SE14
Accretionary Orogens: Their Composition, Structure and Evolution

Main Organiser
Peter Cawood, University of Technology Perth, Australia
icawoodp@info.curtin.edu.au

Co-Organiser(s)
Alfred Kroner, University if Mainz,Germany
kroener@mail.uni-mainz.de

Brian F Windley, University of Leicester, UK
bfw@le.ac.uk

Bor-ming Jahn, National Taiwan University
jahn@ccms.ntu.edu.tw

Brief Description
Classic orogens involve a Wilson cycle of ocean opening and closing, culminating in continental collision. However, this scenario fails to explain the evolution of many orogenic belts in which deformation, metamorphism and crustal growth took place in an environment of ongoing plate convergence. These belts are termed accredtionary orogens and have formed throughout Earth history. They constitute major sites of continental growth and mineralization and include Archaean gneiss-granite-greenstone terrains, Proterozoic to Palaeozoic orogens and Recent orogens of the circum-Pacific and Caribbean. Accretionary orogens form at sites of subduction and consist of magmatic arcs systems along with material accreted from the downgoing plate and eroded from the upper plate. The processes for the initiation and development of accretionary orogens, including their cratonization and in corporation into continental nuclei, are poorly understood, and this multisdisciplinary session will discuss mechanisms of crustal accretion the through Earth history, including well studied areas.