38th parallel structures

Structure Coordinates Hicks Dome 37°30′N 88°18′W / 37.5°N 88.3°W / 37.5; -88.3 (Hicks Dome) Avon 37°48′N 90°12′W / 37.8°N 90.2°W / 37.8; -90.2 (Avon crater) Crooked Creek 37°48′N 91°24′W / 37.8°N 91.4°W / 37.8; -91.4 (Crooked Creek crater) Decaturville 37°54′N 92°42′W / 37.9°N 92.7°W / 37.9; -92.7 (Decaturville crater) Hazelgreen 37°42′N 92°24′W / 37.7°N 92.4°W / 37.7; -92.4 (Hazelgreen crater) Weaubleau-Osceola 38°00′N 93°36′W / 38.0°N 93.6°W / 38.0; -93.6 (Weaubleau-Osceola structure) Rose Dome 37°42′N 95°42′W / 37.7°N 95.7°W / 37.7; -95.7 (Rose Dome)

The 38th parallel structures, also known as the 38th parallel lineament,^[1] are a series of seven circular depressions or deformations stretching 700 kilometres (430 mi) across southern Illinois and Missouri and into eastern Kansas, in the United States, at a latitude of roughly 38 degrees north. Estimated at 300 million years old, two are believed to be impact events from meteorites, but other structures are possibly remnants of volcanos.