Magnetic Fabric Characteristics and Implications for Its Origin of "Wushan Loess"

In this paper we present the magnetic fabric and magnetic susceptibility characters of one newly found Wushan Loess Section,which was also compared with the modern Yangtze River sediments and aeolian loess and Sand-Dune sediments distributed at the Middle Yangtze River.The results are as follows.(1) The κ,P,F,L,E values of the Wushan Loess are close to those of the aeolian loess and Sand-Dune sediments,however these values are obviously lower than those of the modern Yangtze River sediments.(2) Shown on the F-L graph,data of the Wushan Loess converge upon the origin of coordinates,similar to the aeolian loess and Sand-Dune sediments distributed at the Middle Yangtze River,which reveals sedimentary environment with relatively lower power.Data of the modern Yangtze River sediments lies around the F-axis,showing more dominance of F rather than L.(3) Maximum magnetic principal axis of the Wushan Loess is similar to that of the aeolian loess and Sand-Dune sediments distributed at the Middle Yangtze River,with the direction of declination relatively dispersing and the inclination of long axis varying between 36° and 38° and the inclination of the short axis varying between 37° and 39°.However the direction of maximum magnetic principal axis declination of the modern Yangtze River is relatively stable with inclination of the long axis smaller than 10° and short axis bigger than 80°.(4) T values of the Wushan Loess vary between-1 and 1 while T values of the modern Yangtze River are mainly higher than 1.Generally,magnetic fabric characters are similar to aeolian loess and Sand-Dune sediments distributed at the Middle Yangtze River,revealing its aeolian origin.