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Nauru
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The third mejor mineral producer in the region is the island of Nauru which producea
phoephate to the vdue of about USllOO miltion annually. The phosphate b gutrto wtrich has
developed by rcaction between limestone and bird excrernent. It occurs within funows r.p to
12 m deep between pinnaclee of dolomitized limestone (British Suphur Corporation, l9B0).
Reserves are said to be sufficient for 10-15 years further production.
IIi!
The Fijian islands are volcanic temain, in terms of our classification, although there is
evidence of a major tectonic event in the younger geologic record (tne Tholo orogeny in the
late Miocene; Richmond, t98l).
Main mineral production is from the Enperon gold mine which produces silver and gold
worth about USil0 million annually, from quartz-telluride veins in a former volcanic caldera
(Forsythe' 197f ). The largest identif ied mineral nesource is the Waisoi porphyry copper
prospect at Namosir elso in the eroded root of a former volcano; this contains 500 million
tonnes averaging 0.48 percent copper with minor recoverable gold and nnlybdenum.
Cqper-zinc massive sulphide deposits are known on Viti Levu, and gold deposits and
Kuroko-type copper-zinc-leed sulphides with some associated qold and silver sr Vanua Levu
(Greenbaum, 1981).
Thick sediments both mshore end offshore ere currently being tested for hydrocarbons.
Solomon Islands
Tfe Solomon Islands are a mixture of volcanic and collision temain. A variety of
mineralization is known, including porphyry copper and lode and alluvial gold m Guadalcanal,
volcanogenic zuphides in the Florida qroup, lateritic nickel on several islands, baudte on
Rennell and phosphate m Bellona islands, and some heavy mineral sands, and intrusive rocks
which might be prospective for diamonds, on Malaita (Arthurs, 1979; Coulson, f98f ). The only
eunent production is alluvial gold shedding from Gold Ridge on Guadalcanal; total value of
production in 1980 was US$600,000.
The largest porphyry copper prospect is Koloua, m Guadalcanal, with 90 million tonnes
averaging 0.17 pereent copper, .0025 percent molybdenum, 0.06 grams/tonne gold and 0.77
grams/tonne silver (A. Chivas, personal communica[ion, 1982).
Thick sediments in New Georgia Sound (The Slot) mey be prospective for hydrocarbons
(Katz, 1980).
Vanuatu
The Vanuatu islands are mostly volcenic with the exception of some collieional terrein
on Pentecost Island (Macfarlane and Carney, l98I). Manganese was mined m Efate Island
until 1978 but there is currently no mineral production. Magnetite beach sands with high
titanium are found on most islands, weak porphyry-type copper minerelization on Santo and
Malekula, and some copper, nickel and zinc sulphides on Pentecost.
The Slot basin contains up to J km of sediments and these may be prospective for
hydrocarbrrs (Carney and Macfarlane, I980b).
Tonqa
The Tmgan islands are volcanic terrainl oil seeps are known and exploration for
hydrocanbms continues (U Maung et a!.r 1981).