Environment

Plate tectonics and formation of the Fiji Group

A brief summary about the formation of the Fiji Fiji islands

The oldest rock in Fiji is about 35 Million years old and are found in Western Viti Levu. They formed in the Late Eocene when the Pacific plate got pushed under the Australian plate….
The age and origin of the Pacific islands

Check out this site for a plate reconstruction animation (avi format):http://imina.soest.hawaii.edu/GG/MGG/HotPlateRec.html
also, see attached gif map

The Fiji Group of Islands

The Lomaiviti Group is among the geologically youngest in Fiji. The islands formed less than 10 Million years ago through vulcanic activity and resulting magma eruptions.

Brief summary formation Lomaiviti Islands:

10 Ma (million years ago) there was a continuous Melanesian arc including PNG, Solomons, Vanuatu, Fiji and Tonga.

10 – 8 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-Australian plate then subducted under the Pacific.

8-4 Ma the New Hebrides arc swung towards the SW and the Fijian platform was rotated anti-clockwise ~ 130°, during this period the Fijian plate 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, up welling of magma forms the Islands Moala, Gau, Wakaya, Makogai, Vatu and the sea mount E6.

By: romanleslie at hotmail.com