Seven generalized sedimentary-facies types were defined for a unified comparison of core data from the entire study area. All seven color-coded facies for the entire study are shown in the Explanation below. However, not all facies necessarily are present on each transect. Core photographs present individual cores cut into 1-m sections from top (upper left) to bottom (lower right). Discrepancies in core length between the photographs and the diagrams are due to compaction during the coring process. Offshore cores (left) are aligned at core tops. Core locations were chosen to sample thicker Holocene sections and to aid in identifying pre-Holocene stratigraphy. Core elevations were determined from water depth and tide tables. The datum for the barrier-transect cores is the mean lowest low water (MLLW).

Offshore vibracore retrieval ranged from less than 0.5 m to a little over 1 m in length. Sediments consist dominantly of sand-size material rich in blackened grains believed to have been derived from the underlying Miocene sequences. The thin sediment cover and erosional origin of surface sediments illustrate the lack of significant sediment influx to this part of the study area.

The island cross section (Yale, 1997) illustrates the importance of dune and nearshore sediments in construction of this drumstick barrier. Cores from the barrier island typically recovered dune or nearshore sands, with a transition to muddy sands on the landward side of the barrier island. Where cores do not penetrate to bedrock, the control is based on probe-rod data.