IN THIS ISSUE: Exploring the Earth's Basement /2 (Seismic reflection profiling is the technique used in an ambitious cooperative study of the earth's deep crust and upper mantle. Sidney Kaufman, professor of geological sciences, discusses the method, its scientific and economic potential, and some preliminary results.) ... Plate Tectonics and the Origins of Ore Deposits /11 (John M. Bird, professor of geological sciences, explains how plate tectonic models have led to a new understanding of the genesis of ore deposits and may help in efforts to locate them. His particular interest is in the origin of ore bodies in mountain belts.) ... Clues from Marine Geology in the Search for Oil and Minerals /21 (Field studies on an Indonesian arc island are part of a Cornell study of marine geologic processes. The research and its implications are discussed by Daniel E. Karig, associate professor of geological sciences.) ... Hot Springs, Geysers, and Geothermal Energy /30 (The prospect of tapping new sources of geothermal energy has provided impetus to research into the complex processes that occur in geothermal areas. Donald L. Turcotte, professor of geological sciences, considers both scientific and economic aspects of current research in this field.) ... Vantage /35 (A Cornell research group headed by Arthur F. Kuckes, professor of applied physics, is studying electrical conductivity in the earth's deep crust, an indication of geothermal activity.) ... Faculty Publications /37