Fission track and fault kinematics analyses for new insight into the Late Cenozoic tectonic regime changes in West-Central Sulawesi (Indonesia) Olivier Bellier a, * , Michel Se ´brier b , Diane Seward c , Thierry Beaudouin d , Michel Villeneuve e , Eka Putranto f a UMR CNRS 6635- CEREGE (Centre Europe ´en de Recherche et d’Enseignement des Ge ´osciences de l’Environnement), Universite ´ Paul Ce ´zanne Aix-Marseille, BP 80, Europo ˆle Me ´diterrane ´en de l’Arbois, 13545 Aix en Provence Cedex 4, France b UMR CNRS 7072 bTectonique Q, Universite ´ Pierre et Marie Curie, T26-E1, case 129, 4, place Jussieu, 75252, Paris cedex 05, France c Geology Institute, ETH- Zu ¨rich, Sonneggstrasse 5, 8092 Zu ¨ rich, Switzerland d UMR CNRS 8616 bORSAYTERRE Q, Universite ´ de Paris-Sud, 91405 Orsay Cedex, France e URA-CNRS 1208, Univ. de Provence, Marseille, France f DGGMR/PPPG (Geological Research and Development Centre), Bandung, Indonesia Received 24 March 2005; received in revised form 18 August 2005; accepted 24 October 2005 Available online 10 January 2006 Abstract The left-lateral strike-slip Central Sulawesi Fault System (CSFS, composed of the NNW Palu–Koro (PKF) and the ESE Matano faults) is located within the eastern Indonesian triple junction between the Pacific, Indo-Australian and Eurasian plates. Fault kinematic and fission-track analyses show that the Late Cenozoic central Sulawesi deformation results from three successive tectonic regimes: (1) A Late Miocene–early Pliocene (5 Ma) WNW-trending shortening characterized by transpressional deformation along the PKF and compressional in the Poso area. This tectonics resulted from the collision between the Banggai–Sula block with Sulawesi. It produced locally a transpressional regime as a consequence of the northward extrusion of the Central Sulawesi block limited by the PKF. (2) A Pliocene collapse tectonic regime associated with W-trending extension. Coeval with these events regional cooling and exhumation took place. (3) A Quaternary transtensional regime resulting from the combined effects of the Central Sulawesi block northward motion, and extension related to back-arc spreading behind the North Sulawesi subduction (Tomini Gulf). D 2005 Elsevier B.V. All rights reserved. 1. Introduction Sulawesi Island, eastern Indonesia, is located at the junction between the converging Pacific-Philippine, Indo-Australian Plates and the Sundaland, i.e. the south-eastern part of the Eurasian Plate (Fig. 1). Sula- wesi tectonic evolution results from successive colli- sions of continental slivers, island arcs, and oceanic domains with the Sundaland. The Central Sulawesi Fault System (CSFS), one of the major structures in SE Asia, cuts across Sulawesi Island from NW to SE, connecting the North Sulawesi subduction zone to the Banda Sea deformation zones (Fig. 1). Seismicity of Sulawesi as recorded by global seismic networks, as well as local Indonesian networks and historic data, 0040-1951/$ - see front matter D 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.tecto.2005.10.036 * Corresponding author. E-mail address: bellier@cerege.fr (O. Bellier). Tectonophysics 413 (2006) 201 – 220 www.elsevier.com/locate/tecto