Skip to Main Content
Skip Nav Destination
GEOREF RECORD

Syndepositional thrust-related deformation and sedimentation in an ancestral Rocky Mountains basin, Central Colorado Trough, Colorado, USA

Richard G. Hoy and Kenneth D. Ridgway
Syndepositional thrust-related deformation and sedimentation in an ancestral Rocky Mountains basin, Central Colorado Trough, Colorado, USA
Geological Society of America Bulletin (July 2002) 114 (7): 804-828

Abstract

Pennsylvanian-Permian synorogenic deposits (Minturn and Sangre de Cristo Formations) of the Central Colorado trough record an interplay of deformation and sedimentation in an Ancestral Rocky Mountains basin. The Central Colorado trough was a north-trending basin bordered by basement-involved highlands of the Uncompahgre uplift on the west and the Ancestral Front Range and Apishapa uplift on the east. Stratigraphic data show that the Central Colorado trough was an asymmetric basin in which coarse-grained sediments were deposited adjacent to the Sand Creek-Crestone thrust fault system of the Uncompahgre uplift. These deposits pinch out eastward against the Apishapa uplift along the eastern margin of the basin. Lithofacies analysis shows that the Central Colorado trough was filled by fan-delta, fluvial-delta, and turbidite deposits of the Middle Pennsylvanian Minturn Formation and by alluvial-fan, braided-stream, and meandering-stream deposits of the Upper Pennsylvanian-Permian Sangre de Cristo Formation. Geologic mapping has identified three syndepositional structures in the strata of the Central Colorado trough that indicate Pennsylvanian-Permian shortening: (1) the Gibson Peak growth syncline in the footwall of the Crestone thrust fault, which formed by syndepositional rotation of the Crestone Conglomerate Member of the Sangre de Cristo Formation during thrust displacement; (2) the Sand Creek thrust fault, which cuts the lower part of the Crestone Conglomerate Member but is covered by younger deposits of the Crestone Conglomerate Member; and (3) an intraformational angular unconformity in the Sangre de Cristo Formation that separates folded strata from overlying less deformed strata. All three structures indicate general east-west shortening during deposition. We interpret the Central Colorado trough as a flexural basin on the basis of syndepositional thrust-related structures, basin asymmetry, and lithofacies distribution. Displacement on the east-verging Sand Creek-Crestone thrust fault system appears to have controlled uplift of the central part of the Uncompahgre uplift and also subsidence in the adjacent basin. The Apishapa uplift, located along the eastern margin of the basin, is interpreted as a possible flexural forebulge related to crustal loading of thrust sheets along the western margin of the Central Colorado trough. Geologic mapping, subsurface data, and identification of syndepositional structures has also led to a better understanding of post-Paleozoic deformation of Pennsylvanian-Permian strata of the Central Colorado trough and the structural evolution of the present Sangre de Cristo Mountains.


ISSN: 0016-7606
EISSN: 1943-2674
Coden: BUGMAF
Serial Title: Geological Society of America Bulletin
Serial Volume: 114
Serial Issue: 7
Title: Syndepositional thrust-related deformation and sedimentation in an ancestral Rocky Mountains basin, Central Colorado Trough, Colorado, USA
Affiliation: Purdue University, Department of Earth and Atmospheric Sciences, West Lafayette, IN, United States
Pages: 804-828
Published: 200207
Text Language: English
Publisher: Geological Society of America (GSA), Boulder, CO, United States
References: 98
Accession Number: 2002-060659
Categories: Structural geologySedimentary petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. sects., geol. sketch maps
N37°45'00" - N38°15'00", W105°45'00" - W105°25'00"
Country of Publication: United States
Secondary Affiliation: GeoRef, Copyright 2019, American Geosciences Institute. Reference includes data supplied by the Geological Society of America, Boulder, CO, United States
Update Code: 200219
Close Modal

or Create an Account

Close Modal
Close Modal