Ribeyre Island Fault

Part of the Wabash Valley Fault System

Location

White County, Illinois, and Posey County, Indiana (I-8)

References

Bristol and Treworgy 1979, Ault et al. 1980,Tanner et al. 1980a-c, Tanner et al. 1981a-c

Description

The extent of the Ribeyre Island Fault is poorly known because of a lack of well control along its inferred northern portion. It is about 2,000 to 6,000 feet (0.6-1.8 km) west of the New Harmony Fault Zone. The east side is downthrown. Along its southern portion where it is well defined, the Ribeyre Island Fault displaces the West Franklin Limestone Member of the Modesto Formation by 170 feet (52 m), but less than 50 feet (15 m) of offset is shown on the Beech Creek ("Barlow") Limestone (Bristol and Treworgy 1979). Bristol and Treworgy interpreted the Ribeyre Island Fault as dying out northward into a monocline.