Taconic Unconformity

Outcrop of angular anconformity in the New York appalachians. The unconformity separates Ordovician strata from Siluro-Devonian strata, and formed during the Ordovician Taconic orogeny (approximately 475 million years ago). The unconformity itself was tilted (deformed) during the Devonian Acadian orogeny. Image from website: http://www.geo.cornell.edu/geology/classes/Geo101/101images_fall.html