Figure 13. Geologic sections (D-D', E-E', and F-F') illustrating the general distributions and thicknesses of seismic stratigraphic units and major unconformities beneath Vineyard and western Nantucket Sounds. The geologic sections were produced from chirp and boomer seismic-reflection profile interpretations. See figure 9 for descriptions of stratigraphic units and unconformities. Geologic section locations are indicated on figure 14.