Kanimblan Orogeny Kanimblan Orogeny The Kanimblan orogeny was a mountain-building event in eastern Australia toward the end of Early Carboniferous time (about 318 million years ago). It was a terminal orogenic episode forming the Lachlan Fold Belt, which was also known as the Lachlan Geosyncline before the advent of the plate tectonics theory. Uplift and deformation occurred in a 1,000 km belt extending from Tasmania to Cape York. However the original width was 2,000 to 3,000 km wide, with the excess size absorbed by folding and thrust faulting. The Kanimblan orogeny also affected the Tasman Geosyncline, which is aligned parallel with the
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