num has also been found on South Fork of Lewis River, in Clarke County, southwestern Washington.
Russell1
gives a generalized account of the areas of serpentine in the mountains
of central Washington, particularly of a large body about Mount Stuart,
in the Wenatchee Mountains, near Blewett, and of small masses near
Darrington and Twisp and on Methow River.
WYOMING.
The Rambler mine, near Holmes, Albany County, has been developed by the Platinum Mining & Milling Co. Shipments of platinifer-ous concentrates have been made to eastern refiners.
The
Rambler mine has opened a dioritic dike, which is associated with
peridotite. The ore bodies are in crushed altered diorite and contain
copper and iron sulphides and sperrylito (platinum arsenide).
Enrichment by downward-moving waters is shown. The dioritic ore body is
evidently, according to Kemp,2 an intrusive body in the granite gneiss country rock.
FOREIGN.
BORNEO.
Platinum
is found with gold in the gravels of certain streams in southeastern
Borneo, in the Tanath-Laut region. The streams rise in the Bobaris
Mountains, which are formed of crystalline schists and gneiss that have
been intruded by basic dikes ranging from chro-mite to olivine gabbro.
These rocks have been altered to serpentine. In the gravels which are
formed from these rocks olivine, chromite, and platinum are found with
gold.
Analyses
of 10 samples of platinum and 15 samples of native osmium-ruthenium
alloys from the Borneo field have recently been published.3
BRAZIL.
Platinum,
with some iridium and iridosmine, has been known for many years in the
region of Minas Geraes, central Brazil, and has been won in small
quantities from the gold washings of the Rio de Velhas. Gold in alloy
with silver and occasionally with platinum has been found in the Boa
Esperanca veins, at Gongo Sico in veins in syenitic granite, and in the
itabirite of the Minas district. Little has been heard of late years of
these deposits, and apparently no platinum or platinum metals are now
produced from them.
CANADA.
British Columbia.—No
new developments were noted during the year in the Tulameen district.
The production of the district is estimated as 60 ounces for 1916.
Manitoba.—Platinum is reported to occur in several mines and prospects in The Pas district, Manitoba.
1
Russell, I. C, A preliminary paper on the geology of the Cascade
Mountains in northern Washington: TJ. S. Geol. Survey Twentieth Ann.
Rept., pt. 2, pp. 109-111,1900. See also Smith, G. O., U. S. Geol.
Survey Geol. Atlas, Mount Stuart folio (No. 106), 1904.
2 Kemp, J. F., Platinum in the Rambler mine, Wyo.: TJ. S. Geol. Survey Mineral Resources, 1902, pp.: 244-250, 1904.
a Mus. Acad. sci. Fetrograd Trav., vol. 6, pp. 49-95,1915; Chem. Abstracts, vol. 10, p. 440,1916.
