Late Paleozoic Mountain Building
Alleghenian (Appalachian) Orogeny (Hercynian Orogeny in W. Europe)
Final Collision of Euramerica with Gondwanaland (N. America/Europe/Africa)
Provinces of the Appalachians (from East to West)
Coastal Plain (cover sediment of younger age)
Piedmont-metamorphic rocks near suture zone
Blue Ridge-Proterozoic Basement Rocks of the Grenville orogeny thrust westward
Valley and Ridge (fold and thrust belt) sedimentary passive margin sedimentary rocks
that have been folded as a result of the collision
Plateaus (Allegheny, Cumberland, etc), uplifted sedimentary rocks
Ouchita Orogeny
“Thin-skinned” tectonics (no basement involvment) Continuation to the south and west
of the Appalachians in OK/AR/TX. Fold and thrust belt of Paleozoic deep water rocks thrust
northward onto the N.American Craton. Flysch deposits show amazing sedimentary structures
(graded beds-turbidites, and sole marks)
Vertical (“thick-skinned”) block uplifts in the western US created the Ancestral Rockies (eroded
away and the sedimentary wedge is all that is left) due to compressio from E, W, and S.
Modern Rockies are in similar location, “flatirons” along the front range are formed from the
Fountain Fm. (Arkosic Sandstone) which were then later tilted during the formation of the
“modern” Rocky Mountains.
Block uplifts are the basement rocks on which the Capitan Limestone (Permian Reefs) of the SW
grew.
Sonoma Orogeny
continuation of the Antler Orogeny along the western margin of N.America. Continued
closing of the volcanic arc with the craton, thrusting marine sediments onto the craton. Result is
westward growth and extension of the continental margin.