From introduction: Two field parties, one topographic, the other geologic, were engaged in making surveys in the section of the Alaska Range between the Nabesna and Big Tok Rivers in 1934. Most of the area surveyed was on the northeast side of the range, within a drainage area that is tributary to the Nabesna and Tanana Rivers, but it also included a small part of the Copper River Basin.

From abstract: The Curry district lies on the south flank of the Alaska Range, on the southeast side of Mount McKinley. Most of it is west of the Alaska Railroad. The eastern portion can be easily reached from several points along the railroad route, but the western portion is much more difficult of access, owing to the numerous glacial streams and the rugged topography. The relief of the area is great, the elevation ranging from 500 feet along the Chulitna River to 20,300 feet at Mount McKinley. The Chulitna River, a tributary of the Susitna River, drains the larger part of the area described. It flows in a broad valley in the eastern part of the district, and here the maximum relief is about 3,000 feet. The western part of the district is very rugged, with numerous peaks over 6,000 feet in elevation which have sheer slopes and almost unscalable pinnacles. Winding down through this maze of rugged mountains are four major valley glaciers-Eldridge, Buckskin, Ruth, and Tokichitna-and many tributary and smaller glaciers. Practically the entire district, with the exception of the higher peaks and ridges, has been glaciated. Timber grows along the main streams and extends to an elevation …

Abstract: During the spring of 1932 an opportunity was offered by the United States Navy for a geologist to accompany an expedition organized to make a reconnaissance of the western part of Alaska Peninsula and the Aleutian Islands. This expedition visited several localities the geology of which was little known. It was found, as had already been expected, that the islands west of Unimak Pass are composed mainly of basic volcanic lavas and fragmental materials, into which have later been injected dikes, sills, and considerable masses of intrusive rocks, some of which are of acidic types and of granitic texture. These westward islands are bordered both to the north and south by depressions 2,000 fathoms or more in depth, and the islands have apparently been built up from that depth by the ejection and extrusion of volcanic materials since early Tertiary time. No rocks of proved pre-Tertiary age were seen, and the only sedimentary materials present may well have been derived from the erosion of the volcanic islands after they were built up above sea level. On the Alaska Peninsula pre-Tertiary sediments through which the volcanic materials broke to the surface are abundantly present. There is evidence that all the …

From abstract: The report describes the geology and coal deposits of the southwestern part of the San Juan Basin, N.Mex. The field lies northeast of the town of Gallup, on the Atchison, Topeka & Santa Fe Railway, and is an irregular tract of about 630 square miles in central and west-central McKinley County; it includes the southeast corner of the Navajo Indian Reservation.

From abstract: The report is limited to the geology of lode deposits in the northwestern part of the Boise Basin which are in or near mines that were in operation at the time of visit, in 1930. Owing to the recent inactivity of the formerly rich placer (leposits, there is nothing essential regarding them to add to Lindgren's report published in 1898. The area studied is underlain by granitic rock of the Idaho batholith, which is cut by dikes of Miocene(?) age. These dikes are dacite porphyry (intruded early) ; rhyolite porphyry, granophyre porphyry, and granite porphyry (closely related in character and age) ; and several basic varieties (of which some, at least, are of relatively late origin). Diorite porphyry dikes, of undetermined age but probably older than all of those named above, are also present.

From abstract: The Moose Creek area is in the western part of the Matanuska Valley, in south-central Alaska, about 165 miles by railroad north of the coast at Seward. Coal deposits in the valley have been known since the early 1890's, and there have been producing mines since 1916, but the annual production is only about 40,000 tons, or less than one-third of the total amount consumed in the Territory. Early in 1931 Congress authorized the investigation of mineral resources in areas tributary to the Alaska Railroad, which is Government owned and operated, for the purpose of stimulating development and hence increasing the traffic and revenue of the railroad. The technical work of carrying on these studies was entrusted by Col. O. F. Ohlson, general manager of the railroad, to the United States Geological Survey. One of the investigations undertaken was that of the Moose Creek area, where small coal mines are in operation. Difficulties have been encountered in these mines, owing to the faulted character of the formation, which causes unproductive work in mining and also produces a large percentage of fine coal, which is unsuitable for sale in distant markets. Field examination indicated that more favorable mining conditions …

