Abstract:The fluvial quaternary system of the Dongwen River valley consists mainly of:(1)proluvial-alluvial clayey-sandgravel beds of the lower pleistocere series, which containsdiamond and constitutes terrace Ⅱ;(2) the alluvium of the middle pleistoccere reformed bydenudation , of which the main constituents are the residuals of the lower pleistocere sedimentsreformed after its denudation and which contains relatively high amount of diamond;(3)thealluvium of the uppet pleistocere forming terrace Ⅰ which piles up on...