scholarly journals Role of water in the formation of the Late Cretaceous Wetumpka impact structure, inner Gulf Coastal Plain of Alabama, USA

2006 ◽  
Vol 41 (10) ◽  
pp. 1625-1631 ◽  
Author(s):  
David T. King ◽  
Jens Ormö ◽  
Lucille W. Petruny ◽  
Thornton L. Neathery
Keyword(s):  
Late Cretaceous ◽  
Coastal Plain ◽  
Impact Structure ◽  
Gulf Coastal Plain

Late Santonian megaspore floras from the Gulf Coastal Plain (Georgia, USA)

2011 ◽  
Vol 85 (1) ◽  
pp. 1-21 ◽  
Author(s):  
Richard Lupia
Keyword(s):  
New Species ◽  
North America ◽  
Late Cretaceous ◽  
Coastal Plain ◽  
Eastern North America ◽  
Gulf Coastal Plain ◽  
Two New Species ◽  
Western Interior Basin ◽  
Heterosporous Ferns

Fossil megaspore floras from the Late Cretaceous of North America have been studied extensively, but primarily from the Western Interior Basin. Two new megaspore floras are described from eastern North America along the Gulf Coastal Plain. Cumulatively, 10 genera and 16 species of megaspores are recognized from Allon, Georgia and along Upatoi Creek, Georgia (both late Santonian in age, ~84 Ma). Megaspores identified have affinities to both heterosporous lycopsids, e.g., Erlansonisporites, Minerisporites, and Paxillitriletes, and to heterosporous ferns, e.g., Ariadnaesporites, and Molaspora. Lycopsid megaspores are more diverse than fern megaspores in the Allon and the Upatoi Creek floras. Two new species—Erlansonisporites confundus n. sp. and Erlansonisporites potens n. sp.—are proposed.

New Ostracoda species from an Upper Cretaceous oyster reef, northern Gulf Coastal Plain, U.S.A.

1994 ◽  
Vol 68 (6) ◽  
pp. 1321-1335 ◽  
Author(s):  
T. Markham Puckett
Keyword(s):  
New Species ◽  
Late Cretaceous ◽  
Coastal Plain ◽  
Upper Cretaceous ◽  
Oyster Reef ◽  
Oyster Reefs ◽  
Total Thickness ◽  
Topographic Feature ◽  
Gulf Coastal Plain ◽  
Eutaw Formation

This paper describes new species of Ostracoda from Late Cretaceous (late Santonian) oyster reefs of the Eutaw Formation of eastern Alabama. The reefs are composed almost exclusively of Ostrea cretacea Morton, with rarer occurrences of the oysters Exogyra upatoiensis Stephenson and Lopha ucheensis (Stephenson) and the bivalve Anomia preolmstedi Stephenson. Total thickness of the reefs is about 30 m, and the reefs are a major topographic feature across most of Macon and Russell Counties, Alabama, a distance of about 60 km. The reefs are interpreted to have been backbarrier sediments deposited under brackish conditions.Eight species of ostracodes are identified, including five new species described herein. The fauna is typically well preserved, and includes males, females, and juveniles. New species include Haplocytheridea? eutawensis, Antibythocypris dimorphicus, A. nephotrema, Brachycythere asymmetrica, and Eocytheropteron mutafoveata. Also discussed and illustrated are Cytherella tuberculifera Alexander, Haplocytheridea renfroensis renfroensis Crane, and Fissocarinocythere gapensis (Alexander).

Late Cretaceous sediment provenance in the eastern Gulf Coastal Plain (U.S.A.) based on detrital-zircon U-Pb ages and Th/U values

2021 ◽  
Vol 91 (10) ◽  
pp. 1025-1039
Author(s):  
William T. Jackson ◽  
Matthew P. McKay ◽  
Donald A. Beebe ◽  
Carolyn Mullins ◽  
Adelie Ionescu ◽  
...  
Keyword(s):  
Late Cretaceous ◽  
Coastal Plain ◽  
Detrital Zircon ◽  
Detrital Zircons ◽  
Sediment Provenance ◽  
Gulf Coastal Plain ◽  
Spatiotemporal Resolution ◽  
Mississippi Embayment ◽  
Continental Scale ◽  
Appalachian Foreland

ABSTRACT Detrital-zircon U-Pb geochronology documents a regional- to continental-scale drainage reorganization along the eastern Gulf Coastal Plain (USA) from the Late Cretaceous (Cenomanian) to the Paleocene–Eocene. We present detrital-zircon U-Pb ages and Th/U values from the Maastrichtian Ripley Formation to determine the sedimentary provenance and to provide spatiotemporal resolution of drainage reorganization. The Ripley Formation contains a 12.7% overall average abundance of detrital zircons with low (< 0.1) Th/U values relative to the underlying Cenomanian Tuscaloosa Group (3.6%), the overlying Paleocene–Eocene Wilcox Group (2.8%), an Appalachian foreland composite (2.1%), and the laterally equivalent McNairy Sandstone in the northern Mississippi Embayment (3.8%). Multidimensional scaling of detrital-zircon U-Pb spectra shows that the Ripley Formation is dissimilar from underlying and overlying Gulf Coastal Plain units, the McNairy Sandstone, and an Appalachian foreland composite sample because of differences in proportions of Appalachian (490–270 Ma) and Grenville (1250–900 Ma) zircons. We interpret the southern Appalachian Piedmont province as the principal sediment source region for the Ripley Formation to account for the elevated abundance of grains with low (< 0.1) Th/U values and unique detrital-zircon U-Pb age spectra. Results suggest a regional-scale (105 km2) drainage network, which delivered sediment to the Maastrichtian coast followed by northwestward littoral transport and eventual mixing with Appalachian foreland-derived sediment in the northern Mississippi Embayment. This study further brackets drainage reorganization along the eastern Gulf Coastal Plain and demonstrates how simple chemical–age relationships, such as zircon Th/U values coupled with U-Pb ages, can be used to evaluate sediment provenance.

Sign in / Sign up

Export Citation Format

Share Document