PETROLEUM PROSPECTIVITY OF PACIFIC ISLAND ARCS: SOLOMON ISLANDS AND VANUATU

Abstract

The limited petroleum search which has taken place in Pacific island arc areas has focused mainly on deep forearc or intra-arc basins, so far without success. Very few exploration wells have been drilled. The interpretation of the results of marine geophysical and geological surveys and research carried out in the Solomon Islands and Vanuatu, southwestern Pacific, suggests that the thick volcaniclastic depocentres probably lack major petroleum potential. However, the margins of the basins are likely to be much more prospective. Marginal marine environments bordering the basins may generate immense quantities of organic material favourable to petroleum generation, and this material can be fed into deep basins adjacent to reefal reservoirs. In the Solomons and Vanuatu, where no exploration wells have been drilled, this marginal marine play greatly enhances prospectivity - and, by extrapolation, also that of other arc systems. In particular, source beds may be present. Promising target areas in the Solomons and Vanuatu include Iron Bottom Basin adjacent to Guadalcanal, the southwestern flank of the Solomon High from Choiseul through Santa Isabel - Florida Islands - northern Guadalcanal (especially the Manning Strait area), the area between the Shortland Islands and western Choiseul, Vanikolo Basin, the western margins of the North and South Aoba Basins, and possibly the Malekula and Mbokokimbo Basins.