This unit is part of a series of materials produced by a project to develop locally applicable class, lab, and field materials in ecology and social studies for Guam junior and senior high schools. While the materials were designed for Guam, they can be adapted to other localities. This unit is designed to acquaint the students with the geology of Guam. Sections in the book include: (1) rocks, (2) how Guam was formed, (3) weathering and erosion, (4) earthquakes, (5) soil, and (6) water. Both background materials and activities are included. (RH)