Structural geology of New Caledonia and the SW Pacific (source:
Atlas de la Nouvelle-Calédonie. ORSTOM, Paris). The evolution of
New Caledonia's flora and vegetation has been strongly
influenced by its geological and tectonic history (Guillon,
1974; Lapouille, 1981; Lillie and Brothers, 1970; Paris, 1981a,
b). New Caledonia separated from Australia about 65 million
years ago, and drifted to the northeast, reaching its present
position about 50 million years ago (Coleman, 1980; Raven,
1980). During the Tertiary large parts of New Caledonia
underwent a series of submersions, and by the late Eocene nearly
all of the island was covered with up to 2,000 meters of
peridotites, a type of igneous rock formed from ocean crust that
was slowly over-thrust during the preceding tectonic movement
(Guillon, 1975; Moores, 1973; Paris et al., 1979). Geologists
claim that during at least some of this period all of the New
Caledonia must have been below the ocean surface. Inference from
the modern flora, however, indicates that