Date of Graduation

12-2016

Document Type

Thesis

Degree Name

Master of Science in Geology (MS)

Degree Level

Graduate

Department

Geosciences

Advisor

Doy L. Zachry

Committee Member

Matthew D. Covington

Second Committee Member

Adriana Potra

Keywords

Earth sciences; Arkoma basin; Diagenesis; Hartshorne sandstone; Provenance; Sedimentary petrology

Abstract

The Pennsylvanian Hartshorne Sandstone crops out in an east trending belt across central Arkansas immediately north of the Ouachita orogenic belt and south of the Boston Mountains. The unit, composed of massive to cross bedded sandstone ranging to 150m in thickness, was deposited by a west-flowing river system that extended from central Arkansas to southeastern Oklahoma. The source of the sediment has been extensively discussed but not completely established. The object of this thesis is to constrain the source area and terrain based on thin section mineralogy and texture. Thin sections were prepared from outcrops in the Arkoma Basin and were selected from a collection of 45 thin sections for analysis utilizing a petrographic microscope and petrographic analytical techniques.

The Hartshorne Sandstone is composed of quartzose phyllarenite with small amounts amounts of plagioclase and orthoclase feldspar in addition to accessory minerals including zircon, tourmaline and muscovite. Metamorphic rock fragments composed of phyllite dominate the lithic components, schist fragments occur but are rare.

The uplands north of the Arkoma basin are uniformly composed of sandstone composed of quartzarenite interbedded with shale and limestone. Metamorphic rock fragments are rare or absent. Sandstones that compose the Stanley Formation (Mississippian) and the Atoka Formation (Pennsylvanian) of the frontal Ouachita Mountains contain abundant lithic fragments (Atoka) and feldspar (Stanley). The lithic composition of the Stanley and the Atoka is consistent with the lithic composition of the Hartshorne. This suggests that the Hartshorne sediments were sourced from adjacent exposures of the Stanley and Atoka formations south of the Arkoma Basin and that early uplift of the Frontal Ouachitas were instrumental in confining the Hartshorne River system to a westward direction across the incipient Arkoma Basin early in Pennsylvanian time.

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