Soils and Weathering: Students investigate properties of soil by comparing four different soils. They learn that soils are composed of essentially the same types of materials (inorganic earth materials and humus), but the amounts of the materials vary. They begin to explore how rocks break into smaller pieces through physical and chemical weathering. Students go outdoors to explore and compare properties of local soils.
Landforms: Students use stream-table models to observe that water moves earth materials from one location to another. They investigate the variables of slope and water quantity and plan and conduct their own stream-table investigations. Students look for evidence of erosion and deposition outdoors. Students think about what happens to sediments over long periods of time as sediments layer on top of each other. They learn about the different processes that can result in fossils and how fossils provide evidence of life and landscapes from the ancient past.
Mapping Earth's Surface: Students are introduced to the study of topography by building a model of a landform—a mountain. They use the foam model of Mount Shasta to create a topographic map, and use this map to produce another representation of the landforms— a profile of the mountain. Students learn about volcanoes; they use the topographer’s tools to analyze the impact of the Mount St. Helens eruption. Students are introduced to processes that cause rapid changes to Earth’s surface: landslides, earthquakes, floods, and volcanoes.
Natural Resources: Students review what they have learned in Investigations 1–3. Then they focus on earth materials as renewable and nonrenewable natural resources. They learn the importance of earth materials as resources. The class makes a stepping stone out of concrete and goes on a schoolyard walk to find objects and structures and consider what natural resources were used to construct them.