In
geology, a
nappe or
thrust sheet is a large sheetlike body of
rock that has been moved more than or above a
thrust fault from its original position. Nappes form in compressional tectonic settings like
continental collision zones or on the overriding plate in active
subduction zones. Nappes form when a mass of rock is forced (or
"thrust") over another rock mass, typically on a low angle fault plane. The resulting structure may include large-scale recumbent
folds, shearing along the fault plane, imbricate thrust stacks,
fensters and
klippe.