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TitleQuaternary unconsolidated sediment thickness on the Grand Banks of Newfoundland and northeast Newfoundland Shelf; a GIS database
LicencePlease note the adoption of the Open Government Licence - Canada supersedes any previous licences.
AuthorKing, E L
SourceGeological Survey of Canada, Open File 7513, 2014, 44 pages (1 sheet), (Open Access)
PublisherNatural Resources Canada
Documentopen file
Maps1 map
Map Info.surficial geology, sediment thickness, 1:500,000
Mediadigital; on-line
File formatreadme
File formatpdf; shp; mxd; rtf
ProvinceEastern offshore region
AreaGrand Banks; Newfoundland Shelf; Orphan Basin; Placentia Bay; Trinity Trough; St. Anthony Basin; Green Bank; Avalon Channel
Lat/Long WENS-60.3333 -46.0000 52.0000 43.0000
Subjectssurficial geology/geomorphology; marine geology; glacial features; glacial deposits; glacial landforms; seafloor topography; seabottom topography; geophysical surveys; bathymetry; muds; sands; tills; boulders; debris flows; gas; bedforms; sediment distribution; sediment distribution; Cenozoic; Quaternary
Illustrationslocation maps; stratigraphic columns; tables
ProgramOffshore Geoscience, Geoscience East Coast
Released2014 12 17
AbstractThe thickness of Quaternary unconsolidated sediments (overburden) across the Grand Banks of Newfoundland and the Northeast Newfoundland shelf has been compiled and incorporated into a GIS-based geodatabase. It is derived from interpretation of a vast grid of high and mid-resolution seismic reflection profiles collected over about 40 years by the Geological Survey of Canada-Atlantic. This spatial database is in the form of spot thicknesses along survey tracks and thickness-classed zonation interpolated from these points. It comprises over 85 000 point thickness entries, each identifying the stratigraphic unit (or range in units) measured, a code linking to the raw data source, thickness in metres and milliseconds, notes on the source of interpretation and the process and positional accuracy, and generally the stratigraphic unit underlying the sediment at that position. Most records document only the total Quaternary thickness. A total Quaternary thickness zonation map (polygons/contours in six thickness classes) adds considerable interpretive value to the spot thickness measurements. Control for extrapolation and interpolation of the spot thicknesses came from bathymetric shaded relief images (mainly low resolution) where, for example, basins, valleys and ridges, near-seabed bedrock expression and other morphological elements helped provide spatial control for sediment thickness distribution. Till from the last glaciation is dominant volumetrically and locally stacked tills, presumably from older glaciations/statials are also identified. However the thickness database also includes a differentiation of eight separate sediment facies or stratigraphic units. These records are only compiled from select datasets where the appropriate raw data (generally ultra-high resolution profiles) were in a suitable format. This product complements other new map products from the area, both bedrock and surficial geological and a surface and sub-surface geo-features geodatabase.
Summary(Plain Language Summary, not published)
Glaciations across the Grand Banks and the Northeast Newfoundland Shelf left a varied cover of unconsolidated sediments overlying bedrock. These comprise glacial sediments and their shallow water wave and current reworked and sorted products. A database of 85000 spot sediment thickness postings and contoured map draws on new and existing interpretations from seismic reflection profiles. Most postings depict total thickness but also including eight sub-classes of sediment types (e.g. till, glacial mud, sand and gravel). While primarily a GIS product, it also includes a map in Adobe format. It is part of the upgrading and accessibility of geo-knowledge of Canada's offshore towards better resource and geohazard assessment. It complements surficial and bedrock geology maps of the area.