ABNORMAL GEOMAGNETIC FIELD RESPONSE AT INTRAPLATE TECTONIC BOUNDARY IN CONTINENT AND CONTINENTAL MARGIN IN SOUTHEASTERN CHINA   总被引：6，自引：0，他引：6  

TENG Jiwen*  YAN Yafen 《大地构造与成矿学(英文版)》2004,28(2):93-117

South China landmass is located at the southeastern end of Eurasia, adjoining Qinghai-TibetPlateau in the west, bordering Qinling-Dabie orogen in the north and the West Pacific in the east, andbeing connected to South China Sea in the south, hence the topography landscape shows transition froman inland type to a continental marginal type. Ever since Late Achaeozoic to Early Proterozoic,Cathaysia and Yangtze blocks has undergone multiple stages of splitting and amalgamation, and did notfi…  相似文献   

SPATIAL CORRELATION ANALYSIS BETWEEN KARST ROCKY DESERTIFICATION AND LITHOLOGY IN DU‘AN YAO AUTONOMOUS COUNTY IN GUANGXI   总被引：1，自引：0，他引：1  

HU Baoqing  *  JIANG Shufang  LIAO Chimei  HUANG Qiuyan  ZHOU Dequan 《大地构造与成矿学(英文版)》2004,(2):157-167

Karst rocky desertification refers to soil degeneration process such as serious erosion of soils,exposure of basement rocks in great areas, dramatic decrease in soil productivity, and occurrence oflandscapes similar to harsh deserts on ground surface, etc. under vulnerable environmental backgroundtypical of karst in subtropical areas, due to interferences and destruction resulted from the unreasonablesocial and economical activities by human beings (Wang, 2002). As a matter of fact, it was res…  相似文献   

GEOCHEMISTRY AND TECTONIC ENVIRONMENT AND RESERVOIR FORMATION OF MANTLE-DERIVED NATURAL GAS IN THE SONGLIAO BASIN, NORTHEASTERN CHINA   总被引：1，自引：0，他引：1  

LI Zian*  GUO Zhanqian  BAI Zhenguo    LIN Ge 《大地构造与成矿学(英文版)》2004,28(2):168-182

During several decades of exploration, a number of mantle-derived natural gas pools have been discovered in the vicinities of deep faults in the Songliao Basin, northeastern China. The natural gas in these pools has a δ 13C1 value of-16.5‰ to -24.2‰, a reversed arrangement in the amount of carbon isotopes in methane and its endogamous products (namely, Δ13c1 ＞Δ13c2 ＞Δ13c3 ＞Δ13c4 ), a 3He/4He value of 1.97 to 2.34× 10-6, and an 40Ar/36Ar value of 1063 to 1949. This indicates a mantle source for the natural gas. The trace elements Cd, In, Te and Re, never found in organic-sourced hydrocarbons, are highly enriched in certain crude oils from the Basin; respectively, concentrations of these elements were found to be 751, 28, 16 and 323 times the average crustal values in China, and this also supports a mantle-derived natural gas origin. The characteristics of mantled-derived magmatic rocks,hydrothermal fluids and gaseous fractions distributed in and near the deep Songliao Basin faults indicate that rifting tectonics is providing the mechanisms for this outgassing of the mantle. Deep extensional(normal) faults provide pathways for upward movement of these materials, and in the Songliao Basin,these deep riff fault zones are associated with reservoir occurrence and cap rock seals, forming good sites for accumulation of mantle-derived natural gas. Furthermore, a layer of low velocity, low density and high conductivity in the deep crust has been identified as a potential reservoir for mantle-derived natural gas.  相似文献   

Study on Soil and Water Loss Characteristic of the Railway Construction in Mountain Area     

BAI Ming-zhou~  XU Zhao-yi~  HUO Yu-hua~  DONG Yong~ 《地球科学进展》2004,(Z1)

The factor of human project activity is often the immediate cause resulting in soil and water loss. The Baoji-Lanzhou second railway in construction is an example. The soil and water loss law caused by earth and stone mountain railway engineering construction in the northwestern China is studied systematically and that caused possibly by the road bed project, the road moat project, the field project, the tunnel project and the service road project in construction is probed. At the same time, the type, the intensity and influencing factor of soil and water loss in the northwest mountain railway construction are also studied.  相似文献   

Study on the Safety of the Rock Mass in the Tongling Bank of Taipinghu Bridge     

DUAN Hai-peng~ 《地球科学进展》2004,(Z1)

The Taipinghu Bridge is an important engineering construction, and the safety of rock mass of its foundation is very crucial. This article adopts FLAC 3D to analysis the geologic model. The simulating process shows that no mater the excavating process or the loading process the rock mass are safe. The modeling and analyzing process can be used for reference.  相似文献   

