Arc dynamics and tectonic history of Fiji based on stress and kinematic analysis of dikes and faults of the Tavua Volcano, Viti Levu Island, Fiji

Stress analysis of dikes and kinematic analysis of faults within the Tavua Volcano of Viti Levu, Fiji, indicate an apparent migration of the causative maximum principal stress axis (σ 1 ) from NW toward north between ∼5.0 and <3.9 Ma. The dikes and faults are part of successive structural and magmatic events at the arc scale. We present data on the chronological succession of stress indicators in the Tavua Volcano, based on overprinting relationships and published geochronology, which also equate with a counterclockwise rotation of Fiji, assuming an approximately constant N‐S regional compressive stress orientation during this time. The latter interpretation is consistent with paleomagnetism studies that require substantial counterclockwise rotation of the Fiji Platform, since fragmentation of the formerly continuous Outer Melanesian Arc during the latest Miocene to earliest Pliocene. The stress data suggest that the Fiji platform has undergone an ∼50° rotation since ∼5 Ma. Given that rotation apparently stopped at 3 Ma, then particularly fast rotation of ∼25° Myr −1 occurred from ∼5 Ma to 3 Ma. Recent seismicity data indicate the platform is currently subject to N‐S compression. The history of late Miocene and Pliocene events in the region can be related to the consequences arising from collision of an island arc with an oceanic plateau.