Orogeny rheology of the continental lithosphere, and how these properties change during orogenesis. In addition to orogeny, the orogen (once formed) is subject to other processes, such as sedimentation and erosion. The sequence of repeated cycles of sedimentation, deposition and erosion, followed by burial and metamorphism, and then by crustal anatexis to form granitic batholiths and tectonic uplift to form mountain chains, is called the "orogenic cycle". For example, the "Caledonian Orogeny" refers to a series of tectonic events due to the continental collision of Laurentia with Eastern Avalonia and other former fragments of Gondwana in the Early Paleozoic. The "Caledonian
Grenville orogeny continental crust during tectonic extension. The lithosphere may be thinned either convectively or by delamination, in which the bottom portion of the lithosphere is stripped off. Both models have been proposed for the Grenville orogeny. The Grenville orogeny can be categorized into three sections based on structure, lithology, and thermochronology. The three sections, respectively called the Gneiss Belt, Metasedimentary Belt, and the Granulite terrane are all separated by shear zones. The Gneiss Belt is made up of felsic gneisses and amphibolites that were metamorphosed in the upper amphibolite to granulite facies. Thrusting in this section was low angle, but would