Fiji Micro Plate

spinner dolphines

Check out this site:

http://imina.soest.hawaii.edu/GG/MGG/HotPlateRec.html

for a plate reconstruction animation (avi format)

also see attached gif map

However as a brief summary:

10 Ma (million years ago) there was a continious melanesian arc including PNG, Solomons, Vanautu, Fiji and Tonga.
10 Ma subduction that was SW orientated ie. the Pacific plate was subducting under the indo-australian from the NW-SW, switched direction ie. the indo-aus plate then subducted under the Pacific.
8-4 Ma the New Hebridies arc swung towards the SW and the Fijian platform was rotated anticlockwise ~ 130°, during this period the fijian platform was also extending and rotating along N-S and E-W orientated strike slip faults. North Fiji Basin spreading
4-0 Ma Lau Basin opens and continued extension without rotation. Mantle upwelling in Koro sea region. Lomaiviti Group volcanos erupt.