Spain.
—What may prove to be commercial placer deposits have been found in the Sierra Ronda, in southern Spain, about 50 miles northwest of the port of Malaga. The deposits have been discussed in some detail by Duparc.[190] Apparently the gravels have not been rearranged by nature many times, the concentration of platinum is not great, and it is problematical whether extensive development will be warranted.
[190] Duparc, Louis, and Grossett, Augustine: “Etude comparée des gîtes platiniferes de la Sierra de Ronda et de l’Oural”: Soc. Phys. et Hist. Nat. Geneve, Mem., t. 38, fasc. 5, 1916.
Other Countries.
—A small amount of platinum is produced as a by-product from gold dredges on the Irawadi River, in India, and from the tin dredges in the Dutch East Indies. Unconfirmed reports have been received of discoveries of platinum in southern Siberia, at various places in Mexico, and from several localities in Ecuador and Peru. Platinum is known to occur in some of the streams as well as in certain of the gold deposits of the Minas Geraes district of Brazil.
In southwestern Borneo platinum occurs in the Tanath-Laut district. Several Russian writers have given information on this region.
PROBABLE CHANGES IN KNOWN GEOGRAPHIC DISTRIBUTION IN THE NEAR FUTURE
At present the Russian platinum fields are practically idle. The dredges are for the most part not running and the industry is disorganized. It will require considerable expense and several months’ time to rehabilitate the Russian platinum industry. The known deposits of the Russian field are becoming exhausted, and the reserves of known platiniferous gravels are stated by Duparc to have a life of 12 years, based on the pre-war rate of production; or, stated differently, the known deposits are capable of producing between 3,000,000 and 3,600,000 ounces of platinum before they are exhausted.
Colombia seems to have large reserves of unworked platinum-bearing ground, though so little detailed information is available that it is unsafe to predict their future. It is safe, however, to point out that all reports indicate that careful prospecting in the Choco district will probably be repaid by the discovery of considerable areas of platinum-bearing ground.
The Canadian deposits hold some promise of future production. Several recent discoveries of platinum along the Rocky Mountains in British Columbia, from the Tulameen to the Stikeen, indicate that further search may be rewarded. If reports are true, there is a considerable area on the Tulameen, Willow and Peace rivers which can be dredged for the recovery of gold and platinum. The most important Canadian platinum reserves are in the Sudbury nickel deposits, but present metallurgical practice will have to be changed to obtain the maximum output of platinum and palladium from these ores.