Arcadia Formation
| Arcadia Formation | |
|---|---|
| Stratigraphic range: Early Miocene | |
| Type | Geological formation |
| Unit of | Hawthorn Group |
| Sub-units | Nocatee Member, Tampa Member |
| Underlies | Peace River Formation |
| Overlies | Ocala Limestone, Suwannee Limestone |
| Thickness | 600 feet |
| Lithology | |
| Primary | limestones, dolomite, sand, clay |
| Location | |
| Region | Florida |
| Country | United States |
| Extent | Central and southern Florida |
| Type section | |
| Named for | Arcadia, Florida |
| Named by | T. M. Scott, 1988 |
The Arcadia Formation is an Early Miocene geologic formation in Florida, United States. It is part of the Hawthorn Group.
Age[edit]
Period: Neogene
Epoch: Early Miocene
Faunal stage: Aquitanian through early Burdigalian[1]
Location[edit]
The Arcadia Formation extends from at least Polk County in central Florida to Miami-Dade and Monroe counties at the southern end of the Florida peninsula.[2] Parts of the Arcadia Formation are designated the Nocatee and Tampa Members.[3] The Tampa Member and the lower part of the Arcadia Formation form the upper part of the Floridan Aquifer system in parts of southern Florida.[4][failed verification]
Composition[edit]
The Arcadia Formation is composed of limestones and dolomites which are yellowish gray to light olive gray to light brown in color. The texture is micro to finely crystalline with varying sandy, clayey limestones and dolomites containing phosphate. The clays are yellowish gray to light olive gray in color. They are moderately hard as well as sandy, silty, phosphatic and dolomitic. Silicified carbonates and opalized claystone have also been found.[5]
Tampa Member[edit]
The Tampa Member consists predominantly of limestone with subordinate dolomite, sand and clay very similar to that of the subsurface limestone part of the Arcadia Formation. There is considerably less phosphate. The color is white to yellowish gray. It is fossil bearing and variably sandy and clayey mudstone, wackestone, and packstone with little to no phosphate grains. Sand and clay beds are like those in the undifferentiated sediments of the Arcadia Formation.[6]
Paleofauna[edit]
The Arcadia Formation proper contains molds and casts in dolomite containing mollusks. The Tampa Member contains mollusks and corals in molds and casts with silicified pseudomorphs and shell material.
References[edit]
- ^ Compton 1997, pp. 198–199.
- ^ Scott 1988, pp. 60.
- ^ Compton 1997, p. 60.
- ^ Miller, J. A. (1986). Hydrogeologic framework of the Floridan aquifer system in Florida and parts of Georgia, Alabama and South Carolina: Professional Paper 1403-B (Report). United States Geological Survey.
- ^ Scott 1988, pp. 56–79.
- ^ Scott 1988, pp. 65–73.
Sources[edit]
- Compton, John S. (1997). "Origin and Paleoceanographic Significance of Florida's Phosphorite Deposits". In Randazzo, Anthony F.; Jones, Douglas S. (eds.). The Geology of Florida. Gainesville, Florida: University Press of Florida. ISBN 0-8130-1496-4.
- Scott, Thomas M. (1988). The lithostratigraphy of the Hawthorn Group (Miocene) of Florida: Florida Geological Survey Bulletin 59 (PDF) (Report). Florida Geological Survey.
- USGS Lithostratigraphic Units of Florida Archived 2018-08-07 at the Wayback Machine
- Florida Carbonate "Formations" and Conflicting Interpretations of Injection Well Regulations