Brookville Dome

Location

Southwestern Ogle County (A, B-4)

References

Templeton and Willman 1952, Buschbach and Bond 1974, Kolata and Buschbach 1976, Kolata and Graese 1983

Description

Templeton and Willman (1952) reported an anticlinal area, which they termed the Brookville Uplift, in western Ogle and eastern Carroll Counties. Subsequent drilling for a gas storage facility (abandoned) demonstrated the presence of two separate domes. Kolata and Buschbach (1976) named the north dome Forreston and the south one Brookville.

As contoured on the Glenwood Formation (Ordovician), the Brookville Dome is roughly circular, 3 to 4 miles (5-6.5 km) in diameter, and has 138 feet (42 m) of closure (Kolata and Buschbach 1976). Dips are steepest on the northeast side of the dome. The structure persists into the basal Cambrian Mt. Simon Sandstone, which was explored as a potential gas storage reservoir (Buschbach and Bond 1974). The project was abandoned because the caprock proved to be permeable.