In this investigation students will create a model to visualize and predict how sequences of sedimentary rocks give us information about how sea level has changed over time. These changes in sea level can control the lateral and vertical facies near a marine sedimentary basin. Students will observe interactions of sedimentary rocks and grain sizes. Students will use their knowledge to draw a sea-level curve for Paleozoic rocks of the Central Midwestern US. Students will also be able to critique the model they created and identify shortcomings and assumptions in their model.