Allogenic processes, sediment flux, and Carboniferous stratigraphy in the Appalachian basin

Conference · Wed Jan 01 00:00:00 EST 1992 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5973338

Cecil, C B; Dulong, F T; Edgar, N T ^[1]

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1. Geological Survey, Reston, VA (United States)

The origin of Carboniferous strata in the central Appalachian basin is being evaluated as a function of paleoclimatic, eustatic, and tectonic processes. Of these processes, paleoclimate has, in the past, received the least attention but appears to be of primary importance as a control on stratigraphy. For example, Upper Mississippian strata include both marine carbonates and marine dark gray to black shales. The marine carbonate units are underlain and overlain by paleosols that contain calcic peds, pseudomorphs of gypsum, and rhizoconcretions with vertical root structures suggesting low soil moisture. The marine limestone generally is in sharp contact with an underlying paleosol. The lithostratigraphy of such a sequence is consistent with a transgressive-regressive cycle under relatively dry (semiarid) climatic conditions, which limits siliciclastic influx. In contrast, the marine gray and black shales are bounded by leached paleosols containing horizontal rhizomorphs and coal beds suggestive of wet soil conditions. Terrestrial organic matter in marine shales indicate relatively high terrestrial organic productivity, and the shale units are in gradational contact with underling strata. The lithostratigraphy of the marine shale sequences is consistent with deposition under relatively wet climatic regimes (probably seasonal and subhumid), which increased siliciclastic and terrestrial organic matter input. Relatively short-term climate cycles were a primary control on sediment flux within Carboniferous deposystems in the Appalachian basin. Long-term climate change also occurred as eastern North America moved from relatively dry latitudes of the southern hemisphere through the tropical rainy belt into drier latitudes of the northern hemisphere. Long-term tectonic change provided accommodation space. Such controls can readily be observed throughout Carboniferous strata in the Appalachian basin.

• OSTI ID: 5973338
• Report Number(s): CONF-921058-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 24:7; Conference: 1992 annual meeting of the Geological Society of America (GSA), Cincinnati, OH (United States), 26-29 Oct 1992; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
01 COAL, LIGNITE, AND PEAT
04 OIL SHALES AND TAR SANDS
APPALACHIAN BASIN
STRATIGRAPHY
BLACK SHALES
CARBONATE ROCKS
CARBONIFEROUS PERIOD
CLIMATIC CHANGE
COAL DEPOSITS
GEOLOGIC HISTORY
LITHOLOGY
MOISTURE
PALEOCLIMATOLOGY
SEDIMENTATION
TECTONICS
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC STRUCTURES
GEOLOGY
MINERAL RESOURCES
PALEONTOLOGY
PALEOZOIC ERA
PETROLOGY
RESOURCES
ROCKS
SEDIMENTARY BASINS
SEDIMENTARY ROCKS
SHALES
580000* - Geosciences
011000 - Coal
Lignite
& Peat- Reserves
Geology
& Exploration
040200 - Oil Shales & Tar Sands- Reserves
Geology
& Exploration