Basin Geology

• Much of the geologic history of the Moon is controlled by the distribution of large impact structures across its surface.
• As impact structures increase in size, they become increasingly complex, changing from craters with central peaks or groups of peaks to features surrounded by two or more rings.
• This transition occurs for structures with diameters between about 180 and 300 kilometers.
• Features larger than 300 kilometers in diameter are termed impact basins.
• Such large impacts also produce faulting and other deformation over large portions of the Moon.