AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
New Insights into the Stratigraphic and Structural Development of the NE Greenland Margin
(1) GeoArctic Ltd, Calgary, AB, Canada.
(2) ION Geophysical - GX Technology, Houston, TX.
The NE Greenland Shelf is the conjugate margin to the Lofoten and Vøring Margins of Mid-Norway and it lay southwest of the Barents Shelf prior to break up. Deep long-offset seismic data acquired in 2009 and 2010 now covers much of the NE Greenland shelf area north of the Jan Mayen Fracture Zone.
The long-offset and deep tow seismic data images intra- and sub-basalt reflectors in the volcanic province and on the volcanic margin where Seaward Dipping Reflectors (SDRs) are interpreted. Several of the lines cross the Continent Ocean Transition (COT), topped by well developed SDRs, over ocean crust where deep reflectors are seen near 10 km that are interpreted as representing the Moho. These deep reflectors dip west to about 22-25 km depth landward towards the East Greenland continental crust. A high-amplitude deep crustal reflector is evident at about 15km along the outer margin which is possibly related to a lower crustal reflector described on the Norwegian margin, and has been attributed to crustal underplating.
These new data provide strong evidence for a COT closer to the Greenland coastline in the NE Greenland Volcanic Province than many earlier interpretations. This new interpretation has an impact on the break-up history of both the Greenland and conjugate Norwegian margin, north of the Jan Mayen Fracture Zone, likely resulting in a revised plate tectonic model of the North Atlantic.
The PSDM seismic data has also provided new information on the extent and thickness of Mesozoic sediments in Thetis Basin and outer Greenland shelf. A thick sedimentary section is interpreted in the outer shelf areas and can be mapped beneath volcanics thought to be present the south and east and in the northern extension of the Danmarkshavn Basin. There is also clear evidence for the presence of a thick section below the base Cretaceous unconformity in the Thetis Basin, suggesting that rich oil-prone Jurassic source rocks, known elsewhere on the margin, are likely present in this outer Greenland shelf area.
In order to fully understand the evolution of the NE Greenland margin and the opening history of the North Atlantic, comparisons must be made with the conjugate Mid-Norway and Barents Sea margins. The structural development of the region can be used to develop palaeogeographic interpretations which, in turn, can be used to predict source and reservoir deposits.