Shatter cone

As a cone of rays (also pressure cone or English Shatter Cone - " Schmetterkegel " ) refers to an often cone-shaped fracture surface in rocks, fine on the surface, radiation -like marks (striae ) are seen emanating from the tip ( apex).

Cone of rays are found in impact craters. For her education, the current through the rock during meteorite impact shock wave is responsible, the exact mechanism of their formation is still being explored (eg Sagy et al, 2002;. Baratoux and Melosh, 2003). Cone of rays often have a length of a few centimeters, but can reach a size of up to several meters. If they are found in an unchanged position, the axis directions of primary cone always points toward the center of the impact. Addition, however, secondary cones can occur caused by refraction of the shock wave to inhomogeneities in the rock (crystal grains, fossil inclusions, fractures ) and transverse to the primary cones. This can be observed particularly in findings from the Steinheim Basin.

Cone of rays were first detected in 1905 in the Steinheim basin and described ( Branco and Fraas, 1905), where they occur in fine-grained limestone ( Strahlenkalke ) and therefore are particularly pronounced. Its emergence at that time could not yet be explained. Today, they are also known from numerous other terrestrial craters and are considered clear indicators for an impact of a large meteorite (eg, Dietz, 1967; French, 1998). Also in the explosion craters of nuclear weapons tests, the formation of radiation cones could be observed.