Earth's surface is constantly changing. Mountains are built and rivers cut canyons through them. Wind and water carry rock away and deposit it in new locations. Volcanoes erupt, burying former surfaces under new layers of rock. Flat layers become faulted and folded. Everywhere you look, you can find rocks that show evidence of past geologic events.

  !   Click each image to see a larger version. Consider how the rocks in each photograph indicate their geologic history.

1. Identify at least three geologic processes represented in the images.

Look at the photograph of sediment deposition in the Mississippi Delta. Consider how Delicate Arch, pictured to the right of the delta image, indicates processes similar to those occurring in the delta.

2. What evidence might indicate that the processes you described may also have occurred sometime in the past?