Chapter 1 Introduction to New Caledonia: geology, geodynamic evolution and mineral resources

Abstract

Supplementary material: List and content of the GIS files (ESRI format) corresponding to the geological map (Fig. 1.2) and the database structure of Figure 1.3 are available at https://doi.org/10.6084/m9.figshare.c.4984385 New Caledonia is a French overseas territory in the SW Pacific, located in the southern tropical zone between 19 and 24° S. The country consists of several islands that are the emergent parts of two parallel submarine ridges: the Norfolk Ridge to the SW and the Loyalty Ridge to the NE (Fig. 1.1). The total area of the country is 18 350 km2. Grande Terre, the largest and main island, is mountainous, c. 400 km long and c. 50 km wide. The highest points are Mont Panie (1628 m) in the north and Mont Humboldt (1618 m) in the south. Grande Terre is surrounded by a 1500 km long barrier reef complex, the second longest in the world, with parts listed as a UNESCO World Heritage site. By contrast, the Loyalty Islands have a low elevation (127 m maximum height on Mare). As well as Grand Terre and the Loyalty Islands, the New Caledonia archipelago includes the isolated and uninhabited Matthew and Hunter islands to the east and the sandy Chesterfield islets to the west. The New Caledonia Exclusive Economic Zone covers an area of 1 360 000 km2. Fig. 1.1. ( a ) New Caledonia in the SW Pacific. ( b ) New Caledonia archipelago. ( c ) Map of New Caledonia with 1:50 000 scale geological map series (grey rectangle) and index numbers. 1, Iles Belep; 2, Poum–Yande; 3, Paagoumene; 4, Pam-Ouegoa; 5, Pouebo; 6, Koumac, 7, Paimboas; 8, Hienghene; 9, Ouaco-Voh; 10, Goyeta-Pana; 11, 12, Touho-Poindimie; 13, Pouembout; 14, Paeoua; 15, Ponerihouen; 16, Baie Lebris; 17, Poya-Plaine des Gayacs; 18, Me Maoya; 19, Houailou; 20, Kouaoua; 21, Bourail; 22, Moindou; 23, Canala-La …