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TitleQuaternary stratigraphy and geology of the Rocky Mountain Foothills, southwestern Alberta
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AuthorJackson, L E, Jr.; Leboe, E R; Little, E C; Holme, P J; Hicock, S R; Shimamura, K; Nelson, F E N
SourceGeological Survey of Canada, Bulletin no. 583, 2008, 61 pages; 1 CD-ROM, https://doi.org/10.4095/224301
Year2008
PublisherNatural Resources Canada
Documentserial
Lang.English
MapsPublication contains 1 map
Map Info.surficial geology, glacial deposits and landforms, 1:250,000
MediaCD-ROM; digital; on-line
RelatedThis publication contains Jackson, L E, Jr.; Jackson, L E, Jr.; Jackson, L E, Jr.; Jackson, L E, Jr.; Jackson, L E, Jr.; Jackson, L E, Jr.; Jackson, L E, Jr.; Leboe, E R; Leboe, E R; Leboe, E R; Leboe, E R; Leboe, E R; Leboe, E R; Leboe, E R; Little, E C; Little, E C; Little, E C; Little, E C; Little, E C; Little, E C; Little, E C; Holme, P J; Holme, P J; Holme, P J; Holme, P J; Holme, P J; Holme, P J; Holme, P J; Hicock, S R; Hicock, S R; Hicock, S R; Hicock, S R; Hicock, S R; Hicock, S R; Hicock, S R; Shimamura, K; Shimamura, K; Shimamura, K; Shimamura, K; Shimamura, K; Shimamura, K; Shimamura, K; Nelson, F E N; Nelson, F E N; Nelson, F E N; Nelson, F E N; Nelson, F E N; Nelson, F E N; Nelson, F E N; (2008). Figure 5. Generalized surficial geology map of the Eastern Cordillera NATMAP study area, and digitally linked stratigraphic sections (e.g. H1) and correlated cross-sections (e.g
File formatreadme / lisez-moi
File formathtml; pdf (Adobe® Reader® v6.0 is included / est fourni); JPEG2000
ProvinceAlberta
NTS82G/01; 82G/08; 82G/09; 82G/16; 82H; 82J/01; 82J/08; 82J/09; 82J/16; 82O/01; 82O/08; 82O/09
AreaRocky Mountain Foothills; Livingstone Range; Lewis and Clark ranges; Interior Plains; Porcupine Hills; Calgary; Lethbridge; Banff
Lat/Long WENS-114.5000 -112.0000 51.7500 49.0000
Subjectssurficial geology/geomorphology; stratigraphy; glacial deposits; glacial features; glacial landforms; glacial history; Pleistocene; glaciofluvial deposits; glaciolacustrine deposits; eolian deposits; alluvial deposits; colluvial deposits; physiography; bedrock geology; sands; silts; clays; glaciation; postglacial deposits; postglacial evolution; ice retreat; chronostratigraphy; Quaternary; Cenozoic; Tertiary
Illustrationssketch maps; photographs; stratigraphic sections; ternary diagrams; tables; plots; cross-sections
Released2008 05 01
AbstractSurficial geology mapping at a scale of 1:50 000, cosmogenic dating, and detailed stratigraphic and sedimentological logging of 86 cliff-bank exposures and more than 3000 roadcuts and hand-driven auger borings have resolved the century-old controversy as to the number and timing of continental glaciations in the Rocky Mountain Foothills of southwestern Alberta.

The stratigraphy shows a consistent succession repeated throughout much of the area: one to several montane tills are always topped by either one continental till or a complex of continental tills, or a gravel unit containing Canadian Shield lithologies where a continental till has been eroded. Exceptions only occur along the Rocky Mountain Front, at the mouths of major valleys where no continental till is present.
There is no evidence of subaerial erosion or soil-forming processes that would represent long hiatuses between glacial advances responsible for continental till deposition. The same holds true for montane tills, with the exception of those found in the subsurface of Cloudy Ridge and the sediments capping Mokowan Butte. The drift units underlying paleosols at these two sites clearly predate the last interglaciation. The upper elevation limits of glacial erratics from the Canadian Shield and their abrupt western limit indicate that montane glaciers prevented penetration of continental glacial ice up major Rocky Mountain Foothills valleys, hence continental and montane glaciers coalesced during the culmination of the maximum continental ice advance.

Paleomagnetic sampling of the oldest tills infilling buried valley systems shows that all deposition occurred during the Brunhes chron (<0.78 Ma). Cosmogenic 36Cl exposure dating of the foothills erratics train and the former limits of the continental ice-sheet cover constrains the single continental glaciation to the Late Wisconsinan. The area was deglaciated by ca. 11 200 radiocarbon years before present.
GEOSCAN ID224301