Block diagrams of three types of stratigraphic relations: <b>A</b>: an angular unconformity; <b>B</b>: a disconformity; <b>C</b>: a nonconformity.
<a href="//commons.wikimedia.org/wiki/User:Woudloper" title="User:Woudloper">Woudloper</a>
<span class="int-own-work" lang="en">Own work</span>