Flynn Creek crater, is an impact crater situated in Jackson County, approximately 8 km south of Gainesboro, Tennessee, USA. It was formed approximately 360 million years ago as a shallow, saucer-shaped crater, 3.8 km (2.4 mi) in diameter and about 150 m deep. A large central hill, highly deformed rim strata, and a breccia lens 40 m (130 ft) in thickness were produced during formation. Over 2 km2 of flat lying Middle and Upper Paleozoic limestone and dolomite were brecciated and mixed to a depth of 200 m (660 ft), and at least half of the breccia was ejected from the crater. The remaining breccia contains fragments ranging in size from small grains to megabreccia blocks 100 m (330 ft) in length. Undisturbed strata lie 100 m below the original crater floor.