Figure 2. Location map of the outcrop at Big Rock Quarry (star symbol) and tectonic map of the Ouachita salient during the Ouachita orogeny (modified after Whitaker and Engelder, 2006). Foreland basins are shaded; Broken Bow (BBU) and Benton (BU) uplifts are stippled. DRU—Devil's River Uplift; FWB—Fort Worth Basin; AMB—Ardmore/Marietta Basin; AU—Arbuckle Uplift; AB—Arkoma Basin; JM—Jackfork Mountain Fault; MSB—Mississippi Slate Belt; BWB—Black Warrior Basin; OAJ—Ouachita-Appalachian Juncture.