FIELD OPERATIONS DURING SEASON OF 1914.

Areas covered and allotments.-Ten parties were engaged in surveys and investigations during 1914. The area covered by exploratory geologic surveys, on a scale of 1: 500,000 (8 miles to the inch), amounts to 1,000 square miles; by reconnaissance geologic surveys, on a scale of 1: 250,000 (4 miles to the inch), 7,700 square miles; by detailed geologic surveys, on a scale of 1: 62,500 (1 mile to the inch), 325 square miles. Much of the time of the geologists was devoted to the investigation of special field problems in the important mining districts, the results of which can not be presented in terms of area. About 600 square miles was covered by exploratory topographic surveys on a scale of 1: 500,000, 10,300 square miles by reconnaissance topographic surveys on a scale of 1: 250,000, and 10 square miles on a scale of 1: 24,000 (2.64 inches to 1 mile).

The following table shows the allotment, including both field and office expenses, of the total appropriation to the districts investigated. In addition to this, a balance of about $6,000 from last year's appropriation was expended in equipping the parties for the season's field work. In preparing this table the general office expenses were divided among the districts in proportion determined by the cost of the surveys in each district, allowance being made for variations in the character of the work The results are expressed in round numbers. The "general investigations" include the cost of special studies of geology and mineral resources which were not of an areal character. The unallotted balance has been used for equipment of field parties and expenses up to the close of the fiscal year 1915.

Approximate geographic distribution of appropriation for Alaska investigations, 1914.

In the following table the approximate amount of money devoted to each class of investigations and surveys is indicated. It is not possible to give the exact figures, as the same party or even the same man may have carried on two different kinds of work, but this statement will help to elucidate a later table, which will summarize the complete areal surveys.

Year.

Approximate allotments to different kinds of surveys and investigations, 1914.

salaries, office supplies and equipment, and map compilation. Allotted to field investigations, 1915...

14, 800

11,000

100,000

Progress of work.—The following table exhibits the progress of investigations in Alaska and the annual appropriations since systematic surveys were begun in 1898:

Sq.m.
2,070

Sq. m. Miles.

a The Coast and Geodetic and International Boundary surveys and the General Land Office have also made topographic surveys in Alaska. The areas covered by these surveys are, of course, not included in these totals.

General work.-Alfred H. Brooks, geologist in charge, was engaged in office work until July 6, when he started for Alaska. He visited Survey parties at Juneau, Valdez, Kotsina River, and Fairbanks, returning to Washington October 7.

George C. Martin was engaged during the summer on the Mesozoic stratigraphy of Alaska. Mr. Martin, accompanied by R. M. Overbeck as assistant, visited important localities in southeastern Alaska and in the Chitina and Yukon valleys. Arthur Hollick was employed for 64 days in continuing the study of Alaska Cretaceous and Tertiary floras.

R. H. Sargent continued the general supervision of the topographic surveys and map compilation in addition to carrying on his own field work. E. M. Aten continued as office assistant to the geologist in charge and supervised the office work during the field season. He also continued to assist in collecting statistics of the production of precious metals in Alaska.

Southeastern Alaska.-D. C. Witherspoon worked on detailed topographic surveys in the Juneau district. Rain prevented work on 45 days and greatly hampered it much of the rest of the season. Nevertheless, Mr. Witherspoon covered the area by triangulation and mapped 9.75 square miles on a scale of 1: 24,000, with 50-foot contours. Mr. Eakin devoted about 10 days in the fall to the study of mining developments in the Juneau and Berners Bay districts.

Copper River and Susitna basin.-Detailed geologic mapping of the west end of the Kotsina-Chitina copper belt, begun in 1912, but interrupted in 1913, was completed in 1914 by F. H. Moffit, assisted by J. B. Mertie, who together mapped the geology and studied the mineral resources of an area of 185 square miles.

A topographic reconnaissance survey was carried by J. W. Bagley from Copper Center to the head of Klutina River and thence northwestward to the Susitna, an area of 4,000 square miles being surveyed by phototopographic methods, on a scale of 1:250,000, with 200-foot contours. Theodore Chapin, who accompanied the party as geologist, mapped an area of about 3,600 square miles. He also examined the gold placers of the Nelchina basin. This survey is an important connecting link between areas previously mapped in the Copper, Susitna, and Matanuska valleys.

Prince William Sound.-A detailed geologic survey and study of mineral resources of the Port Valdez district was begun in 1914 by B. L. Johnson, assisted by G. L. Harrington, covering 140 square miles.

Lake Clark-Iditarod region.-An exploration of the large, almost unknown region lying between Lake Clark and the Iditarod district was undertaken in 1914 by a party under R. H. Sargent, topographic engineer, and P. S. Smith, geologist. The topographic surveys

covered 4,800 miles and the geologic surveys 3,500 square miles. Some of the quicksilver deposits of the Kuskokwim region were also examined.

