A Lower Ordovician sponge/algal facies in the southern United States and its counterparts elsewhere in North America
- Vanderbilt Univ., Nashville, TN (USA)
- Geological Survey, Reston, VA (USA)
Subsurface Ordovician rocks in the Black Warrior Basin, Mississippi Embayment, and the eastern part of the Arkoma Basin reflect a different depositional history than coeval rocks exposed in the Nashville Basin, Ozark Dome, and southern Appalachians. The succession consists of four informal lithologic units. From top to bottom these are: (1) Stones River limestones, (2) upper dolostone, (3) sponge/algal limestones characterized by the presence of Nuia, and (4) lower dolostone. Of these, the sponge/algal limestone unit is the most atypical. It has a conspicuous biotic assemblage which can be recognized petrographically in well cuttings. The diagnostic fossil allochems are: sponges, sponge spicules, Nuia, Girvanella, and Sphaerocodium. Conodonts from the sponge/algal limestones are probably entirely Early Ordovician (Canadian) and include cold- and deep-water species found in the North Atlantic Province, whereas those in the overlying dolostones represent exclusively warm-water, shelf environments. The conodonts in the Black Warrior Basin suggest that an unconformity between Lower and Middle Ordovician carbonates (Knox unconformity) does not exist in much of that region. The sponge/algal limestones represent a different facies than their coeval shelf rocks in the interior of the continent. The limestone contains a distinctive biotic assemblage recognized in Lower Ordovician rocks in Newfoundland, in the Arbuckle and Wichita mountains of Oklahoma, in West Texas, and in the Great Basin of Nevada and Utah.
- OSTI ID:
- 6966827
- Journal Information:
- Palaois; (USA), Journal Name: Palaois; (USA) Vol. 4:3; ISSN PALAE
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sedimentological cross section of Cambro-Ordovician carbonate shelf (Knox group, Conassauga Formation) in central Alabama: facies, diagenesis, potential reservoirs
Sedimentological cross section of Cambro-Ordovician carbonate shelf (Knox group, Conasauga Formation) in central Alabama: facies, diagenesis, potential reservoirs
Related Subjects
580000* -- Geosciences
ALABAMA
ALGAE
APPALACHIAN BASIN
AQUATIC ORGANISMS
ARKANSAS
CANADA
CARBONATE ROCKS
CORRELATIONS
DEPOSITION
FEDERAL REGION IV
FEDERAL REGION IX
FEDERAL REGION VI
FEDERAL REGION VII
FEDERAL REGION VIII
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGIC STRATA
GEOLOGIC STRUCTURES
GEOLOGY
HABITAT
ISLANDS
LIMESTONE
LITHOLOGY
MISSISSIPPI
MISSOURI
NEVADA
NEWFOUNDLAND
NORTH AMERICA
OKLAHOMA
ORDOVICIAN PERIOD
PALEOCLIMATOLOGY
PALEONTOLOGY
PALEOZOIC ERA
PETROGRAPHY
PLANTS
ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
STRATIGRAPHY
TECTONICS
TENNESSEE
TEXAS
USA
UTAH