Environmental records of lacustrine sediments in different time scales: Sediment grain size as an example   总被引：2，自引：0，他引：2  

CHEN Jing’an  WAN Guojiang  David Dian Zhang  ZHANG Feng & HUANG Ronggui . State Key Laboratory of Environmental Geochemistry  Institute of Geochemistry  Chinese Academy of Sciences  Guiyang  China  . Department of Geography  Geology  University of Hong Kong  Pokfulam Road  Hong Kong  China 《中国科学D辑(英文版)》2004,47(10):954-960

Understanding the past is the key to know thepresent and to predict the future. As a core project ofthe International Geosphere Biosphere Program, PastGlobal Changes (PAGES) aims to reconstruct theevolution history of global climate, global environ-ment and global ecosystem with resort to all kinds ofnatural records, so as to reveal the change rules(change processes, change amplitude and change rate)of the global environment and thus provide scientificbasis for predicting climate changes p…  相似文献   

Discovery of agglutinated foraminifers from the Longzhaogou Group in eastern Heilongjiang Province   总被引：1，自引：1，他引：0  

LI Gang & YU Shanmao. State Key Laboratory of Paleobiology Stratigraphy  Nanjing Institute of Geology  Paleontology  Chinese Academy of Sciences  Nanjing  China  .th Coal-prospecting Team of Geological Bureau  NE China  Inner Mongolia Coal Company  Jixi  China Correspondence should be addressed to Li Gang 《中国科学D辑(英文版)》2004,47(2):122-127

The low diversity agglutinated foraminifers are recovered from the Qihulin Formation of the Longzhaogou Group in eastern Heilongjiang, China. The foraminiferal fauna consists of 9 species of 5 genera. The common members are Cribrostomoides nonioninoides (Reuss), Haplophragmoides concavus (Chapman), H. gigas minor Nauss. Although the diagnostic zonal taxa are absent in the agglutinated fauna, according to the global stratigraphic distribution of the above-mentioned species, and the associated Pseudohaploceras ammonite fauna, the foraminiferal fauna may be of a Barremian-Aptian (Early Cretaceous) age.  相似文献   

Ore-forming fluid and mineralization of Caijiaying and Dajing polymetallic ore deposits   总被引：3，自引：0，他引：3  

WANG Lijuan  WANG Jingbin  WANG Yuwang & ZHU Heping. Key Laboratory of Mineral Resources  Institute of Geology  Geophysics  Chinese Academy of Sciences  Beijing  China  . Beijing Institute of Geology for Mineral Resources  Beijing  China Correspondence should be addressed to Wang Lijuan 《中国科学D辑(英文版)》2004,47(2):97-107

Fluid inclusions from the Dajing and Caijiaying deposits have nearly the same ho-mogenization temperature. Correlation between temperature and salinity shows that both Sn-and Cu-bearing fluids Sn and Cu were present in the Dajing deposit but only one kind of fluids continuously evolved in the Caijiaying deposit. Study on rare earth elements (REE) in ancient fluid from the inclusions indicates that the fluid of Sn mineralizing stage in Dajing was derived from remelting magma of the continental crust, and the fluid of Cu-Pb-Zn mineralizing stage in the Dajing deposit and the fluid of Cu-Pb-Zn mineralization in the Caijiaying deposit were derived from the mantle. It is concluded that the Cu-Pb-Zn mineralizations in the Dajing and Caijiaying deposits resulted from the identical tectono-thermal event of magma-fluids induced by Mesozoic tectonic transition and extension in the eastern part of North China Craton.  相似文献   

Co-seismic ground deformation and source parameters of Mani M7.9 earthquake inferred from spaceborne D-InSAR observation data   总被引：4，自引：0，他引：4  

SHAN Xinjian  MA Jin  WANG Changlin  LIU Jiahang  SONG Xiaoyu & ZHANG Guifang .Institute of Geology  Laboratory of Tectonophysics  China Seismological Bureau  Beijing  China  .Institute of Remote Sensing Application  Chinese Academy of Sciences  Beijing  China 《中国科学D辑(英文版)》2004,47(6):481-488

In recent ten years, Differential Interferometric Synthetic Aperture Radar (D-InSAR) has become a major technique of space-based geodesy together with GPS, VLBI and SLR. Interferometric Synthetic Aper-ture Radar (InSAR) has many advantages, such as all-weather, all-time, strong stability and dynamic survey property, and no requirements for ground sta-tions. In particular, the surveying results by InSAR can cover a large range of the ground deformation field in succession and has gr…  相似文献   

Wind tunnel simulation experiment and investigation on the electrification of sandstorms     

QU Jianjun  YAN Muhong  DONG Guangrong  ZHANG Hongfa  ZU Ruiping  TUO Wanquan  ZHAO Aiguo  XlAO Zhenghua  LI Fang & YANG Bao Key Laboratory of Desert  Desertification  Cold  Arid Regions Environmental  Engineering Research Institute  Shapotou Desert Research  Experiment Station  Chinese Academy of Sciences  Lanzhou  China 《中国科学D辑(英文版)》2004,47(6):529-539

