Shock Metamorphism

Different stages between an impact of an extreterrestrial object at the surface of the Earth (or other planets) and the subsequent shock metamorphism

Different stages between an impact of an extreterrestrial object at the surface of the Earth (or other planets) and the subsequent shock metamorphism
Image Credit: MBG

Aerial view of Meteor (or Barringer) Crater, Arizona (USA).

Aerial view of Meteor (or Barringer) Crater, Arizona (USA).
Image Credit: Michael Collier, AGI webpage

Shock metamorphism exclusively occurs locally around impact craters and possibly around some diatremes. It is characterized by extremely high P/T conditions (tens of hundred of kilobars) over very short time spans. These conditions result from the passing of a shock wave through the rocks.

Figure 2:  Aerial view of Meteor (or Barringer) Crater, Arizona (USA). This broadly circular bowl is ca 180 m deep and over ca 1250 m  in diameter. The ridge or rim surrounding the crater is 100 to 60 m  above the plateau and is composed of angular debris. The debris was ejected from the crater when a meteorite impacted;

Source: Michael Collier, AGI webpage.