NEW DATA ON THE LOESS ROCKS OF CHINA

Loess and similar rocks of China occur in five distinct environments: 1) on the slopes of high and moderately high mountains, 2) in belts of weathered talus and coarse residual deposits in foothills, 3) on floors of intermontane basins, 4) in thick deposits on high plateaus, and 5) on valley terraces. Loess rocks are found in the following types of deposits: primary loess, weathered slump and talus, stream alluvium, and coarse eluvial deposits. Engineering characteristics of the loess differ depending on environment and type of deposit. Specific gravity ranges from 1. 0 to 1. 5, porosity is generally high but decreases at depth, permeability ranges widely, compaction capacity is greater in loesses of lower specific gravity. — M. Russell