Four compulsory introductory activities, involving learning to use a stream tray, observing the relationship between water speed and entraining, transporting and depositing sediments, studying the formation of sedimentary rocks, and examining several types of sedimentary rocks, are completed by all students using the unit prepared for Australian secondary schools. Students may then choose from the following list of options: "Crumbling Rocks"; "Raging Torrents and Slow Trickles"; "River Valleys"; "The Shifting Sands"; "Scratching the Surface" (glaciation); "Sediments with a Difference" (pyroclastics, precipitants, and fossiliferous sediments); "How Fast? How Long?" How Much?"; and "Maps for the Geologist." The teacher's guide to the unit outlines the activities, lists necessary materials, and provides hints on managing classroom investigations. The student's booklet contains instructions for the activities in the core and optional activities, including some photographic "data" for exercises on rivers and landforms, diagnostic tests, and test answers with explanatory comments. There is a separate student record book. (This is a revision of ED 058 099). (AL)