Quaternary vegetation history of the Mississippi embayment

Journal Article · Tue Jan 01 00:00:00 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), Vol. 13
• Country of Publication: United States
• Language: English

Related Subjects

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