Publication Date

1973

Document Type

Dissertation/Thesis

First Advisor

Morris, Robert C. (Robert Clarence), 1928-

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Geology

LCSH

Petrology--Arkansas

Abstract

The Mississippian Hot Springs and Tenmile Creek Formations are flysch-like rocks that crop out in the Southern Ouachita Mountains of Arkansas. The Hot Springs Sandstone, 100 to 200 feet thick in its type area at Hot Springs, Arkansas, thins to a feather edge to the soutDekooning34h and west. Sandstone is dominant with lesser amounts of chert breccias and shale. Parallel and undulatory laminations in some of the sandstone beds suggest deposition from turbidity currents in the upper flow region. The thick, shaly Tenmile Creek Formation is generally poorly exposed and structural details are obscure so that a complete section could not be determined. The lack of well-defined zones of siliceous shale does not permit the same stratigraphic refinements as in Oklahoma. Field studies show that it is feasible to divide the Hot Springs and Tenmile Creek Formations into facies based on bedding type. The Hot Springs is predominantly a non-scoured, proximal turbidite facies. The Tenmile Creek is dominantly shale, but sandy flysch and non-scoured proximal turbidites predominate in the sections that were studied. Chert breccias, present in the basal Stanley, express the only pattern in the types of disturbed bedding. They are thickest near Hot Springs and thin rapidly to the west and south. Paleocurrent data from 115 Tenmile Creek sole markings indicate the dominance of northwesterly current flow, with components of easterly and southwesterly flow, suggesting that a southern or southeastern provenance was active during Tenmile Creek deposition. Thinning of the Hot Springs to the west and south suggests a source to the northeast. The Hot Springs and Tenmile Creek sandstones are petrographically distinct. The Hot Springs sandstones are quartz arenites that generally contain less than 1 percent feldspar. Tenmile Creek sandstones are quartz and lithic wackes with more than 5 percent feldspar. The Hot Springs sandstones probably were derived from a cratonic source, whereas a mixed low-rank metamorphic and sedimentary source supplied the clastic materials for the Tenmile Creek sandstones. Factor analysis and discriminant function analysis were utilized to investigate compositional and textural relationships among the sandstones studied. Both methods show that there is no difference which is related to either paleocurrent direction or position within the study area. This suggests only one major dispersal point for the Tenmile Creek sandstones. The depositional area was probably an abyssal plain. The Hot Springs sandstones entered the depositional trough from the northeast via submarine canyons and were deposited in or at the heads of the canyons with minor amounts spilling further onto the abyssal plain. The Tenmile Creek turbidites entered the depositional trough from the south or southeast by submarine canyons and built up submarine cones or fans upon the abyssal plain.

Comments

Includes bibliographical references.||Includes illustrations and maps.||Pagination repeats number 40.

Extent

viii, 93 pages

Language

eng

Publisher

Northern Illinois University

Rights Statement

In Copyright

Rights Statement 2

NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.

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Text

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