Figure 9. Pliocene–Pleistocene unconformity surface with Precambrian Reelfoot rift faults. B—Big Lake, S—Lake St. Francis, CR—Crowley's Ridge, J—Joiner ridge, GRTZ—Grand River tectonic zone; CMTZ—Central Missouri tectonic zone; OFZ—Osceola fault zone; BMTZ—Bolivar-Mansfield tectonic zone; WRFZ—White River fault zone. EM—Eastern Rift Margin faults, AF—Axial fault, WM—Western Rift Margin fault, RF—Reelfoot fault, NM—New Madrid. AR—Arkansas, IL—Illinois, KY—Kentucky, MO—Missouri, MS—Mississippi, TN—Tennessee. Tiptonville dome is a culmination on the Lake County uplift. Crowley's Ridge south of lat 35°N not shown.