检索结果-南通市图书馆

Mantle-derived rare-gas releasing features at the Tianchi volcanic area, Changbaishan Mountains

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第9期42卷 768-771页

作者： SHANGGUAN Zhiguan and SUN Mingliang1. institute of geology, state seismological bureau, Beijing 100029, china 2. Lanzhou institute of geology, Chinese Academy of Sciences, Lanzhou 730000, china institute of geology State Seismological Bureau Beijing China Lanzhou institute of geology Chinese Academy of Sciences Lanzhou China

TIANCHI volcano,Changbaishan Mountains isthe largest modern active volcano in East *** times strong volcanic erupting activ-ities occurred in the Cenozoic *** vol-canic activities have revived again in the *** investi... 详细信息

关键词： Tianchi volcanic area Changbaishan Mountains mantle-derived rare gas 3He/ 4He 40 Ar/36 Ar 4He/20 Ne 4He/40Ar isotope ratios.

δD values of escaped H_2 from hot springs at the Tengchong Rehai geothermal area and its origin

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第2期47卷 146-149页

作者： SHANGGUAN Zhiguan & HUO Weiguo institute of geology, china seismological bureau, Beijing 100029, china institute of geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, china institute of geology China Seismological Bureau Beijing 100029 China

Here we give the δD values of escaped H2 from hot springs at the Tengchong Rehai and adjacent regions, and deal with a genetic correlation between the increment H2 in escaped gases from middle-shallow reservoirs and the H2S, CH4 derived from deep sources. Isotopic compositions of H2 indicate that the generation of increment H2 may be related to recent strong activity of N-W trending fault at the Rehai area. Trace monitoring the H2 release could be significant in order to keep watch on present activity of that fault.

关键词： Rehai geothermal area hydrogen stable isotopic composition.

LONGITUDINAL STREAM-PROFILES AS INDICATORS FOR GEOMETRIC SEGMENTATION OF THE LANGSHAN- HUANGBAISI FAULT ZONE, NORTHWEST BEIJING

在线全文

学校读者我要写书评

暂无评论

地震地质 1991年第4期 300-305+299页

作者： Cheng Shao-ping, Yang Gui-zhi and Yang Zhe(institute of geology, state seismological bureau, Beijing 100029, china)

The Langshan-Huangbaisi fault zone in northwest Beijing is the southwestern part of the normal fault zone on the northern margin of the Yanqing basin, 35.5km long and NNE-NEE-trending in general, on which two major 13.°- 140° bends separate it into three segments with different *** the Hack’s method, 71 longitudinal stream-profiles along the fault zone are analysed, shawing a well geomorphic response to the fault geometry. On these two major bends the gradient indices,K values, are relatively high. These three segments greatly differ in K *** stream-profiles are good tectonic-geomorphic indicators for geometric Segmentation of normal faults and will prqvide insight into segmented kinematics and paleoseismology.

关键词： Beijing Langshan-Huangbaisi fault zone Longitudinal stream-profile Geometric segmentatoin Gradient index

Some Evidence for a Possible Extraterrestrial Event at/near Permian-Triassic Boundary

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of china University of Geosciences 2002年第2期13卷 151-156页

作者： Xu Daoyi institute of geology, china seismological bureau, Beijing 100029 institute of geology China Seismological Bureau Beijing 100029

A selection of evidence, including a carbon isotopic excursion, iridium anomaly, fullerenes (C 6. and C 70 ) with trapped noble gases, microspherules and shocked quartz, is discussed in this paper. All the evidence in hand favors the hypothesis that the PTB event was probably related to an extraterrestrial cause, and the impact would lead to great physical change, including large volcanic eruptions on the earth's surface. The ET markers for the CTB event could be considered only as an example, and cannot be taken as a unique standard of an ET event.

关键词： Permian Triassic boundary extraterrestrial event iridium anomaly carbon isotopic excursion.

PROSPECTING FOR THE HIDDEN ACTIVE FAULT BY MEASURING THE 218p0 AND 210p0

在线全文

学校读者我要写书评

暂无评论

地震地质 1992年第1期 17-22页

作者： Zhang Yusong Hu Yutai Li Jianhua(institute of geology,state seismological bureau,Beijing 100029)

A method of prospecting for the concealed active fault by simultaneous measuring both 218Po and 210Po is *** is a radioactive *** concentration of radon near the fault can be determined from the activities of its daughters 218Po and *** the fault,there is a good passage for gases,and the radioative gas from crustal depths can be easy to get to the *** a result,the level of the radioactivity there is quite high,but low at both sides far from *** observational points where the *** of 218Po and 210Po is much higher than their background values can be regarded as the position of the hidden fault we want to seek.A number of observations at the known faults and hidden active ones indicate that seeking hidden active faults on certain conditions of their outcrops by measuring 218Po and 210Po is an effective,efficient-and hopeful way.

关键词： 218Po 210Po Daughter 222Rn Activity Hidden activy fault Hebei

SEISMICITY TENDENCY PREDICTION BEFORE 2020 IN china MAINLAND FROM ASTRONOMIC PERIODICITIES

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

地震地质 1990年第1期 6-11页

作者： Du Pin-ren (institute of geology,state seismological bureau)

The correlations between large earthquakes in china continent and periodicities of the Moon’s movement and the solar activity are statistically analysed and the following points are revealed:1. The earthquakes with ≥7.5 in Qing-Zang fault-block region have 18.6.yr periodicity of the Moon’s nodes motion.2. The earthquakes with M≥7.1 in Xinjiang fault-block region have 8.85-yr periodicity of the Moon’s perigee motion.3. The earthquakes with M≥7.0 in china mainland have the tendency to cluster around times of minima of sunspot cycles and in the even solar cycles.4. The earthquakes with M≥8.0 in china continent have the tendency to cluster around the valley times of the secular cycles of the solar *** to above correlations, the prediction of seismicity tendency can be given as follows: In china continent, especially Western china, the current active seismic period should continue up to the end of this century. The next active period would be 2006.2015.

