Kanimblan Orogeny Kanimblan orogen. 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
Grenville orogeny here. Ages are approximated from the magmatic activity associated with the individual cycles of the orogeny. The gaps in the ages of the compression cycles and isotope analysis of hornblende, biotite, and potassium feldspar suggest that extension was occurring when compression had momentarily ceased. Rivers' 2008 paper has now examined the timing of the different periods of the orogeny and reconstructed the timeline based on the spatial and temporal metamorphism of the rocks present. According to this newer version of the timeline which is a composite of Rivers 1997 and Gower and Krogh 2002, the Elzevirian orogeny occurs from 1240