Monturaqui Impact Glass
Monturaqui is an impact crater in Chile. It lies south of the Salar de Atacama and was formed 663,000 ± 90,000 years ago by the impact of an IAB meteorite. It is 350 m × 370 m wide and 34 m deep and contains a salt pan. Only a few remnants of the meteorite that formed the crater have been collected, with most of the rocks being of local origin. The crater was discovered in 1962 and identified as an impact crater in 1966.
The crater was first suspected to be an impact crater in 1962, when it was found on aerial images. After geologic research on the site found evidence of the impact event, it was identified as an impact crater in 1966. The crater has not been drilled. Its name is derived from the mountain range where it is located and from the town of Monturaqui 70 km.
Monturaqui lies in a remote region of the Atacama Desert south of the Salar de Atacama, in the "precordillera". The city of Antofagasta lies 200 km northwest of the crater. Administratively, the crater is in the Antofagasta Region.
The impact has produced rocks such as impact glass, coesite and shocked quartz; some rocks were completely melted during the impact and others were turned to glass. Impact-generated rocks formed mostly from granite and meteorite material. They are mostly found at the east-southeast side of the crater, with lesser amounts on its inside.
Only a few or no fragments of the meteorite have been recovered. Given the proximity of the crater to an old road, this may be due to traders and herdsmen removing meteorite fragments but it may also be due to the metals being oxidized over time.
I was at Monturaqui crater and could find some nice pieces of impact glass, that is shown here.