| Title | Cretaceous strata at the west edge of the Canadian Rocky Mountains - a piggyback basin remnant of the western Canada foreland basin |
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| Author | McMechan, M E ;
Currie, L D; Matthews, W A; Sweet, A R; Reyes, J |
| Source | Geological Society of America Bulletin vol. 130, no. 7-8, 2018 p. 1216-1230, https://doi.org/10.1130/B31821.1 |
| Image |  |
| Year | 2018 |
| Alt Series | Earth Sciences Sector, Contribution Series 20160405 |
| Publisher | Geological Society of America |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf (Adobe® Reader®); html |
| Province | British Columbia; Alberta |
| NTS | 82F/01; 82F/02; 82F/07; 82F/08; 82F/09; 82F/10; 82F/15; 82F/16; 82G/03; 82G/04; 82G/05; 82G/06; 82G/11; 82G/12; 82G/13; 82G/14; 82J/03; 82J/04; 82J/05; 82J/06; 82J/11; 82J/12; 82J/13; 82J/14; 82K/01; 82K/02;
82K/07; 82K/08; 82K/09; 82K/10; 82K/15; 82K/16; 82N/01; 82N/02; 82N/07; 82N/08; 82O/03; 82O/04; 82O/05; 82O/06 |
| Area | Rocky Mountains; Main Ranges; Front Ranges; Rocky Mountain Foothills |
| Lat/Long WENS | -117.0000 -114.0000 51.5000 49.0000 |
| Subjects | stratigraphy; geochronology; tectonics; fossil fuels; geochemistry; paleontology; sedimentary basins; tectonic setting; faulting; crustal uplift; burial history; intrusions; stocks; depositional
history; thermal history; detrital minerals; zircon; provenance; radiometric dating; uranium lead dating; zircon dates; bedrock geology; structural features; faults; faults, thrust; folds; anticlinoria; bedrock geology; lithology; sedimentary rocks;
mudstones; clastics; limestones; conglomerates; siltstones; carbonates; sandstones; cherts; dolostones; shales; bedding planes; depositional environment; petroleum resources; hydrocarbons; hydrocarbon potential; coal; mineral occurrences;
stratigraphic correlations; palynology; vitrinite reflectance; modelling; stratigraphic analyses; Canadian Cordillera; Western Canada Foreland Basin; Porcupine Creek Anticlinorium; Purcell Anticlinorium; Kootenay Arc; Redwall Fault; Blairmore Group;
Beaverfoot Formation; Tegart Formation; McKay Group; Jubilee Formation; Horsethief Creek Group; Simpson Pass Thrust Fault; Bourgeau Thrust Fault; Rocky Mountain Fold-and-thrust Belt; Lussier River Stock; Mount Haley Stock; Hall Lake Thrust Fault;
Lewis Thrust Fault; Lussier River Thrust Fault; McConnell Thrust Fault; Mount Forester Thrust Fault; Moyie Thrust Fault; Rundle Thrust Fault; Sulfur Mountain Thrust Fault; Cedared Formation; Burnais Formation; Harrogate Formation; Glenogle Formation;
Beaver Mines Formation; Gladstone Formation; Cadomin Formation; Kootenay Group; Whitehorse Formation; Sulphur Mountain Formation; Spray Lakes Group; Etherington Formation; Sassenach Formation; Yahatinda Formation; Mount Wilson Formation; Hamill
Group; Purcell Supergroup; geological contacts; Phanerozoic; Mesozoic; Cretaceous; Jurassic; Triassic; Paleozoic; Permian; Carboniferous; Devonian; Silurian; Ordovician; Cambrian; Precambrian; Proterozoic |
| Illustrations | location maps; geoscientific sketch maps; correlation charts; lithologic sections; photographs; photomicrographs; schematic sections; histograms; geochronological charts; plots; schematic
cross-sections |
| Program | Geoscience for New Energy Supply (GNES) Shale-hosted petroleum resource assessment |
| Released | 2018 02 21 |
| Abstract | Outliers of Cretaceous strata at the west edge of the Canadian Rocky Mountains, deposited 110 km west of the Western Canada foreland basin foredeep, provide the first direct evidence of a piggyback
basin in the Canadian Cordillera and impart new insights on the stratigraphy, U-Pb detrital zircon provenance, burial history, and tectonic setting of this area. Three successions are preserved in down-dropped, fault-bounded slices along the Redwall
fault: late Middle Albian to Upper Albian Blairmore Group mixed clastics and minor limestone deposited in floodplain and swamp environments; unnamed Cenomanian mixed clastic floodplain deposits; and an unnamed alluvial/fluvial conglomeratic unit
dominated by proximal eastern-sourced pebble to cobble conglomerate of probable Coniacian to Santonian age. All units are in the oil window. Estimated maximum temperatures for Cenomanian strata are 115-135 °C. U-Pb detrital zircon ages indicate that
Upper Cretaceous units were primarily recycled from Mesozoic and Upper Paleozoic strata with minimal input from both older sedimentary and western sources. Blairmore strata overlapped an eroded Upper Jurassic-Lower Cretaceous orogenic wedge and
appear to have been contiguous with the foredeep succession. Upper Cretaceous conglomerates were derived from highlands to the east formed by uplift along thrust faults. These sediments were deposited in a piggyback basin on the hinterland side of
the Simpson Pass and Bourgeau thrusts and were carried >70 km toward the foreland while being buried by an additional 4-5 km of sediment. The presence of this piggyback basin indicates a very low taper wedge with an extremely weak basal detachment.
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| Summary | (Plain Language Summary, not published)
Unique Cretaceous exposures at the western edge of the southern Canadian Rocky Mountains provide new insights on the evolution of the Western Canada
Foreland Basin. These middle and upper Cretaceous strata are in the oil window. The youngest preserved deposits are derived from uplifted thrust sheets to the east and deposited in a piggyback basin that was latter carried some 70 km further to the
east. Their presence indicates the Rocky Mountains had a very low angled upper slope at the end of thrust fault deformation some 50 million years ago. |
| GEOSCAN ID | 299826 |
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