| Title | A revised sea level history for the northern Strait of Georgia, British Columbia, Canada |
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| Author | Fedje, D; McLaren, D; James, T S ; Mackie, Q; Smith, N F; Southon, J R; Mackie, A P |
| Source | Quaternary Science Reviews vol. 192, 2018 p. 300-316, https://doi.org/10.1016/j.quascirev.2018.05.018  Open Access |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20180005 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf; html; docx |
| Province | British Columbia |
| NTS | 92K/03; 92K/06 |
| Area | Quadra Island; Read Island; Discovery Islands; Strait of Georgia; We Wai Kai First Nation; Wei Wai Kum First Nation; K'ómoks First Nation; Kwiakah First Nation; Klahoose First Nation; Xwemalkhwu First
Nation |
| Lat/Long WENS | -125.4167 -125.0000 50.3333 50.0000 |
| Subjects | marine geology; surficial geology/geomorphology; paleontology; geochronology; geophysics; History and Archaeology; tectonics; Nature and Environment; paleoenvironment; paleogeography; paleo-sea levels;
sea level changes; postglacial emergence; shoreline changes; raised beaches; beach ridges; terraces; isostatic rebound; marine sediments; lagoons; organic deposits; bogs; peat; gyttja; wetlands; marshes; clays; silts; sands; gravels; glacial history;
deglaciation; ice sheets; ice movement; climate; transgressions; regressions; geophysical surveys; organic materials; core samples; macrofossils; fossil plants; microfossils; diatoms; basins; radiometric dating; radiocarbon dating; surface waters;
lakes; disconformities; tectonic setting; seismicity; earthquakes; subsidence; slumps; tsunami; depositional environment; salinity; Younger Dryas; marine terraced sediments; Archaeological investigations; elevations; Global positioning systems;
Phanerozoic; Cenozoic; Quaternary |
| Illustrations | location maps; time series; photographs; photomicrographs; lithologic sections; bar graphs; profiles; graphs; geophysical images; schematic cross-sections; geoscientific sketch maps |
| Program | Climate Change Geoscience Coastal Infrastructure |
| Released | 2018 06 13 |
| Abstract | A refined relative sea level (RSL) history spanning the past 14,300 calendar years is described for the Quadra Island area in the northern Strait of Georgia on the Pacific coast of Canada. Here marine
shorelines dating to the time of earliest post-glacial emergence are at least 197m above present-day sea-level at 14,300 years ago. RSL fell rapidly, reaching two to three metres above present-day by 12,000 years ago. A series of raised marine
terraces at ca. 4, 10 and 30m above present day high tide level suggest the rapid fall in RSL during early post-glacial time may have been briefly interrupted by factors such as regional ice advances and recessions and global meltwater pulses
generated by climatic variations. A possible minor sea-level transgression of 1-2m around 12,000 to 11,400 years ago was followed by slow regression to modern levels. This sea-level reconstruction is providing critical input for efficient discovery
and cataloging of late Pleistocene and early Holocene archaeological sites on ancient raised shorelines in the region. Integration of the sea-level history with LiDAR imagery has proven successful in locating a number of archaeological sites on these
ancient shorelines. |
| Summary | (Plain Language Summary, not published)
Fieldwork was carried out to better define the history of sea-level on Quadra Island from the time that glaciers retreated from the area about 14,500
year ago to the present. The refined sea-level history documents a period of rapid sea-level fall, similar to previous work, followed by a possible still-stand and minor sea-level rise of 2 or 3 m around 11,500 years ago. The fluctuation in
sea-level may be related to variations in surface loading caused by glacier growth and decay in the southern Coast Mountain, or by fluctuations in global sea-level. The refined relative sea-level curve contributes to targeted archeological
investigations of early human habitation in the region. |
| GEOSCAN ID | 308116 |
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