New Harmony Fault Zone (New Name)

Part of the Wabash Valley Fault System
Old Name: Mt. Carmel-New Harmony Fault

Location

Wabash and White Counties, Illinois, and Gibson and Posey Counties, Indiana (I-7, 8; J-7)

References

Pullen 1951, Cady et al. 1955, Bristol and Treworgy 1979, Ault et al. 1980, Tanner et al. 1980a-c, Tanner et al. 1981a-c, Braile et al. 1984, Ingram and Molinda 1988

Description

The New Harmony Fault was originally identified in Indiana and in White County, Illinois. It was named after the town of New Harmony, Indiana. A fault in Wabash County, Illinois, was named the Mt. Carmel Fault after the county seat. Bristol and Treworgy (1979) established that the two faults connected and combined the names as Mt. Carmel-New Harmony Fault. The name Mt. Carmel, however, also is used for a large fault in south-central Indiana, east of the Wabash Valley Fault System. In an attempt to avoid confusion, the Mt. Carmel-New Harmony Fault is changed to the New Harmony Fault Zone; the word "zone" is being added to reflect the compound nature of the faulting.

The New Harmony Fault Zone is composed of parallel, overlapping, normal faults that strike N25°E and dip 65° or steeper to the west (figs. 56, 57). The zone is about 43 miles (69 km) long and as much as 0.5 miles (0.8 km) wide. In areas of close well control, as many as five separate faults have been mapped within the zone. Displacements are down to the west. The maximum throw is 450 feet (137 m), which was measured in a well that cuts a fault in Posey County, Indiana (Ault et al. 1980). A set of three east-trending cross faults, connecting overlapping ends of two major fault segments, was observed in an underground coal mine in Wabash County, Illinois (Bristol and Treworgy 1979). The New Harmony Fault Zone splits and becomes more complex upward through the sedimentary section. This is shown by both the borehole data (Bristol and Treworgy 1979) and the seismic profiles of Braile et al. (1984).

Figure(s)

Figure 57   Drill core penetrating a segment of the New Harmony Fault Zone, Wabash County. Pennsylvanian siltstone at top of core is in the hanging wall and displays nearly horizontal laminations. Remainder of the core consists of gouge and breccia. Note steep angle of fault plane (compare with fig. 56). Scale is graduated in tenths of feet.