The auriferous quartz is dull white, shows in places comb structure, and much of it contains visible gold in the hand specimens. Some of the associated minerals are iron pyrites, stibnite, sphalerite, and galena. Complex sulphides containing antimony are probably also present. The specimens collected by the Geological Survey's party show no trace of tellurium, though this mineral has been reported by prospectors.

Development work has been confined to surface prospecting, sinking on the veins to depths of less than 100 feet, and tunneling along them to distances not much exceeding 100 feet. The material has been treated in small lots by means of a small stamp mill established at the town of Fairbanks during the winter of 1909.

Although insufficient development work has been done on these veins to determine definitely their importance, some of them are nevertheless of a character to warrant the effort that is being made to develop them and to encourage the search for other lode deposits in this district.

Other districts of Yukon-Tanana region.-Of the districts adjacent to Fairbanks, Hot Springs and Birch Creek were most prosperous, but mining was also done in the Rampart, Tenderfoot, and Salchaket regions. In the Hot Springs and Birch Creek districts several large plants were operated during most of the season. In addition to the smaller mining enterprises, three dredges were in operation in the Fortymile Basin in 1909. One of these is on the south fork of Fortymile and two are on Walkers Fork. It is significant that dredges are successfully operated in this district-one of the most isolated placer districts of Alaska. The initial cost of these plants is probably double what it would be in some of the other districts, and, moreover, at two of these dredges the ground has to be thawed.

Bonnifield district. Work was begun on the construction of a large hydraulic plant on Gold King Creek.

Much lode prospecting has been done during the year in the Bonnifield district, which lies about 40 miles south of Fairbanks. Some promising prospects are said to occur in a belt that follows closely the base of the Alaska Range. One large ore body has been reported on Jerome Creek, a tributary of Wood River. Systematic prospecting of this property with the use of a small stamp mill was begun in 1909.

Chandalar and Koyukuk districts.-There was but little placer mining in the Chandalar district in 1909, and interest was centered on lode prospecting. Several quartz veins were opened which carried free gold.

The Koyukuk district, which has been growing in importance as a gold producer, has been developed practically without the aid of outside capital. The productive placers of this district fall into three groups, which appear to mark three auriferous belts and include (1) those of Myrtle, Marion, Missouri, and Gold creeks; (2) those of Vermont, Nolan, and Emma creeks; and (3) those of Mascot Creek. Up to 1907, when the deep placers of Nolan Creek were discovered, mining was confined to shallow deposits. In 1909 probably 90 per cent of the gold was taken from the deep gravels of Nolan Creek. The Koyukuk district is difficult of access and mining costs are high, but in spite of the adverse conditions the value of its gold output in 1909 was more than $400,000.

Innoko district.-In 1909 the Innoko district produced gold to the value of probably $300,000. This indicates that systematic mining has begun. In midsummer placer gold was found on Otter Creek, which flows into the Iditarod, a northeastern tributary of the Innoko. The information at hand indicates that these placers lie in what would be an extension of the Innoko auriferous zone. So far as prospected the gold seems to be more uniformly distributed than in the Innoko gravels. This information appears to form the basis for the "stampede" to the Iditarod which took place from Fairbanks and other points in Alaska late in the summer of 1909. The fact that gold has been found also on the Tuluksak, a tributary of the Kuskokwim, in what appears to be an extension of the Innoko and Iditarod belt, makes this general field attractive to the prospector.

SEWARD PENINSULA.

In 1909 the placer districts of the Seward Peninsula produced gold to the value of $4,302,000, compared with a production of $5,120,000 in 1908. This falling off was largely owing to the fact that many of the richest placers have been mined out and no adequate preparations have been made for exploiting the extensive bodies of low-grade gravels. It is to be expected, therefore, that the value of the annual production will continue to decline until large plants are constructed.

