Most of the fine skeletal particles are fragmented neritic grains, such as coralline algae and benthic foraminifers. These alternating intervals probably result from high frequency sea level changes. These calciturbidites are enriched in coarse skeletal detritus, such as larger benthic foraminifers. In addition, the cyclic variability observed in the sediments is also seen in natural gamma radiation and magnetic susceptibility data. Glauconite is abundant, both as pellets and infills of intraskeletal porosity.
Quartz grains are present and become particularly abundant at the base of the unit.
The top of Unit V is defined by the first occurrence of coarse periplatform sediments. The base of lithologic Unit V is defined by a sharp transition to volcaniclastic breccia and basalt. This unit was divided into two subunits. Native sulfur mineralization is observed. The dark breccia is overlain by grainstone rich in larger benthic foraminiferal tests that were originally produced in middle-neritic water depths, possibly in an open shelf setting where they were rounded and mixed.