Martinsville Anticline (New Name)

Old Name: Martinsville Dome

Location

Southwestern Clark County (G-8)

References

Moulton 1926a, Mylius 1927, Moulton and Young 1928, Cohee 1941,Clegg 1965a, b, Bristol and Buschbach 1973, Stevenson et al. 1981

Description

Although the structure is reflected on Bristol and Buschbach's (1973) map of the Galena Group and the Stevenson et al. (1981) map of the New Albany Group, the most detail of the Martinsville Anticline was presented by Clegg (1965b), who mapped three Pennsylvanian coals. Clegg's maps of the Colchester, Herrin, and Danville Coal Members all show similar configurations. The structure has been called a dome, but it is better described as an anticline with a slightly sinuous north-south axis. In cross sectional view, it is an asymmetrical box fold. The steep east limb, shared with the Marshall- Sidell Syncline, has 425 to 500 feet (130-150 m) of relief. The west limb is also steep and shows 200 to 300 feet (60-90 m) of relief. The crest or axial zone is 1.5 to 2.5 miles (0.8-4 km) wide and carries several small irregular domes and depressions. The Martinsville structure narrows and plunges to the south, whereas it merges with the larger Westfield Dome to the north. Significant reservoirs in Pennsylvanian, Valmeyeran, Devonian, and Galena (Trenton) strata have been exploited during its productive, 80-year history. The name should be changed from Martinsville Dome to Martinsville Anticline.