Links
- Document: Pamphlet (7.42 MB pdf) , XML
- Sheet: Sheet (1.47 MB pdf)
- Related Work: USGS Data Report 1209 - Petrography and Mineralogy of Selected Pre-Middle Jurassic Basement Rocks Beneath the Atlantic and Gulf Coastal Plains in Florida
- Data Releases:
- USGS data release - Geochemical data from selected pre-Middle Jurassic basement rocks beneath the Atlantic and Gulf Coastal Plains in Florida and Alabama
- USGS data release - Mineral abundances of selected pre-Middle Jurassic basement rocks beneath the Atlantic and Gulf Coastal Plains in Florida and Alabama from whole-rock powder X-ray diffraction analysis and the Rietveld method
- USGS data release - Database for the geologic map of pre-Middle Jurassic basement rocks beneath the Atlantic and Gulf Coastal Plains in Florida
- USGS data release - Photographs and photomicrographs of selected pre-Middle Jurassic basement rocks beneath the Atlantic and Gulf Coastal Plains in Florida (ver. 1.1, June 2026)
- USGS data release - Borehole data for pre-Middle Jurassic basement rocks beneath the Atlantic and Gulf Coastal Plains, Florida and Alabama (ver. 1.1, June 2026)
- Download citation as: RIS | Dublin Core
Abstract
Much of the southeastern United States, including all of Florida, is covered by flat-lying sedimentary strata of the Atlantic and Gulf Coastal Plains which have accumulated since Middle Jurassic time. The pre-Middle Jurassic rocks that underlie these coastal plains in Florida, here collectively referred to as “basement,” are known only from a relatively small number of boreholes. This scientific investigations map presents an interpretation of the basement geology in a 1:1,000,000-scale subsurface geologic map with supporting text, data, and figures. The subsurface mapping methodology integrates petrographic, geochronological, thermochronological, geochemical, and mineralogical analyses of drill cores and cuttings in the context of regional geophysical data.
The pre-Middle Jurassic rocks of Florida consist of the Gondwanan (West African) Suwannee terrane which was accreted to Laurentia during the Alleghanian orogeny and subsequently intruded by Permian granites, superposed by early Mesozoic rift basins, and partially overlain by bimodal Jurassic volcanic rocks. The younger basement components, specifically the Southwest Florida volcanic province, North Florida tholeiites, early Mesozoic rift basins, and Alleghanian granitoids, have correlative and contemporaneous units throughout the Appalachian orogen. In contrast, Florida’s older basement rocks, including Paleozoic siliciclastic strata of the Suwannee basin, North Florida volcanic series, Osceola and Gaskin intrusive complexes, and the St. Lucie Metamorphic Complex, have neither surface exposures nor unequivocal correlates. Major structures include early Mesozoic normal faults and northwest-striking transfer zones such as the Jay fault. Many of these faults define the boundaries of subbasins within the South Georgia rift system. Top-of-basement structure contours show gentle arches and embayments that are also recognized in overlying coastal plain strata.
Suggested Citation
Deasy, R.T., Horton, J.W., Jr., Glock, S.N., Lupo, M.E., Crider, E.A., Jr., and Daniels, D.L., 2026, Geologic map of pre-Middle Jurassic basement rocks beneath the Atlantic and Gulf Coastal Plains in Florida: U.S. Geological Survey Scientific Investigations Map 3543, 1 sheet, scale 1:1,000,000, 31-p. pamphlet, https://doi.org/10.3133/sim3543.
ISSN: 2329-132X (online)
Table of Contents
- Abstract
- Introduction
- Previous Work and Geologic Setting
- Suwannee Terrane
- Alleghanian Granitoids
- Early Mesozoic Rift-Related Rocks
- Metamorphism
- Structure
- Tectonics
- Map Applications
- Description of Map Units
- References Cited
| Publication type | Report |
|---|---|
| Publication Subtype | USGS Numbered Series |
| Title | Geologic map of pre-Middle Jurassic basement rocks beneath the Atlantic and Gulf Coastal Plains in Florida |
| Series title | Scientific Investigations Map |
| Series number | 3543 |
| DOI | 10.3133/sim3543 |
| Publication Date | June 17, 2026 |
| Year Published | 2026 |
| Language | English |
| Publisher | U.S. Geological Survey |
| Publisher location | Reston, VA |
| Contributing office(s) | Florence Bascom Geoscience Center |
| Description | Pamphlet: ix, 31 p.; Sheet: 34.03 x 42.24 inches; 5 Data releases |
| Online Only (Y/N) | Y |
| Additional Online Files (Y/N) | N |