Volume 14 Australasia - dana ward's homepage

—FRENCH MELANESIA. 339In New Caledonia tbe prevailing formations are sj-enites, serpentines, dioritcs,metamorphic schists, and trachites. The very pumice cast up as flotsam by thewaves attests the existence of former eruptive centres.The great geological resemblanceof these rocks to the East Australian ranges at one time held out expectationsof rich auriferous discoveries ; but the financial results of the local mining operationshave not hitherto been encom-aging. The metals which really occur inabundance, and which may j-et contribute to the industrial prosperity of NewCaledonia, are iron, nickel, cobalt, antimonj', and chromium. Copper mines havealso been worked, and coalfields, though of little economic value, have been discoveredat the foot of the serpentine rocks on the seaboard.Fig. 144.New Caleponia.Snlr. I : 5,(X»-i noo.1,000 Fathomsand upwards.New Caledonia is at least doubled in size by the reefs skirting its shores andextending it in the direction of the north-west and south-east. The hydrographicsurveys of Chambovron and other explorers leave no doubt of the existence ofthese fringing and barrier reefs on the east side, though their presence had beendenied by Darwin and Dana. Towards the southern extremity, however, theencircling coralline rocks disappear below the surface, at first a few yards, therfrom 16 to 20 fathoms, forming, north of the central passage, near the Isle ofPines, a continuous bank, above which ri.*e at intervals chaplcts of coral, sonicz 2