Onlap
Onlap or overlap is the geologic phenomenon of successively wedge shape younger rock strata extending progressively further across an erosion surface cut in older rocks. It is generally associated with a marine transgression. It is a more general term than overstep, in which the younger beds overlap onto successively older beds. The opposite is offlap.
This article is issued from Wikipedia - version of the Tuesday, July 14, 2015. The text is available under the Creative Commons Attribution/Share Alike but additional terms may apply for the media files.