created a great demand for information concerning the geology of this region. This has been met by a geologic reconnaissance of about 8,500 square miles of southwestern Nevada and eastern California. The area surveyed has been designated the Amargosa region, and includes the Goldfield, Bullfrog, Tokop, Silverbow, Kawich, Lida, and other mining districts, as well as a large part of Death Valley. A general report on the geology of this region has been practically completed. The Goldfield and Bullfrog districts were mapped and studied in detail, and complete geologic reports are in preparation. A preliminary outline of these investigations, with notes on the Manhattan, Searchlight, Eldorado, and other mining districts in the south western part of the State, is now ready for publication.

Other investigations of the precious metals, lead, and copper of the West include a report on the ore deposits, chiefly gold, of the Silver Peak quadrangle, Nevada, which was completed and is now in the hands of the Public Printer; a detailed report on the geology and ore deposits, principally lead and silver, of the Coeur d'Alene mining district, in Idaho, which was carried nearly to completion; a detailed report on the copper deposits of the Butte, Mont., district, which is nearly completed and will be submitted for publication before the close of the present calendar year; a detailed report on the Park City mining district, Utah, including a reconnaissance report on the neighboring Cottonwood mining region, which was carried nearly to completion and will be finished before the end of the year; a brief study of the copper deposits of the Sierra Nacimiento and the neighboring Zuni Mountains, the results of which have been embodied in brief reports that will appear as chapters in the general report on the mineral deposits of New Mexico; a short study of the placer gold deposits near Hahns Peak, Colorado, which resulted in the preparation of a contour map, covering about 25 square miles, and a brief report, published in the annual economic bulletin; and the completion of the special geologic map of the "Downtown district" of the Leadville region, Colorado.

In addition to the foregoing the annual economic bulletin contains a number of short papers on the precious metal and copper resources of other localities in the Western States.

A special study was also made to determine the horizon of the supposed Jurassic rocks of the northern Sierra Nevada, in which are contained the extensive metalliferous deposits of that region. This investigation, however, was not completed, and another season of field work will be necessary before the results can be prepared for publication.

Fuels.--In response to the demand for information regarding the fuel resources of the country a number of reconnaissance surveys were made of the coal fields of the West, notably the following: An area

of approximately 2,250 square miles in southwestern Wyoming, surveyed with special reference to coal and oil; an area of about 1,200 square miles, comprizing the coal lands in the valley of Yampa River, in Routt County, Colo.; the lignite coal fields of southwestern North Dakota, northwestern South Dakota, and eastern Montana; the Durango-Gallup coal field, in the northwestern part of New Mexico and the adjacent part of Colorado. Brief reports on all of these surveys were prepared for the annual economic bulletin, and detailed reports have been completed and submitted for publication.

In cooperation with the General Land Office an investigation of certain contested coal lands in Utah was undertaken, with a view to the classification of the lands according to their mineral or nonmineral character. During the season surveys were made of the Book Cliffs coal field and of the coal lands in the vicinity of Coalville and Provo. Brief reports were prepared for the annual economic bulletin, and detailed reports were completed and submitted to the General Land Office. During the last four months of the fiscal year the Survey cooperated with the Department of Justice in the investigation of coal-land frauds in Utah and Colorado. These investigations are still in progress.

A detailed report on the three southernmost oil fields of California was completed and submitted for publication, and a brief report on the recently developed Salt Lake oil fields near Los Angeles was prepared for the annual economic bulletin. In addition, the annual economic bulletin contained the following reports on the fuel resources of the West: The Engle coal field of New Mexico; the coal of the Mount Diablo Range, Monterey County, Cal.; the mineral resources, chiefly coal and lignite, of the Bighorn Mountains and the Bighorn Basin, Wyoming.

Iron ores.-In pursuance of the systematic investigation of the iron ores and iron industry of the United States the following investigations were made during the year in the Rocky Mountain and Pacific Coast States: A reconnaissance of the iron ores of central Colorado, including deposits near Ashcroft and White Pine in the Sawatch Range, those in the Cebolla district south of Gunnison, and in the preCambrian rocks in the vicinity of Salida; the detailed mapping of the deposits of Iron County in southern Utah and a study of the genesis of the ores; an examination of the deposits near Daggett, in San Bernardino County, Cal.; an examination of the deposits in the Seminole Mountains, northwest of Rawlins, Wyo.; laboratory studies of the western iron ores. A brief paper on the iron ores of the western United States and British Columbia was also prepared for the annual economic bulletin.

Miscellaneous economic investigations.-The special investigation of the relation of hydraulic mining and natural stream erosion in the

Sierra Nevada to agriculture, grazing, and other industries in the Sacramento Valley, which is being made in response to a memorial to the President and in cooperation with the division of hydrography, was well advanced, but owing to the intricacy of the problem and the many and conflicting interests at stake additional field and laboratory work will be necessary before the results can be prepared for publication. In connection with this investigation a laboratory has been equipped at Berkeley for the purpose of studying the natural laws which control the transportation of débris by streams, the 'necessary space, power, and other facilities for the experiments being contributed by the State University of California.

Other economic investigations in the West included the following: A reconnaissance of the mineral deposits of New Mexico, a special report on which was completed and submitted for publication; an examination of the asphalt lands near Thistle Junction, Utah, and of the ozokerite deposits near Colton and Soldiers Summit in the same State, brief reports on which were prepared for the annual economic bulletin, the detailed reports being submitted to the General Land Office.

