Evolution of the Mount Woods Inlier, northern Gawler Craton, Southern Australia: an integrated structural and aeromagnetic analysis Peter G. Betts a, * , Rick K. Valenta b , Jim Finlay c a Australian Crustal Research Centre, School of Geosciences, Monash University, Clayton, Victoria 3800, Australia b MIM Exploration Pty Ltd., Level 2, 55 Little Edward Street, Spring Hill, Queensland 4001, Australia c Department of Geospatial Science, RMIT University, GPO Box 2476V, Melbourne 3001, Australia Received 4 April 2002; accepted 7 February 2003 Abstract Structural mapping integrated with interpretation and forward modelling of aeromagnetic data form complimentary and powerful tools for regional structural analysis because both techniques focus on architecture and overprinting relationships. This approach is used to constrain the geometry and evolution of the sparsely exposed Mount Woods Inlier in the northern Gawler Craton. The Mount Woods Inlier records a history of poly-phase deformation, high-temperature metamorphism, and syn- and post-orogenic magmatism between ca. 1736 and 1584 Ma. The earliest deformation involved isoclinal folding, and the development of bedding parallel and axial planar gneissic foliation (S 1 ). This was accompanied by high-temperature, upper amphibolite to granulite facies metamorphism at ca. 1736 Ma. During subsequent north – south shortening (D 2 ), open to isoclinal south – southeast-oriented F 2 folds developed as the Palaeoproterozoic successions of the inlier were thrust over the Archaean nuclei of the Gawler Craton. The syn-D 2 Engenina Adamellite was emplaced at ca. 1692 Ma. The post-D 2 history involved shear zone development and localised folding, exhumation of metamorphic rocks, and deposition of clastic sediments prior to the emplacement of the ca. 1584 Ma Granite Balta Suite. The Mount Woods Inlier is interpreted as the northern continuation of the Kimban Orogen. D 2003 Elsevier Science B.V. All rights reserved. Keywords: Aeromagnetic interpretation; Mount Woods Inlier; Gawler Craton; Proterozoic 1. Introduction Structural analysis in regions of limited outcrop makes correlation of individual fabric generations and structural histories more difficult and therefore in- creases the likelihood of an erroneous interpretation. The increased availability of high-resolution aeromag- netic datasets has provided an additional tool to map poorly exposed regions (Valenta et al., 1992; Jessell et al., 1993; Gunn et al., 1997; Jacques et al., 1997). There is a strong unity of objectives between aero- magnetic analysis and structural geology. Interpreta- tion and forward modelling of aeromagnetic data (and 0040-1951/03/$ - see front matter D 2003 Elsevier Science B.V. All rights reserved. doi:10.1016/S0040-1951(03)00062-3 * Corresponding author. Tel.: +61-3990-54150; fax: +61-3990- 55062. E-mail address: pbetts@mail.earth.monash.edu.au (P.G. Betts). www.elsevier.com/locate/tecto Tectonophysics 366 (2003) 83– 111