Coosawhatchie Formation
The Coosawhatchie Formation is a Miocene geologic formation with an outcrop in North Florida. It is within the Hawthorn Group.
Age
Period: NeogeneEpoch: Miocene ~23.03 to 5.33 mya, calculates to a period of
Faunal stage: Arikareean through Hemphillian
Location
The Coosawhatchie Formation is located on the eastern flank of the Ocala Platform near southern Columbia [County, Florida|Columbia County] and southern Marion County, Florida. It extends south-southeast and is present in Alachua, Marion, Sumter, and Lake County. It is exposed or lies beneath a thin overburden.Lithography
The Coosawhatchie Formation varies in color from a light gray to olive gray. It is poorly consolidated, variably clayey and phosphate containing sand which occasionally contain a dolomitic component but rarely is it dominated with dolomite or limestone.Silicified nodules are often present in the sediments and may contain 20% or more phosphate. The permeability factor of the Coosawhatchie sediments is generally low, forming part of the intermediate confining aquifer system.