Layers of sedimentary rock, hardened from materials left by ancient seas and streams, create the park’s bedrock. The oldest rocks rest at the bottom, with successively younger layers on top. Between 410 and 286 million years old, the bedrock dates from the Paleozoic Era. CVNP's most common bedrock includes Bedford Shale, formed by sea deposits, and Berea Sandstone, probably created by slow-moving streams. They can be seen at Brandywine Falls, where the harder sandstone caps the waterfall. The highly textured Sharon Conglomerate, formed from sand and quartz pebbles carried here by ancient streams, crops out at the spectacular Ritchie Ledges.