Structural Elements and Hydrocarbon Systems in the Baffin Bay, Davies Strait and Labrador Sea
Jens C. Olsen1, Sverre Planke2, and Reidun Myklebust3
1TGS, Vanløse, Denmark.
2VBPR, Oslo, Norway.
3TGS, Asker, Norway.
The sedimentary basins in the Baffin Sea, Davies Strait and Labrador Sea are surrounded by old continents consisting of 2.4 to 3.6 bill year Proterozoic and Archean rocks. The old continents may have been connected or very close once upon a time. Coastal exposures and geophysical data demonstrate marine deposition during Archean and Protorezoic and from Cambrian and onwards in the basins and grabens between the continents.
The basins and grabens were not formed simultaneously in the entire region but as a consequence of continent drift. Triassic rifting opened deep narrow grabens and parallel linear extensional fault zones in the Labrador Sea. Listric faults allowed over time a total drift of the continents up to 300 km in the Labrador Sea but diminishing drift northwards in the Baffin Sea as a consequence of strike slip movements in the Ungava Fault Zone between the Labrador Sea Graben and the Baffin Sea Graben.
It may be demonstrated that Greenland has drifted northeastwards compared to Canada, while at the same time rotating slightly anticlockwise. Major strike slip movements caused both divergent subsidence and convergent uplifting. The main periods of Triassic, Jurassic and Tertiary extension are supported by dyke swarms in onshore basement, and rifting has locally happened so fast that volcanic rocks was extruded along fracture zones in the deep oceanic basins.
The dominant part of the region is however underlain by continental crust that only locally is stretched so much that intrusive rocks create local areas resembling oceanic crust. Many of the sediment basins are very deep. This is also the case for the grabens that connect from the Labrador Sea to the Baffin and act as narrow seaways possibly from Triassic time. Both the grabens and basins contain organic material that generates oil and gas. This is documented in wells along Canadian Labrador coast, in scientific wells and from oil seeps onshore west-central Greenland. And also two out of six old offshore wells have shows of hydrocarbons.
There is no conclusion yet as we still are building data bases and trying to understand this huge potential hydrocarbon province. But there are questions: Are we looking at a new North Sea size region or will we find something larger?
AAPG Search and Discover Article #90096©2009 AAPG 3-P Arctic Conference and Exhibition, Moscow, Russia