Through the Generations

The tradition of Rocky Mountain geology remains strong at all scales, spatially and temporally. This volume fosters that tradition with its collection of peer-reviewed papers associated with the 2010 GSA Annual Meeting in Denver, Colorado. Spatially, this volume discusses theories of continental mountain building events in tandem with microscopic observations and parts per billion trace element concentrations. Temporally, the volume covers geologic history from the Precambrian to modern issues of climate change and energy, groundwater contamination, geologic hazards, and landscape evolution. Many of the trips propose new interpretations of famous geologic ideas and environs such as Laramide deformation, the Colorado Mineral Belt, the Lewis and Clark Line, the Chalk Cliffs, and Garden of the Gods.
Lewis and Clark Line, Montana: Tectonic evolution of a crustal-scale flower structure in the Rocky Mountains
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Published:January 01, 2010
Abstract
The Lewis and Clark line (LCL) is a major transverse structure that crosses the North American Cordillera from northeastern Washington to central Montana. It initiated as a rift structure within the Mesoproterozoic Belt basin and reactivated several times during the Phanerozoic. This field trip examines the internal structure of the LCL along a transect in central-western Montana. Structural plunge permits examination of a 25-km-thick crustal section of a flower structure that formed along the LCL during Late Cretaceous-late Paleocene sinistral transpression. We will observe changes in structural style from the deepest parts of the Belt Supergroup upward to the syntectonic depositional surface.
- Belt Supergroup
- Cenozoic
- Colorado
- continental crust
- Cretaceous
- crust
- faults
- field trips
- flower structures
- guidebook
- Lewis and Clark Lineament
- Mesoproterozoic
- Mesozoic
- Mineral County Montana
- Missoula County Montana
- Montana
- North America
- North American Cordillera
- outcrops
- Paleogene
- Precambrian
- Proterozoic
- reactivation
- rift zones
- road log
- Rocky Mountains
- shear zones
- structural analysis
- tectonics
- Tertiary
- transpression
- U. S. Rocky Mountains
- United States
- Upper Cretaceous
- upper Precambrian
- western Montana