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TitleDetrital zircon geochronology and the evolution of clastic source areas, Liard Basin, Northeast British Columbia
AuthorMcMechan, M; Currie, L; Matthews, W; Ferri, F; Guest, B
SourceGeoConvention 2015: new horizons, abstract; 2015 p. 1-4
Alt SeriesEarth Sciences Sector, Contribution Series 20140566
MeetingGeoconvention 2015: new horizons; Calgary; CA; May 4-8, 2015
Lang.English; French
Mediapaper; on-line; digital
File formatpdf
ProvinceBritish Columbia
Lat/Long WENS-121.0000 -120.0000 60.0000 59.0000
ProgramShale Reservoir Characterization, Geoscience for New Energy Supply (GNES)
AbstractLaser ablation mass spectrometry U-Pb detrital zircon age distributions for Lower Cambrian to Cretaceous (Cenomanian) samples from the Liard Basin show how their source areas evolved with time. Samples from Cambrian quartzites are dominated by detrital zircon ages of ca.1500-3000 Ma and are consistent with derivation from Laurentian basement rocks. A minor component of ca. 620-680 Ma detrital zircon found in Middle Cambrian graben-fill sediments suggests some west-derived material reached the basin at that time. Mississippian-Pennsylvanian sandstones have detrital zircon ages from ca. 350-3000 Ma with relatively few grains between ca. 500-900 Ma and ca.1900-2500 Ma. The abundance of ages around 450 Ma and 1000-1800 Ma indicate input from a new source area or areas. Not surprisingly the Permian sandstone detrital signatures are similar to those of the underlying Mississippian-Pennsylvanian sandstones. Uppermost Albian sandstones known to be west-derived, based on thickness and facies relationships, contain remarkably few detrital zircon grains young enough to be first-cycle detritus from the west. This suggests the bulk of the zircons in these samples have been recycled. Cenomanian sandstone and conglomerate is dominated by Cretaceous detrital zircons sourced from the Cordillera to the west.
Summary(Plain Language Summary, not published)
The Liard Basin is a sub-basin of the Western Canada Sedimentary Basin that is characterized by very thick Upper Paleozoic and mid-Cretaceous strata. The basin contains significant unconventional resources in Upper Paleozoic and possibly mid-Cretaceous shale units. New U-Pb detrital zircon ages from Lower Cambrian to Cretaceous (Cenomanian) sandy units in the BC part of the Liard Basin show how the source areas for the basin evolved over time.