Early pennsylvanian currents in the southern Appalachian Mountains

Geological Society of America Bulletin
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Abstract

Measurement of more than 1200 cross-beds in lower Pennsylvanian sandstones of the southern Appalachian Mountains reveals a broad pattern of sediment transport to the southwest and west. Most of the sand appears to have been derived from the east and to have moved south-westward parallel to the axis of the Appalachian geosyncline. The pattern has a similar alignment to that in the Illinois basin, but it is at right angles to earlier Paleozoic dispersal directions in the Appalachian geosyncline. Little or no sand has been contributed from the Cincinnati arch.

The cross-beds are in sheetlike sandstone formations; the sandstone is conglomeratic, contains plant impressions, and is composed of lenticular, channeling, quartzose sedimentation units. The variation in thickness and lateral persistence of sedimentation units is also reflected in a moderate variability of mean cross-bedding directions between adjacent formations, and even within the same formation. Cross-bedding variability between adjacent units is thought to be due to regional changes in the position and orientation of channel-way systems from deposition of one sandstone formation to the next. Changes of cross-bedding azimuths within the same formation may result from channel curvature of local meanderlike deposits or from channel migration as the sands coalesced into a blanket deposit.

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Publication type Article
Publication Subtype Journal Article
Title Early pennsylvanian currents in the southern Appalachian Mountains
Series title Geological Society of America Bulletin
DOI 10.1130/0016-7606(1963)74[1439:EPCITS]2.0.CO;2
Volume 74
Issue 12
Year Published 1963
Language English
Publisher Geological Society of America
Description 13 p.
First page 1439
Last page 1451
Country United States
State Kentucky, Tennessee, Alabama, Georgia
Other Geospatial southern Appalachian Mountains
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