Geometric framework; a certain family of lines must exist where thrust surfaces join along branch lines or end at tip lines. The order in which the fault slices form has a marked effect on the geometry of the thrust system. These systems must be identified to understand the provenance of the synorogenic sediments. Part of a thrust belt may be dominated by one particularly large thrust sheet. In front and beneath these dominant sheets, there is a characteristic sequence of thrust systems with a regular pattern to the involvement of basement. New insight into some classic areas Mountain City and Grandfather Mountain windows, in the Southern Appalachians, Jura to the Pennines (in the Western Alps).--Modified journal abstract.