Isotope Method for Confined Groundwater Recharge of the Lower Reaches of the Heihe River, Inner Mongolia, China          下载免费PDF全文

CHEN Jiansheng ZHAO Xia FAN Zhechao WANG Jiyang 《《地质学报》英文版》2007,81(4):668-673

Environmental isotopes have been applied to analyze confined groundwater recharge in the lower reaches of the Heihe River,Inner Mongolia.CFC is regarded as a tracer that determines the date of groundwater,the date being less than 45 a.The confined groundwater within the Gurinai area and Ejin Basin other than the surface water of Heihe River might have originated from precipitation from Qilian Mountain or/and the Tibetan Plateau.The deep confined groundwater overflows into an upper aquifer and emerges into the ground,forming springs and lakes within the low-lying area.The recharge volume is estimated to be around 400 million-cubic meters.  相似文献   

Evolution of the Mesozoic Granites in the Xiong''ershan-Waifangshan Region,Western Henan Province,China,and Its Tectonic Implications          下载免费PDF全文

Franco PIRAJNO 《《地质学报》英文版》2007,81(2)

Based on the new data of isotopic ages and geochemical analyses, three types of Mesozoic granites have been identified for the Xiong'ershan-Waifangshan region in western Henan Province: high-Ba-SrⅠ-type granite emplaced in the early stage (～160 Ma),Ⅰ-type granite in the middle stage (～130 Ma) and anorogenic A-type granite in the late stage (～115 Ma). Geochemical characteristics of the high-Ba-SrⅠ-type granite suggest that it may have been generated from the thickened lower crust by partial melting with primary residues of amphibole and garnet. Gradual increase of negative Eu anomaly and Sr content variations reflect progressive shallowing of the source regions of these granites from the early to late stage. New 40Ar/39Ar plateau ages of the early-stage Wuzhangshan granite (156.0±1.1 Ma, amphibole) and middle-stage Heyu granite (131.8±0.7 Ma, biotite) are indistinguishable from their SHRIMP U-Pb ages previous published, indicating a rapid uplift and erosion in this region. The representative anorogenic A-type granite, Taishanmiao pluton, was emplaced at～115 Ma. The evolution of the granites in this region reveals a tectonic regime change from post-collisional to anorogenic between～160 Ma and～115 Ma. The genesis of the early- and middle-stageⅠ-type granites could be linked to delamination of subducted lithosphere of the Qiniing orogenic belt, while the late-stage A-type granites represent the onset of extension and the end of orogenic process. In fact, along the Qiniing -Dabie-Sulu belt, the Mesozoic granitoids in western Henan, Dabieshan and Jiaodong regions are comparable on the basis of these temporal evolutionary stages and their initial 87Sr/86Sr ratios, which may suggest a similar geodynamic process related to the collision between the North China and Yangtze cratons.  相似文献   

陆相沉积的天文地层研究方法简介——以井下地层为例   总被引：2，自引：5，他引：2  

XU Dao-yi )  ZHANG Hai-feng )  HAN Yan-ben )  YIN Zhi-qiang )  LI Bao-li )  YAO Yi-min ) ) Institute of Geology  China Earthquake Administration  Beijing    ) Geological Scientific Research Institute of Shengli Oilfield Company  SINOPEC  Dongying    ) National Astronomical Observatories  Chinese Academy of Sciences  Beijing 《地层学杂志》2007,(Z2)

通过对我国大陆三十余口井的测井资料研究成果,归纳出对陆相地层进行天文地层研究的方法。介绍了所用的新的天文周期理论值、测井资料的选取及预处理方法,重点说明谱分析的数据点数的选定、不同参数(自然伽玛、自然电位和岩屑)的测井资料谱分析结果的对比,以实例说明如何选定主要优势旋回和AR值,以及FIR数字滤波器的基本性质和数字滤波结果,小波分析的特点和通过小波图进行调频的方法,并介绍了地层单位的延续时间计算和年龄确定方法。  相似文献   

Distribution Patterns of Pentacyclic TriterpenoidHydrocarbons in Low-Mature Source Rocksfrom Eastern China     

