| Title | Deglacial and postglacial paleoseismological archives in mass movement deposits of lakes of south-central Quebec |
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| Author | Trottier, A -P; Lajeunesse, P; Normandeau, A ; Gagnon-Poire, A |
| Source | Canadian Journal of Earth Sciences vol. 56, no. 1, 2018 p. 60-76, https://doi.org/10.1139/cjes-2018-0167  Open Access |
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| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20180268 |
| Publisher | Canadian Science Publishing |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html |
| Province | Quebec |
| NTS | 21L/13; 31I/06; 31I/16 |
| Area | Lac Maskinongé; Lac Aux-Sables; Lac St-Joseph |
| Lat/Long WENS | -73.5000 -71.5000 47.0000 46.2500 |
| Subjects | surficial geology/geomorphology; geophysics; stratigraphy; sedimentology; seismology; earthquakes; epicentres; landslides; landslide deposits; seismicity; seismic zones; seismic risk; earthquake risk;
surface waters; lakes; bathymetry; geophysical surveys; acoustic surveys; lake sediment cores; geological history; tectonic history; glacial history; deglaciation; depositional history; isostatic rebound; gullies; hummocks; isotopic studies; lead;
cesium; Western Quebec Seismic Zone; Charlevoix--Kamouraska Seismic Zone; Champlain Sea; submergence, marine; lacustrine sediments; Phanerozoic; Cenozoic; Quaternary |
| Illustrations | geoscientific sketch maps; location maps; tables; geophysical images; profiles; 3-D images |
| Program | GSC Atlantic Division |
| Released | 2018 09 14 |
| Abstract | Investigation of seismic activity in eastern Canada is important for natural hazard management as two major active seismic zones with many historical records are located in the region: the Western
Québec seismic zone (WQSZ) and the Charlevoix-Kamouraska seismic zone (CKSZ), with the latter being the most active in northeastern America. This paper describes and analyses a dataset of high-resolution swath bathymetric imagery, sub-bottom
profiles, and sediments cores collected in three lakes (Maskinongé, Aux-Sables, and St-Joseph) located between two active seismic zones. The geomorphology observed on high-resolution swath bathymetric imagery, the acoustic sub-bottom profiles, and
the sediment analysis indicate that the lakes were disturbed by three phases of seismically induced mass movements since deglaciation: (i) during the deglacial Champlain Sea transgression and the rapid initial glacio-isostatic rebound between ~13 and
10.5 ka cal BP; (ii) around 1180 AD; and (iii) the well-documented CKSZ 1663 AD M >7 historical earthquake. The second phase of earthquake events (1180 AD) corresponds chronologically to a previously documented large landslide in western Québec,
dated at ~1020 years BP. This earthquake is responsible for remobilizing the largest volume of sediments in the entire stratigraphic sequence of Lake Maskinongé, the westernmost lake. This earthquake was not recorded in Lake Aux-Sables and St-Joseph,
which are located eastward from Maskinongé, but the largest mass movement deposits are associated with the well-known 1663 AD event of eastern Québec. Therefore, both earthquake events are interpreted to have different epicenters and the lakes of
southeastern Québec recorded earthquakes from both seismic zones. |
| Summary | (Plain Language Summary, not published)
We have identified mass movement deposits in lakes of south-central Québec that were triggered by earthquakes. The recurrence of earthquakes during the
last 10 000 years was assessed. |
| GEOSCAN ID | 313028 |
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