Five large dredges, besides a number of small ones, were operated during the season of 1909. In addition to these, several others were in process of erection. Aside from the work of these dredges the most important mining operations were near Nome, in the Solomon Basin, on Ophir Creek, on the Kougarok and its tributaries, and in the Fairhaven precincts. The shortage of water for most of the large enterprises forced many miners who had previously worked for companies to seek employment by working for themselves. As a result, there were more small mining operations in 1909 than there had been for

years.

ARIZONA.

By V. C. HEIKES.

PRODUCTION.

There were 268 producing mines reported in Arizona during 1909, of which 25 were placers. The value of the combined yield of these mines was $44,053,023 for gold, silver, copper, lead, and zinc. Although copper production increased more than 6 per cent, Arizona, which was the leading copper producer in 1908, was second to Montana in 1909. The material increase in gold production may be credited to the siliceous ores, as the output from copper ores decreased. Mines in Cochise, Mohave, Yavapai, and Yuma counties produced most of the gold, and the greatest increase was in Yuma County; the production was also larger in Mohave, Pinal, and Maricopa counties. A very small part of the gold output was credited to placers. Copper production increased generally, the only important decrease being in Graham County. There was a slight increase in output of lead, the production being small, except in Cochise County. Zinc ore was produced in Cochise and Mohave counties. Arizona made a gain of more than $2,000,000 in value of total output in spite of decreases

made in Graham and Yavapai counties. Ores aggregating 216,910 tons and 1,220 tons of old tailings, treated at cyanide and amalgamation plants, produced gold precipitate and bullion, which yielded more than half of the total gold and nearly one-tenth of the silver, with a total value of $1,535,093, or an average value of $7.04 per ton. There was, in 1909, an increase, compared with 1908, of $118,756 in the total value of gold and silver recovered from ores and tailings. At concentration mills 1,485,724 tons of ore produced 248,969 tons of concentrates, which was 30,957 tons more ore, but 3,636 tons less concentrates, than in 1908. The concentrates, containing gold, silver, copper, lead, and zinc, were valued at $8,179,115, or a total average value of $32.85 per ton. The ore shipped directly to the smelters aggregated 2,184,432 tons, valued at $34,308,396 for the gold, silver, copper, lead, and zinc, and it averaged $15.70 per ton. The metal contents recovered from old slag and flue dust and some copper precipitates, aggregating 141,669 tons, are included in the crude ore totals. Compared with the figures of 1908, the tonnage of ore smelted increased 274,354 tons in 1909.

The statement of production for 1908 and 1909, showing increase and decrease, and valued at each year's average commercial prices, is as follows:

Mine production of gold, silver, and associated metals in Arizona in 1908 and 1909.

Arizona's production of ore and its content for five years are as follows:

Total tons of ore sold or treated in Arizona in 1904-1909, and total content of gold, silver, and associated metals.

The smelting plants operated in 1909, distributed by counties, were as follows: Cochise, 3; Gila, 2; Graham, 3; and Yavapai, 1-a total of 9 in 1909, against 8 in 1908. Two new copper plants were erected and they produced matte, which was shipped during 1909. These were the Arizona-Commercial, at Globe, and the Arizona-United, at

Johnson. The smelter at Humboldt, in Yavapai County, was prepared for resuming operations in 1910. The bulk of the copper ores was smelted at Arizona smelters. Zinc ores and concentrate were largely shipped to Oklahoma buyers, but some went to Colorado plants in 1909. Nearly all the lead ores were purchased by the smelter at El Paso, Tex., but some were shipped to Needles, Cal. Much of the gold bullion and gold precipitates from cyanide mills was shipped to the Selby Works, near San Francisco, and some was sold to eastern refineries. The Government mints at Denver and San Francisco received the larger part of the refined gold and silver bullion.

ORE PRODUCTION IN 1909.

