This Subcommittee was organized in November 1941. It first selected the areas in which the terminology of sediments was confused and needed clarification, and drew up preliminary definitions to serve as a basis of discussion. These definitions were then distributed as widely as possible among the persons in this country who are active in the sediment field, and their views were requested. Their replies contained many valuable suggestions. The comments on each definition were assembled and the preliminary definitions were modified in the light of these views. In cases where there were distinct differences of opinion, alternate definitions were prepared and voted upon by the Subcommittee. On the majority of items adopted, the vote of the Subcommittee was unanimous, or nearly no, but on several there was considerable difference of opinion.