Approximately 50 preliminary sites for Transect EG65 were selected along seismic Line DLC9709 prior to the leg (Fig. F2). Final site selection was based on sparker seismic Line DLC99-3 shot during the leg. Two separate areas were targeted for drilling:
Sites in the inner area were selected to sample the basin fill and surrounding basement, while those in the outer area targeted as large an age and stratigraphic coverage of the seaward dipping reflectors as possible.
The Dana air gun data (seismic Line DLC9709) (Fig. F2) show potential drilling sites near the coast on basement highs and on what is interpreted to be the earliest basin fill. The sparker seismic data (seismic Line DLC99-3) (Fig. F3) indicate that the main part of the basin below the deeper trough further offshore is covered by 5 to 10 m of glacial marine sediment. Potential shallow drill sites were located on highs, in particular, toward the younger and upper part of the basin fill next to the escarpment that separates the basin from the dipping-reflector plateau (Fig. F3). However, drilling in this area mostly failed to recover bedrock below the glacial sediments (Sites SEG32–SEG35). Site SEG32 was successful in recovering continental basement.
The outer area contains a series of basement highs suitable for drilling (Figs. F2, F4). Very little sedimentary fill is seen in the seismic profile between these highs. Where drilling encountered sediment overburden, a clear reflector between the glaciomarine sediment and basement was often lacking. This limited the usefulness of the sparker data and forced the Shipboard Scientific Party to rely heavily on the drillers' judgment of coring conditions. In some instances, basalt was exposed at the seafloor (Fig. F5).
Several holes were attempted within the youngest part of the basin fill next to the escarpment leading up to the seaward-dipping sequence (Fig. F4A). The most landward of these sites yielded core of olivine phyric basalt (Site SEG77), unexpected from the features seen in the seismic profiles interpreted to represent small fault blocks with basin fills. Continued drilling attempts eventually recovered micaceous sandstone (Site SEG80) next to the escarpment east of Site SEG77. The volcanic unit recovered at Site SEG77 is interpreted as representing a thin lava cover on top of the basin fill and therefore probably represents some of the very earliest break-up volcanism.
Drilling closer to the flank of the basin was attempted but had to be abandoned because of dangerous ice conditions. In total, 50 drill sites were located in the outer area.