Geology of New Caledonia

Fig.1 A simplified geological map of New Caledonia with a cross-section, modified by Xu and Liu (2019)[1]

The geology of New Caledonia includes all major rock types (igneous, sedimentary, and metamorphic), which here range in age from ~290 million years old (Ma) to recent.[2] Their formation is driven by alternate plate collisions and rifting.[2] The mantle-derived Eocene Peridotite Nappe is the most significant and widespread unit (labelled as "Ophiolites" and coloured in bright green in Fig. 1).[2] The igneous unit consists of ore-rich ultramafic rocks thrust onto the main island.[3] Mining of valuable metals from this unit has been an economical pillar of New Caledonia for more than a century.[4][2]

New Caledonia is located on the Indo-Australian Plate and the largely submerged continent of Zealandia.[5] After New Zealand, it is the second-largest subaerial landmass, and the northernmost part of this continent.[5] As shown on the map, the landmass is elongated in a NW-SE orientation, which is similar to the distribution patterns of most of the geological units. Thrusting, exhumation and folding of some of the units have contributed to the rugged topography of the elongated main island, with Mont Panié and Mount Humboldt being the highest points (over 1,600 m).[6]

  1. ^ Xu, Yang; Liu, Chuan-Zhou (2019-06-01). "Subduction-Induced Fractionated Highly Siderophile Element Patterns in Forearc Mantle". Minerals. 9 (6): 339. Bibcode:2019Mine....9..339X. doi:10.3390/min9060339.
  2. ^ a b c d Cluzel, Dominique; Maurizot, Pierre; Collot, Julien; Sevin, Brice (March 2012). "An outline of the Geology of New Caledonia; from Permian-Mesozoic Southeast Gondwanaland active margin to Cenozoic obduction and supergene evolution". Episodes. 35: 72–86. doi:10.18814/epiiugs/2012/v35i1/007. Retrieved 26 September 2021.
  3. ^ Cite error: The named reference PearceA was invoked but never defined (see the help page).
  4. ^ Lillie, A. R.; Brothers, R.N. (1970). "The geology of New Caledonia". New Zealand Journal of Geology and Geophysics. 13 (1): 145–183. doi:10.1080/00288306.1970.10428210.
  5. ^ a b Wood, Ray; Stagpoole, Vaughan; Wright, Ian; Davy, Bryan; Barnes, Phil (2003). New Zealand's Continental Shelf and UNCLOS Article 76 (PDF). Institute of Geological and Nuclear Sciences Limited. Institute of Geological and Nuclear Sciences series 56. Wellington, New Zealand: National Institute of Water and Atmospheric Research. p. 16. NIWA technical report 123. Archived from the original (PDF) on 21 February 2007. Retrieved 22 February 2007.
  6. ^ "Données Géographiques". Nouvelle-caledonie.gouv.fr (in French). Archived from the original on 30 October 2012. Retrieved 2013-01-30.