[meteorite-list] Carolina Bays and Wells Creek Structure

From: Paul H <bristolia_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:52 2004
Message-ID: <20040322143842.25001.qmail_at_web21403.mail.yahoo.com>

Mark A. Massey asked:
Sat, 20 Mar 2004 23:07:53 -0800 (PST)

>I was wondering if anybody may have some good
>information regarding Wells Creek,TN?.

Tiedemann, Herbert A., 1997, The Wells Creek
Structure, Tennessee ; from heaven or hell? In
Ames structure in northwest Oklahoma and similar
features; origin and petroleum production (1995
symposium, Kenneth S. Johnson and Jock A.
Campbell, eds., pp. 265-271. Oklahoma
Geological Survey Circular, vol. 100.

The abstract to this article stated:
 
"The Wells Creek structure in northwestern middle
Tennessee is an anomalous geologic feature whose
origin has been the subject of speculation since
its discovery. Detailed mapping of Wells Creek by
geologists at Vanderbilt University revealed a
circular structure, 8 mi in diameter, with a
brecciated Lower Ordovician central core
surrounded by concentric horst-and-graben rings
of Lower Mississippian strata. The dominant
relative movements in Wells Creek were
downdropping of the grabens, uplift of the central
block, and lateral offset along radial faults.
Wells Creek is generally considered to be due to
a meteorite impact because of its typical impact
structure and the presence of shatter cones. The
buried Ames structure in Major County, Oklahoma,
another feature with typical impact structure,
lacks shatter cones, but contains shocked quartz
and has granite basement involved in the
structure. I consider Ames and Wells Creek similar
enough in size and structural elements--central
uplift, horst-and-graben zones, radial faulting,
and brecciation--to warrant considering Wells
Creek as a structural model for Ames."

Other articles:

Stearns, R. G. Wilson, C. W., Jr., Tiedemann,
H. A., Wilcox, J. T. and Marsh, P. S. 1968b,
The Wells Creek structure , Tennessee. In
Shock metamorphism of Natural Materials, B.M.
French and N. M. Short, eds., pp. 323-338, 1st
Conference, Greenbelt, Md., 1966, Proceedings,
Mono Book Corp, Baltimore, Md.

Wilson, C. W., Jr., Sterns, R. G., Tiedemann,
H. A., Wilcox, J. T., and Marsh, P. S., 1968a,
Geology of the Wells Creek structure , Tennessee
Tennessee, Division of Geology Bulletin no. 68.
Tennessee Department of Conservation, Division
of Geology, Nashville, Tennessee. 236 pp.

A webpage with lots of citations is:

Wells Creek
http://www.unb.ca/passc/ImpactDatabase/images/wells-creek.htm

>Also, I was just going to ask if anybody has info
>regarding Carolina Bays?. Thanks in advance.
>What a great website!!!.

An excellent reference on Carolina Bays is:

May, J. H. and Warne, A. G., 1999, Hydrogeologic
and Geochemical Factors Required for the
Development of Carolina Bays Along the Atlantic
and Gulf of Mexico, Coastal Plain,USA.
Environmental & Engineering Geoscience. vol. V,
no. 3, pp. 261-270. (Fall 1999)

They argue that "Carolina Bays" found within the
coastal plains of the Atlantic Coastal Plain and
the Gulf coastal plain of Mississippi and Alabama
are siliclastic karst. (Yes, there are "Carolina
Bays" along the Gulf of Mexico coastal plain.)

In part, the abstract reads:

"More than 60 years of intense study and debate
have yet to resolve the origin of the Carolina
Bays. Carolina Bays are circular to elliptical
depressions located along the Gulf of Mexico and
Atlantic Coastal Plains. Proposed processes of
initiation and development of these karst-like
features include meteorite impacts, substrate
dissolution, wind, ice, marine waves and currents.
Based on field studies throughout the Atlantic and
Gulf Coastal Plains and on review of coastal plain
literature, we propose that Carolina Bays
initially developed as silica-karst features."

and

"Localized infiltration of phreatic water induced
extensive desilicification of the sandy and clayey
substrates, resulting in volume loss and development
of karst-like depressions.
Particularly relevant to initial bay development
was alteration of kaolinite to gibbsite, which can
produce a 34-percent loss in clay material volume,
and concurrent dissolution of iron oxide. The
initial silica-karst depressions along the
Atlantic and Gulf coasts were later modified by
eolian and, perhaps, ice-push processes, which
enhanced their elliptical form."

and

"Silica-karst features, similar to Carolina Bays
in their initial stages of development, are common
geologic features. Moreover, silica-karst
processes are active today in warm temperate,
subtropical, and tropical areas in sandy
substrates where ground-water levels are well below
the ground surface and can cause subsidence
or disrupt developing wetlands."

They argue that the development of Carolina Bays
occurred during "...Pleistocene sea-level
lowstands, water tables in the Atlantic Coastal
Plain were up to 30 m lower than today..." and
that they are currently relict, inactive
landforms.

Other citations about siliclastic karst are:

Isphording, W. C., 1996, Siliclastic karst
development on Citronelle Formation sediments,
Southeastern United States (Alabama-Mississippi).
Geological Society of America Abstract with
Programs. vol. 28, no. 2, p. 17.

Isphording, W. C. and Flowers, G. C., 1988, Karst
development in coastal plain sands; a "new"
problem in foundation engineering. Bulletin of
the Association of Engineering Geologists. vol.
25, no. 1, pp. 95-104.

Some other references:

Brooks, M. J., Taylor, B. E. and Grant, J. A.,
1996, Carolina bays and Holocene landscape
evolution on the Upper Coastal Plain of South
Carolina. Geoarchaeology. vol. 11, pp. 481-504

Brooks, M. J., Taylor, B. E., Stone, P. A., and
Gardner, L. A., 2001, Pleistocene encroachment
of the Wateree River Sand Sheet into Big Bay on
the middle coastal plain of South Carolina.
Southeastern Geology. vol. 40, no. 4.,
pp, 241-257.

Grant, J. A., Brooks, M. J., and Taylor, B.E.
1998, New constraints on the evolution of Carolina
bays from ground-penetrating radar. Geomorphology.
vol. 22, pp. 325-345.
http://www.uga.edu/srel/Reprint/2276.htm

Also, people might be interested in looking at:
"NEBRASKA'S CAROLINA BAYS" by ZANNER, C.
William at:
http://gsa.confex.com/gsa/2001AM/finalprogram/abstract_22324.htm

Some web pages;

Early Hunter-Gatherer Use of Carolina Bays by
Mark J. Brooks and Barbara E. Taylor at:
http://www.srarp.org/research/research/bays.html

"Age and Climatic Correlates of Carolina Bays
and Inland Dunes of the South Atlantic Coastal
Plain: New Data" at
http://www.cla.sc.edu/sciaa/srs.html

Yours,

Paul
Baton Rouge, LA


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Received on Mon 22 Mar 2004 09:38:42 AM PST