Impact Crater Diagram
Schematic cross sections of (a) a simple crater and (b) a complex crater showing idealized form, structure and distribution of impact units.
Simple crater forms are typical of structures with rim diameters of less than about 4 kilometers (on Earth); above this transition diameter, craters are characterized by complex morphologies exhibiting central uplifts, shallow floor depths, and slumped rims.
For complex craters with diameters of about 4 to 50 kilometers the central uplift occurs as a single peak. Larger impact structures can have complex, ring-shaped central uplifts.
Image Credit: NASA
Credit: Lunar and Planetary Institute