WATER-RESOURCES INVESTIGATIONS REPORT 87-4112 STRATIGRAPHIC AND HYDROGEOLOGIC FRAMEWORK OF THE ALABAMA COASTAL PLAIN By Marvin E. Davis Precambrian to Paleozoic Metamorphic and Igneous Rocks LpperEocene to Holocene.undifferentiated ft UNITED STATES DEPARTMENT OF THE INTERIOR " GEOLOGICAL SURVEY DEPARTMENT OF THE INTERIOR DONALD PAUL HODEL, Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, Director For additional information write to: Copies of this report can be purchased from: Regional Hydrologist U.S. Geological Survey U.S. Geological Survey 75 Spring Street, S.W., Suite 772 Books and Open-File Reports Atlanta, Georgia 30303 Box 25425, Federal Center Denver, Colorado 80225 CONTENTS Page Abstract ................................................................. 1 Introduction ............................................................. 1 Purpose and scope ................................................... 3 Previous investigations ............................................. 3 Acknowledgments ..................................................... 4 Method of study ..................................................... 4 Physiographic features ............................................... 6 Coastal Plain Province ......................................... 8 East Gulf Coastal Plain section ........................... 8 Fall Line Hills ....................................... 8 Black Prairie Belt ................................... 8 Chunnennuggee Hi 11s .................................. 8 Southern Red Hills ................................... 9 Lime Hills ........................................... 9 Southern Pine Hills .................................. 9 Geology .................................................................. 10 Regional setting .................................................... 10 Structural features in the Coastal Plain ............................ 12 Stratigraphy ............................................................. 14 Pre-Cretaceous System ............................................... 14 Cretaceous System ................................................... 15 Lower Cretaceous Series ........................................ 15 Upper Cretaceous Series ........................................ 15 Tuscaloosa Group .......................................... 15 Coker Formation ...................................... 16 Gordo Formation ...................................... 16 ^ Eutaw Formation............................................. 16 Selma Group ............................................... 17 Mooreville Chalk and Blufftown Formation ............. 17 Demopolis Chalk ...................................... 18 Ripley Formation ..................................... 18 Prairie Bluff Chalk and Providence Sand .............. 18 Tertiary System ..................................................... 18 Paleocene Series ............................................... 18 Midway Group .............................................. 18 Clayton Formation .................................... 19 Porters Creek Formation .............................. 19 Naheola Formation .................................... 19 Wiicox Group .............................................. 20 Nanafalia Formation and Baker Hill Formation ......... 20 Tuscahoma Formation .................................. 21 Eocene Series .................................................. 21 Wiicox Group .............................................. 21 Hatchetigbee Formation and Bashi Formation ........... 21 Claiborne Group ........................................... 21 Tallahatta Formation ................................. 21 Lisbon Formation ..................................... 21 Gosport Sand ......................................... 22 Jackson Group ............................................. 22 iii CONTENTS Continued Page Moodys Branch Formation .............................. 22 Yazoo Clay and Ocala Limestone ....................... 22 Oligocene Series ............................................... 23 Red Bluff Formation and Bumpnose Formation ................ 23 Vicksburg Group ........................................... 23 Mint Springs Formation and Marianna Formation ........ 23 Glendon Formation .................................... 23 Bryam Formation ...................................... 23 Bucatunna Formation .................................. 23 Chickasawhay Formation .................................... 23 Paynes Hammock Formation .................................. 24 Miocene Series ................................................. 24 Pliocene Series ................................................ 24 Citronelle Formation ...................................... 24 Quaternary System ................................................... 