Abstract: By grinding minerals under water it has been found that they yield relative and reproducible measurements of the hydrogenion concentration resulting from their hydrolysis. Many silicate minerals and two glasses have been studied in this way by a colorimetric method of determining hydrogen-ion concentration, and some of them have been studied more quantitatively by means of the hydrogen electrode. The results of these tests are a rough index of the weathering qualities of different silicate minerals. The effect of silicate minerals on underground waters and upon geochemical changes is discussed.

From introduction: From the time of the publication of the Leadville monograph 2 by the United States Geological Survey, in 1886, the general geology and stratigraphy of the Mosquito Range around the Leadville and Alma districts have been known. In the recent resurvey of the area, however, it has been found necessary to undertake much more detailed studies of most of the formations. In particular, the sediments of Pennsylvanian age and the overlying red beds have received considerable attention and thought. This study was necessary to determine the amount of displacement along some of the notable faults and the depth to older strata that had contained valuable ore deposits in the larger mining districts. In some places the outcrops appear to have been improperly correlated in the older reports. These were given additional study, and considerable revision of stratigraphic sections has been necessary.

Abstract: The identification of new collections of fossil plants from the Green River formation of middle Eocene age made it necessary to reexamine the megascopic types of the Green River flora. This study resulted in the reassignment of some species and the rejection of such species as were based on fragmentary, indefinable specimens. The recent collections yielded 22 new species. Exclusive of the microscopic forms of thallophytes and pollens, the flora now numbers 135 megascopic species that are considered to be recognizable and distinctive. The new elements found in the flora do not alter the previously expressed opinion that the megascopic Green River flora lived in a warm-temperate well-watered environment.

From introduction: This paper describes a small fossil flora from the vicinity of Leadville, central Colorado. The beds from which the flora was collected have long been referred to as the "Weber formation ", though with considerable doubt on the part of many geologists that all the beds so named in Colorado are correlative with the Weber quartzite of northeastern Utah. In current usage these Colorado beds are designated the " Weber (?) formation."

Abstract: The author describes 75 species of plants from the Miocene of about 30 localities in Idaho. These plants represent 40 genera in 28 families and 17 orders, and the most common types are species of Acer, Quercus, Populus, Betula, and Laurus. There are 2 ferns, 3 monocotyledons, and 70 dicotyledons, 18 of which are no longer present in the northwestern United States. There are some xerophytic types, but the majority are mesophytic, possibly indicating a mixture from different altitudes. The beds are correlated with the Latah formation and considered to be of upper Miocene age.

From abstract: This paper is a continuation of the study of the kaolin minerals, in the first part of which, published in 1931, the kaolin minerals kaolinite, dickite, and nacrite were described. In that paper the application of chemical, optical, X-ray, and dehydration methods to the investigation of clay materials were discussed. The present study shows that halloysite is a fourth mineral of the kaolin group, closely related to but distinct from kaolinite. The chemical, optical, X-ray, and dehydration properties of a representative group of halloysites are recorded, all these being new data determined by the authors on separate portions of single samples whose purity has been carefully tested.

From page 127: For the last few years Mr. Henry E. Lee, of Rapid City, S.Dak., has been sending me selected material from the lower part of the Lance formation of Harding County, S.Dak., the exact locality being what is locally known as the Jump Off, an erosion basin of the headwaters of the South Fork of the Grand River, 10 miles north of the East Short Pine Hills. 1 The matrix is a soft gray friable sandstone, and consequently only the coarser, more resistant plants are preserved. In view of the coarseness of the matrix the preservation is excellent, although usually the finer details of venation are obscure. In the sands overlying the plant beds are thin seams of impure lignite.