检索结果-南通市图书馆

General regularity of dynamic responses of slopes under dynamic input

在线全文

学校读者我要写书评

暂无评论

Science China(Technological sciences) 2003年第z1期46卷 120-132页

作者： QI Shengwen, WU Faquan & SUN Jinzhong Institute of geology and geophysics,{2.,{3., China College of Engineering Technique, China University of Geo{4., beijing 100083. China chinese Acad Sci Inst Geol & Geophys Beijing 100029 Peoples R China China Univ Geosci Coll Engn Techn Beijing 100083 Peoples R China

Through lots of numerical simulations with FLAC3., dynamic responses of slopes are comprehensively studied in this paper and the general regularities of the isoline of the coefficient of the displacement, velocity and acceleration of the slope section are reached. Given a certain material slope, if the height of the slope is less than a certain value, the displacement, velocity and acceleration linearly enlarge with elevation in the vertical direction; if the height of the slope surpasses the certain value, the displacement,velocity and acceleration do not linearly enlarge with elevation any more, on the other hand, they fluctuate with a certain rhythm. At the same time, the rhythm appears in the horizontal direction, and the displacement, velocity and acceleration of the slope surface enlarge near the slope surface. The distribution form of the isoline of the coefficient of displacement, velocity and acceleration in the section of the slope is remarkably affected by the slope angle. In the certain area near the slope surface, the isoline of displacement,velocity and acceleration is parallel to the surface of the slope; in the mean time the strike direction of the extremum area is parallel to the surface of the slope, too. The charts of the slope dynamic responses can be depicted with two indexes, one is the strike direction of the isoline, and the other is the number of the rhythm extremum area of the direction parallel to the surface of the slope.

关键词： slope, dynamic response, regularity, rhythm.

在线全文

学校读者我要写书评

暂无评论

Science China Earth sciences 2004年第10期47卷 886-895页

作者： TANG Liangjie1,2. JIA Chengzao3. PI Xuejun4. CHEN Suping1,2. WANG Zhiyu5, XIE Huiwen4.1. Key Laboratory for Hydrocarbon Accumulation of Education Ministry, {2. 102.4., China 2. Basin & Reservoir Research Center, University of Petroleum, {2. 102.4., China 3. PetroChina Company Limited, {2. 100011, China 4. Tarim Oilfield Company, PetroChina Company Ltd., Kurle 84.000, China 5. Department of {3., University of Petroleum, {2. 102.4., China 1. Key Laboratory for Hydrocarbon Accumulation of Education Ministry 102249 Beijing China 2. Basin & Reservoir Research Center University of Petroleum 102249 Beijing China 3. PetroChina Company Limited 100011 Beijing China 4. Tarim Oilfield Company PetroChina Company Ltd. 841000 Kurle China 5. Department of geology University of Petroleum 102249 Beijing China

The salt beds of Lower Tertiary developed in the mid-segment of Kuqa foreland fold belt, northern Tarim basin. They considerably controlled structural deformation of the belt. Ac- cording to the field observation, seismic profile interpretation and drilling data, three different structural styles of supra-salt, intra-salt and sub-salt occurred in the Kuqa foreland fold belt. Su- pra-salt structural styles mainly include thrust faults and fault-related sags. Intra-slat structural styles essentially are salt-pillows, intra-salt faults and folds, and salt weld structures. Sub-salt structural styles mainly consist of imbricated thrust faults, duplex structures, pop-up and fault-related folds. It is indicated that great differences exist among supra-salt, intra-salt and sub-salt structures of Kuqa foreland fold belt. The salt-related structures were formed in the same structural stress field. The dynamic mechanism of the salt-related structures is mainly associated with gravitation, compression and plastic flow of salt beds.

关键词： salt-related structural style, supra-salt structure, intra-salt structure, sub-salt structure, Kuga foreland fold belt.