Ore mined and sold or treated in 1909 aggregated 4,029,955 tons, and in addition a relatively small quantity of old tailings and slag were re-treated. The production increased 333,017 tons in quantity and decreased in value per ton from $11.30 in 1908 to $10.92 in 1909. Production of siliceous ore decreased from 375,500 tons in 1908 to 237,078 tons in 1909. The greatest quantity of this kind of ore was produced in Cochise County in 1908, Yuma County leading in 1909. Copper ore increased from 3,315,140 tons in 1908 to 3,741,713 tons in 1909. Graham County had the greatest output of copper ore, Cochise County following. Lead ore increased in output from 5,519 tons in 1908 to 27,658 tons in 1909; zinc ore increased from 695 tons in 1908 to 6,696 tons in 1909; copper-lead ore increased from 84 tons in 1908 to 16,810 tons in 1909. The average yield per ton of gold and silver in siliceous ore in 1909 was $7.31, as against $5.32 in 1908; in copper ore, 48 cents, as against 53 cents in 1908; in lead ore, $6.39 in 1909, as against $15.64 in 1908; in copper-lead ore, $18.47 in 1909, as against $23.49 in 1908; and in zinc ore, $8.78 in 1909, as against $2.91 in 1908. The total tonnage, by kinds of ore sold or treated, in Arizona during 1909 is shown in the following table:

Subdivision of tonnage of ore sold or treated in Arizona in 1909, by counties, in short tons.

The increase of gold output in 1909 may be credited to the lead ores, zinc ores, and copper-lead ores, as the total recovered from copper ores decreased. Most of the gold came from mines in Cochise, Mohave, Yavapai, and Yuma counties. The greatest increase was in the output of Yuma County; other increases were in Mohave, Pinal,

and Maricopa counties. Yavapai County fell short of its usual gold output. In 1909, Arizona mines produced 132,426.56 fine ounces of gold, valued at $2,737,500. Compared with the figures of 1908, this indicated an increase of $305,523. Milling plants equipped for treating the ores by the cyanide process and by amalgamation extracted 67,769.45 fine ounces from 216,910 tons of ore, averaging $6.46 per ton. Some of the mills, especially those in Yavapai County, where cyanide and amalgamation methods are in use, are also equipped to save concentrate. Three classes of concentrate were shipped to smelters. The auriferous iron sulphide is produced in greatest quantity and contained more gold than copper-lead and lead concentrates, which also yielded important totals. At milling plants equipped only for concentration, 1,485,724 tons of ore were treated, yielding 248,969 tons of concentrates, containing 11,619.18 ounces of gold, valued at $240,189, or an average value per ton of $0.96. The concentrates were of three kinds-copper, lead, and zinc. Copper concentrates in largest quantities were produced at mills near Clifton, in Graham County, but the amount of gold yield was not important, nor was it from lead and zinc concentrates produced at one mill in Cochise County. Smelting ores shipped directly to the smelters aggregated 2,184,432 tons, yielding 51,652.09 ounces of gold, valued at $1,067,745, or an average value per ton of $0.49. Gold production from placers decreased from $30,937 in 1908 to $28,648 in 1909. Yavapai, Yuma, and Pima County placers produced the largest quantities of placer gold. Yavapai County made a decided increase in placer yield, and it may be expected in the next two years to make greatly increased production. Gold dredges were reported to be under construction in several parts of Arizona. The large dredge built in 1909 on Colorado River, near the Arizona side, opposite Eldorado Canyon, Nev., was of the suction type and rated at 7,000 yards daily, but this is probably a high estimate. It was built to work the sand bars and failed on first test to extract the fine gold. It was subsequently carried from its moorings by high water and was wrecked during the spring of 1910. The active development of the gold region of western Arizona continued during 1909 with most encouraging results, especially in Yuma and Mohave counties (where new properties have been opened), in Payson district in northern Gila County, in the eastern section of Graham County, and in Cochise County.

Source of gold production in Arizona by kinds of ore in 1909, by counties, in fine ounces.