From the Known to the Unknown: Extrapolating Basin-models from the Norwegian Shelf, and East Greenland Fjords, into the East Greenland Shelf

Ebbe H. Hartz¹, Dani Schmid², Lars H. Rüpke², Jan Inge Faleide³, Bjørn B. Martinsen¹, and Vincent Lien^1
1Det norske oljeselskap, Oslo, Norway.
²Geomodelling Solutions, Zürich, Switzerland.
³Department of Geoscience, Oslo University, Oslo, Norway.

Despite the common Wilson cycle models for the Northeast Atlantic, the Cenozoic break-up is remarkably skewed with respect to older structures. Most Mesozoic (and older?) structures are cut obliquely, some even perpendicular, between Greenland and Norway. Thus the oceanic crust is close to northern Norway (Lofoten) but distant to central Norway, and opposite on the Greenland side. Here we present a new reconstruction of the Northeast Atlantic, which takes into account the northwards drift of Greenland in the early Cenozoic. The new fit matches major continental structures so that basin and highs appear continuous, or at least aligned, from the Barents Sea across the Northeast Greenland Shelf into the Mid-Norwegian Margin, across the Jan Mayen Transform Zone into the Jan Mayen micro-continent, and farther south, into the Rockall region. Our reconstruction allows for structural comparisons of basin and highs across these regions. Data from well-studied areas can be used to extrapolate into areas where break-up related flood basalts or ice-cover obscure direct imaging. Using basin modeling tools (TecMod2D) we discuss the age and tectonic history of basins on the Greenland shelf, where only the shallowest reflectors are dated, and compare these to the aligned basins of the Barents Sea and Vøring areas. For example, published seismic sections across the Danmarkshavn Basin, allow interpretations of the basin as either intensely faulted, or virtually non-faulted, and that the basin is mostly Paleozoic, early Mesozoic or late Mesozoic. However, tectonic phases broadly have to match across the much younger break up zones, and onto land, allowing elimination of some of the most extreme models. As a quality test of this type of work we apply the method to the well exposed profiles along the fjords of central East Greenland, and compare results to actual thermal and maturity data for these regions including the huge (10 + billion barrel) exhumed paleo-oil field of Traill Ø. One of the most important results of this exercise is that it confirms an erosional, rather than thermal, uplift of these Mesozoic marine basins into mountains. We suggest that our combined paleogeographic and 2D basin-modeling approach allows for an interesting ‘what if’-game, where basin models can be tested, debating, for example, the timing of hydrocarbon maturation versus trap formation for a variety of scenarios.

AAPG Search and Discovery Article #90130©2011 3P Arctic, The Polar Petroleum Potential Conference & Exhibition, Halifax, Nova Scotia, Canada, 30 August-2 September, 2011.