St. Marks Formation

St. Marks Formation
Stratigraphic range: Miocene
Type Geological formation
Unit of None
Sub-units None
Lithology
Primary Limestone & sand
Location
Named for St. Marks River
Named by J. Finch, 1823
Region Florida Panhandle
Country  United States
Extent Jefferson, Leon, and Wakulla counties

The St. Marks Formation is a Miocene geologic formation in the eastern Florida Panhandle.

Contents

Age

Period: Neogene
Epoch: Miocene ~23.03 to 5.33 mya, calculates to a period of 17.7 million years
Faunal stage: Arikareean through Hemphillian

Location

The St. Marks Formation is exposed in Wakulla, southern Leon and southern Jefferson County, Florida on the northwestern flank of the Ocala Platform and along with Suwannee Limestone and Ocala Limestone makes up the upper part of the Floridan Aquifer in the eastern panhandle.[1]

Composition

The St. Marks Formation consists of a white to yellowish gray, poorly to moderately hard, sandy, fossil bearing rock in molds and casts within packstone to wackestone.

Fossils

The fossils are in molds and casts and include:

References