GEOSCAN Search Results: Fastlink


TitleLate Quaternary deglaciation and sea-level history of eastern Juan de Fuca Strait, Cascadia
AuthorMosher, D C; Hewitt, A T
SourceQuaternary International vol. 121, 2004 p. 23-39,
LinksAbstract - Résumé
Alt SeriesGeological Survey of Canada, Contribution Series 2003052
PublisherElsevier BV
Mediapaper; on-line; digital
File formatpdf
ProvinceBritish Columbia; Western offshore region
NTS92B/02; 92B/03; 92B/04; 92B/05; 92B/06; 92B/07
AreaJuan de Fuca Strait; Cascadia; Washington State; Vancouver Island; Victoria; Discovery Island; Smith Island; Whidbey Island; Olympic Peninsula; Admiralty Inlet; Puget Sound; Haro Strait; Portage Inlet; Esquimalt Harbour; San Juan Island; Lopez Island; Rosario Strait; Port Angeles; Green Point; Race Rocks; Trial Island; Salmon Bank; Constance Bank; Middle Bank; Larson Bank; McArthur Bank; Hein Bank; Eastern Bank; Partridge Bank; Dungeness Spit; Dallas Bank; Ediz Hook; Canada; United States of America
Lat/Long WENS-123.7500 -122.5000 48.5000 48.0000
Subjectssurficial geology/geomorphology; geochronology; glacial history; deglaciation; sea level changes; sea level fluctuations; radiocarbon dating; seismic reflection surveys; bathymetry; seafloor topography; unconformities; Wisconsinan Glaciation; Cenozoic; Quaternary
Illustrationslocation maps; bathymetric maps; topographic maps; tables; digital images; seismic reflection profiles; bathymetric profiles; stratigraphic sections; graphs
AbstractEastern Juan de Fuca Strait of southwestern British Columbia/northwestern Washington State is near the western and southern terminus of Late Wisconsinan glaciation in North America. Seismic-reflection profiles, bathymetric data, sediment core data and 41 new radiocarbon dates provide insight into the history of ice retreat and sea-level change in the eastern portion of the strait. The retreating ice margin appears to have passed through the area between 14,460±200 and 13,595±145 14C yr. Glacial marine sediments date between 12,889±50 and 11,110±50 14C yr BP. Wave-eroded unconformities, drowned prograded deposits and a partially isolated low-stand basin are evidence attributed to low-stand sea levels following deglaciation and five new control points on the local eustatic sea level curve are assigned based on radiocarbon dating of these features. Sea-level change was rapid: from +75 m immediately after deglaciation to possibly ?60.4 m at 9920±60 14C yr BP. After this time, gradual sea level transgression took place. Relative sea level reached its approximate present position by 5470±115 14C yr BP. Since then, relative sea level has remained constant suggesting eustatic rise is balanced by crustal uplift.

Date modified: