The Scotian Basin is located offshore Nova Scotia where it extends for 1200 km from the Yarmouth Arch / United States border in the southwest to the Avalon Uplift on the Grand Banks of Newfoundland in the northeast (Figure 1). With an average breadth of 250 km, the total area of the basin is approximately 300,000 km2. Half of the basin lies on the present-day continental shelf in water depths less than 200 m with the other half on the continental slope in water depths from 200 to >4000 m.
The Scotian Basin formed on a passive continental margin that developed after North America rifted and separated from the African continent during the break-up of Pangea (Figure 2). It consists of a series of alternating "highs and lows", or platforms and depocentres. From the southwest to the northeast they are named the Shelburne Subbasin, La Have Platform, Sable and Abenaki Subbasins, Banquereau Platform, Orpheus Graben and Laurentian Subbasin (Figure 1). The boundaries of these platforms and basins may have been defined by regularly-spaced oceanic fracture zones that extended landward onto continental crust (Welsink et al., 1990). A northeast-trending basement hinge zone is also present along the margin, defining the landward limit of maximum tectonic extension and an abrupt seaward increase in basement depth due to thermal subsidence (Figure 3). Together, these basement elements asserted a strong control on sediment distribution in the region for more than 190 million years.
Figure 1:
Figure 2:
Figure 3: Composite seismic section across the Sable Subbasin; the track is shown in Figure 1. This 200 kilometer long composite profile starts landward of the Jurassic carbonate bank, runs across the Sable Subbasin through several gas fields, over the shelf break and the slope across the Annapolis and Crimson deepwater wells, and out into the salt canopy complex. The profile is composed of the following data sets and used with the kind permission of the respective organizations (from west to east): Canadian Superior Marquis 2D (Geophysical Service Incorporated), ExxonMobil Mega-Merge 3D (ExxonMobil), ExxonMobil North Triumph 3D (ExxonMobil), Marathon 3D (CGGVeritas) and the TGS Regional 2D (TGS-NOPEC). A comprehensive description of this line can be found in Kidston et al., 2007.
