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TitleRegional Cenozoic stratigraphic correlations on the passive margin of the North Atlantic: Comparison between Orphan Basin and the Labrador Margin
AuthorDafoe, L T; Dickie, K D; Williams, G L; Keen, C E
SourceThe Atlantic Geoscience Society (AGS), Program with Abstracts; 2017 p. 24-25
Alt SeriesNatural Resources Canada, Contribution Series 20170242
PublisherAtlantic Geoscience Society
MeetingThe Atlantic Geoscience Society (AGS), 43rd Colloquium and Annual Meeting; Fredericton; CA; February 10-11, 2017
Mediapaper; on-line; digital
File formatpdf
ProvinceEastern offshore region
AreaLabrador Sea
Subjectsstructural geology; biostratigraphy; basins; ODP 645 well; Labrador Shelf; Orphan Basin; Gudrid Formation; Kenamu Formation; Saglek Formation; Cretaceous; Cenozoic; Tertiary
ProgramBaffin Petroleum Systems, GEM2: Geo-mapping for Energy and Minerals
LinksOnline - En ligne
AbstractThe extensive passive margin of offshore eastern Newfoundland and Labrador developed during rifting and opening of the North Atlantic Ocean. Rift grabens are typically filled with sediments that exhibit growth against the controlling faults 25 and are draped by late-rift and/or post-rift units. New age constraints from palynological analyses of Labrador Shelf and Orphan Basin wells, combined with paleoenvironmental and seismic interpretations, have allowed us to make regional stratigraphic correlations in the latest Cretaceous and Cenozoic sections. The Base Tertiary horizon of Orphan Basin is a regional seismic marker of late Maastrichtian-Danian age, and a similar-aged maximum flooding surface is observed in a condensed late Maastrichtian section in offshore Labrador. The Gudrid Formation on the Labrador Shelf represents shingled, Paleocene to basal Ypresian forced regressive lobes. A similar shingled package can be recognized along the northern rim of Orphan Basin, where related distal sediments are preserved in Hare Bay E-21. In the middle Eocene of offshore Labrador, the Leif Member of the Kenamu Formation forms a thin sheet of sandstone -- a tertiary play for that area. This unit correlates in age to a well-developed shelf-edge delta in Orphan Basin related to a significant regression. Another major regression is documented in offshore Labrador in the lowermost clinoform of the Saglek Formation. New palynological constraints put the age of the base of this unit in the late Rupelian, which correlates with another major shelf-edge delta in Orphan Basin. It is unclear whether the younger Miocene Saglek clinoform of the Labrador margin has a correlative unit in Orphan Basin. However, a major regression is well constrained in Orphan Basin around the Miocene-Pliocene boundary. This section is well preserved in the basin, but was removed across much of the Labrador margin during the Laurentide Glaciation. These correlations show that global sea-level fluctuations are one of the main influences on sedimentation across the two margins, resulting in regional transgressive and regressive events. Local variation related to elevated continental basement blocks, proximity to fluvial discharge, and glacial lowstand erosion, result in stratigraphic variation across the margin; although, key surfaces and packages are similar. Correlations between basins along this vast margin reveal a common geologic evolution in the latest Cretaceous and Cenozoic. This model will extend north into Baffin Bay, where shelf-building packages can be recognized and Neogene stratigraphic intervals are constrained by the ODP 645 well.
Summary(Plain Language Summary, not published)
Basins offshore of Newfoundland and Labrador share a similar formation history as the North Atlantic Ocean and subsequent Labrador Sea opened. The early stage of this process resulted in faulting and the development of graben structures that allowed for nonmarine and shallow marine sediments to accumulate. However, as rifting moved offshore the latest Cretaceous and Cenozoic sections are primarily influenced by global sealevel fluctuations. Here we show that regional correlations can be drawn during this time frame between the Orphan Basin to the south and Labrador margin to the north.