Title

Constraints on the Geologic History of the Karst System in Southern Missouri, U.S.A. Provided by Radiogenic, Cosmogenic, and Physical/chemical Characteristics of Doline Fill

Abstract

The Ozark Plateaus region of southern Missouri is underlain by dominantly carbonate marine platform rocks of Paleozoic age. The region has been sub-aerially exposed since the late Paleozoic and is characterized by extensive karst. To better understand the geologic history of this regional karst system, we examined the stratigraphic record preserved in the fill of a large doline near the largest spring in the region. Samples of fill from natural exposures and drill core were analyzed using thermoluminescence (TL) and 10Be cosmogenic techniques, and the physical/chemical characteristics of the fill material were determined by visual inspection, X-ray analyses, and grain-size measurements. Drill-hole data indicate that the allochthonous doline fill is 36.3 m thick and rests on at least 15.6 m of cave breakdown and sediment. The doline fill is divisible into 7 zones. Analysis of 10Be concentrations suggest that the entire doline fill was derived from local residuum during the middle (Illinoian) to late Pleistocene (Wisconsinan). X-ray diffraction analyses of clays throughout the doline fill indicate that they consist of nearly equal amounts of kaolinite and illite, consistent with terrestrial weathering.

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

Ozarks; Southern Missouri

Library of Congress Subject Headings

Cosmogony
Karst
Thermoluminescence

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2004 Slovenian Academy of Sciences and Arts, All rights reserved.


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