24 Pleistocene and Holocene Series ................................ 24 Relation of geologic units to aquifers and confining units ............... 24 Tuscaloosa aquifer .................................................. 25 Eutaw aquifer ....................................................... 26 Providence-Ripley aquifer ........................................... 27 Nanafalia-Clayton aquifer ........................................... 27 Lisbon aquifer ...................................................... 28 Floridan and Gulf Coastal Lowlands aquifer systems .................. 28 Summary .................................................................. 29 Selected references ...................................................... 31 iv ILLUSTRATIONS Page Figure 1. Alabama Coastal Plain study area, Southeastern Coastal Plain Regional Aquifer System Analysis study area, and parts of adjacent Regional Aquifer System Analysis study areas ........ 2 2. Interpretation of representative electric logs of oil-test wells showing correlation of formation tops and changes in lithology between eastern and western Alabama ................ 5 3. Physiographic provinces of Alabama ............................. 7 4. Diagrammatic geologic section showing stratigraphic relations of Upper Cretaceous formations in Alabama .................... 10 5. Correlation chart of outcropping stratigraphic units of Late Cretaceous age in the upper part of the Coastal Plain in Alabama ............................................. 11 6. Location of prominent salt-related structural features in the Alabama Coastal Plain .................................... 13 TABLE Table 1. Well data for stratigraphic sections in the Coastal Plain of Alabama .................................................... 35 PLATES (Plates are in pocket) Plate 1. Map showing location of key wells and stratigraphic sections in the Coastal Plain of Alabama 2. Stratigraphic section A-A^ 3. Stratigraphic section B-B' 4. Stratigraphic section C-c" 5. Stratigraphic section D-D' 6. Stratigraphic section E-E^ Plate 7-15. Maps showing: 7. The configuration of base of the Cretaceous System 8. The configuration of top of the Lower Cretaceous rocks undif f erentiated ILLUSTRATIONS continued Plates 7-15. Maps showing: continued 9. The configuration of top of the Coker Formation 10. The configuration of top of the Gordo Formation 11. The configuration of top of the Eutaw Formation 12. The configuration of top of the Selma Group 13. The configuration of top of the Midway Group 14. The configuration of top of the Wilcox Group 15. The configuration of top of the Claiborne Group 16. Generalized correlation chart showing stratigraphic and hydrogeologic units in the Coastal Plain of Alabama 17. Generalized outcrop of the Selma Group in the northeastern part of the Coastal Plain in Alabama and lines of measured geologic profiles. A, Map showing outcrop of the Selma Group and lines of measured geologic profiles (A-A^, B-B', and C-C^). B, Lithologic columns from measured profiles showing correlation and facies changes in the outcropping formations of the Selma Group vi STRATIGRAPHIC AND HYDROGEOLOGIC FRAMEWORK OF THE ALABAMA COASTAL PLAIN By Marvin E. Davis ABSTRACT Tertiary and Cretaceous sand aquifers of the Southeastern United States Coastal Plain comprise a major multistate aquifer system informally defined as the Southeastern Coastal Plain aquifer system, which is being studied as part of the U.S. Geological Survey's Regional Aquifer System Analysis (RASA) program. The major objectives of each RASA study are to identify, delineate, and map the distribution of permeable clastic rock, to examine the pattern of ground-water flow within the regional aquifers, and to develop digital computer simulations to understand the flow system. The Coastal Plain aquifers in Alabama are being studied as a part of this system. This report describes the stratigraphic framework of the Cretaceous, Tertiary, and Quaternary Systems in Alabama to aid in delineating aquifers and confining units within the thick sequence of sediments that comprises the Southeastern Coastal Plain aquifer system in the State. Stratigraphic units of Cretaceous and Tertiary age that make up most of the aquifer system in the Coastal Plain of Alabama consist of clastic deposits of Early Cretaceous age; the Coker and Gordo Formations of the Tuscaloosa Group, Eutaw Formation, and Selma Group of Late Cretaceous age; and the Midway, Wilcox, and Claiborne Groups of Tertiary age. However, stratigraphic units of late Eocene to Holocene age partially overlie and are hydraulically connected to clastic deposits in southern Alabama. These upper carbonate and clastic stratigraphic units also are part of the adjoining Floridan and Gulf