Impact Origin of Carolina Bays Argued For at 2007AGU Meeting
Paul bristolia at yahoo.com Sun Mar 11 11:04:01 EDT 2007
Sterling K. Webb wrote on Sun March 11, 2007
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Hi, List, >
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Thanks, Paul, for those links. You and the list might be interested to know that
there is a competing session Carolina Bays. A more
mainstream point of view on their formation will be
given at the Geological Society of America Southeastern
Section-56th Annual Meeting (29-30 March 2007) in a
session titled "S6. Geology and Ecology of Carolina
Bays" at:
http://gsa.confex.com/gsa/2007SE/finalprogram/session_18800.htmThe paper in this session include 1. "The Sedimentology
and Ages of Carolina Bays Sand Rims" by Dr. Ivestor at:
http://gsa.confex.com/gsa/2007SE/finalprogram/abstract_119179.htmThis abstract states in part:
"Water-lain pebbles intercalated with eolian sands indicate
that these are typical shoreline deposits resulting from
fluctuations in water level."
"At individual bays where concentric rims occur, dating has
established that rims are progressively younger toward the center
of the bay, reflecting a regressive sequence and confirming that
the bays are not single-event features but evolve as a result of
processes active episodically over a long period of time. Active
shorelines and associated eolian deposition occurred during
marine isotope stage (MIS) 2 to late MIS 3 (~12 to 50 ka), MIS 4
to very late MIS 5 (60-80 ka), and late MIS 6 (120 to 140 ka)
based on a cumulative total of 45 OSL dates. These age ranges
also correspond with the ages of other eolian landforms in the
Coastal Plain, including sand sheets and dunefields, and suggest
a climatic threshold was crossed during the transition toward
glacial stadials, initiating both bay and dune activity."
Another abstract is "Geomorphic History of the Carolina Bays"
by Ray Kaczorowski at:
http://gsa.confex.com/gsa/2007SE/finalprogram/abstract_118906.htmNeedless to say, this activity will be quite fun to watch as
all of these ideas are sorted out.
Best Regards,
Paul H.
