Shock melting of the canyon diablo impactor: constraints from nickel-59 contents and numerical modeling
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 came 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.
Schnabel
C
Department of Chemistry, Rutgers University, Piscataway, NJ 08854, USA. Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 87521, USA. Graduate School of Oceanography, Narragansett Bay Campus, University of Rhode Island, Narraganse.
Pierazzo
E
Xue
S
Herzog
GF
Masarik
J
Cresswell
RG
di Tada ML
Liu
K
Fifield
LK