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 __________________________________ Do you Yahoo!? Yahoo! Finance Tax Center - File online. File on time. http://taxes.yahoo.com/filing.html ______________________________________________ Meteorite-list mailing list [EMAIL PROTECTED] http://www.pairlist.net/mailman/listinfo/meteorite-list
