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

• A new approach by the multiple inverse method with calcite twin is proposed.
• Combination analysis of calcite twins and fault‒slips yields consistent stress states.
• Stress states from continental collision were successfully detected in South Sulawesi.
• East Walanae fault was activated as a reverse fault with dextral shear in the Pliocene.

A new approach for paleostress analysis using the multiple inverse method with calcite twin data including untwinned e-plane was performed in the East Walanae fault (EWF) zone in South Sulawesi, Indonesia. Application of untwinned e-plane data of calcite grain to constrain paleostress determination is the first attempt for this method. Stress states caused by the collision of the south-east margin of Sundaland with the Australian microcontinents during the Pliocene were successfully detected from a combination of calcite-twin data and fault–slip data. This Pliocene NE–SW-to-E–W-directed maximum compression activated the EWF as a reverse fault with a dextral component of slip with pervasive development of secondary structures in the narrow zone between Bone Mountain and Walanae Depression.