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TitleA clinoform trajectory model for Late Cretaceous and Cenozoic sedimentation on the Labrador-Baffin Island margins
AuthorDafoe, L T; Dickie, K; Williams, G L
SourceConjugate Margins Conference, abstracts volume; 2018 p. 74
Alt SeriesNatural Resources Canada, Contribution Series 20180096
PublisherAtlantic Geology
Meeting2018 Conjugate Margins Conference; Halifax, NS; CA; August 19-22, 2018
Mediapaper; digital
File formatpdf
ProvinceNewfoundland and Labrador; Nunavut; Northern offshore region
NTS13; 14; 15; 16; 27
AreaLabrador; Baffin Island; Labrador Sea; Davis Strait
Lat/Long WENS -72.0000 -56.0000 72.0000 55.0000
Subjectsstratigraphy; paleontology; tectonics; models; tectonic history; sea floor spreading; rifting; depositional history; continental margins; continental shelf; geophysical surveys; seismic surveys, marine; seismic reflection surveys; seismic interpretations; paleoenvironment; biostratigraphy; basin geometry; sea level changes; Pleistocene; Neogene; Paleogene; Upper Cretaceous; Maastrichtian; deltaic sediments; fans; Labrador-Baffin Seaway; North American Plate; Labrador Margin; clinoforms; shelf-breaks; Phanerozoic; Cenozoic; Quaternary; Tertiary; Mesozoic; Cretaceous
ProgramBaffin Petroleum Systems, GEM2: Geo-mapping for Energy and Minerals
Released2018 08 01
AbstractThe Labrador-Baffin Seaway formed when Greenland pulled away from the North American Plate in the Early Cretaceous, with earliest seafloor spreading commencing in the Maastrichtian and ending by latest Eocene time. As a result of this shared rift history, integration of well and seismic information on the Labrador Margin can help elucidate stratigraphic trends for the broader frontier region. We present a Late Cretaceous through Cenozoic clinoform trajectory model for this margin that highlights major regressive/transgressive events.
Paleoenvironmental and biostratigraphic analyses are combined with seismic interpretation to identify shoreline clinoforms and shelf-edge breaks. The clinoforms display a variety of morphologies including: high-angle offlapping lobes; long wavelength, low-angle lobes; and complex aggradational clinoforms. The Late Cretaceous transgression is characterized by two backstepping shoreline clinoforms with maximum flooding reached in the Maastrichtian. A major Selandian to basal Eocene regression forces the shoreline basinward forming two distinct progradational units. Relative sea level rises with an early Eocene transgression forming a Ypresian-aged clinoform near the basin margin, which is further onlapped as the shoreline is pushed landward beyond the limitations of the data. Slow progradation and aggradation ensues, but is punctuated by a regression in the Bartonian forming low-angle, progradational shoreline clinoforms, a shelf-edge break, and distal fan deposits. The Bartonian shoreline is transgressed and overlain by a thick late Eocene to early Oligocene aggradational and progradational package interrupted by minor flooding events. The base of the Chattian is coincident with another major regression and development of an aggradational, "shelf-edge delta"-type clinoform comprised of two stacked lobes and a related fan deposit. Transgression in the early Miocene caps this clinoform, and is followed by a mid-Miocene regression producing another aggradational clinoform and related fan deposits. Plio-Pleistocene cooling and concomitant drop in global sea level forces the shoreline far seaward to form the current day shelf edge.
Our model helps to refine the stratigraphy of the Labrador Margin, but can also be linked to offshore studies in Baffin Bay where sampling is more limited, as well as onshore sections of the adjacent Bylot Island (Canada) that preserve proximal equivalents.
Summary(Plain Language Summary, not published)
Basins offshore of Labrador formed during rifting between North America and Greenland, which eventually formed the Labrador Sea. The early stage of this process resulted in faulting and the accumulation of sediments in isolated geological structures. However, later in the process, during the Late Cretaceous and Cenozoic global sea level fluctuations played a large role in the location of the shoreline and related sandstone accumulations. We map the presence of shoreline clinoform breaks and shelf-edge breaks through time and relate these features major regression-transgression cycles forming the sedimentary wedge along the margin.