A Study of Mesoproterozoic Iron Cosmic Micro-spherules from 1.8 Ga and 1.6 Ga Old Strata in the Ming Tombs District,beijing

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2007年第4期81卷 649-657页

作者： SONG Tianrui HE Zhengjun WAN Yusheng and LIU Yanxue Institute of geology,chinese {2. of Geological {3.,{4. 10003. Institute of geology Chinese Academy of Geological Sciences Beijing 100037

Numerous iron cosmic micro-spherules have been discovered from Mesoproterozoic strata including the Changzhougou Formation （1.8 Ga） and the Dahongyu Formation （1.6 Ga） of the Ming Tombs district, beijing. There are 1 to 3. grains of cosmic spherules per 2.kg of a sandstone sample taken from the bottom of a coarse sandstone bed of the Changzhougou Formation and 56 grains per 3.69 kg of a rock sample from silicified carbonate rocks of the Dahongyu Formation. The surface textures of cosmic spherules analyzed by means of the secondary electron imagery are identical with those reported from references either domestic or abroad. So far the geo-ages of 1.8 Ga and 1.6 Ga of cosmic spherules from the Changzhougou and Dahongyu formations might be older than those reported in the world. Table 1 gives the electron probe analysis data of cosmic spherules for 3. spherule grains and 4. testing points as follows （%）： FeO, 80-95; Cr2.3. 0-9.56; NiO, 0-0.78; CoO, 0-0.4.; indicating that the Cr2.3.content is higher and FeO content lower in the Changzhougou Formation than in the Dahongyu Formation. The helium isotopic data of cosmic spherules as well as their host rocks vary greatly between the Changzhougou and the Dahongyu formations as shown in Table 2. The data of cosmic spherules of the Changzhougou Formation vs the Dahongyu Formation are 57.5/1.2. in ^3.e/^4.e （10^-8）; and 55.54.809.60 in ^4.e （10^-6cm^3.TP/g）; those of coarse sandstone of the Changzhougou Formation vs silicified carbonate of the Dahongyu Formation are 3.3./2.59 in ^3.e/^4.e （10^-8） and 4.56/2.3.2}in ^3.e （10^-6cm^3.TP/g）. The ratio of analytic data of helium isotopes are different for cosmic spherules and their host rocks; for example, the ^3.e/^4.e （10^-8） values are 16.96 and 0.4., and the ^4.e （10^-6 cm^3.TP/g） are 12.18 and 3.2}.98 for the Changzhougou and Dahongyu formations respectively. It was reported that the world＇s oldest micrometeorites had been found in the Meso-Proterozoic Satakunta Formation, Finland

关键词： Proterozoic cosmic spherule helium isotopes extraterrestrial material carbonaceous chondrite

Mineral provinces and material provenance of the surficial sediments near the Zhongsha Islands in the South China Sea

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2007年第1期26卷 66-76页

作者： YAN Quanshu1, 2. 3. SHI Xuefa2., WANG Kunshan2.. Institute of Oceanology,{3., Qingdao 2.6071, China2. Key Laboratory of Marine Sedimentology and Environment geology of State Oceanic Administration, First Institute of Oceanograghy, State Oceanic Administration, Qingdao 2.6061, China3. Graduate School,{3., {3. 10004., China Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China

Characteristics and distribution patterns of clastic minerals (0.063.0.12. mm) in bottom sediments represent a significant indicator for the identification of the origin of sediment. One hundred and fourteen surface sediment samples, which were collected from the area near the Zhongsha Islands in the South China Sea, were analysed to identify the mineral suites and their distributions in the study area. The area can be divided into three mineral provinces: (Ⅰ) a province of biogenic minerals, which mainly originate from the Zhongsha Atoll; (Ⅱ) a province of volcanogenic minerals, which are mainly derived from local basaltic seamounts and small-scale volcanoes that are probably erupting, with some influences from the island-arc volcanic region around the South China Sea; and (Ⅲ) a mixed mineral province whose material source includes biogenic minerals, volcanogenic minerals and terrigenous minerals; the last province can be subdivided into a mixed mineral sub-province of the northeastern part of the study area, in which terrigenous minerals are mainly derived from China’s Mainland and do not exceed 17°N, and a mixed mineral sub-province of the southeastern part of the study area, in which terrigenous minerals are derived from Kalimantan and Indochina Peninsula and might be further transported into the deep sea basin through submarine canyons.

