Magnetic Fabrics Cluster Analysis And The Sedimentary Dynamic Direction Of A Fossil Horizon In Erlian Basin,Inner Mongolia

To help understand the links between magnetic fabric and macroscopic structure inspections, such as the statistical analysis of the elongate bone orientations in recovering paleocurrent directions. A section was investigated in Chaganboerhe, Inner Mongolia, through the AMS (anisotropy of magnetic susceptibility) analyses of 414 oriented samples. For the strong hydrodynamics at alluvial fan, the major orientations of maximum susceptibility axes (Kmax) were perpendicular to the dynamic orientations showing a E-W paleocurrent direction. When the power fades, orientations of Kmax were aligned with paleocurrent direction in surrounding rocks around the fossils at about 90°, which coincide with the elongate bone orientations at 70°-115°. Both magnetic fabrics and elongate bone orientations show the paleocurrent direction in the same direction, from east to west. In addition, to compare magnetic fabric and other sedimentary bedding-plane features like gravel arrangement and sedimentary bedding stratification in the study of dynamics, we also analysis the result of these methods from the samples at Datong River valley and Jing River terrance. They all indicate similar results and support the consistency between macroscopic and macroscopic structure inspections. Statistic methods of AMS based on large quantitative samples have the same interpretations as the results from sedimentary structure analysis.In addition, we apply the method of cluster analysis to all samples for verifying the sensitivity of magnetic fabric to sedimentary dynamics. The statistical results of large number of river-lake facies samples show that linear approximation divisions the profiles basis for the intensity of flowing water and hierarchical cluster reconstructs the groups to every sample jumping out former sections. Both methods can indicate the intensity and stability, which prove the close correlation between magnetic fabric and sedimentary dynamics.In case the macroscopic-indicators are invisible, AMS analysis can always provide a reliable substitute solution for the extensive research of sedimentary dynamics in future.