By the end of the 1970s, 120 impact structures had been identified in various parts of the world and a suite of characteristic rock forms common to many craters had been described.
Eku heleni ka malembe yava 1970s, swivumbeko swa 120 swikumekile eka tindzhawu to hambana hambana ta misava naswona swikomba swilo leswi endlaku maribye lawa yanga hlamuseriwe eka swirhengele leswi.