Figure 4. Segment of Uniboom seismic-reflection profile collected across a bathymetric high in the eastern part of the study area (RV Asterias 75-6, line 31; O'Hara and Oldale, 1980; McMullen and others, 2009b). The high is cored by coastal plain sediments and mantled by glacial till, as evidenced by the presence of boulders on the sea floor. Location of seismic profile is shown in figure 21.