TY - DATA T1 - The nappe rule: why does it work? PY - 2016/06/21 AU - Uwe Ring AU - Osama M.K. Kassem UR - https://geolsoc.figshare.com/articles/dataset/The_nappe_rule_why_does_it_work_/3454472 DO - 10.6084/m9.figshare.3454472.v1 L4 - https://ndownloader.figshare.com/files/5426042 L4 - https://ndownloader.figshare.com/files/5426045 KW - Italian Alps KW - Gran Paradiso Massif KW - nappe rule stresses KW - imbrication emplaces nappes KW - nappe rule KW - Geology N2 - The nappe rule stresses that imbrication emplaces nappes with higher metamorphic grade above those with lower grade. This means that the overriding nappes must be exhuming during nappe stacking; otherwise metamorphic grade would increase structurally downwards. The high-grade metamorphic internides of many orogens are characterized by a pervasive nappe-emplacement-related subhorizontal foliation indicative of vertical ductile shortening (thinning). By quantifying finite strain in the Gran Paradiso Massif, Italian Alps, we show that vertical ductile thinning associated with a nappe-emplacement-related subhorizontal foliation caused sufficient exhumation of the overriding nappes and can thus explain the occurrence of higher-grade rocks above lower-grade ones. ER -