In Monroe County, the fault trends mostly north-south and cuts through Lake Lemon and the east end of Monroe Lake. The fault plane is inclined steeply westward, and the downthrown side is to the west. Probably dates from the Mississippian time or later. It has apparently not been active since the beginning of the Pleistocene and has not been active in recent history.
Adjacent to the fault on the west, the downthrown side, is the Leesville Anticline (red line on the above map). The fault and the anticline form one of the largest and most significant geological structures exposed n Indiana. Four domes lie along the crest of the anticline in Monroe County. Oil and gas have been produced from Devonian and Ordovician limestones in tow of these domes; two domes are now used for natural-gas storage.
The extent of its throw in places exceeds 200-300 feet. In a general way it parallels the western limits of the Knobstone outcrop. The downthrown side is west of the fault line. The faulting and the subsequent erosion has result in a limestone belt bordered on the east and west by Knobstone, the limestone being on the downthrown side and thus protected from the erosion which caused the removal of the limestone of the same age lying at a higher elevation both east and west. Since the normal dip of the rocks is southwest, the downward drop of the block toward the east resulted in a fold lying parallel with the fault plane to the west. As the fault changes its directions in some places north and south components of dip are produced in the fold at such places and conditions favorable for the accumulation of oil and gas produced. One such place occurs in Lawrence County and considerable gas and a showing of oil obtained west of Leesville. Another favorable structure exists near Unionville in Monroe County.
About one mile west of the Mt Carmel fault is a second fault. It was named the Heltonville Fault because the rift is exposed a short distance east of Heltonville in the bed of the north fork of Leatherwood Creek. This fault lies approximately parallel with the Mt Carmel fault. The limestone has been faulted down against the Knobstone
You can see the fault line where the sandstone and the limestone meet in this location near the large sycamore tree. You can park along the side of the road in the wide shoulders.
To log this earthcache, send the answers to my registered account:
- Which level is higher, the sandstone or limestone?
- How many fossils do you see?
- Describe the rocks that you see. Do the sandstone and limestone rocks compare in texture, sound, or appearance?
- Do you think there is a chance of a major earthquake coming to Bloomington and why?
Post a picture of yourself (face not required) or a personal item at the Mt. Carmel fault line.