IN THIS ISSUE: Geology at Cornell: An Adventure Story /2 (The diversity and vitality of the Department of Geological Sciences, which is expanding at a time of new impetus in the discipline, is discussed by department chairman Jack Oliver.) ... The Changing Mosaic of Oceans and Continents: Plate Tectonics as a Unifying Model of the Earth /10 (Ocean-floor exploration and the study of mountain building are among aspects of the geological sciences discussed by Professor John M. Bird in a comprehensive assessment of plate tectonics.) ... The Descent of Crustal Rock into the Earth's Interior: Seismological Studies of Convection /27 (Aspects of Cornell research on earthquakes are interpreted by Bryan L. Isacks, associate professor of geological sciences.) ... Studying Ice Ages in the South Pacific /27 (A record of sea-level changes caused by the advance and retreat of glaciers is preserved in coral reefs of the South Pacific. Arthur L. Bloom, associate professor of geological sciences, explains a mode of research with obvious attractions.) ... Finding New Sources for Metals: A Challenge for Geologists /32 (Problems associated with the rapidly increasing demand for metals are discussed by Bill Bonnichsen, assistant professor of geological sciences.) ... Vantage /39 (Geology Day this spring provided members of the local community an opportunity to see what is going on in the geological sciences at Cornell.) ... Register /44 ... Faculty Publications /49