Tectonostratigraphic evolution of Cenozoic marginal basin and continental margin successions in the Bone Mountains, Southwest Sulawesi, Indonesia

Paleostress reconstruction from calcite twin and fault–slip data using the multiple inverse method in the East Walanae fault zone: Implications for the Neogene contraction in South Sulawesi, Indonesia

“…2 and 3). The strata in this zone are sliced in variously sized fragments and tend to dip moderately to steeply eastward (Van Leeuwen et al, 2010). In the Walanae Depression, four mapscale gentle folds occur (Fig.…”

“…Based on the results of previous studies on the regional tectonics of Sulawesi (e.g., Hamilton, 1979;Yuwono et al, 1988;Coffield et al, 1993;Priadi et al, 1994;Bergman et al, 1996;Polvé et al, 1997;Macpherson and Hall, 1999;Hall, 2002Hall, , 2011Hall, 2003, 2007;Van Leeuwen and Muhardjo, 2005;Bellier et al, 2006;Van Leeuwen et al, 2010), the history of tectonics in Western Sulawesi including the South Sulawesi area during the NeogeneeQuaternary was as intra-plate extension followed by contraction during continentemicrocontinents collision. Stress states during this tectonic sequence are expected to be recorded in mesoscale faults and calcite twins that pervasively developed in the strata along the EWF.…”

“…The Walanae fault zone is also a major structure with prominent linear landform features that is traceable over 150 km through the southern arm of Sulawesi (Fig. 1b;Van Leeuwen, 1981;Sukamto, 1982;Berry and Grady, 1987;Van Leeuwen et al, 2010). The Walanae fault system comprises two parallel faults, the West Walanae fault (WWF) and the East Walanae fault (EWF), with a narrow topography depression in between.…”

“…The two faults purportedly formed during the end of the Middle Miocene (Van Bemmelen, 1949;Van Leeuwen, 1981;Sukamto, 1982) along the eastern margin of the western mountain range and the western margin of the Bone Mountains, respectively. The geomorphic trace of the EWF can be recognized as a distinct line between the Bone Mountains and the Walanae Depression, around which an intensive deformation zone characterised by various scales of faults, folds and related structures has developed (Van Leeuwen et al, 2010). Therefore, the EWF is thought to have played a major role in the structural and landform developments in this region during the Neogene.…”

“…Therefore, the EWF is thought to have played a major role in the structural and landform developments in this region during the Neogene. The predominance of a sinistral strikeeslip motion in the EWF has been assumed on the basis of its linear topographic feature and the shear sense of its neighboring major faults, including the Masupu fault in the northern area (Hamilton, 1979;Coffield et al, 1993;Guritno et al, 1996;Van Leeuwen et al, 2010). However, the timing and sense of fault motion plus associated deformation have not been sufficiently investigated (Hall and Wilson, 2000;Van Leeuwen et al, 2010).…”