Facies analysis and depositional environment of the Ames Marine Member of the Conemaugh Group in the Appalachian Basin
The lithologic and paleontological aspects for fifty localities of the Ames Marine Member were examined. The regional stratigraphic reconstruction shows that it is variably composed of limestone and shale, and often associated with a thin basal coal seam. A generalized, composite stratigraphic section of the Ames Member consists of the following units from top to bottom: the Grafton Sandstone, Nonmarine Shale, Upper Ames Shale, Upper Ames Limestone, Middle Ames Shale, Lower Ames Limestone, Lower Ames Shale, Ames Coal, Nonmarine Silty Shale, and Harlem Coal. Harlem coal is commonly the basal coal in Ohio, and the Ames Coal is common in Pennsylvania and West Virginia. Insoluble residue analysis of 223 samples shows that quartz and glauconite are the major and significant residues. The major petrographic components of the Ames rocks are bioclastic grains of echinoderm, brachiopods, molluscs, bryozoa, and foraminifera in a matrix variably composed of clay and calcium carbonate. A quantitative microfacies study applying factor and cluster analysis reveals five basin-wide biofacies and four lithofacies reflecting a gradient from shoreline to an offshore position. The areal and vertical distribution of the different facies reflects the transgression-regression history of the Ames Cycle. A uniform slow eustatic rise of sea level with an early rapid transgression was responsible for the deposition of most of the Ames marine section. The small, upper, underdeveloped regressive section suggests a rapid regression by active prograding deltaic deposits which rapidly terminated the marine conditions over most the the Appalachian Basin.
- Research Organization:
- Pittsburgh Univ., PA (USA)
- OSTI ID:
- 6974024
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
011000* -- Coal
Lignite
& Peat-- Reserves
Geology
& Exploration
APPALACHIA
CARBONATE ROCKS
CHALCOGENIDES
COAL DEPOSITS
COAL SEAMS
FEDERAL REGION III
FEDERAL REGION V
FOSSILS
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
GEOLOGY
LIMESTONE
LITHOLOGY
MINERAL RESOURCES
MINERALS
NORTH AMERICA
OHIO
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PALEONTOLOGY
PENNSYLVANIA
PETROGRAPHY
QUARTZ
RESOURCES
ROCKS
SEDIMENTARY ROCKS
SEDIMENTATION
SHALES
SILICON COMPOUNDS
SILICON OXIDES
STRATIGRAPHY
USA
WEST VIRGINIA