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TitleThe record of orogenic cyclicity in the Alberta Foreland Basin, Canadian Cordillera
AuthorQuinn, G; Hubbard, S M; van Drecht, R; Guest, B; Matthews, W; Hadlari, T
SourceLithosphere vol. 8, no. 3, 2016 p. 317-332,
Alt SeriesEarth Sciences Sector, Contribution Series 20160054
Mediapaper; on-line; digital
File formatpdf
NTS83E/06; 83E/07; 83E/11; 83E/10
AreaGrand Cache
Lat/Long WENS-119.1667 -118.8333 54.1167 53.8333
Subjectsstratigraphy; geochronology; zircon; uranium lead dates; tectonostratigraphic zones; Alberta foreland basin; Cordilleran orogeny; Rocky Mountain foothills; Jurassic; Cretaceous
Illustrationsstratigraphic correlations; stratigraphic columns; location maps; geological sketch maps; plots; diagrams
ProgramShale-hosted petroleum ressource assesment, Geoscience for New Energy Supply (GNES)
AbstractJurassic-Cretaceous sedimentary rocks of the Alberta Foreland Basin are a key record of the evolution of the Canadian Cordillera. A recent model for cyclical development of Cordilleran orogenic systems is tested using detrital zircon analysis for the major sandstone units deposited between 145 and 80 Ma exposed in the Rocky Mountain Foothills near Grande Cache, Alberta. The basin history is well constrained by decades of study and the stratigraphy has been previously subdivided into tectonostratigraphic wedges. U-Pb data from fourteen detrital zircon samples are included in this study. All the major magmatic provinces of North America are represented in each sample with the relative proportions varying between samples. The samples are assigned to five groups with the aid of Multidimensional Scaling. Groups 1-3 are interpreted to record recycling from specific units of passive margin strata of western North America with varying input form the Cordilleran magmatic arc. Group 4 is interpreted to record recycling from sedimentary strata in the United States and dispersal by basin-axial fluvial systems. Group 5 is dominated by Mesozoic zircon grains interpreted to have originated in the Cordilleran magmatic arc. Detrital zircon age spectra do not group based on the tectonostratigraphic wedges from which they were sampled; rather, within each tectonostratigraphic wedge, they exhibit evolution from diverse age spectra to a less diverse distribution of detrital zircon ages. A proxy for magmatic flux of the Cordilleran magmatic arc is constructed using detrital zircon ages younger than 200 Ma; it shows three modes at ~165, 115, and 74 Ma. These ages are considered high-flux episodes of magmatism that are linked by cyclical uplift and plateau formation in the orogen. This cyclical process is interpreted to: 1) control sedimentation rates in the foreland; 2) account for evolving provenance by altering catchments, and; 3) be a plausible mechanism for the deposition of the tectonostratigraphic wedges in the Alberta Foreland Basin.
Summary(Plain Language Summary, not published)
This contribution enhances our understanding of the tectonics and therefore driving mechanisms for the formation of the Western Canada Sedimentary Basin. This provides context for Jurassic and Cretaceous strata and explores why the basin subsided and was starved during deposition of shale reservoir rocks.