Two mappings of a folded thrust fault in the Appalachian Valley and Ridge, 100 years apart

The curving black lines in the 1924 map are the Pulaski Thrust, which correctly encloses a narrow sliver of Cambrian rock (peach) between two extensive Devonian (dark green) outcrop fields (south of “Creek” in the Beaverdam Creek label and the 45 dip measurement). The cross sections below compare the 1924 interpretation (line of section is the straight black line in the 1924 map) with my 2021 interpretation, with colors adjusted to match. New mapping is spatially much better; the 1924 map cannot be draped onto an existing surface map with decent accuracy.