Active strike-slip tectonics and block rotations
After the Middle Miocene collision of the Bangai-Sula microcontinent with East Sulawesi, the present-day • West-ward convergence of the Pacific Plate relative to the Eurasian Plate (Sundaland) is accommodated in Sulawesi by:
1. movements along major active sinistral strike-slip fault zones the NW-SE trending Palu Koro, Matano, Lawanopo major strike slip faults (causing clockwise rotation of 'Sula Block') (Magetsari et al. 1987, etc.) (Figure V. 1.1 );
2. multiple thrust belts: off the North Arm of Sulawesi, West Sulawesi (onshore and Makassar Straits) and offshore SE Sulawesi (see below).
The major left-lateral Palu-Koro Fault zone has been known for a long time (Katili 1969, 1970, Tjia 1978).
One significant effects of the ongoing strike-slip faulting is significant rotation of parts of Sulawesi relative to Sundaland: clockwise rotation of the North, NW and East Arms of 2.5-3.0°/ Myr, and counterclockwise rotation of SW Sulawesi and parts of the SE Arm by 1.5°/ Myr (Figure V.1.1; Socquet et al. 2006). The cumulative effect of these rotations, as estimated from paleomagnetic data, is 60° counterclockwise rotation of the SW arm of Sulawesi and 90° clockwise rotation of the North arm (e.g. Panjaitan and Mubroto, 1994).
The active Pacific- Eurasia convergence in the Sulawesi region created young fold-and-thrust belts/
accretionary prisms at:
1. the North side of the North Arm, between North Sulawesi and the Minahassa Trench, reflecting subduction of several 100's kilometers of Celebes Sea oceanic crust;
2. the Majene-Kalosi foldbelt at the west side of Sulawesi and its offshore continuation in East Makassar Straits basin, with age of thrusting and uplift latest Miocene and younger (see below and Figure V.1.11), with underthrusting (subduction?) of a large part of the North Makassar Straits basin floor below West Sulawesi (Pubellier et al. 2005);
3. the East Sulawesi/ Tola trench/foldbelt East of SE Sulawesi.
Significant young uplift of various parts of Sulawesi is clear from various observations. including the outcrops of Late Miocene- Pliocene granites that formed at depths of -4-12 km, and are now exposed at altitudes of 3000m (Maulana et al. 2016).

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