Regional correlation of Mesozoic-Palaeogene successions in the Canadian-Greenland shelf areas

Data from the Canadian offshore wells have provided important new information, leading to refinement and improving previous interpretations of the Cretaceous and Palaeogene successions in West Greenland. The new data from the 1500m thick continuous Lower Campanian to Upper Maastrichtian and lowermost Palaeogene marine succession In Skolp E-07 has provided us with new information to reevaluate the dating of the youngest Cretaceous succession of Ikermiut-1 and Qulleq-1 that both seems to be of Early Campanian age, suggesting a hiatus related to uplift during the Upper Campanian and Maastrichtian. This event has been recorded in large parts of the areas offshore West Greenland. but has not been seen onshore Nuussuaq, West Greenland and on parts of the Labrador Shelf where the Maastrichtian to Upper Campanian succession is more or less complete. In contrast to the onshore deposits on Nuussuaq in West Greenland, the Lower Paleocene (Danian) succession is general thin or absent in the offshore Canadian and Greenland wells. A preliminary correlation of the seven selected exploration wells on the Labrador and South-East Baffin shelves and offshore and onshore West Greenland has been carried out. The lithological interpretation of the four Canadian wells is done on information from log data and the Master Log prepared by the mud logger. The log correlation is based on biostratigraphic data, and the biostratigraphic events are placed disregarding the log pattern. The knowledge on especially marine oil-prone source rock intervals in the northern Labrador Sea - Baffin Bay region is relatively sparse since source rock intervals have only been drilled in a few wells. However, both direct and indirect evidence of their presence exists from seeping oil in West Greenland and from some of the Canadian discovery wells. A compilation of geochemical analysis of five Canadian and eight Greenland wells has been carried out out in order to characterise possible source rocks intervals. However, only little or no petroleum source potential has been recorded with the possible exceptions of the Hekja 0-71 and Umiivik-1 wells. Furthermore, the analyses of the five Canadian wells could not confirm that the organic rich marine mudstones of the Markland Formation and the Lower Cretaceous lignites and coals of the Bjarni Formation represent regional source rocks. It has earlier been proposed that the petroleum accumulations found in the Hekja 0-71 well are sourced from surrounding Paleocene organic rich marine mudstones. This could not be confirmed since the mudstones are thermally immature in the area around the well. Nevertheless, the presence of active hydrocarbon systems in the region shows that mature, oil-prone source rocks exist. The hydrocarbons are therefore probably generated from an as yet unknown source. Geochemical evidence from seeping oil in Greenland and from the stratigraphically deep Umiivik-1 well suggests that a marine source rocks of possible Cenomanian-Turonian age, comparable to the prolific source rock in the Kanguk Formation on Ellesmere Island, is present in West Greenland. However, knowledge on this - or maybe even older - source rock is still very sparse and depends on either results from stratigraphically deep exploration wells or from sea bed sampling of structurally inverted regions