GEOLOGY AND :MINERAL RESOURCES. The coast ranges of the southern extremity of Alaska are granitic in character, and their elevation was comparatively recent, geologically, being probab ly at some time between the Triassic and Creta ceous eras. The archipelagoes belong to them in geological character and history, and everywhere there is evidence of great glaciation. Much more recent than this, even, and probably the youngest mountain range on the continent, are the St. Elias Alps, which Russell considers to have been elevated, with tremendous disturbance of the strata, since the close of the Tertiary period,when the rocks of the Yakutat series were deposited. The peninsula of Aliaska, the Aleutian chain, and the hills along the border of Bering Sea are mainly of volcanic origin, including several volcanoes which have been active within historic times or are now subject to frequent eruptions. (See nocosLov.) blot medicinal springs are nu merous, and might he of great hygienic impor tance to the skin-diseased natives if they could be induced to utilize the waters. The line of vol canie upheaval and activity along the south coast is as long as the distance from Florida to Nova Scotia, and the whole of Alaska and the Bering Sea basin are steadily rising. The moun tains of the southeastern interior and along the Canadian border consist of an ancient granitic axis overlaid by schists, quartzites, and other stratified rocks, which have been uplifted and greatly disturbed and altered by dikes and other igneous intrusions and overflows, and are sub stantially a part of the northern, mineral-hearing Rocky Mountain system traceable southward into central British Columbia.
Coal has been found in many places in Alaska. Its deposits near Cape Lisbourne and elsewhere along the Arctic coast have long been known and occasionally utilized by whaling steamers and revenue cutters. tt, also occurs on the Yu kon, in the Aleutian Islands, near Kadiak, on the Kenai Peninsula, at the head of Prince William Sound, and elsewhere. Costly experiments have been made in mining and using it on the south coast, but it is everywhere found to be only a lignite, frequently good enough for domestic use, but poor for steam-making, because so full of sulphur, etc. This poor quality, together with the competition of imported coal, has prevented its serious use thus far. Petroleum, somewhat exploited, iron of poor quality, copper, and many minerals, earth and building stones (marble. etc..) are known, but are not yet commercially valuable. Silver ore has been found in alloy wherever gold occurs, and some galena ores are known, but little profitable working has been undertaken. The total value of the silver prod uct in 1S99 was estimated at $181,000. Gold.
however, is widespread, and is now the chief source of attractiveness and wealth in Alaska. Gold llining.—The presence of gold in the sands of interior rivers and on the southern beaches was known to the Russians and to the fur-traders long ago, but prospecting- was dis couraged. About 1S70 prospecting began, and resulted in discoveries of auriferous placers and quartz veins of varying richness. The first one of importance was on Douglas Island. where a "camp" of miners soon gathered to work the placers. Soon afterward ledges of quartz ore were discovered, and bought by John Treadwell, who organized a company to develop the mines. Works were erected. the town of Juneau arose on the neighboring mainland, and these mines are now one of the richest gold-producing prop erties in the world. The ore is easily can be rolled down into the stamp-mills by grav ity-tramways, and all machinery (including electric hoists, etc.) is operated by water power. This cheapness enables a low grade of ore to be worked at a large profit, and about 1500 stamps are kept in continuous and almost auto matic operation, while Douglas Island and the space under Gastineau Channel and the neigh boring shore are being completely honeycombed with tunnels and stopes. Slany other good mines have been opened in the neighborhood; and workings have been developed satisfactorily on Barano• Island near Sitka, on Smndum Bay, at the head of Lynn Canal, and elsewhere in the Alexander Archipelago and on the mainland. The beach sands and river gravels have yielded profitable gold about Yakutat Bay, at Turnagain Arm at the head of Cook's Inlet, and on the shores of Radial: and Unga islands. The discov ery of rich gold placers in the Yukon district in 1897 led to vigorous prospecting of the whole Yukon Valley and its tributaries within the mountains, and auriferous deposits, often of great richness, were found along the river course at and near the Canadian boundary and especial ly along the Tanana. (See YUKON.) This led to an exploration of the coast hills, and resulted in several about Norton Sound. of which the most remarkable was that at Cape Nome, where the sands of the beach yielded extraordi nary richness, and where later extensive placers were disclosed along neighboring streams. The output of the whole territory increased from $2,700.000. in 1897, to $7.531,000 in 1900. The output in 1900 surpassed that of the preceding year by $2,406,000, the Nome district being re sponsible for the greater part of this amount. Circle City, .Jack Wade, Munoek, and Kyokuk districts in the interior of Alaska produced alto gether about $1,000,000.