The following additional brief reports were prepared for the annual economic bulletin: A Nevada zinc deposit; Cement resources of Washington; Some magnesite deposits of California; Gypsum deposits of the Uncompahgre region, Colorado; Gypsum deposits and bentonite of the Laramie Basin, Wyoming; Volcanic ash near Durango, Colo.

GENERAL SCIENTIFIC INVESTIGATIONS.

Geologic map of the United States. In order to meet the demand for revised geologic maps of the United States and of the several States which shall represent the present condition of knowledge, a map of the United States on the scale of 1:2,500,000 was undertaken and considerable progress made in its preparation, also in the assembling of data for the preparation of geologic maps of the States, or of groups of States, on the scale of 1:1,000,000. The United States map awaits the completion of the base, on which as rapid progress as possible is being made, and the data for the State maps, which will necessarily be more detailed, are being rapidly collated.

Special geologic map of North America.-In cooperation with the Governments of Canada and Mexico, a geologic map of North America on the scale of 1:5,000,000 is in preparation by the Geological Survey. A preliminary edition of this map will be issued at the expense of the International Geological Congress to be held in the City of Mexico in September, 1906, and an edition will later accompany a professional

paper.

Earthquakes. The record catalog of earthquakes occurring in the United States has been continued. It contains information obtained

thru newspapers, thru reports of the Weather Bureau, thru the LightHouse Board, and by special correspondence. The severe earthquake which occurred in California on the morning of April 18 was made the subject of a special investigation, in which the Geological Survey cooperated with the State of California and the Carnegie Institution. Two officers of the Geological Survey became members of the commission appointed by Governor Pardee, of California, and a third was temporarily detailed to assist in the work. This commission is studying the phenomena of the earthquake in a systematic manner, and has already made a preliminary report. The Geological Survey has also investigated the injury to buildings and other structures in San Francisco and vicinity, for the purpose of ascertaining what materials and forms of construction are best adapted to withstand earthquake vibrations.

PALEONTOLOGIC WORK.

In addition to the usual routine work of the paleontologists—that of aiding, by the identification of contained fossils, in the determination of questions of age and stratigraphy-which is performed for members of the Survey and the various State surveys, many special paleontologic investigations were carried on during the year.

Tertiary and Quaternary.-The study of the marine Tertiary fauna of the Pacific coast, which has been of fundamental importance in determining the oil and petroleum horizons of that region, was considerably advanced during the year, especially by the large collections of fossils obtained in Fresno, King, Kern, and San Luis Obispo counties, Cal. Satisfactory progress was made in the preparation of a monograph on this fauna, and in connection with it a bibliography and reference card catalog of the several thousand Tertiary and Quaternary species of the coast was prepared in order to facilitate the identification and study of fossils from those horizons.

The knowledge of Tertiary faunas was especially augmented by a large collection of Pliocene and Pleistocene fossils from Port Limon, Costa Rica, which have an important bearing upon the relations of the Tertiary of California to that of the Gulf of Mexico.

The monograph on the Tertiary corals of North America was also well advanced, and considerable progress was made in the preparation of a report on the Miocene of the Coos Bay region of Oregon.

The study of large collections of fossils from Georgia, gathered in connection with the investigation of underground waters, resulted in mapping the Tertiary formations of a large part of southeastern Georgia of which previously little or nothing was known, while an interesting collection from the Oligocene of Florida threw much light on the Tertiary of that region.

Cretaceous. Considerable progress was made in the study and description of the Lower Cretaceous fauna of Texas, a work which

has been in preparation for several years, such time as could be spared from immediately pressing duties being devoted to it.

Triassic. Satisfactory progress was made in the preparation of the monograph on the Triassic cephalopods of America. A large quantity of valuable material was collected from the Upper Trias of Shasta County, Cal., and that previously collected from the Triassic of Nevada, Idaho, and California was classified and studied in detail. The work in Shasta County resulted in clarifying certain stratigraphic problems of that region which have a direct bearing upon the study of the economic resources.

Carboniferous. The manuscript for a professional paper on the unique Guadalupian fauna of Texas, which is widely different from the typical Pennsylvanian, from the Permian of the Mississippi Valley, and from the Russian Permian, altho bearing some resemblances to the latter, was completed and submitted for publication, and the manuscript for a professional paper on the Lower Carboniferous orebearing beds of Missouri was partly written. The latter study was made in order to facilitate the correlation of the different ore-bearing horizons of the Missisippian series with one another and with the standard section of the Mississippi Valley in Missouri and Iowa.

The Devono-Carboniferous series of Pennsylvania was made the subject of a special geologic and paleontologic study, but additional field work will be necessary before the results can be prepared for publication.

Devonian and Silurian.-The Devonian and Silurian stratigraphy and faunas were the subject of an investigation with reference to the modifications which they exhibit in passing north and northwest from central Kentucky to Wisconsin, a question which has an important bearing on the distribution of the lead and zinc deposits of that region.

Cambrian. A monograph on the Cambrian brachiopods was brought very nearly to completion and will be submitted for publication early in the next year. Field investigations in the extensively developed Cambrian formations of western Montana and central Utah were continued.

General. Special paleontologic field studies were made in southeastern Alaska for the purpose of determining the limits of the principal geologic horizons and the order of succession. A bulletin on the paleontology of the Santa Cruz region in California, based on material gathered in connection with the areal and economic survey of that quadrangle, was well advanced. The monograph on the Ceratopsia was completed and is now in the hands of the printer, and considerable progress was made on the Sauropoda and Titanothere monographs, but owing to the magnitude and difficulty of the tasks additional work remains to be done. This study is being greatly facilitated by the notes and collections incidentally made by geologists