The surface geology of the Kosse Mine is dominated by the Eocene-aged Calvert Bluff Formation, which is mostly composed of "mudstone with various amounts of sandstone, lignite, ironstone concretions, and in the uppermost part, locally glauconitic" (Proctor et al. 1970). The floodplain of Steele Creek and the lower reaches of its largest tributaries (Owens Creek and Polecat Creek) are dominated by Holocene alluvial deposits that include "indistinct low terrace deposits; gravel, sand, silt, silty clay, and organic matter" (Proctor et al. 1970). Some of the gravel in the Holocene alluvial deposits may have been suitable for knapping by local prehistoric populations and is the most likely raw material source for the chert and quartzite lithic artifacts recovered during previous survey within the mine (cf. Dixon and Sherman 2010; Sherman and Watkins 2007; Sherman et al. 2006). The sandstone and ironstone in the Calvert Bluff Formation, if it outcrops locally, may have served as a raw material resource for prehistoric populations for making ground stone tools and grinding implements or for use in roasting pits (see Sherman et al. 2007). Significant deposits of clay suitable for pottery manufacture were recorded in southern Limestone County and northern Robertson County, and specifically, near Headsville (Potter and McKnight 1931). A large outcrop of kaolinite, which appeared to have been exploited at least historically, was identified at site 41LT424 (Sherman and Watkins 2007). The ........

The Kosse Mine began extracting lignite (coal) in 2007. The project area is approximately eight miles east of the town of Kosse, Texas; is contained within the Oletha and Bald Prairie 7.5-minute USGS quadrangle maps; and is in the following USGS Hydrologic Units: 120701030203 (Middle Steele Creek), 120701030204 (Lower Steele Creek), and 120701030403 (Upper Duck Creek). The proposed project area is generally contained within the following area: west of an oil well road; south of Heads Creek; north of Robertson County Road 477 and various property tracts; and east of an existing rail line from the mine to the Oak Grove Steam Electric Station.

Surface mining operations would continue with conventional open pits excavated by large draglines and supported by standard earth moving equipment such as front-end loaders, hydraulic excavators, hydraulic backhoes, haulers, motor graders, dozers, end dumps, and scrapers. Infrastructure in support of the operation would include (1) construction of ponds and diversions to control surface water drainage, (2) placement of groundwater well fields to dewater overburden and relieve underburden pressures, (3) relocation of pipelines, and (4) construction of service roads.

Continued mining of the Kosse Mine would provide Luminant Generation Company LLC reliable access to an additional reserve of low cost lignite fuel resource to fuel the adjacent Oak Grove Steam Electric Station. In addition, this fuel resource is necessary t ........