Shatter Cones
Introduction
Shatter cones are a geological structure that are formed under very specific conditions, primarily during the impact of a meteorite. They are one of the only forms of impactite that have a distinct shape and pattern, making them a valuable tool in the study of meteorite impacts.
Formation
Shatter cones form during the intense pressure and heat that is associated with a meteorite impact. The shock wave from the impact passes through the rock, causing it to shatter in a very specific pattern. This pattern is what gives shatter cones their distinctive shape. The formation of shatter cones is still not fully understood, but it is believed to involve a process known as shock metamorphism, where the structure of the rock is altered by the intense pressure and heat.
Characteristics
Shatter cones have a distinct conical shape, with the point of the cone pointing towards the source of the impact. They also have a striated pattern on the surface, which is another key identifying feature. The size of shatter cones can vary greatly, from less than a centimeter to over a meter in length. The size is believed to be related to the size of the meteorite and the distance from the impact site, with larger cones found closer to the impact site.
Distribution
Shatter cones have been found at nearly all confirmed impact sites in the world, making them an important tool in the identification of these sites. They are not found in any other geological setting, making them a unique indicator of a meteorite impact. Some of the most notable sites where shatter cones have been found include the Sudbury Basin in Canada, the Vredefort Crater in South Africa, and the Chicxulub Crater in Mexico.
Importance in Research
Due to their unique formation and distribution, shatter cones are an important tool in the study of meteorite impacts. They can provide valuable information about the size and direction of the impact, as well as the type of rock that was impacted. Shatter cones have also been used to date impact sites, as the age of the rock in which the cones are found can often be determined using various radiometric dating methods.