Geology topics
Research about Montana
Source-linked reports with geographic coverage including Montana.
Brachyceratops, a ceratopsian dinosaur from the Two Medicine formation of Montana, with notes on associated fossil reptiles
The fossils on which this paper is based were collected by me and my assistant, Mr. J. F. Strayrer, during the summer of 1913, while working under the auspices of the United States Geological Survey on the Blackfeet Indian Reservation, in northwestern Montana. The specimens were obtained from exposures of the Two Medicine formation along Milk River near the Canadian boundary, in T. 37 N., R. 8 W., about 30 miles northwest of the town of Cut Bank, Mont., and along Two Medicine River in T. 31 N., R. 7 W., about 15 miles southwest of Cut Bank. Vertebrate remains were found at these places in, 1911 and 1912 by Eugene Stebinger, while he was engaged in Geological Survey work, and he was the first to note that the localities are good fields for finding specimens of fossil vertebrates. 2 Although the present collection is small, it is of considerable scientific interest because it supplements the collections made in neighboring areas by other investigators, and because it contains a new genus of Ceratopsia in addition to other recognizable specimens which afford evidence that considerably extends the geologic and geographic ranges of forms heretofore described. The beds from which the collection was made constitute the upper part of the Two Medicine formation, which includes the equivalent of the Judith River formation and some older beds. The fossiliferous beds are also the equivalent of the upper part of the Belly River formation as found in neighboring areas of Canada. The fauna of the American Judith River formation, although diversified, is very inadequately known. Many of the genera and species have been founded on specimens so scant and fragmentary that it is almost impossible to refer to them subsequently discovered and more perfect materials. Recent collections made by L. M. Lambe, of the Canada Geological Survey, and by Barnum Brown, of the American Museum of Natural History, from the Belly River formation along Red Deer River in Canada, however, have placed this fauna on a more solid basis. The purpose of this paper is to give as complete and detailed a description of the skeletal anatomy of Brachyceratops montanensis as the material at hand will permit and to discuss briefly, in systematic order, other forms represented by specimens in the collection made in 1913. I take this opportunity to express my thanks for assistance rendered and for courtesies extended at many times, both in the field and during the preparation of this report, by Messrs. M. R. Campbell, T. W. Stanton, and F. H. Knowlton, and especially by Mr. Eugene Stebinger, all of the United States Geological Survey.
Glaciers of Glacier National Park
Glacier National Park derives its name and much of its interest from the presence of many small glaciers. Very much of the grandeur of its wonderful Alpine scenery, the final sculpturing of the great mountain valleys and of the amphitheaters at their heads, and the production of the basins of its many beautiful lakes are due to the action of the more extended glaciers of the past. There are in the park about 90 small glaciers ranging in size from Blackfeet Glacier, with its 3 square miles of ice, down to masses but a few acres in extent yet exhibiting the characteristics of true glaciers. The most easily accessible of these from the beaten trails are the Blackfeet and Sperry Glaciers and the small glaciers at Iceberg Lake and at Ahern Pass. Some of the others can be reached by tourists who are willing to undergo the exertions of mountain climbing. Among these are Grinnell, Chaney, Shepard, Vulture, and Carter Glaciers, and one or two at Brown Pass. (See map facing page 17.) After examining these features one can easily picture to himself, as he looks down the valleys, the great rivers of ice which in ages past cascaded from the cliffs below the upper cirques, converged as tributaries from the many branch valleys, and united in great trunk glaciers. In imagination lie can see these great glaciers many hundreds of feet ill depth filling the great mountain volleys from side to side, and deploying thence upon the bordering plains. lie seems to see these mighty engines plucking away the rock ribs of the mountains, smoothing, grinding, and polishing the irregularities and sweeping away the debris to be spread on the plains below. These glaciers developed and extended three times and, after each development, the congealed masses melted away on the return of milder climatic conditions, until at length only the small cliff glaciers of the present day are left lurking in the protected recesses at the heads of the capacious valleys. Many of the rock-walled amphitheaters are no longer occupied by ice, but from all there issue streams fed by the melting snow or ice. These plunge over the cliffs in beautiful foaming cascades and rush on down the mountain gorges. The melting glaciers left many inclosed basins large and small, and in these the waters rest a while and mirror in their crystal depths the dark green of the surrounding forests, the rich colors of the rugged mountain walls, and the deep blue of the cloud-flecked sky. On again from lake to lake the waters flow and finally start down their long courses to the sea to merge at length with the chill waters of Hudson Bay, the balm t ides of the Gulf of Mexico, or the rolling billows of the Pacific. Compared in size with the great glaciers of Alaska the glaciers of Glacier National Park are insignificant. They are even surpassed in size by those of the Alps, of the Canadian Rockies, and of Mount Rainier, Washington. They are, however, thought small, among the best examples of this interesting type of phenomena now existing in the United States. They have also a splendid setting in magnificent Alpine scenery, unsurpassed in grandeur anywhere. Hidden away in the recesses of the mighty mountain ranges these rare and wonderful features form a climax to many of the interesting trips open to the tourist.
