Figure 3. Segment of Uniboom seismic-reflection profile collected across a part of Block Island Sound (RV Asterias 81-2, line 10; Needell and Lewis, 1984). Profile shows that (1) marine, fluvial, and estuarine deposits are thin or absent in the northern part of the study area, but thicken southward on the floor of the sound, (2) glaciolacustrine sediments comprise most of the sedimentary section, and (3) outliers of coastal plain cap some of the bedrock highs. Location of seismic profile is shown in figure 18.