In geology, tectonics called (after Greek τεκτονικός tektonikós " the architecture concerning " ) the doctrine of the earth's crust and from taking place in their large-scale movements. Also, structures and movements in the upper part of the mantle ( lithosphere ) are the field of view of the tectonics. As Geotektonik the more global aspects and theories of Earth's development are referred to.
On the other hand, refers to the tectonic structure of the crust and the geodynamic movements themselves, in particular the shift of the tectonic plates and their effects ( plate tectonics ).
Types of tectonic processes
From the observed disturbances in the terrain and folding of rock packages as well as the characteristics of the affected rocks such as jointing, foliation and metamorphic grade, the geologist infers direction, intensity, duration and timing of these movements.
According to the prevailing geological structures can be distinguished:
- Fault or fault tectonics: Near the earth's surface result in lateral pressure, but also stress relief, for fracturing the rock layers and to shifts in the package of rocks against each other, along partly open joints, crevices, gaps and distortions. This does not occur by cross- folding of the rocks in the rule. Examples are the formation of tectonic trenches and Horsten. Also at the depression of sedimentary basins and the lateral displacement of areas of the crust against each faulting is often involved. Sudden stress relief at the participating fault zones generates an earthquake.
- Faltentektonik: The exact time of the beginning of the folding depends on the nature of the relevant rock. Under certain conditions, wrinkles appear already at a small depth below the surface. However, in most cases, the rocks begin in greater depth, ie, at higher pressures and temperatures, plastic deformation (ductility ) and folded. The formation of open fissures is now no longer possible, and the movement of rock packages against each other not only takes place at faults, but also by internal deformation and movement of regional shear zones. The rocks are doing a conversion, the metamorphic rocks generated. This conversion can all rocks of a region relate to ( regional metamorphism ).
- Überschiebungstektonik: Under suitable conditions, such as folded unfolded rocks can push each other to be tectonic ceilings. In this case, rock packets can be transported over long distances by a large extent. The construction of this overthrust body can be very complicated in detail.