Publication Date

1980

Document Type

Dissertation/Thesis

First Advisor

Webb, Peter-Noel

Degree Name

M.S. (Master of Science)

Department

Department of Geology

LCSH

Geology--Arkansas||Petrology--Arkansas||Geology, Stratigraphic--Pennsylvanian

Abstract

The Atoka Formation, an early Pennsylvania clastic succession up to 28,000 feet thick, occurs within the Ouachita Mountains and Arkoma basin of Arkansas. Deltaic, continental shelf, and deep-sea fan systems deposited clastic sediment into a westerly trending geosynclinal trough. A depositional model has been constructed illustrating relationships of depositional systems and their associated facies. The basin filled quickly with clastic material derived from cratonic and extracontinental sources. The cratonic sediments were dispersed chiefly by shallow water dispersal systems that inter- fingered with a deep-water fan system supplied by extracontinental elastics. A paleocurrent study using sole markings and ripple marks indicates bi-directional material discharge. Ripple marks in shallow-water deltaic and continental shelf sandstones generally indicate southerly flow directions whereas deep-water turbidites repeatedly show west to southwest flow directions. Active deposition with synchronous subsidence gave rise to down-to-the-basin growth faults, resulting in collapse of the northern shelf and migration of the trough axis northward. A period of major mountain building during late Atoka deposition created numerous east-west trending thrust faults, anticlines, and synclines in the Ouachita province, but there appears not to have had any effect on sediment composition.

Comments

Includes bibliographical references.

Extent

123 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.

Media Type

Text

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