Basin Developement and Structure of the Area Covered by Tertiary Basalts, Offshore Central West Greenland - Implications For Subvolcanic Plays
Richard C. Whittaker, Kevin J. Bate, James A. Chalmers,
Christian Marcussen, Flemming G. Christiansen, and T. C. R. Pulvertaft
The West Greenland shelf area between 68° and 72° is covered by Lower Tertiary basalts and has so far proved difficult to explore seismically compared to the offshore basins farther north (Melville Bay) and south (southern West Greenland).
A first seismic and geological interpretation of the basalt area has lead to a better understanding of the tectonic events during the Tertiary and their implications for hydrocarbon exploration. After a period of extension accompanied by basalt volcanism in the Paleocene, a period of transpression occurred related to sea-floor spreading in the Labrador Sea and Baffin Bay. The crests of the anticlines formed were then eroded and transgressive marine sediments infilled the irregular topography and formed a number of restricted basins. Strike-slip faulting continued throughout the Eocene.
Ongoing geophysical studies, including acquisition of additional seismic data in 1995, are aimed at improving seismic resolution beneath the basalts and determining the structure and nature of the underlying sedimentary section. It has been possible, locally, to interpret horizons beneath the Paleocene volcanics where a thick sedimentary section is inferred to be present. The geological development of this succession has to be extrapolated from offshore southern West Greenland and the nearby onshore Nuussuaq basin. Active exploration including drilling started in the onshore basin in 1995 after the discovery of hydrocarbons in basalts at the surface and in shallow wells.
The most promising play concept is subbasaltic reservoir sandstones with a mid-Cretaceous marine or a Paleocene deltaic oil-prone source rock. A possible post-basaltic play has also been identified and several large structural leads have been identified by mapping the Top Paleocene Volcanics horizon.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California