The Atacama Desert in northern Chile is home to Pica glass, created by an intense explosion of meteorites. The glass shows unusual deformations and fluid flows indicating a dynamic mode of creation. Read more.
Intense meteorite explosions
In northern Chile, in the Atacama Desert, there is a fascinating phenomenon called the Pica glass. This glass was created by almost simultaneous, intense explosions of meteorites near the earth's surface. These explosions led to the creation of silicon dioxide glass under ultra-high temperatures. It’s reminiscent of the man-made Trinitite. The Pica glass is a silent witness to a suspected cometary impact shortly after humans arrived in the area.
The Pica glass is concentrated at five sites in a 75-km-long north-south oriented area, south of the town of Pica. The glass was formed on deposits from the Pleistocene period. What makes the Pica glass so special are the deformations and fluid flows that indicate a dynamic mode of formation. Meteorite grains similar in composition to the primitive chondrites of the CI group have also been found in the glass.
Hypotheses about genesis
Researchers have two hypotheses about how the Pica glass formed. The first hypothesis is that the glass was formed by short, intense radiant heat from the final explosion. The second hypothesis is that the Pica glass was formed by the same short, intense radiant heat combined with heated gas and violent winds. Although both hypotheses are possible, the latter hypothesis seems most likely because it can explain the fluid flows. The meteorite responsible for the Pica glass is almost certainly a comet, given the identical composition of the meteorite dust in the Pica glass and the samples we have of comets.