Geology of Oceania

New Zealand is a scenic wonderland. It separated from Australia in the Mesozoic and its geology reflects its location astride the boundary between the Australian and Pacific plates.

The North Island, lying on the overriding plate above the Hikurangi subduction zone, is noted for its volcanic and geothermal landscapes, and for active faulting. As examples of living with hazards, the city of Auckland is built on an active volcano field, and the city of Wellington is built on the active Wellington fault.

The South Island, formed largely from the continental fragment of the Chatham Rise indenting the Australian Plate, has spectacular alpine geology, permanent glaciers, and fiords. Its active faults include the 600 km long Alpine fault with a 25 mm/yr slip-rate.

Papua New Guinea also exhibits fascinating alpine and volcanic geology, in a tropical setting. It features major ophiolite belts, active tectonism, volcanism in arcs and back arc basins, uplifted coral terraces, and gold and copper mines.

The many smaller islands dotted through Oceania are characterised by volcanics, high level intrusives and coral reefs. Many international tourists are attracted to their tropical climate, beautiful scenery and beaches.

Vanuatu and the Solomons have interesting volcanic suites.

The geological features of countries to the northwest of Australia–Indonesia, Malaysia, the Philippines and Timor Leste–are dominated by island arcs and trenches, reflecting tectonic and volcanic activity during the long collision of the Australian, Eurasian and Pacific plates.

Hydrothermal copper and gold deposits occur in igneous complexes and thick marine sedimentary sequences host petroleum and coal accumulations. Again, beautiful coastal and mountain scenery abounds in tropical settings.