Studies were made of three soils from Wright Valley, one relatively young, one of intermediate age, and one old; in order to establish whether the increase of silt and clay from younger to older soils is due to synthesis of clay minerals or to comminution or both. The preliminary conclusion of this study is that mineral synthesis is occurring in Antarctica; however, additional dating by the fission-track method is needed, for ascertaining whether the mica is detrial or authigenic in the young and intermediate soils.