The valley of Anaktuvuk Pass crosscuts the Brooks Range, Alaska, near longitude 152 degrees , exposing 6,300 feet of Upper Devonian non-marine clastics, 4,700 feet of Mississippian marine clastics, carbonates, and chert, and 400 feet of Permian marine clastics. Post-Paleozoic forces from the south produced overturned folds, and both deep-seated and shallow low angle thrusts. The oldest rock exposed, the Upper Devonian Hunt Fork Shale, is believed to be the base of a zone of regional decollement. The more shallow (Anaktuvuk) thrust displaces Mississippian and younger rocks northward at least eight miles. Stratigraphic units and structural features are discussed in detail; bibliography is pertinent and comprehensive.

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