| Title | Sub-bottom profiling and coring of sub-basins along the lower French River, Ontario: insights into depositional environments within the North Bay outlet |
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| Author | Brooks, G R ;
Medioli, B E |
| Source | Journal of Paleolimnology vol. 47, 2012 p. 447-467, https://doi.org/10.1007/s10933-010-9414-8 |
| Image |  |
| Year | 2012 |
| Alt Series | Earth Sciences Sector, Contribution Series 20080597 |
| Publisher | Springer Nature |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Province | Ontario |
| NTS | 31L/04; 31L/05; 31L/06; 41I/01; 41I/02 |
| Area | Lake Huron; French River; North Bay; Great Lakes; Georgian Bay |
| Lat/Long WENS | -81.2500 -79.0000 46.5000 45.7500 |
| Subjects | hydrogeology; environmental geology; Nature and Environment; Holocene; basins; basin analysis; lakes; bottom sediments; lake sediment thickness; lake sediments; lake sediment cores; lacustrine deposits;
lacustrine environments; hydrologic environment; Huron Basin; Georgian Basin; Climate change; Cenozoic |
| Illustrations | location maps; stratigraphic columns; tables; profiles; photographs |
| Program | Climate Change Geoscience
Paleoenvironmental Perspectives on Climate Change |
| Program | Enhancing resilience in a changing climate |
| Released | 2010 05 23 |
| Abstract | Sub-bottom profiling was conducted at eight sub-basins within the lower French River area, Ontario, to investigate deposits preserved within the ancient North Bay outlet. Ten cores were collected that
targeted the four depositional acoustic facies identified in the sub-bottom profiling records. The rhythmically laminated/bedded glaciolacustrine deposits of facies I are interpreted to have aggraded within glacial Lake Algonquin and its associated
recessional lakes that persisted between 13,000 and 11,300 cal BP (*11,100 and 9,900 BP). The majority of the facies II, III and IV lacustrine deposits accumulated between about 9,500 cal BP (*8,500 BP) and the mid-Holocene, based on radiocarbondated
organic materials. These deposits represent sedimentation within a 'large' lake during the late portion of the Mattawa-Stanley phase, and the Nipissing transgression, Nipissing Great Lakes and post-Nipissing recession phases of lake levels. Two sets
of organic-rich sand beds are preserved within facies II deposits and reveal that the large lake lacustrine depositional environment was interrupted during the late Mattawa-Stanley phase between 9,500 - 9,300 and 9,000 - 8,400 cal BP (*8,500 - 8,300
and *8,000 - 7,600 BP), when the water surface of Lake Hough fell below the outlet threshold and the lake basin became hydrologically closed. Pre- 9,500 cal BP (*8,500 BP), the early and middle portions of the Mattawa-Stanley phase were dominated by
erosion, as reflected by an unconformity at the base of facies II that occurs widely in the subbasins and the general lack of preserved deposits for these intervals in the cores. This erosion is attributed to wave action and fluvial scouring within
the outlet mouth during the early and mid-Stanley-Hough low stages and relates specifically to the period when the flowing portion of the North Bay outlet was situated over the lower French River area. This study reveals that the majority of the
post-glacial deposits accumulated after the outlet threshold had shifted permanently eastwards and the lower French River area was inundated under the multiple phases of the large lake occupying the Nipissing Lowlands and Georgian- Huron basins,
extending well into the mid-Holocene. The occurrence of deposits marking two closed-basin intervals during the late Stanley-Hough stage are well preserved locally within the lacustrine depositional sequence, but identifying earlier closed-basin
intervals from the French River stratigraphy is hindered by the lack of preserved pre-9,500 cal BP (*8,500 BP) post-glacial deposits. |
| GEOSCAN ID | 226282 |
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