What are some of the factors that might unnecessarily exclude people from learning about or working in the geosciences? Culture? Ethnicity? Sex? Language? A disability? Where they live? How much they earn? Something else?
Geologic maps show the locations of various kinds of rocks at the surface. In places where rivers have eroded the surface, deeper layers become exposed. The opposite occurs when lake levels rise; rocks along the shore are covered by water. Geologic clues in each layer can be used to tell a story of Earth’s history. Differences between one layer and the next reveal changes in the Earth system.
Geologic maps and Google Earth™ images provide images that are snapshots of the times they were made. Weathering, erosion, and deposition continue to break down and build up Earth’s surface. In this activity you will explore the channel of the Colorado River that is submerged by Lake Powell and look for evidence of change.
Part A: Younger Deposits
Active erosion wears away surface rocks while deposition piles loose sediments on top of existing surfaces. Over time loose sediments may be compacted and cemented, which forms sedimentary rocks. Younger rocks and sediments are also shown on the geologic map. Let’s look for evidence of young rocks and active deposition using the map and other tools.
Try this activity from the Association of American State Geologists!