Characteristics of frequency-dependent magnetic susceptibility in Bartington MS2 and Kappabridge MFK1-FA, and its application in loess-paleosol, red clay and lacustrine sediments

Magnetic susceptibility (MS) of typical samples from Luochun loess-paleosol sequence, Zhuanglang core red clay, and Heqing core lacustrine sediments had been measured by Bartington MS2 and Kappabridge MFK1-FA meters. These two devices have five frequencies (two in MS2 and three in MFK1-FA) in all, and could get four frequency-dependent susceptibilities. MS achieve its peak value in low and high frequency when samples contain more and less fine grained particles respectively. Because of strong pedogenesis, loess-paleosol samples contain more fine grained particles, and could be detected by frequency-dependent susceptibility in both devices. However, for application in red clay and lacustrine sediments which lack fine grained ferrimagnetic particles, the low-frequency (465 Hz) in Bartington MS2 can not achieve peak value of magnetic susceptibility, and frequency-dependent susceptibility can not indicate the concentration of fine grained particles well. But Kappabridge MFK1-FA can do it well for its higher low-frequency (F, is 976 Hz, and F-2 is 3905 Hz).