Orthogonal fracture system
In an orthogonal fracture system , also referred to as a fundamental fracture system or right-angled fracture system , all the fissures formed in a rock are perpendicular to one another. Together, the three fissures delimit a characteristic cube-shaped or cuboid-shaped rock body.
Origin and Distribution
First, when a rock is exposed to tectonic stress, a fissure opens up parallel to the greatest main stress . From a geomechanical point of view, the fissure families in a right-angled system are fissure or expansion fractures in the rock.
Sometimes they trace cooling surfaces ( granite ), slate or stratified surfaces ( sedimentary rocks ) running parallel to the earth's surface . Depending on the geotectonic tension, the individual fissures differ from each other in their fissure width and the nature of the fissure areas.
Orthogonal fracture systems are particularly found in a wide variety of rocks, such as sandstones , silica schists , limestones, and coal . The right-angled fracture systems are particularly often formed in the granite . Starting from the fissures, many of the granites on the surface are weathered and form characteristic rock formations in the form of wool sacks , mattresses or yeast dumplings ( wool sack weathering ).
Orthogonal fracture system in granite
Orthogonal fracture system in mudstone
Orthogonal fracture system at Eaglehawk Neck, Australia
Right-angled fracture system in the sandstone of the Externsteine
Stinky lime near Marsberg with an irregular orthogonal fracture system
Individual evidence
- ↑ Claus-Dieter Reuther: Basics of Tectonics - Forces and tensions of the earth on the track . Springer Spectrum, Berlin Heidelberg 2012, ISBN 978-3-8274-2065-7 , p. 24
- ^ Günther Möbus: Tectonics . German publishing house for basic industry, Leipzig 1989, ISBN 3-342-00403-7 , p. 270