OCEANIA (INCLUDING FIJI, PNG AND SOLOMONS) 111 Figure Geological map of Papua New Guinea, showing active (solid triangles) and inactive or slow acting trenches (open triangles), transforms, and spreading ridges; major thrust faults on land (solid triangles) are also indicated There are four geologic provinces: Platform in the south west, collisional in the centre, volcanic arcs in the north east, and Ontong Java Plateau Map drawn by L Cotterall, Geology Department, Auckland University