Downloaded from http://sp.lyellcollection.org/ by guest on October 2, 2021 Accretionary orogens through Earth history PETER A. CAWOOD1*, ALFRED KRO¨ NER2, WILLIAM J. COLLINS3, TIMOTHY M. KUSKY4, WALTER D. MOONEY5 & BRIAN F. WINDLEY6 1School of Earth and Environment, University of Western Australia, 35 Stirling Highway, Crawley, WA 6009, Australia 2Institut fu¨r Geowissenschaften, Universita¨t Mainz, 55099 Mainz, Germany 3School of Earth Sciences, James Cook University, Townsville, Qld 4811, Australia 4Department of Earth and Atmospheric Sciences, St. Louis University, St. Louis, MO 63103, USA 5US Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, USA 6Department of Geology, University of Leicester, Leicester LE1 7RH, UK *Corresponding author (e-mail:
[email protected]) Abstract: Accretionary orogens form at intraoceanic and continental margin convergent plate boundaries. They include the supra-subduction zone forearc, magmatic arc and back-arc com- ponents. Accretionary orogens can be grouped into retreating and advancing types, based on their kinematic framework and resulting geological character. Retreating orogens (e.g. modern western Pacific) are undergoing long-term extension in response to the site of subduction of the lower plate retreating with respect to the overriding plate and are characterized by back-arc basins. Advancing orogens (e.g. Andes) develop in an environment in which the overriding plate is advancing towards the downgoing plate, resulting in the development of foreland fold and thrust belts and crustal thickening. Cratonization of accretionary orogens occurs during con- tinuing plate convergence and requires transient coupling across the plate boundary with strain concentrated in zones of mechanical and thermal weakening such as the magmatic arc and back-arc region.