Chapter 26.1, Problem 1CC

Summary Introduction

To determine: The oldest rock layer in the given photo.

Introduction: Sedimentary rocks are formed from particles of older rocks broken apart by water or wind. The particles may be in the form of gravel, sand or mud. These particles subsequently settle and bury living and dead organisms at the bottom of rivers, lake, and oceans. Eventually, the sediments at the bottom of the pile become rock. The lower layers are usually older than the upper layers in a sequence of layered rock.