Quaternary vegetation history of the Mississippi embayment

Journal Article · Tue Jan 01 04:00:00 EST 1980 · Quat. Res. (N.Y.); (United States)

DOI:https://doi.org/10.1016/0033-5894(80)90086-1· OSTI ID:5242535

Delcourt, P A ^[1]; Delcourt, H R; Brister, R C; Lackey, L E

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1. Univ. of Minnesota, Minneapolis

Nonconnah Creek, located in the loess-mantled Blufflands along the eastern wall of the Lower Mississippi Alluvial Valley in Tennessee displays a sedimentary sequence representing the Altonian Substage through the Woodfordian Substage of the Wisconsinan Stage. The site has a biostratigraphic record for the Altonian and Farmdalian Substages that documents warm-temperate upland oak-pine forest, prairie, and bottomland forest. At 23,000 y B.P., white spruce and larch migrated into the Nonconnah Creek watershed and along braided-stream surfaces in the Mississippi Valley as far as southeastern Louisiana. The pollen and plant-macrofossil record from Nonconnah Creek provides the first documentation of a full-glacial locality in eastern North America for beech, yellow poplar, oak, hickory, black walnut, and other mesic deciduous forest taxa. During the full and late glacial, the Mississippi Valley was a barrier to the migration of pine species, while the adjacent Blufflands provided a refuge for mesic deciduous forest taxa. Regional climatic amelioration, beginning about 16,500 y B.P., is reflected by increases in pollen percentages of cool-temperature deciduous trees at Nonconnah Creek. The demise of spruce and jack pine occurred 12,5000 y B.P. between 34/sup 0/ and 37/sup 0/N in eastern North America in response to postglacial warming.

• OSTI ID: 5242535
• Journal Information: Quat. Res. (N.Y.); (United States), Journal Name: Quat. Res. (N.Y.); (United States) Vol. 13; ISSN QRESA
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580100* -- Geology & Hydrology-- (-1989)
AGE ESTIMATION
CENOZOIC ERA
CLIMATES
FOSSILS
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GERM CELLS
GLACIERS
MISSISSIPPI RIVER
NORTH AMERICA
PALEONTOLOGY
PLANTS
POLLEN
QUATERNARY PERIOD
RIVERS
SOUTHEAST REGION
STRATIGRAPHY
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TENNESSEE
USA