Consistent kinematic architecture in the damage zones of intraplate strike-slip fault systems in North Victoria Land, Antarctica and implications for fault zone evolution Fabrizio Storti a, * , Federico Rossetti a , Andreas L. La ¨ufer b , Francesco Salvini a a Dipartimento di Scienze Geologiche, Universita ` “Roma Tre”, Largo S. L. Murialdo 1, I-00146 Rome, Italy b Bundesanstalt fu ¨r Geowissenschaften und Rohstoffe, Stilleweg 2, 30655 Hannover, Germany Received 27 January 2005; received in revised form 8 August 2005; accepted 16 September 2005 Available online 28 October 2005 Abstract Cumulative, polymodal normal (Gaussian distribution) statistics was applied to subsidiary fault data collected from damage zones associated with the Cenozoic Lanterman and Priestley intraplate right-lateral strike-slip fault systems in North Victoria Land, Antarctica. Results show that five Gaussian peaks out of seven in the Lanterman Fault and five out of nine in the Priestley Fault have almost coincident azimuthal values. We named these Gaussian peak pairs as consistent fault sets, arranged in a consistent kinematic architecture that is compatible with the Cenozoic regional strike-slip environment. Angular and kinematic relationships among subsidiary fault sets within the consistent kinematic architecture provide constraints for the inference of the state of stress along the Lanterman and Priestley fault systems. We interpret the fault pattern of the consistent kinematic architecture to be produced by early localisation of the principal displacement zone along pre-existing mechanical discontinuities inherited from the Early Paleozoic Ross Orogeny. Shear localisation was followed by subsidiary faulting at an angle to the principal displacement zone according to the Mohr–Coulomb–Byerlee failure criterion. q 2005 Elsevier Ltd. All rights reserved. Keywords: Subsidiary fault; Consistent fault set; Consistent kinematic architecture; Cumulative statistics; Paleostress; Antarctica 1. Introduction Intraplate strike-slip fault systems can accommodate tens to hundreds of kilometres of horizontal displacement between adjacent lithospheric blocks (Woodcock and Schubert, 1994; Storti et al., 2003a). They typically include almost straight belts alternated with bends and offsets in individual segments, each of them consisting of complex arrays of anastomosing fault strands (Deng et al., 1986; Vauchez et al., 1995; Ludman, 1998; Holdsworth and Pinheiro, 2000; Li et al., 2001; Faulkner et al., 2003). The kinematics of the fault strands depends on their orientation with respect to the total stress field along the principal displacement zone (PDZ in Tchalenko (1970)). The total stress field results from the interplay between the stress field produced by fault motion (i.e. the kinematically-induced stress) and the regional stress field (e.g. Davis, 1984; Mandl, 2000). Strike-slip, transpressional and transtensional fault segments typically coexist along intraplate strike-slip fault systems (Woodcock and Schubert, 1994). This may occur at different scales and may result in the development of very complex fault patterns (in space, time and kinematics; Sylvester, 1988). In many cases, large-offset faults are not preserved within strike-slip fault systems at the continental scale, due to the progression of the tectonic activity and to preferential erosion and sedimentation in highly fractured fault zones (Price and Carmichael, 1986; Umhoefer, 2000). Never- theless, small-scale subsidiary faults are widespread in the damage zones of major fault strands (Keller et al., 1995; McGrath and Davison, 1995; Little, 1996; Kim et al., 2004). Detailed fieldwork on the three-dimensional architecture of subsidiary faults along intraplate fault systems provides important information on the modalities of fault propagation and displacement accommodation (Deng and Zhang, 1984; Pachell and Evans, 2002), the role of fault re-activation (e.g. Journal of Structural Geology 28 (2006) 50–63 www.elsevier.com/locate/jsg 0191-8141/$ - see front matter q 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.jsg.2005.09.004 * Corresponding author. E-mail address: storti@uniroma3.it (F. Storti).