关键词： South China Sea Zhongsha Islands light mineral minerals province material provenance

Chengdeite-A New Mineral of Ordered Natural Iron-iridium Alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1996年第1期70卷 27-32,108页

作者： Yu Zuxiang Institute of geology, chinese {2. of Geological {3., {4.

Chengdeite occurs in chromite orebodies in dunite as well as in placers in their neighbourhood. The mineral occurs as granular aggregates in association with inaglyite and in some cases occurs as graphic intergrowths with native iridium. It is opaque with a metallic lustre, colour steel-black, streak black,HM = 5.2. VHN50=4.2.kg/mm2. cleavage not observed, fracture not observed, strongly magnetic. Its reflection colour is bright white with a yellowish tint. It has no internal reflection, bireflectance or pleochrism, and shows *** chemical analyses were carried out by means of the electron microprobe. The mean percentages of the data obtained in the 13.analyses ares S 0.001, Fe 7.9, Ni 0.03. Co 0.03. Cu 0.83. As 0.02. Rh 0.19, Pd 0.00, Os 0.06, Ir 88.5, Ft 2.2.and Pb 0.00. The simplified formula is Ir3.e, which requires Ir 91.17 and Fe 8.83. the total being 100.00 (% ).Five strongest lines of X-ray powder diffraction (hkl, d, I)are: 111, 2.18 (80);2.0, 1.89 (60); 2.0, 1.3.1}(70);3.1, 1.14. (100);2.2.1.094.(80).Through indexing of the X-ray powder diffraction data, the mineral has been determined to be cubic with Pm 3., a = 0.3.92.5)nm, V = 0.054.3.m and Z = 1.

关键词： new mineral chengdeitc chromite ore

Tectonic Evolution of the Himalayan Collision Belt

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1997年第2期71卷 133-143页

作者： Cui Junwen Institute of geology, chinese {2. of Geological {3., {4. Institute of geology Chinese Academy of Geological Sciences Beijing [?]Cui Junwen Born in 193. graduated from the specialty of geological structure Department of Geology and Geography Peking University in 1965. Now he is research professor at the Institute of Geology Chinese Academy of Geological Sciences and mainly undertakes the study of deformation dynamics of the lithosphere and deep tectonics.

This paper discusses the tectonic divisions of the Himalayan collision belt anddeals with the tectonic evolution of the collision belt in the context of crustal accretion in thefront of the collision belt, deep diapirism and thermal-uplift extension and deep material flow-ing of the lithosphere-backflowing. Finally it proposes a model of the tectonic evolution-progressive intracontinental deformation model-of the Himalayan belt.

关键词： Himalayan collision belt thermal-uplift spreading thermal-uplift extension backflowing progressive intracontinental deformation at model

Geochemical Characteristics of Granitoids in the Eastern Sector of the Northern Tianshan Mountains in Xinjiang

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 1990年第1期64卷 55-67页

作者： Wang Bixiang Li Zhaonai Zhao Guangzan Wang Fubao Zhang Shuizhe Fei Wenheng Institute of geology, chinese {2. of Geological {3., {4. Institute of geology Chinese Academy of Geological Sciences Beijing

