Document Type

Teacher Resource

Grade Level

Grade Level: 4th Grade

Publication Date



Sedimentary rock layers are found in places all around the world. They can provide useful clues to the past. Sometimes a waterway cuts through the layers revealing a geologic record of the past. In other locations, scientists must dig trenches to see the layers. As the lower layers generally formed first, they are the oldest. Fossils within the rocks may allow some layers to be dated with accuracy. In other locations, clues may be sparse.



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