Lineation (geology)

The term linear refers to geology through tectonic processes arisen, line exemplary structure on a natural rock surface. Linear occur on shift, foliation and fault surfaces. The usually very fine, parallel lines are divided according to their origin into different types.

Runzellineare

Wrinkle or Krenulationslineare also arise in the intensive pleats very finely stratified sedimentary rocks or in the puckering of shale surfaces. Individual lines have amplitudes of micrometers to a few millimeters.

Linear blending

Linear blend created by the blending of two differently oriented face assemblies in a rock body. An important for geologists Linear is formed by the blending of stratification and foliation surfaces. This, in the technical literature also called δ - linear element is, generally parallel to the folding axis, allowing the indirect determination of their spatial position even when the axes are not accessible for measurement. Another frequently occurring linear is formed by the blending of two differently oriented crowds of foliation surfaces. This, also known as β - linear element described, shows a multi-phase tectonic deformation.

Linear stretching

Linear stretching occur in shear zones during ductile deformation at greater crustal depths. This isometric rock constituents such as cobbles, individual minerals or fossils are stretched in the direction of tectonic transport through recrystallization of the mineral matter originally. At the same time fibrous minerals in the same direction can re- crystallize and lead on a rock surface to form additional lines.

Gleitstriemen

Gleitstriemen and armor built on fault planes during tectonic movement, in a manner comparable stretching Linear. In Gleitstriemen however outweigh the mechanically generated deepening of grooves on a polished by the juxtaposition of rock sliding packages surface. Such Gleitstriemen can also occur on bedding planes at the fold. In the concentric layers around a single bend folding hinge, the core of a fold is more curved than more external layers. This is compensated by the sliding of the outer layers in the direction of the folding hinge. Gleitstriemen occur generally at lower crustal depth than linear stretching.