Chapter 9 Mineral resources and prospectivity of non-ultramafic rocks of New Caledonia

Abstract

The mineral resources of the non-ultramafic rocks of New Caledonia and its Exclusive Economic Zone can be classified according to their host rocks. The metallic mineral resources are essentially associated with volcanic and magmatic activity. Non-economic volcanogenic massive sulfide deposits with Cu and Au are located in the Late Carboniferous Koh Ophiolite and in the Late Cretaceous Poya Terrane. Base metals, Au and Ag of the sedimentary–exhalative type are present in the metamorphic Diahot-Panié Metamorphic Complex, associated with syn-rift volcanism. An Au–Sb metallogenic province is associated with the post-obduction Late Oligocene granitoids and co-genetic hydrothermal silica–carbonate (listwanite) zones in the Peridotite Nappe; Au is disseminated in the granites and Sb occurs as lodes in the silica–carbonate. Among the non-metallic mineral resources, barite, gypsum, magnesite, phosphate, clays, dimension stones, limestone for use as cement and as a neutralizer, and aggregates are all present. Gemstones such as jade and chrysoprase are only used locally. Late Cretaceous coal, which was briefly exploited in the past, is now considered to be a source rock for an offshore potential oil and gas system. Petroleum prospectivity is currently focused on the Fairway Basin. Several low-enthalpy thermo-mineral springs with a weak geothermal energy potential are known on Grande Terre.

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

“…Mineral resources have always been important to the economy of New Caledonia. Chapter 9 (Maurizot et al 2020e) and Chapter 10 (Maurizot et al 2020f) provide an exhaustive review of the metallic, non-metallic, gemstone, hydrocarbon and thermal resources of the archipelago and its Exclusive Economic Zone (EEZ). Both chapters deal with nickel and cobalt, which are actively mined, as well as resources which are not currently exploited.…”

The Chemistry of Hyperalkaline Springs in Serpentinizing Environments: 1. The Composition of Free Gases in New Caledonia Compared to Other Springs Worldwide

“…Although they have been included in previous studies of New Caledonia alkaline springs (Cox et al, 1982;Deville & Prinzhofer, 2016;Vacquand et al, 2018), the springs of the Canala area are somewhat different than those further South. The geological substratum is different and the pH (≈9) of its waters is lower than that at the other studied sites (Cox et al, 1982;Maurizot et al, 2020;Quéméneur et al, 2021).…”

“…The Prony Bay hydrothermal field (PBHF), that has been studied during the HYDROPRONY cruise in 2011 (Pelletier et al., 2011), comprises several underwater springs in the Prony Bay, with the Aiguille de Prony being the most prominent, and two costal main sites at the northernmost part of the Prony Bay, the Bain des Japonais, a spring that is uncovered at low tide and the Bain des Kaoris that is located above the water level (Monnin et al., 2014). A number of other springs and seepages of high pH waters are known inland from the coast (Grande Terre) many tens of kilometers north from Prony Bay (Maurizot et al., 2020; Figure 1). We here present in situ measurements of pH, oxidation‐reduction potential (ORP), dissolved oxygen.…”

Alkalicella caledoniensis gen. nov., sp. nov., a novel alkaliphilic anaerobic bacterium isolated from ‘La Crouen’ alkaline thermal spring, New Caledonia

“…In New Caledonia (Southwest Pacific), several thermal springs are located in the southeastern half of the main island [6] (see the map in [7]). Such springs are found further south in the Prony Bay area and the area close to the city of Canala [7].…”

“…In New Caledonia (Southwest Pacific), several thermal springs are located in the southeastern half of the main island [6] (see the map in [7]). Such springs are found further south in the Prony Bay area and the area close to the city of Canala [7]. A sampling campaign was conducted in November 2014 during which water and sediment samples were collected at one of the springs of the Canala region, namely the spring feeding the abandoned spa facility of ‘La Crouen’ (165° 53′ 20.6″ E 21° 32′ 06.6″ S).…”