science2011，22，4： | 18 |
您所在的机构暂未开通此部分的功能，请联系管理员