关键词： Ascending node Perigee Solar activity Seismicity

The Geoscience Transect from Xiangshui,Jiangsu Province to Mandal,Inner Mongolia

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) 1992年第1期66卷 1-21页

作者： Ma Xingyuan Liu Changyuan Liu Guodong Jiang Minxi institute of geology,state seismological bureau,Beijing Geophysical Exploration Pafrty,state seismological bureau,Zhengzhou. 2institute of geology State Seismological Bureau Beijing. 3Geophysical Exploration Party State Seismological Bureau Zhengzhou.

The Xiangshui to Mandal geoscience transect, which has a total length of 1,200 km, extends diagonally,from SE to NW, across the Sino-Korean plate and its ancient continental margin, passing through nine tectonicunits: the Subei-Jiaonan terrane, West Shandong block, North china rift basin, Taihang-Wutai block, Ordosblock, Hu-Bao (Hohhot-Baotou) Basin, Yinshan block and Inner Mongolian fold system. The graphic display of the transect is compiled according to the Guidelines for the Global GeoscienceTransect (GGT) Project on the basis of an integrated study of all available geological, geochemical andgeophysical data, thus bringing light to the process of cratonization of the Sino-Korean plate and its relation-ship with the transitional zone of the ancient continental margin, and the features of intraplate structures pro-duced by subsequent tectonic modifications and intraplate dynamics.

关键词： The Geoscience Transect from Xiangshui Jiangsu Province to Mandal Inner Mongolia

Partial Melting and Its Implications for Understanding the Seismic Velocity Structure within the Southern Tibetan Crust

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2003年第1期77卷 64-71页

作者： YANG Xiaosong, MA Jin, JIN Zhenmin, GAO Shan and MA Shengli geology institute, china seismological bureau, Beijing 100029 Laboratory of Tectonophysics, china seismological bureau, Beijing 100029 Faculty of Earth Sciences, china University of Geosciences, Wuhan, Hubei 430074 china Seismol Bur Inst Geol Beijing 100029 Peoples R China china Seismol Bur Lab Tectonophys Beijing 100029 Peoples R China china Univ Geosci Fac Earth Sci Wuhan 430074 Hubei Peoples R China

In order to constrain the crustal wave velocity structure in the southernTibetan crust and provide insight into the contribution of crustal composition, geothermal gradientand partial melting to the velocity structure, which is characterized by low average crustalvelocities and widespread presence of low-velocity zone(s), the authors model the crustal velocityand density as functions of depth corresponding to various heat flow values in light of velocitymeasurements at high temperature and high pressure. The modeled velocity and density are regarded ascomparison standards. The comparison of the standards with seismic observations in southern Tibetimplies that the predominantly felsic composition at high heat flow cannot explain the observedvelocity structure there. Hence, the authors are in favor of attributing low average crustalvelocities and low-velocity zone(s) observed in southern Tibet mainly to partial melting. Modelingbased on the experimental results suggests that a melting percentage of 7-12 could account for thelow-velocity zone(s).

关键词： partial melting intracrustal low-velocity zone high-pressure andhigh-temperature experiments Tibetan plateau

THE GLOBAL TECTONIC SYSTEMS AND A LATITUDINAL MOUNTAIN-PLATEAU CHAIN ON THE NORTH HEMISPHERE

在线全文

学校读者我要写书评

暂无评论

地学前缘 2000年第S1期7卷 344-345页

作者： Ma Zongjin(institute of geology,china seismological bureau,Beijing 100029,china)

Three global tectonic systems that formed since the middle Jurassic (16.Ma ago)are outlined based on the global map of the Cenozoic and Mesozoic tectonics edited by Ma Zongjin et al.(1996..They are the circum\|Pacific tectonic system,the mid\|ocean ridge tectonic system and the intra\|continental tectonic system of the north *** map shows that about 80% of the total length of the continental orogens are concentrate on the north hemisphere of the earth,of which a latitudinal mountain\|plateau chain occur within a zone between north latitude 20°and 50°.Seismic and volcanic activities demonstrate that the intracontinental tectonic system on the north hemisphere is still *** distribution of the continental deep\|focus earthquakes and almost ultra high\|pressure rock found so far over the World,that are assumed both related to recent or previous deep subduction of continent,along with this *** latitudinal mountain\|plateau chain is subdivided into four active tectonic region of Qinghai—Xizang(Tibet),Iranian,eastern mediterranean and North American,both characterized by an individual similar mountain\|plateau\|basin structure with major active boundaries or controlling faults (Fig.1).These active regions are all close to primary dynamic boundaries of continent\|continent *** of source mechanisms shows that regional tectonic stress field in these regions are dominated by a nearly NS or NNE—SSW direction compression corresponding to a local plate motions and a global compressive *** between the formation of the continental latitudinal mountain\|plateau chain on north hemisphere and the oceanic plate tectonics is discussed using the information of the “Map of Magnetic Lineations of the World’s Ocean Basins (Cande et al.,1989)”and the Cenozoic and Mesozoic tectonic evolution in the *** 49 accretion units formed during 6.accretion stages of the ocean spreading in three chief oceans (the Pacific,the India and th

关键词： global asymmetrical system geodynamics mountain\| plateau chain seismotectonic system latitudinal tectonic zone