Troy Grove Dome
Part of the La Salle Anticlinorium
Location
T34 and 35N, R1E, La Salle County (B,C-5)
References
Bell 1961, Buschbach and Bond 1974, Kolata et al. 1983
Description
Troy Grove Dome is an irregular faulted dome near the northern end of the La Salle Anticlinorium. The western limb of the dome coincides with the Peru Monocline (new), which has approximately 1,500 feet (450 m) of relief on the Franconia Formation (Kolata et al. 1983; fig. 17). The other limbs of the dome dip gently. As mapped on the basal Cambrian Mt. Simon Sandstone, Troy Grove Dome has about 100 feet (30 m) of closure and is about 5 miles (8 km) north to south by 3 miles (5 km) east to west (Buschbach and Bond 1974). Four faults trending east to west have been mapped across the central part of the dome. They form a series of grabens that have maximum vertical offset of about 180 feet (55 m). The dome has been developed as a gas storage field with the Mt. Simon as the principal reservoir and additional storage in sandstones in the lower part of the overlying Eau Claire Formation.
