Pedogenesis affecting the Matuyama-Brunhes polarity transition recorded inChinese loess?

A detailed record of the Matuyama-Brunhes (M-B) transition has been obtaine d from the loess unit 8 (LS) at Duanjiapo (34.2 degreesN, 109.2 degreesE), Shannxi Province of China. An investigation of the rock magnetic properties using hysteresis loops, thermomagnetic analyses identifies pseudo-single d omain magnetite as the main carrier of the remanence, with a small contribu tion from maghemite and hematite. The paleo-direction records obtained reve al: (i) The M-B transition was recorded in the middle and lower part of L8, and comprises of five fast reversals. (ii) The duration of the M-B polarit y transition related to the directional change is about 4800 a. (iii) The v irtual geomagnetic pole (VGP) path during the transition is confined over A frica, peaked 90 degrees away from the sampling site, in contrast with the results obtained from the Weinan loess section. The different VGPs are prob ably attributed to the pedogenesis.