The granitioids in question are located in the geosynclinal fold belt of the Northern Tianshan Mountains.The magmas are intruded into a Carboniferous marine volcanic-sedimentary rock series. forming a contempo-raneous. intermediate-basic to acid. composite intrusion. With a whole-rock Rb-Sr isochron age of 3.5.7 Ma. itis considered to be of middle Heicynian age. The granitoids have a SiO_2.content of 4.-78%, a calc-alkali indexof 60 and silica-alkali indices ρ=2.2.2.4.and σ=1.5-2. From basic to acid compositions, the total REE con-tent increases from 3. to 14. ppm. δEu ranges from 0.4. to 0.86 and the Eu anomalies are negative. Thenormalized curves of REE of various rock types are very similar. These coupled with the characteristics of traceelement geochemistry show that the intrusion is an island arc-continental margin, calc-alkaline one. Theδ^(18)O values range from 5.8 to 8.9‰ and the ^(87)Sr/^(86)Sr initial ratio is 0.705. The materials of the intrusion arecomposed of a mixture of the magmas at the top of the upper mantle and in the lower crust, This indicates thatthe rocks might be consanguineous. differentiated and evolved products and possess the characteristics of Ⅰtype granites.

关键词： Geochemical Characteristics of Granitoids in the Eastern Sector of the Northern Tianshan Mountains in Xinjiang

Ages and Compositions of the Precambrian High-grade Basement of the Qilian Terrane and Its Adjacent Areas

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2001年第4期75卷 375-384页

作者： WAN Yusheng, XU Zhiqin, YANG Jingsui and ZHANG Jianxin Institute of geology, chinese {2. of Geological {3., {4. 10003. Institute of geology Chinese Academy of Geological Sciences Beijing 100037 [?]2.an Yusheng Born in 1958 graduated from China University of Geosciences in 1981 received the Ph.D. degree in 1993 now senior geologist at the Institute of geology Chinese Academy of Geological Sciences engaged in the study of geochemistry. Tel: 010–683.0}4.1 e-mail: wanysh@***

Based on geological, chronological, geochemical and Nd isotopic studies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilian terrane consists mainly of meta-argillo-arenaceous rocks and granites and its bulk part was formed in the period of 0.8–1.0 Ga (the Jinningian period); (2. most of the meta-argillo-arenaceous rocks and granitic rocks have strong negative Eu and Ba anomalies (Eu/Eu*= 0.4.–0.71 and Ba/Ba*=0.16–0.64., with fDM and ENd (1.0 Ga) ranging from 1.87 to 2.2. Ga and from ?8.54.to ?4.06 respectively, showing relatively high maturity; and (3. the Jinningian granitic rocks are a typical product of continent-continent collision, being probably related to the formation of the supercontinent Rodinia. These studies, combined with the study of high-grade basement rocks near the Qilian terrane, suggest that before the Jinningian period, the Qilian-Qaidam northern-margin terrane and Dunhuang-Alxa terrane were separated from each other, belonging to different plate systems of the North China craton and Yangtze platform respectively. The Qilian orogenic belt was the same as or similar to the Qiling orogenic belt in terms of the geological evolution history at least before the Jinningian period.

关键词： Qilian terrane chronology Nd isotope geochemistry Precambrian basement

Petrology and ^(4.)Ar/^(3.)Ar iso-topic ages of blueschists in Gangmar, central Qiangtang, northern Tibet

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2001年第5期46卷 423-427页

作者： DENG Xiguang, DING Lin, LIU Xiaohan & ZHOU YongLaboratory of Lithospheric Tectonic Evolution, Institute of geology and geophysics,{2.,{3., China Laboratory of Lithospheric Tectonic Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing China

The petrology and mineral assemblages of blueschists in the Gangmar, central Qiangtang, northern Tibet were examined, which indicates that the metamorphic condition is high-pressure low-temperature. In this note, we reported the 4.Ar/3.Ar dating results of glaucophane from two blueschist samples. Their apparent ages are (2.5.0±1.3. Ma and (2.7.6±2.3. Ma and similar isochron ages are (2.5.0±0.9) Ma and (2.2.4.0.8) Ma, respectively. These iso-topic datings show the high-pressure metamorphism occurring in Lower Permian. The ages also coincide with the evolution of Palaeo-Tethys ocean in Late Palaeozoic.

关键词： glaucophane blueschist 3.Ar/4.Ar age Palaeo-Tethys Gangmar northern Tibet.