Xiong Pingsheng1.2
(1. Geography and planning School of GanNan Normal university,Ganzhou,Jiangxi 341000,China;
2. Academy of Geography Science Southwest University,Chongqing 400715,China)
Abstract: Grain-size distbution of the red earth of Huangjin profile(HJ) and Shahe profile (SH) was measured in Gannan region,the results show that:(1)Grain-size distributions of two red earth sections in Gannan region are very similar,The average content of silt fraction(4-63μm) particle group in HJ and SH profile are respectively 51.51%、55.02%, The average content of coarse silt fraction (10~50μm)There are apart 29.14% and30.79%,The average content of clay (<4μm) are respectively 28.69%、23.13%.The basic fraction of dust is rich.indicating there is Aeolian characteristics of the red earth in Gannan region. The average content value of clay(> 63μm) are respectively 19.78%、21.84%.the grain-size frequency curves are made up of three-peak part. The probability accumulation curves of red earth could be divided into three-segment pattern by two flex point of 1.5Φand10.5Φ.The component of suspended particles is dominant,the other two part are very similar.which probably indicates aeolian characteristics from their parent materials in Gannan red earth ,The sedimental parent materials were reconstructed by water erosion process and the weathering process.(2) The vertical change curve among magnetic susceptibility、Kd value and weathering coefficient exist remarkablycorrelation.There are six- cyclic both curve Peak and valley. The particle distribution and particle parameters are correlation. Indicating the existence of six-cycles of depositional alternating with pedogenic process in Gannan red earth, accordingly there are six-cycles of climate change.
Key word: HJ and SH Red earth profie; Grain-size distribution; six-cyclic change
EARTH AND ENVIRONMENT Vol. 39, No.4, Tot No.286, 2011, Page 485-491
