The siliciclastics are quartz and vary in color from white to light olive gray. They are unconsolidated to poorly indurated (hard), slightly clayey sands with minor phosphate to light gray to bluish gray, poorly consolidated, variably silty clay (Dogtown Member). The siliciclastics are sporadically fossiliferous and often contain oyster shells as found in the Seaboard Air Line Railroad site.
The carbonate sediments contain phosphate and are white to light olive gray. They are generally not hard but variably sandy with clay. This unit is also fossiliferous with both molds and casts and includes limestone (mudstone and wackestone). The limestones often grade into calcareous-cemented sands.
The Dogtown Member is time transgressive with older aged material at ~15.9–15.3 Ma. and found in the south while the younger material is in the north.[2]
Overlay
The Torreya Formation overlies the Floridan aquifer and forms part of the intermediate confining unit/aquifer system. (USGS)
