This paper describes the program module ＂GRAPHS＂ which was developed for data processing in geobotany and ecology fields. The ＂GRAPHS＂ has a simple interface and is integrated into the Microsoft Excel. This allows...This paper describes the program module ＂GRAPHS＂ which was developed for data processing in geobotany and ecology fields. The ＂GRAPHS＂ has a simple interface and is integrated into the Microsoft Excel. This allows users to use all features of Microsoft Excel for storage and preparation data for analysis. Calculation of the most common similarity indexes （Jaccarda. Sorenson, Ohai etc.） and their visualization by using different algorithms of the graph theory or hierarchical cluster analysis allows simplifying and accelerating the process of data analysis in ecology or geobotany and makes it clearer. Also, three ordination methods--PCA （principal components analysis）, CA （correspondence analysis）. NMS （nonmetric multidimensional scaling）-were implemented in the module. The module can be used for vegetation classification, and be used to allocate diagnostic species or to search environmental factors most strongly impact on vegetation. Algorithms of data analysis which were implemented in the module ＂GRAPHS＂ have universal nature so they can be applied in many other fields of science.展开更多
The Ordos block is a stable tectonic unit since the Cenozoic. Whether low-resistivity layers exist in the middle and lower crust of this kind block is an open question. This work attempts to reveal the entire crustal ...The Ordos block is a stable tectonic unit since the Cenozoic. Whether low-resistivity layers exist in the middle and lower crust of this kind block is an open question. This work attempts to reveal the entire crustal structure of the block based on interpretation of magnetotelluric data collected along the profile across this region. The result shows that a layered structure characterizes the crust of the Ordos block, with a low-resistivity layer at depth of about 20km, presumably associated with fluids there. In contrast, in the areas of active tectonics on the east and west of the block, there are no such layered electric structures in the crust, and the low-resistivity zones may be related to the decollement zones (or ductile shear zones) in the crust. The difference in electric structure of crust between the Ordos Block and neighboring areas is of significance to analyze the movement and deformation of varied blocks in the continent.展开更多
Present-day hot spots and Phanerozoic large igneous provinces(LIPs) and kimberlites mainly occur at the edges of the projections of Large Low Shear Wave Velocity Provinces(LLSVPs) on the earth's surface. If a plat...Present-day hot spots and Phanerozoic large igneous provinces(LIPs) and kimberlites mainly occur at the edges of the projections of Large Low Shear Wave Velocity Provinces(LLSVPs) on the earth's surface. If a plate contains accurately dated LIPs or kimberlites, it is possible to obtain the absolute paleoposition of the plate from the LIP/kimberlite and paleomagnetic data. The presence of Middle Ordovician kimberlites in the North China Block provides an opportunity to determine the absolute paleoposition of the block during the Middle Ordovician. In addition to paleobiogeographical information and the results of previous work on global plate reconstruction for the Ordovician Period, we selected published paleomagnetic data for the North China Block during the Middle Ordovician and determined the most reasonable absolute paleoposition of the North China Block during the Middle Ordovician: paleolatitude of approximately 16.6°S to 19.1°S and paleolongitude of approximately 10°W. The block was located between the Siberian Plate and Gondwana, close to the Siberian Plate. During the Cambrian and Ordovician periods, the North China Block may have moved toward the Siberian Plate and away from the Australian Plate.展开更多
文摘This paper describes the program module ＂GRAPHS＂ which was developed for data processing in geobotany and ecology fields. The ＂GRAPHS＂ has a simple interface and is integrated into the Microsoft Excel. This allows users to use all features of Microsoft Excel for storage and preparation data for analysis. Calculation of the most common similarity indexes （Jaccarda. Sorenson, Ohai etc.） and their visualization by using different algorithms of the graph theory or hierarchical cluster analysis allows simplifying and accelerating the process of data analysis in ecology or geobotany and makes it clearer. Also, three ordination methods--PCA （principal components analysis）, CA （correspondence analysis）. NMS （nonmetric multidimensional scaling）-were implemented in the module. The module can be used for vegetation classification, and be used to allocate diagnostic species or to search environmental factors most strongly impact on vegetation. Algorithms of data analysis which were implemented in the module ＂GRAPHS＂ have universal nature so they can be applied in many other fields of science.
基金sponsored by Earthquake Research Project for Public Affair(2008419010)the National Natural Science Foundation of China(40374032, 40534023)+4 种基金the Basic Scientific Research Special Program of the Institute of Geology,CEA(DFIGCEA0607117)the Basic Scientific Research Fund of the State Level Institutes for Commonweal (DF-IGCEA-0607-1-17)the National Basic Research Program(2004CB418402),Chinathe National Key Basic Research Program (95-13-02-02)the Key Program of the Natural Science Foundation of China (40534023)
文摘The Ordos block is a stable tectonic unit since the Cenozoic. Whether low-resistivity layers exist in the middle and lower crust of this kind block is an open question. This work attempts to reveal the entire crustal structure of the block based on interpretation of magnetotelluric data collected along the profile across this region. The result shows that a layered structure characterizes the crust of the Ordos block, with a low-resistivity layer at depth of about 20km, presumably associated with fluids there. In contrast, in the areas of active tectonics on the east and west of the block, there are no such layered electric structures in the crust, and the low-resistivity zones may be related to the decollement zones (or ductile shear zones) in the crust. The difference in electric structure of crust between the Ordos Block and neighboring areas is of significance to analyze the movement and deformation of varied blocks in the continent.
基金the National Basic Research Program of China (Grant No. 2009CB219302)
文摘Present-day hot spots and Phanerozoic large igneous provinces(LIPs) and kimberlites mainly occur at the edges of the projections of Large Low Shear Wave Velocity Provinces(LLSVPs) on the earth's surface. If a plate contains accurately dated LIPs or kimberlites, it is possible to obtain the absolute paleoposition of the plate from the LIP/kimberlite and paleomagnetic data. The presence of Middle Ordovician kimberlites in the North China Block provides an opportunity to determine the absolute paleoposition of the block during the Middle Ordovician. In addition to paleobiogeographical information and the results of previous work on global plate reconstruction for the Ordovician Period, we selected published paleomagnetic data for the North China Block during the Middle Ordovician and determined the most reasonable absolute paleoposition of the North China Block during the Middle Ordovician: paleolatitude of approximately 16.6°S to 19.1°S and paleolongitude of approximately 10°W. The block was located between the Siberian Plate and Gondwana, close to the Siberian Plate. During the Cambrian and Ordovician periods, the North China Block may have moved toward the Siberian Plate and away from the Australian Plate.
