Classic Concepts and New Directions: Exploring 125 Years of GSA Discoveries in the Rocky Mountain Region
The Rocky Mountain Region has been the subject of continuous, exhaustive scientific work since the first organized geologic trips to the area began in the 1860s. Despite almost 150 years of scrutiny, the region's magnificent geology continues to challenge, perplex, and astound modern geoscientists. It is a testing ground for geologists and for big geologic ideas. This volume, prepared for the 2013 GSA Annual Meeting in Denver, Colorado, serves both as a progress report on what we have learned over those years of study and a guide to forthcoming scientific questions about the region. The guide's fourteen chapters, which span the region's 1.7-billion-year history, give a retrospective glimpse of early geologic ideas being forged, bring the latest mapping and analytical results from classic locations, and introduce techniques that will form the bedrock of our geologic understanding in the years to come.
New views on late Paleozoic climate and tectonics in the Ancestral Rocky Mountains
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Published:January 01, 2013
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CiteCitation
Gerilyn S. Soreghan, Dustin E. Sweet, 2013. "New views on late Paleozoic climate and tectonics in the Ancestral Rocky Mountains", Classic Concepts and New Directions: Exploring 125 Years of GSA Discoveries in the Rocky Mountain Region, Lon D. Abbott, Gregory S. Hancock
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Abstract
Recent research in Pennsylvanian-Permian strata of the Fountain Formation adjacent to the Front Range uplift and the Cutler Formation adjacent to the Uncompahgre uplift (Colorado) has resulted in new hypotheses about the climate and tectonics of the Ancestral Rocky Mountains. The Fountain and the Cutler formations are iconic deposits; the thick and coarse-grained nature of these units has been cited for nearly a century as documenting the Ancestral Rockies. Long considered the products of alluvial fan deposition in warm climates, new data support the hypothesis of proglacial deposition for these units, and thus glaciation of the Ancestral Rocky highlands. This bears on our understanding of Late Paleozoic climate in western equatorial Pangaea, as well as global climate at this time. Furthermore, new mapping in the Uncompahgre region indicates substantial onlap and possible burial of Precambrian highlands by Permian strata. The argument for Permian subsidence of the uplift emanates from the hypothesis that Unaweep Canyon, which bisects the Uncompahgre Plateau (paleo Uncompahgre uplift) originated as a Permian paleolandscape. This trip will include visits to (1) the Fountain and Cutler formations to discuss and debate the sedimentologic origin(s) of these deposits, and (2) Unaweep Canyon to examine evidence for both a possible Paleozoic age and glacial origin for this canyon, and its late Cenozoic history as a former stream course of the ancestral Gunnison River.
- alluvial fans
- canyons
- climate
- Colorado
- Cutler Formation
- depositional environment
- facies
- field trips
- Fountain Formation
- Front Range
- glacial features
- glacial sedimentation
- glaciation
- guidebook
- Gunnison River
- North America
- paleogeography
- paleorelief
- Paleozoic
- Pangaea
- Permian
- road log
- Rocky Mountains
- sedimentation
- stratigraphy
- subsidence
- tectonics
- tectonostratigraphic units
- Uncompahgre Uplift
- United States
- uplifts
- upper Paleozoic
- Unaweep Canyon