HOU Dujie  ZHANG Linye  WANG Tieguan Research Centre for Organic Geochemistry  Jianghan Petroleum Institute  Jingzhou  Hubei Applied Geochemistry Section  Dept. ofGeosciences  China University of Petroleum  Changping  Beijing Geochemistry Research Section  Shengli Petroleum Geological Sciences Institute  Shengli Petroleum Administration Bureau  Dongying  Shandong 《《地质学报》英文版》1998,72(4):399-408

Four typical distribution patterns of pentacyclic triterpenoid hydrocarbons (types A-D) are distinguished in the low-mature source rocks from eastern China. Type A has a relatively high content of pentacyclic triterpenes. It exists in immature sediments and the distribution and abundance of triterpenes vary with the maturity of the sediments. An unknown C30 triterpene (UCT2) has also been detected in very shallow sediments. This compound is very unstable and disappears rapidly with the increase of depth. Type B is characterized by a relatively high amount of 17α(H), 21β(H)-30-homohopane. This kind of distribution pattern is common in coals and terrestrial sediments of low maturity. Type C has a relatively high content of diahopane and neohopane series. The analysis shows that this distribution pattern may have an indirect relationship with the input of higher plants despite its microbial source. There are C30-unconfirmed triterpane (UCT2) and a relatively high content of C35 hopane in type D. The dist  相似文献   

Mapping of Regional Soil Salinities in Xinjiang and Strategies for Amelioration and Management   总被引：2，自引：0，他引：2  

WANG Fei  CHEN Xi  LUO Geping  HAN Qifei 《中国地理科学(英文版)》2015,(3):321-336

Information on the spatial distribution of soil salinity can be used as guidance in avoiding the continued degradation of land and water resources by better informing policy makers. However, most regional soil-salinity maps are produced through a conventional direct-linking method derived from historic observations. Such maps lack spatial details and are limited in describing the evolution of soil salinization in particular instances. To overcome these limitations, we employed a method that included an integrative hierarchical-sampling strategy(IHSS) and the Soil Land Inference Model(So LIM) to map soil salinity over a regional area. A fuzzy c-means(FCM) classifier is performed to generate three measures, comprising representative grade, representative area, and representative level(membership). IHSS employs these three measures to ascertain how many representative samples are appropriate. Through this synergetic assessment, representative samples are obtained and their soil-salinity values are measured. These samples are input to So LIM, which is constructed based on fuzzy logic, to calculate the soil-forming environmental similarities between representative samples and other locations. Finally, a detailed soil-salinity map is produced through an averaging function that is linearly weighted, which is used to integrate the soil salinity value and soil similarity. This case study, in the Uyghur Autonomous Region of Xinjiang of China, demonstrates that the employed method can produce soil salinity map at a higher level of spatial detail and accuracy. Twenty-three representative points are determined. The results show that 1) the prediction is appropriate in Kuqa Oasis(R2 = 0.70, RPD = 1.55, RMSE = 12.86) and Keriya Oasis(R2 = 0.75, RPD = 1.66, RMSE = 10.92), that in Fubei Oasis(R2 = 0.77, RPD = 2.01, RMSE = 6.32) perform little better than in those two oases, according to the evaluation criterion. 2) Based on all validation samples from three oases, accuracy estimation show the employed method(R2 = 0.74, RPD = 1.67, RMSE = 11.18) performed better than the multiple linear regression model(R2 = 0.60, RPD = 1.47, RMSE = 14.45). 3) The statistical result show that approximately half(48.07%) of the study area has changed to salt-affected soil, mainly distributed in downstream of oases, around lakes, on both sides of rivers and more serious in the southern than the northern Xinjiang. To deal with this issue, a couple of strategies involving soil-salinity monitoring, water management, and plant diversification are proposed, to reduce soil salinization. Finally, this study concludes that the employed method can serve as an alternative model for soil-salinity mapping on a large scale.  相似文献   

Composition and Origin of Ferromanganese Crusts from Equatorial Western Pacific Seamounts     

WANG Guozhi  JANSA Luba  CHU Fengyou  ZOU Can  SUN Guosheng 《中国海洋大学学报(英文版)》2015,(2):217-227

