Turonian (Eaglefordian) stratigraphy of the Atlantic Coastal Plain and Texas
A stratigraphic analysis of 14 localities from New England to Georgia and of 1 well from the type area of the Eaglefordian Stage at Dallas, Texas, has resulted in a reevaluation of the ages of both formal and informal stratigraphic units previously established for the Atlantic and eastern Gulf Coastal Plains. Lower Turonian strata, once thought to be absent beneath the Atlantic Coastal Plain, are present. The study focused on a stratigraphic interval that is characterized by the presence of distinctive calcareous nannofossil and pollen floras. The Complexiopollis-Atlantopollis pollen assemblage zone, widespread throughout the Atlantic and Gulf Coastal Plains and previously dated as late Cenomanian, is now shown to be late Cenomanian-early Turonian on the Gulf Coast on the basis of its occurrence with calcareous nannofossils, planktic foraminifers, and mollusks of that age. On the Atlantic Coast, only the lower Turonian part of the Complexiopollis-Atlantopollis zone is known to be present. Stratigraphic units that are now assigned to the lower Turonian include: (1) the Woodbridge Clay and Sayreville Sand Members of the Raritan Formation, New Jersey; (2) the upper part of the Raritan equivalent beneath the eastern shore of Virginia; (3) the Tuscaloosa equivalent (informal units K2, E, and part of F) in the South Carolina and Georgia coastal region; (4) the Tuscaloosa Formation of eastern Alabama and western Georgia; and, beneath the Gulf Coastal Plain; (5) the Coker Formation of western Alabama; and (6) the upper Britton and lowermost Arcadia Park Formations at Dallas, Texas. Cenomanian strata beneath the Atlantic Coastal Plain are now interpreted to be much thinner than previously supposed. The lower Turonian there is bounded by upper Turonian and uppermost Cenomanian hiatuses of regional extent, whereas the upper Cenomanian-Turonian section is relatively complete at Dallas, Texas. 75 refs., 10 figs., 1 tab.
- Research Organization:
- Geological Survey, Denver, CO (USA)
- OSTI ID:
- 5260255
- Report Number(s):
- USGS-PP-1315; ON: TI85902206
- Country of Publication:
- United States
- Language:
- English
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Relative sea level changes in the Late Cretaceous (Cenomanian and Turonian stages) as reflected in the Tuscaloosa Group in the subsurface of southwest Alabama
Sequence stratigraphy of the Upper Cretaceous (Cenomanian and Turonian) Tuscaloosa Group in the subsurface of the eastern Gulf Coastal plain area