lens) ~20m max pre-impact relief ~15m max depth of water at time of impact ~40m avg breccia thickness ~140m avg breccia depth below crater floor ~35% max radial shortening of rim strata ~90-190m range for bolide diameter roughly polygonal shape lateral zone of disturbance averages 1000 m in extent from crater wall lowermost size limit for complex craters with central uplifts 1700 m of sediments overlying crystalline basement in area estimated length of time for initial crater formation: <60 seconds conodonts found in immediate crater infill indicate marine environment central uplift is composed of strata which have been structurally uplifted 300 m above normal position 11.2–72 km/s--max velocity range for terrestrial impacting bodies 25 km/s--total vaporization of stony bolides References External links Exploration of the Flynn Creek crater Landforms of Jackson County, Tennessee Impact craters of the United States Devonian impact craters Geology of Tennessee