FOSSIL PLANTS AND PALYNOMORPHS FROM THE LATE PALEOZOIC CUTLER FORMATION, EASTERN PARADOX BASIN

The late Paleozoic Cutler Formation, where exposed near the modern-day town of Gateway, Colorado, has traditionally been interpreted as the product of alluvial fan deposition within the easternmost portion of the Paradox Basin. The Paradox Basin formed between the western margin of the Uncompahgre Uplift segment of the Ancestral Rocky Mountains and the western paleoshoreline of the North American portion of Pangea. The Paradox Basin region is commonly thought to have experienced semi-arid to arid conditions and warm temperatures during the Pennsylvanian and Permian. Evidence described in this paper support prior interpretations regarding paleoclimate conditions and the inferred depositional environment for the Cutler Formation near Gateway, Colorado. Plant fossils collected from the late Paleozoic Cutler Formation in The Palisade Wilderness Study Area (managed by the U.S. Department of the Interior, Bureau of Land Management) of western Colorado include Calamites, Walchia, Pecopteris, and many calamitean fragments. The flora collected is interpreted to have lived in an arid or semi-arid environment that included wet areas of limited areal extent located near the apex of an alluvial fan system. Palynological analysis of samples collected revealed the presence of the common Pennsylvanian palynomorphs Thymospora pseudothiessenii and Lophotriletes microsaetosus. These fossils suggest that warm and at least seasonally and locally wet conditions existed in the area during the time that the plants were growing. All evidence of late Paleozoic plant life collected during this study was found along the western margin of the Uncompahgre Uplift segment of the Ancestral Rocky Mountains. During the late Paleozoic, sediment was eroded from the Uncompahgre Uplift and deposited in the adjacent Paradox Basin. The preservation of plant fossils in the most proximal parts of the Paradox Basin is remarkable due to the fact that much of the proximal Cutler Formation consists of conglomerates and sandstones deposited as debris flow and by fluvial systems. The plants must have grown in a protected setting, possibly an abandoned channel on the alluvial fan, and been rapidly buried in the subsiding Paradox Basin. It is likely that there was abundant vegetation in and adjacent to low-lying wet areas at the time the Cutler Formation was deposited.

Upper Mississippian Faunas of Western Montana

The author has made a study of an assemblage of fossils from the Blacktail Range near Dillon Montana with the purpose in view of attempting a correlation of that group with the fauna of the Big Snowy Group. Fossils have also been obtained from a limestone formation in northwestern Montana and from four different areas in the Amsden formation in central and western Mont­ana.

Geology of Iron Deposits at Princeton Montana and Economic Aspects of Iron Ore in Montana

The purpose of this paper is to introduce to the reader, an iron deposit in the Princeton district, about 19 miles northeast by highway from Philipsburg, Montana. Heretofore there has been no written literature on this deposit. It is also intended to investigate the economic possibilities of iron ore in general in the State of Montana.

An Isopach Map and Discussion of the Marine Jurassic of Western United Sates and Canada

Recent demands for petroleum to carry on the war effort have resulted in widespread prospecting in the northern Great Plains. Nearly all oil wells now drilled are of a depth to penetrate the marine Jurassic formations. It is known that these strata differ in thickness from place to place, but information of distribution, thickness, and lithology has not yet been compiled.

Vermiculite, Occurence, Character, and Concentration of Mineral from the Pony District, Madison County, Montana

The purpose of this paper is to investigate the occurrence and character of the vermiculite deposits approximately four miles northwest of Pony; Madison County, Montana. The deposits are situated in rolling foothills at the northern end of the Tobacco Root Mountains.

Distribution and Lithology of Sedimentary Rocks in Montana and Adjacent Areas

The general features of the sedimentary rocks in a region, their distribution, and the relationships of these rocks to other rocks of the area and of adjacent areas, are some of the things in which most geologists are interested, for reasons of general curiosity or for obtaining a better understanding of their specific prob­lems

Glaciation in Montana

Glacial deposits are increasingly entering into consideration in engineering projects, soil surveys, ground-water supply, sources for industrial materials, and other economic enterprises. In the field of en­gineering, glacial deposits if present must be consider­ed in connection with reservoir sites, dam or bridge abutments, road building, and other types of construction work.

Upper Cretaceous Sediment in Montana

Cretaceous sediments in Montana record events during a period of unusual geologic interest. After a long period of extensive submergence of the area during Jurassic time, came a period of varying continental and marine deposition with consequent variations in the types of sediments laid down. A study of these variations, their extent, and their cause has been the primary object of this thesis.

General Geology and Mines of Northwestern Montana

The five counties discussed in this paper compose the northernmost and westernmost counties in Montana. On the eastern boundary are Glacier National Park and the Continental Divide; on the southern boundary are Missoula and Powell counties; Idaho lies on the southwestern and western side; and the Canadian border lies along the northern edge. The region is on the Pacific Ocean side of the Rocky Mountains. Three major rivers, the Clark Fork, the Flathead, and the Kootenai drain this area into the Columbia River.

The Separation of Tungstic Oxide from Scheelite and its Subsequent Reduction with Hydrogen

The largest known deposits of tungsten ores occur in the continuation of the Indo-Malayan Mountains, which extends through Burma, Malaya, China, Japan, and Chosen. Production of tungsten concentrates was started in 1910 in Burma, and in 1911 this country was the world's largest producer. China produced but little until 1916, but has since supplied over fifty per cent of the world's requirements.

The Geology and Ore Deposits of the Ruby Gulch Mine

The Ruby Gulch Mine, owned and operated by the Ruby Gulch Mining Company, Zortman, Montana, is one of the most important low-grade gold producers in the state. Sit­uated in the Little Rocky Mountains, the mine has had an interesting history since its discovery shortly before the turn of the century.

Mayflower, Renova Basin, and South Boulder Creek Areas

In Montana at the turn of the century a great many men sought the riches buried in the earth's crust. Prospectors fanning out from Butte and other early Montana mining areas located veins at the Mayflower, Renova, and Gold Hill areas.

Geology of Upper Bear Gulch and Dry Boulder Creek Area Madison County, Montana

Potential gold mines lie high among the rugged peaks of the Tobacco Root Mountains of southwestern Montana. This is a region where little geologic work has been done, though extensive mine operations have been carried on, and valuable ore has been shipped.

The Geology and Mineral Deposits of British Columbia

The province of British Columbia, with an area of 359,279 square miles, includes a large part of the Canadian Cordillera that is the western mountains of Canada. It is the leading province of Canada in the production of lead, zinc, and silver, and third among the provinces in the output of gold, copper, and coal.

The Physiographic History of Western Montana and Northwestern Idaho

Millions of years of physiographic changes have conditioned us to the fact that our present drainage is a temporary feature. Rivers once flowing opposite to their present direction is not an unusual condition for physiographers to suggest.