Window (geology)
From Wikipedia, the free encyclopedia

A tectonic window is a geologic structure formed by erosion or normal faulting on a thrust system. In such a system the hanging wall block is called a nappe. When erosion or normal faulting produces a hole in the nappe where the underlying autochthonous rocks crop out this is called a window.
Windows can be almost any size, from a couple of meters to hundreds of kilometers.