In the equatorial western Pacific, iron-manganese oxyhydroxide crusts(Fe-Mn crusts) and nodules form on basaltic seamounts and on the top of drowned carbonate platform guyots that have been swept free of pelagic sediments. To date, the Fe-Mn crusts have been considered to be almost exclusively of abiotic origin. However, it has recently been suggested that these crusts may be a result of biomineralization. Although the Fe-Mn crust textures in the equatorial western Pacific are similar to those constructed by bacteria and algae, and biomarkers also document the existence of bacteria and algae dispersed within the Fe-Mn crusts, the precipitation, accumulation and distribution of elements, such as Fe, Mn, Ni and Co in Fe-Mn crusts are not controlled by microbial activity. Bacteria and algae are only physically incorporated into the crusts when dead plankton settle on the ocean floor and are trapped on the crust surface. Geochemical evidence suggests a hydrogenous origin of Fe-Mn crusts in the equatorial western Pacific, thus verifying a process for Fe-Mn crusts that involves the precipitation of colloidal phases from seawater followed by extensive scavenging of dissolved trace metals into the mineral phase during crust formation.  相似文献   

A note on the discovery of a 2M_⊙ pulsar     

Xiao-Yu Lai  Ren-Xin Xu School of Physics  State Key Laboratory of Nuclear Physics  Technology  Peking University  Beijing  China 《中国天文和天体物理学报》2011,(6)

It is conventionally thought that the state equation of dense matter softens and thus cannot result in high maximum mass if pulsars are quark stars and that a recently discovered 2M⊙ pulsar (PSR J1614-2230) may make pulsars unlikely to be quark stars. However, this standard point of view would be revisited and updated if quark clustering could occur in cold quark matter because of the strong coupling be- tween quarks at realistic baryon densities in compact stars. It can be argued that the state equation of...  相似文献   

Accelerating Oil and Gas Exploration in Western China by Studies of Formations of Hydrocarbon Accumulations in Superimposed Basins—A Preface     

PANG Xiongqi 《《地质学报》英文版》2010,84(5):i-ii

<正>The superimposed basins in the western region of China are a hot research topic for earth scientists home and abroad for their vast area and rich oil and gas resources.Their complex geological conditions and resultant great exploration difficulties have received much attention of the scientists.This issue presents the advances of several scholars in their long-term research on the mechanisms of oil and gas accumulation and the patterns of oil and gas distribution.These studies are part of the National 973 Project entitled "Mechanism of Oil and Gas Accumulation and  相似文献   

Geological Evolution of Longhushan World Geopark in Relation to Global Tectonics     

Timothy M Kusky  叶明和  王军鹏  王璐 《中国地质大学学报(英文版)》2010,(1)

The South China fold belt has experienced a complex series of tectonic events that span 1.0 billion years of earth history. Longhushan (龙虎山) World Geopark is located on the Proterozoic suture between the Yangtze craton and Cathyasia block and highlights the long history of this belt. Collision of the Cathyasia and Yangtze cratons 1.0 billion years ago was associated with the formation of the Rodinian supercontinent where most of the planet's landmasses were amalgamated into one block. Jurassic through Early...  相似文献   

REE and Sr-Nd Isotope Geochemistry for Yixian Fluorite Deposit,Western Liaoning Province,China,and Its Geological Implications     

孙祥  邓军  杨立强  王庆飞  杨子荣  龚庆杰  王长明 《中国地质大学学报(英文版)》2010,(2)

Up to now,there were no systematic studies of geochemistry and isotopic age for the Yixian(义县) fluorite deposit,western Liaoning(辽宁) Province,China.Based on the analysis of metallogenic geological setting,we studied the REE,Rb-Sr and Sm-Nd isotopes.The chondrite-normalized REE patterns of fluorite are characterized by moderate LREE depletion(LREE/HREE=0.95-3.57,(La/Yb)N=0.08-2.84) and enrichment of Sr(146×10-6-596×10-6) and moderately positive Eu anomalies(δEu=1.10-1.34),which are similar to those of the ho...  相似文献