Rotate block  Erode and deposit layers

This movie shows a history in which mountains are eroded to a low plain that is then covered by a succession of younger layers. The buried erosion surface, between the older tilted layers and the younger horizontal ones, is an unconformity.  An unconformity represents a long time interval between the deposition of layers.  Within this break in time, layers that were previously deposited can be tilted, folded, faulted, and/or intruded and then eroded.  After the tilting, folding, etc., new layers are deposited on top of this surface.  An unconformity can also be tilted after it is formed.  When in this movie does the unconformity form?

Unconformities Example