Degradation of Microbes for the Crude Oil Contaminants     

LIU Xiao-yan  SHI Peng-fei  SUN De-zhi 《地球科学进展》2004,(Z1)

Production and storage-transportation of crude oil can not only give rise to soil pollution but also destroy ecological environment. Degradation of microbes for oily soil was studied with the instnunent, Geofina Hydrocarbon Meter (GHM), by experimental analysis qualitatively and quantitatively in the paper. Analytical result showed that the crude oil could be considerably degraded by eating-oil microbes in oily soil and the number of eating-oil microbes increased while the working hours of oil-well rising. As a result, contaminated oil could be degraded more quickly by a lot of eating-oil microbes in the soil. At the same time, the degradation rate of contaminated oil increased gradually as the time went on. In addition, amount of gaseous component in the oily soil samples increased with degraded time and the microbes could selectively consume contaminated oil strongly, so biedegradation might alleviate the degree of contamination and destruction to the soil and environment in the process of oil product  相似文献   

天然样品中微量铀的光谱化学分析     

莫罗什金娜  普罗 《铀矿地质》1963,(5)

在各种矿石与矿物中直接测定含量在10~(-3)-10~(-4)％的铀具有很大的实际意义。在我们所知的一些文献中,作者们都未能获得较高的灵敏度。此外,在上述这些文献中有一篇,由于标准样品与被分析样品的化学成份不完全符合,因而发生了工作曲线的位移。制备适合于分析各种不同化学组分的矿石与矿物的标准,会遇到严重的困难。在采用了以被分析的样品制备标准并以增量法进行分析之后,我们克服了这些困难。大家知道,铀就象大多数难挥发元素一样,具有不高的光谱灵敏度。  相似文献   

NUMERICAL EXPERIMENT ON THE SEASONAL VARIATION OF GLOBAL OCEAN AND THE EL NINO PROCESS:PARTI:CONTROL EXPERIMENT ON THE SEASONAL VARIATION OF GLOBAL OCEAN          下载免费PDF全文

(陈隆勋)  (徐俊) 《Acta Meteorologica Sinica》1994,(2)

A 6-layer,4°×5° horizontal resolution global ocean model has been designed and improved.After a 100-year in-tegration,an equilibrium state has been reached from the upper to lower layers.By taking the mean state of last l0 mod-el years as climatic state,we analyzed the characteristics of the seasonal variation in our model integration.The resultsshow that the simulated seasonal variation is similar to the observed.So the design of our model is successful.Then,us-ing the simulated climatic state of the seasonal variation as the initial state,and the observed stress and thermal state asthe atmospheric forcing,we simulated the process of El Nino in 1972—1973 successfully.The simulated results of sea-sonal variation using our model will be presented in part I.  相似文献   

NUMERICAL SIMULATION OF FRONTOGENESIS FORCED BY DUST RADIATIVE HEATING          下载免费PDF全文

(申绍华)  (陈受钧) 《Acta Meteorologica Sinica》1994,(2)

In this paper,the frontogenesis forced by dust radiative heating and the radiative effects of an isolated duststorrn ona frontal circulation system are examined by means of two-and three-dimensional numerical models.Results indicatethat as a duststorm breaks out, frontogenesis is caused in by dust radiative heating in the lower atmosphere.A markedisentropic potential temperature layer is formed in the middle troposphere.The low-level convergence occurs along thedirection of the front movement.Atnight,dust radiative cooling results in frontolysis in the lower atmosphere.An obvious vertical circulation is forced by radiative heating of an isolated duststorm along the direction of the pre-vailing wind.It is stronger at day,weaker and reverse at night.The response of the horizontal wind field to dust radiativeforcing is different at different levels.  相似文献   

STUDY　ON　THE　MATHEMATICAL　MODEL　OF　HEAVY－METAL　POLLUTANT　TRANSPOPT－TRANSFORMATION　IN　RIVERS     

Sui-liang Huang  Zhao-hui Wan 《国际泥沙研究》1994,(3)

ＳＴＵＤＹＯＮＴＨＥＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＨＥＡＶＹ－ＭＥＴＡＬＰＯＬＬＵＴＡＮＴＴＲＡＮＳＰＯＰＴ－ＴＲＡＮＳＦＯＲＭＡＴＩＯＮＩＮＲＩＶＥＲＳ￥Ｓｕｉ－ｌｉａｎｇＨｕａｎｇａｎｄＺｈａｏ－ｈｕｉＷａｎ（ＰｏｓｔｄｏｃｔｏｒａｌＦｅ...  相似文献