Geology and ore deposits of the Philipsburg quadrangle, Montana
The Philipsburg quadrangle is bounded by parallels 46° and 46° 30' and meridians 113° and 113° 30'. Its length from north to south is 34.5 miles, its average width east and west 23.8 miles, and its area 827.42 square miles. As shown on the index map (fig. 1), it is not far from the western border of Montana and nearly midway between the northern and southern boundaries of the State. The nearest large town is Anaconda, the site of the great smelter of the Amalgamated Copper Co., which is on Warm Spring Creek, a mile or two beyond the eastern boundary of the quadrangle. Philipsburg lies about midway between the eastern and western limits of the Rocky Mountain system, if the term be used in the broad sense prevailing in the United States. In the general latitude of Montana the system as defined by American usage is bounded on the west by the Columbia River basalt plain and on the east by the Great Plains. The western limit is fairly definite, but on the east there is no very definite line between the plains and mountains; the mountains are fairly continuous west and north of the Philipsburg quadrangle, but to the east and southeast mountains alternate with broad stretches of semiarid lowland. The quadrangle therefore overlaps the line between two physiographic provinces, one characterized by isolated mountain groups, of which the Flint Creek Range is the most westerly, and the other by more continuous elevations, of which the Sapphire Mountains are an example.
Geology of certain lignite fields in eastern Montana. The Baker lignite field, Custer County, Montana. The Terry lignite field, Custer County, Montana. The Glendive lignite field, Dawson County, Montana. The Sidney lignite field, Dawson County, Montana. The Culbertson lignite field, Valley County, Montana
No abstract available.
Cenozoic mammal horizons of western North America, with faunal lists of the Tertiary Mammalia of the West
No abstract available.
Geology of the Marysville mining district, Montana: A study of igneous intrusion and contact metamorphism
The Marysville mining district had been for many years previous to 1899 one of the noted gold-producing centers of Montana. The mines are situated around the margins of in irregular batholith of quartz diorite, whose surface exposure is from half a mile to 1 1/2 miles broad and 2 1/2 miles long. This invasion of igneous rock, which as shown on later pages of this report was primarily the cause of the location of the mineral wealth in this district, is but 6 miles at its nearest point from the exposed surface of the far greater Boulder batholith, a granitic mass which is petrographically a quartz monzonite in normal composition. The Boulder batholith possesses a general rudely rectangular form, occupying about 60 miles in latitude by about 35 in longitude, and holds within its confines the mining city of Butte, from which for many years past has poured a flood of silver and a quarter of the world's copper. Other smaller mining centers also lie within this large granitic area, while such important ore deposits as those of Elkhorn and Unionville, south of Helena, have been found about its margin. Thus the Boulder batholith, with the outlying related areas at Marysville and at Granite, constitutes one of the more important centers of mining for the precious metals within the United States. · The necessity of studying such regions from the scientific point of view is evident, not only in order to develop the phases of immediate economic bearing, such as the limits of occurrence of the ore deposits, the degree of their continuity in depth, and other similar questions, but also because of the broader bearing which such studies must have on theoretical and applied geology in general.
The Montana lobe of the Keewatin ice sheet
Just south of the forty-ninth parallel and east of the Rocky Mountains is an area that is of much interest to glacialists. It is the area which lay between the Keewatin ice sheet and the mountain glaciers coming from the west. Although it has been known for nearly twenty years that the bodies of drift deposited by the ice coming from opposite directions were closely associated, little detailed field work has been done in this region. As early as 1881 Sir James Geikie prophesied that a careful study of the region would clear up many important points in glaciology. In 1885, Dr. T. C. Chamberlin and Prof E. D. Salisbury, in a reconnaissance of the region, determined roughly the course of the terminal moraine of the eastern ice sheet and obtained data concerning the character and extent of the mountain glaciation. In 1890 Mr. G. E. Culver, while a member of the military party under the command of Lieutenant Ahern, U. S. Army, gathered many data concerning the geology of the region, publishing the results of his investigations in the Transactions of the Wisconsin Academy of Sciences, in 1891. Doctor Dawson and Mr McConnell, of the Canadian Survey, have worked out the geology of the region north of the boundary line. Their reports are unusually complete, but the area to the south offers better opportunity for study, and somewhat different conclusions were reached from a study of that region. The work on which the following discussion is based was done during the field seasons of 1901, 1902, and 1903. During the first season the writer was accompanied by Mr. Bruce McLeish, then a student at the University of Chicago. The second year Mr. Porter Graves, of the Kansas City High School, rendered valuable assistance. The writer is most deeply indebted to Dr. T. C. Chamberlin and Prof. R. D. Salisbury, of the University of Chicago, for friendly interest shown while superintending the compiling of this manuscript. Professor Salisbury also personally directed a portion of the field work and made many practical suggestions. Thanks are also due Dr. G. K. Gilbert for careful criticism of the report. The area covered by this investigation lies along the eastern front of the Montana Rockies, between longitude 108° and 113° 40', and latitude 47° 15' and 49° 30'. Over the eastern and northern part of this area the ice from the northeast deposited its drift. Over the western part the ice from the Rockies pushed down the mountain valleys and, deploying on the plain, deposited large and well-defined terminal moraines. Extending from the Canadian line to the Missouri there is a strip of country, varying greatly in width, which the ice did not cover.
Petrography and geology of the igneous rocks of the Highwood Mountains, Montana
No abstract available.