Fold mountains
>>As I recall, those folds are thought by some to be related to the
Applachians. Do you know how they were dated?
Dating has been done w/seismic data corellated to oil wells drilled in the
area. The Late Permian Wolfcamp and Leonard Formations show exotic blocks of
Mississippian, Pensylvanian and earlier rocks. The postion of the exotics is
consistant with thrusting during the deposition of the Wolfcamp/Leonard. This
pretty well puts the initial tectonic activity in the late Permian in West
Texas. There are unaffected Triassic sediments to the north of the area, in
areas that show Pensylvanian/Permian tectonic activity, but this may have been
independent of the Marathon/Ouichita thrust belt.
Jim