Lower Kuskokwim basin.-A. G. Maddren, assisted by Burt Kennedy, made a reconnaissance in the lower Kuskokwim basin. From Iditarod they went overland to Kuskokwim River, down that river, and up several tributary streams, making an examination of the Aniak-Tuluksak placer district and exploratory topographic surveys of about 600 square miles. Besides the gold placers, some copper and quicksilver deposits were examined.

Seward Peninsula.-In view of important developments in the York tin district a supplementary examination of this field was undertaken by H. M. Eakin, who also investigated the mining developments near Nome and made a brief study of the iron deposits in the Sinuk basin, about 40 miles from Nome.

Yukon basin.-Owing to the development of gold placers in the Chisana district in the upper Tanana Valley C. E. Giffin was detailed to extend the topographic surveys in this field. He surveyed Skolai Pass, extended the previous mapping in the Tanana and White River basins eastward to the international boundary, made reconnaissance surveys of about 1,500 square miles, for publication on a scale of 1: 250,000, and revised about 1,500 square miles of the old mapping. The wagon road from Willow Creek to Chitina, a distance of 40 miles, together with the adjacent country, was also surveyed in the autumn, making an additional area of revision of about 150 square miles. S. R. Capps made a study of the Chisana placer district and mapped the geology of an adjacent area of about 600 square miles.

H. M. Eakin devoted about three weeks to the investigation of the mining developments in the Hot Springs and Fairbanks districts.

FIELD AND OFFICE WORK FOR SEASON OF 1915.

Alfred H. Brooks will continue his general geologic investigations in different parts of Alaska. G. C. Martin will complete the preparation of a report on the Mesozoic stratigraphy of Alaska. A. G. Maddren will complete reports on the Kuskokwim region, the Yakataga region, and the international boundary region in northeastern Alaska. Arthur Hollick will continue work on a report on Cretaceous and Mesozoic floras. G. A. Waring is investigating the hot springs of Alaska and will also collect data on the quality of the surface waters. D. C. Witherspoon is continuing the preparation of a new base map of the Juneau district on a scale of 1:24,000. The water powers of southeastern Alaska are being investigated by George H. Canfield, in cooperation with the Forest Service. Theodore Chapin is studying the geology and mineral resources of the Ketchikan district. A recon

naissance geologic survey and investigation of the mineral resources of the upper Chitina basin is being made by F. H. Moffit and R. M. Overbeck. B. L. Johnson is completing a detailed geologic survey and study of the mineral resources of the Port Valdez district. He will later extend a reconnaissance geologic survey in the Prince William Sound region. Topographic and geologic reconnaissance surveys and investigations of mineral resources are being made in the Knik and Turnagain Arm region by J. W. Bagley and S. R. Capps. Time permitting they will also make similar surveys north of the Willow Creek district. Eliot Blackwelder is engaged in studying the Paleozoic stratigraphy of the upper part of the Yukon basin in Alaska. Topographic reconnaissance surveys of the Ruby district and the region lying to the south as far as Kuskokwim River are being made by R. H. Sargent and C. E. Giffin, and the geology and mineral resources of the same region are being studied by J. B. Mertie and G. L. Harrington. H. M. Eakin will explore the region lying between Cosna River, tributary to the lower Tanana, and the Ruby district, on the Yukon.

COLLECTION OF STATISTICS.

The work of collecting statistics of the annual production of gold, silver, and copper, begun in 1905, was continued during the year. Preliminary estimates of mineral production were published on January 1, 1915. The progress report for 1914 (Bulletin 622), containing figures on mineral production, was transmitted in June. An abstract of this report, including the mineral statistics, was also transmitted in June for inclusion in the Survey's annual volume, Mineral Resources of the United States, for the calendar year 1914.

PUBLICATIONS.

During the year one professional paper (No. 87), three bulletins (Nos. 576, 578, 592), one water-supply paper (No. 342), and one separate of a water-supply paper (No. 345-F) relating to Alaska were issued.

Two Alaska maps were issued for sale—a general map of Alaska (scale 1:1,500,000) and a map of the Port Valdez district (scale 1: 62,500).

Three bulletins (Nos. 605, 607, 608), one water-supply paper (No. 372), and one separate of a professional paper (No. 95-D) are in press. Manuscripts of the following reports have been completed: Mineral resources of Alaska, report on progress of investigations in 1914, by Alfred H. Brooks and others (Bulletin 622); the YukonKoyukuk region, Alaska, by H. M. Eakin; and the Chisana-White River district, Alaska, by S. R. Capps.