Offshore West Greenland - Implications from the Ungava Trend and the Sisimiut Lineament on Geological Evolution and Petroleum Systems

Jan Stilling

The large offshore areas of West Greenland have been suggested subdivided into four structural provinces; from north to south Baffin Bay, Disko West, Nuuk West and Cape Farewell. The separation of the Disko- and Nuuk West provinces largely coincides with the Ungava Fault Zone and the Sisimiut Lineament. We believe a better understanding of these large and long lived structural features will contribute to an improved understanding of recent exploration results and future establishment of analog models for definition of petroleum systems, plays and prospect. The Ungava Trend is a very prominent feature defined especially well by potential field and seismic data. Within the entire Disko West province the Ungava Trend stands out clearly at the top Paleocene volcanic surface as a strike-slip fault system, where movements have peaked in the Early Eocene. On the contrary the expression of the Sisimiut Lineament is much more subtle and recognized only as a NE-SW oriented boundary characterized by a change in magnetic and gravity facies. However, it is believed that the lineament has been very important during Cretaceous continental rifting controlling location, segmentation or even jumps of the rift. It is postulated, that these large and long lived elements on a regional scale control the evolution of offshore marine basin circulation and onshore drainage patterns. We believe that they together form a natural boundary between two major geological provinces and provide a framework in which to interpret data and rank the most relevant assumptions and analogs for source and reservoir evaluation. In addition, the Ungava Fault Zone and the Sisimiut Lineament form a boundary across which significant differences in structural style and timing of structuring is recognized. Interpretation of the spatial and temporal evolution of structures across the boundary has to be carried out with caution. Indeed, the Ungava Fault Zone and the Sisimiut Lineament constitute the southern boundary of the Disko West province, which is the main locus of Paleocene volcanism and Tertiary exhumation. The boundary and the basement crustal nature north and south of the boundary may also have a significant role to play considering these important geological events. West Greenland is still a frontier in the early days of exploration and data is scarce compared to many other places. However, results do seem to make a pattern, which indicate the presence of some important large scale geological trends. It has been possible to establish distinctive geological provinces, which provide a framework for the future planning of exploration activities and evaluation of new data. As a major boundary between two geological provinces the evolution of the Ungava Fault Zone and the Sisimiut Lineament warrants further investigation and calibration.

AAPG Search and Discovery Article #90177©3P Arctic, Polar Petroleum Potential Conference & Exhibition, Stavanger, Norway, October 15-18, 2013