Shock melting of the Canyon Diablo impactor: Constraints from nickel-59 contents and numerical modeling

SCHNABEL, C.; PIERAZZO, E.; XUE, S.; HERZOG, G.F.; MASARIK, J.; CRESSWELL, R.G.; DI TADA, M.L.; LIU, K.; FIFIELD, L.K.

SCIENCE

AMER ASSOC ADVANCEMENT SCIENCE

Año: 1999 vol. 285 p. 85 - 88

0036-8075

Two main types of material survive from the Canyon Diablo impactor, which produced Meteor Crater in Arizona: iron meteorites, which did not melt during the impact; and spheroids, which did. Ultrasensitive measurements using accelerator mass spectrometry show that the meteorites contain about seven times as much nickel-59 as the spheroids. Lower average nickel-59 contents in the spheroids indicate that they typically carne from 0.5 to 1 meter deeper in the impactor than did the meteorites. Numerical modeling for an impact velocity of 20 kilometers per second shows that a shell 1.5 to 2 meters thick, corresponding to 16 percent of the projectile volume remained solid on the rear surface; that most of the projectile melted; and that little, if any, vaporized.