Title | Quaternary stratigraphy and glacial history at Peace River, Alberta |
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Author | Paulen, R ;
Beaudoin, A ; Ross, M ; Botterill, S |
Source | GAC®-MAC 2021, London, Canada: Exploring Geosciences Through Time and Space/GAC®-MAC 2021, London, Canada : Explorer les géosciences à travers le temps et l'espace; Geological Association of
Canada-Mineralogical Association of Canada, Joint Annual Meeting, Abstracts Volume vol. 44, 2021 p. 245
Open Access |
Links | Online - En ligne (complete
volume - volume complet, PDF, 2.45 MB)
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Image |  |
Year | 2021 |
Alt Series | Natural Resources Canada, Contribution Series 20210236 |
Publisher | Geological Association of Canada |
Meeting | Geological Association of Canada-Mineralogical Association of Canada Joint Annual Meeting 2021; London, ON; CA; November 1-5, 2021 |
Document | serial |
Lang. | English |
Media | digital; on-line |
File format | pdf |
Province | Alberta |
NTS | 84C |
Area | Peace River |
Lat/Long WENS | -118.0000 -116.0000 57.0000 56.0000 |
Subjects | surficial geology/geomorphology; stratigraphy; geochronology; Nature and Environment; Science and Technology; glacial history; glaciation; Wisconsinian glacial stage; ice flow; sediment transport;
sediment dispersal; landslides; sedimentation; bedrock geology; lithology; sedimentary rocks; shales; radiometric dating; radiocarbon dating; sediments; glacial deposits; tills; loess; paleosols; fossils; fossil plants; Laurentide Ice Sheet; Canadian
Shield; Molluscs; Shaftesbury Formation; ice-flow directions; glaciofluvial sediments; alluvial sediments; Phanerozoic; Cenozoic; Quaternary; Mesozoic; Cretaceous; Precambrian |
Program | GEM-GeoNorth: Geo-mapping for Energy and Minerals Central Arctic Research Priority Area - Central Arctic Activity 1 |
Released | 2021 11 01 |
Abstract | The Quaternary stratigraphy documented in Alberta's Peace River lowlands has been subject to many conflicting interpretations. This is probably due to the lack of a complete stratigraphic sequence
preserved at a single section because of extensive landsliding along the Peace River valley, as well as a lack of chronologic control for lower parts of the sequence. There is ongoing debate over the number and style of Laurentide glacial advances in
the Peace River district of western Alberta and eastern British Columbia. Given its northern Alberta location, resolving the glacial record of this area has important implications for understanding the evolution of the Laurentide Ice Sheet. The
valley-fill sediments located at the confluence of the Heart and Peace rivers, at the town of Peace River, Alberta, provide perhaps the best record in western Canada of a continuum of Quaternary sedimentation from the preglacial bedrock surface to
present. The composite stratigraphy of the Peace River valley (Fig. 1), which is 187 m thick, records the transition from preglacial fluvial sedimentation (unit 1), to a penultimate proglacial sedimentary sequence (units 2 and 3) conformably overlain
by interstadial fluvial sediments (unit 4) of possible MIS-3 age, or older (based on radiocarbon). In turn, these are overlain by a Late Wisconsin ice advance/retreat cycle of sedimentation from the Laurentide Ice Sheet (units 5-8). The sequence is
capped with Holocene cliff-top loess with paleosols, yielding mollusc and plant macrofossils. The only till unit in the stratigraphy (Unit 7) is from the Late Wisconsin glacial advance. The Canadian Shield lithologies in the lower fluvial sediments
are from westward draining catchments, derived from the Buffalo Head Hills, where multiple, older glacial sediments have been documented. Consequently, there is evidence for only a single Laurentide glaciation in the eastern Peace River district,
similar to what is defined to the southwest in other exposures on the Smoky River. Figure 1. Composite stratigraphy at the confluence of the Heart and Peace rivers. The Quaternary sediments overlie Early Cretaceous (Albian) Shaftesbury Formation
shale, and consist of nine major units, approximately 187 m thick. |
Summary | (Plain Language Summary, not published) Summary of the glacial event stratigraphy for the northwestern sector of the Laurentide Ice Sheet, in one of the largest preglacial valleys in northwest
Canada. The sedimentary units exposed there have rarely been documented in their entirety. This is important for constraining older ice sheet models. |
GEOSCAN ID | 328876 |
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