English: Atacamaites are black-colored impact splash glasses recovered from the Atacama Desert in Chile, South America. They've been interpreted as being deposited relatively close to the impact site, which is currently undiscovered. Many impact splash glasses are given the generic name "tektite", but that term appears to be restricted to objects deposited far from an impact site. Both proximal and distal impact glasses form when a meteoroid or asteroid impacts Earth. The impact event pulverizes, ejects, heats, and melts target rocks. As the material falls back to Earth, rapid cooling of the melt results in glass.
Atacamaite morphology ranges from bulbous to elongated to raindrop-shaped to dumbbell-shaped to irregular. Compositionally, they are close to dacite, a type of volcanic rock. Atacamaite chemistry shows that they also consist of some meteoritic material. The impacting object was probably a group IIAB iron (the other types of meteorites are stony and stony-iron). Fission-track dating indicates the impact occurred during the Late Miocene, about 7.83 million years ago.
Locality: Atacamaite Strewn Field, east of the town of Paposo & south-southeast of the town of Antofagasta, Atacama Desert, northern Chile
Much info. synthesized from:
Gattacceca et al. (2021) - A 650 km2 Miocene strewnfield of splash-form impact glasses in the Atacama Desert, Chile. Earth and Planetary Letters 569(117049). 10 pp.