Date of Graduation

5-2015

Document Type

Thesis

Degree Name

Master of Science in Geology (MS)

Degree Level

Graduate

Department

Geosciences

Advisor

Doy Zachry

Committee Member

Ralph David

Second Committee Member

Jason Patton

Abstract

The crushed stone mining industry is valued at nearly one billion dollars in Arkansas alone. Physical properties of the rock dictate whether or not an area may be suited for the establishment of an aggregate quarry. The Gum Log quarry located 10 miles northeast of Russellville, Arkansas is geographically well situated near areas in need of aggregate material, as well as physically competent rock. The rock mined in Gum Log is located in the Upper Atoka Formation, a Middle Pennsylvanian aged member of the Arkoma Basin. There are five different lithologic facies identifiable in the quarry (Facies 1-5 respectively): A shallow marine, fissile shale unit marks the oldest facies observable in the quarry; a distal bar sandstone with macerated plant debris; thick, highly cross-bedded distributary-mouth-bar sandstone; a tidal flat siltstone facies; and highly cross-bedded distributary channel sandstone, which is the youngest facies observed in Gum Log.

By using LA Abrasion test results on the different facies of Gum Log quarry the aggregate potential of the rock can be evaluated. Facies 1 is not well suited for aggregate mining and is unable to be tested with the LA Abrasion method because the process is not designed to test shale. Facies 2 has an average LA percentage of 47.6% and is not suitable for aggregate material. Facies 3 is separated into three units based on engineering properties, and have average LA percentages of 27.4, 31.6, and 43.1% from top to bottom in the section. This facies is the primary unit mined in Gum Log quarry and is well suited for aggregate material. Facies 4 has average LA percentages over 60% as is not suitable for aggregate material. Facies 5 has an average LA percentage of 27.3% and is very well suited for aggregate material; however current prices deem the unit uneconomic. Based on the results of this analysis, mining in Gum Log quarry should continue north and east, following the thick sandstone of Facies 3 and avoiding the overlying siltstones of Facies 4.

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