(2) folded structure Explanation: In geology, a nappe or thrust sheet is a large sheet like body of rock that has been moved more than 2 km or 5 km from its original position by faulting or folding. They 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 largescale recumbent folds, shearing along the fault plane.