Geologic units in Baker county, Florida

Additional scientific data in this geographic area

Undifferentiated sediments (Pliocene/Pleistocene) at surface, covers 89 % of this area

Undifferentiated Tertiary-Quaternary Sediments - These sediments are siliciclastics that are separated from undifferentiated Quaternary sediments solely on the basis of elevation. Based on the suggestion that the Pleistocene sea levels reached a maximum of approximately 100 feet (30 meters) msl (Colquhoun, 1969), these sediments, which occur above 100 feet (30 meters) msl, are predominantly older than Pleistocene but contain some sediments reworked during the Pleistocene. This unit may include fluvial and aeolian deposits. The undifferentiated Tertiary-Quaternary sediments occur in a band extending from the Georgia-Florida state line in Baker and Columbia Counties southward to Alachua County. These sediments are gray to blue green, unconsolidated to poorly consolidated, fine to coarse grained, clean to clayey, unfossiliferous sands, sandy clays and clays. Organic debris and disseminated organics are present in these sediments. The undifferentiated Tertiary-Quaternary sediments are part of the surficial aquifer system.

Hawthorn Group, Statenville Formation (Miocene) at surface, covers 5 % of this area

The Statenville Formation occurs at or near the surface in a limited area of Hamilton, Columbia and Baker Counties on the northeastern flank of the Ocala Platform. The formation consists of interbedded sands, clays and dolostones with common to very abundant phosphate grains. The sands predominate and are light gray to light olive gray, poorly indurated, phosphatic, fine to coarse grained with scattered gravel and with minor occurrences of fossils. Clays are yellowish gray to olive gray, poorly consolidated, variably sandy and phosphatic, and variably dolomitic. The dolostones, which occur as thin beds, are yellowish gray to light orange, poorly to well indurated, sandy, clayey and phosphatic with scattered mollusk molds and casts. Phosphate occurs in the Statenville Formation in economically important amounts. Silicified fossils and opalized claystones are found in the Statenville Formation. Permeability of these sediments is generally low, forming part of the intermediate confining unit/aquifer system.

Trail Ridge sands (Pleistocene) at surface, covers 4 % of this area

Undifferentiated sediments - Undifferentiated Quaternary Sediments - Much of Florida's surface is covered by a varying thickness of undifferentiated sediments consisting of siliciclastics, organics and freshwater carbonates. Where these sediments exceed 20 feet (6.1 meters) thick, they were mapped as discrete units. In an effort to subdivide the undifferentiated sediments, those sediments occurring in flood plains were mapped as alluvial and flood plain deposits (Qal). Sediments showing surficial expression of beach ridges and dunes were mapped separately (Qbd) as were the sediments composing Trail Ridge (Qtr). Terrace sands were not mapped (refer to Healy [1975] for a discussion of the terraces in Florida). The subdivisions of the Undifferentiated Quaternary Sediments (Qu) are not lithostratigraphic units but are utilized in order to facilitate a better understanding of the State's geology. The siliciclastics are light gray, tan, brown to black, unconsolidated to poorly consolidated, clean to clayey, silty, unfossiliferous, variably organic-bearing sands to blue green to olive green, poorly to moderately consolidated, sandy, silty clays. Gravel is occasionally present in the panhandle. Organics occur as plant debris, roots, disseminated organic matrix and beds of peat. Freshwater carbonates, often referred to as marls in the literature, are scattered over much of the State. In southern Florida, freshwater carbonates are nearly ubiquitous in the Everglades. These sediments are buff colored to tan, unconsolidated to poorly consolidated, fossiliferous carbonate muds. Sand, silt and clay may be present in limited quantities. These carbonates often contain organics. The dominant fossils in the freshwater carbonates are mollusks.

Cypresshead Formation (Pliocene) at surface, covers 0.9 % of this area

The Cypresshead Formation named by Huddlestun (1988), is composed of siliciclastics and occurs only in the peninsula and eastern Georgia. It is at or near the surface from northern Nassau County southward to Highlands County forming the peninsular highlands. It appears that the Cypresshead Formation occurs in the subsurface southward from the outcrop region and similar sediments, the Long Key Formation, underlie the Florida Keys. The Cypresshead Formation is a shallow marine, near shore deposit equivalent to the Citronelle Formation deltaic sediments and the Miccosukee Formation prodeltaic sediments. The Cypresshead Formation consists of reddish brown to reddish orange, unconsolidated to poorly consolidated, fine to very coarse grained, clean to clayey sands. Cross bedded sands are common within the formation. Discoid quartzite pebbles and mica are often present. Clay beds are scattered and not areally extensive. In general, the Cypresshead Formation in exposure occurs above 100 feet (30 meters) above mean sea level (msl). Original fossil material is not present in the sediments although poorly preserved molds and casts of mollusks and burrow structures are occasionally present. The presence of these fossil "ghosts" and trace fossils documents marine influence on deposition of the Cypresshead sediments. The permeable sands of the Cypresshead Formation form part of the surficial aquifer system.

Wicomico Shoreline Complex - marsh and lagoonal facies (Pleistocene) at surface, covers 0.1 % of this area

Wicomico Shoreline Complex - marsh and lagoonal facies

Hawthorn Group, Coosawhatchie Formation (Miocene) at surface, covers < 0.1 % of this area

The Coosawhatchie Formation is exposed or lies beneath a thin overburden on the eastern flank of the Ocala Platform from southern Columbia County to southern Marion County. Within the outcrop region, the Coosawhatchie Formation varies from a light gray to olive gray, poorly consolidated, variably clayey and phosphatic sand with few fossils, to an olive gray, poorly to moderately consolidated, slightly sandy, silty clay with few to no fossils. Occasionally the sands will contain a dolomitic component and, rarely, the dominant lithology will be dolostone or limestone. Silicified nodules are often present in the Coosawhatchie Formation sediments in the outcrop region. The sediment may contain 20 percent or more phosphate (Scott, 1988). Permeability of the Coosawhatchie sediments is generally low, forming part of the intermediate confining unit/aquifer system.

Wicomico Shoreline Complex - barrier island facies (Pleistocene) at surface, covers < 0.1 % of this area

Wicomico Shoreline Complex - barrier island facies