~~Wind tunnel simulation experiment and investigation on the electrification of sandstorms~~  相似文献   

Comparison of the dynamic response of a saturated soil between two models     

LIN Mian Institute of Mechanics  Chinese Academy of Sciences  Beijing  China 《中国科学D辑(英文版)》2004,47(6):551-558

The dynamic response of marine sediment to ocean surface waves is treated extremely by marine geotechnical and coastal engineers. In the area of conventional hydrodynamics, the assumption of im-permeable rigid seabed has been used as the boundary of water waves theories and the waves parameters de-duced from the theory have not referred to the interac-tion of water waves and seabed. In the area of soil mechanics, many engineers regard the response as slow loading according to the Zienkewiczs[1…  相似文献   

Palynological record during the Pleistocene (between 1.05 Ma and 0.36 Ma) from ODP1144, northern South China Sea     

HUANG Fei & SUN XiangjunInstitute of Geology  Paleontology  Chinese Academy of Sciences  Nanjing  China  Institute of Botany  Chinese Academy of Sciences  Beijing  China  Key Laboratory of Marine Geology  Ministry of Education  Tongji University  Shanghai  China Correspondence should be addressed to Huang Fei 《中国科学D辑(英文版)》2004,47(1):30-36

This paper presents the pollen record from the lower section of ODP1144 (depth 501.3-225.7 m, ca. 1.05-0.36 Ma). Two pollen zones (PA and PB) and eleven pollen subzones are recognized. Within zone PB, the 11 pollen subzones (PB21-11) are defined according to the pine, fern and herb variations, and are equivalent to the marine isotope stages 21-11 (MISs 21-11). The interglacial periods are typified by an increase in pine pollen and fern spores, and a decrease in herbaceous pollen, while the patterning during the glacial periods is just the opposite. During the interglacial periods, pollen assemblages were dominated by pine similar to those of the present day, suggesting that the paleoenvironment of the interglacial periods was similar to that of the present day, whereas the glacial periods are marked by an increase in herbaceous pollen, mainly Gramineae and Cyperaceae, indicating that grassland covered the exposed continental shelf when sea level declined. Increased Artemisia percentages and the highest  相似文献   

Synthesis of todorokite by refluxing process and its primary characteristics     

FENG Xionghan  LIU Fan  TAN Wenfeng  LIU Xiangwen & HU Hongqing . College of Resources  Environment  Huazhong Agricultural University  Wuhan  China  . Testing Center  China University of Geosciences  Wuhan  China 《中国科学D辑(英文版)》2004,47(8):760-768

Todorokite is one of the common manganese ox-ides in manganese ore deposits, weathering product of manganese-bearing rocks, soils and sediments. It is also an important component in the abundant marine manganese nodules. Since todorokite was firstly found in Japanese Todoroki mine in 1934, its properties and origination have appeared to be very interesting to many researchers[1—3]. It has a stable structure similar to porous molecular sieves, constructed of triple MnO6 octahedral chains. Th…  相似文献   

Land cover change over the last three centuries due to human activities: The availability of new global data sets   总被引：15，自引：0，他引：15  

Kees?Klein GoldewijkEmail author  Navin?Ramankutty 《GeoJournal》2004,61(4):335-344

Land use and land cover change is an important driver of global change (Turner et al., 1993). It is recognized that land use change has important consequences for global and regional climates, the global biogeochemical cycles such as carbon, nitrogen, and water, biodiversity, etc. Nevertheless, there have been relatively few comprehensive studies of global, long-term historical changes in land cover due to land use. In this paper, we review the development of global scale data sets of land use and land cover change. Furthermore, we assess the differences between two recently developed global data sets of historical land cover change due to land use. Based on historical statistical inventories (e.g. census data, tax records, land surveys, historical geography estimates, etc) and applying different spatial analysis techniques, changes in agricultural land cover (croplands, pastures) were reconstructed for the last 300 years. The two data sets indicate that cropland areas expanded from 3–4 million km² in 1700 to 15–18 million km² in 1990 (mostly at the expense of forests), while grazing land area expanded from 5 million km² in 1700 to 31 million km² in 1990 (mostly at the expense of natural grasslands). The data sets disagree most over Latin America and Oceania, and agree best over North America. Major differences in the two data sets can be explained by the use of a fractional versus Boolean approach, different modelling assumptions, and inventory data sets.  相似文献   

The land-use projections and resulting emissions in the IPCC SRES scenarios scenarios as simulated by the IMAGE 2.2 model   总被引：1，自引：0，他引：1  

Bart?StrengersEmail author  Rik?Leemans  Bas?Eickhout  Bert?de?Vries  Lex?Bouwman 《GeoJournal》2004,61(4):381-393

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