关键词: 广东, 风化晕, 晚更新世测年, 地貌面

Abstract: The thickness of weathering rind on sandstone gravels from river terrace and alluvial fan deposits in Guangdong area increases with time. The growth curve of weathering thickness has been determined by using age control from radio carbon, thermolumi-nesecence and ESR techniques, showing the exponential decay of weathering rate. Weathering-rind thickness thus provives a measure of the age of deposits or geomorphic surfaces:T = 1485D^4.13 Where T=age in years, and D = weighted mean thickness in mm of about 50 gravels from the surficial part of deposit.Using this method, the authors have determined the ages of two types of geomorphic surfaces in Guangdong area. The ages of the first and second river terraces are determined as 1 000-13300 yrs, and 8600-26500 yrs., respectively; while those of the first-and second-order alluvial fans along the northern front of Zhaoqing basin as 51500 and 24400 yrs., respectively. Based on these data and geomorphic analysis of tectonic deformation, the rates of vertical faulting for three major NE-trending fault zones in the area can be estimated as 0.6-1.6mm/yr. for the period before mid-Holocene, and much less value for Latest Pleistocene.

Key words: Guangdong Province, Weathering rind on sandstone gravel, Growth curve of weathering-rind thickness, Late-Pleistocene age-dating, Geomorphic surface