Mafic and Ultramafic Xenoliths from Volcanic Rocks of the Western United States (open access)

Mafic and Ultramafic Xenoliths from Volcanic Rocks of the Western United States

From abstract: Mafic and ultramafic xenoliths in the Western United States are present in volcanic rocks ranging from lamprophyric to dacitic in composition and are found in every major tectonic province from the Coast ranges from California to the Great Plains. Xenoliths from 68 localities are described here, but new localities are being discovered, and much remain to be learned about their distribution with respect to the tectonic and geophysical framework of the Western United States.
Date: 1988
Creator: Wilshire, Howard Gordon; Meyer, C. E.; Nakata, John K.; Calk, L. C.; Shervais, John W.; Nielson, J. E. et al.
System: The UNT Digital Library
Gold Quartz Veins of the Alleghany District, California (open access)

Gold Quartz Veins of the Alleghany District, California

From Outline of the Report: The Alleghany district, in the southern part of Sierra County, Calif., has long been famous for the high-grade gold ore of its quartz veins. The oldest rocks of the district (pp. 6-17) are of sedimentary and volcanic origin and correspond to part of the Calaveras formation as mapped in the Colfax and Downieville folios of the Geologic Atlas of the United States. These rocks are divided into five formations, of which three-the Blue Canyon, Relief, and Cape Horn formations follow the definitions laid down by Lindgren in the Colfax folio, and two-the Tightner and Kanaka formations-are new units required by the more detailed nature of the present study. It is thought possible that a conglomerate which forms the basal part of the Kanaka formation is of glacial origin. Intrusions of gabbro and more basic rocks, the latter now completely serpentinized, crop out over nearly half the area in which pre-Tertiary rocks are exposed. Small granitic dikes of later age than the basic intrusives are found in the western part of the district. Overlying and largely concealing the older rocks are auriferous gravel of Eocene and Miocene age, andesitic breccia of probable Miocen age, basalt flows …
Date: 1932
Creator: Ferguson, Henry G. & Gannett, Roger W.
System: The UNT Digital Library
Miocene Foraminifera of the Coastal Plain of the Eastern United States (open access)

Miocene Foraminifera of the Coastal Plain of the Eastern United States

From introduction: In the following report the species of Foraminifera found in the Miocene of the Coastal Plain region of the eastern United States from Florida to Maryland are described and recorded. Numerous papers have been published on this region, some of which, however, are largely lists. Where the original material on which a paper was based has not been available for the present study, the records have been omitted, as it is very difficult to place the species in their proper position without seeing the actual specimens.
Date: 1933
Creator: Cushman, Joseph A. & Cahill, Edgar D.
System: The UNT Digital Library
The Geology and Ore Deposits of Goldfield, Nevada (open access)

The Geology and Ore Deposits of Goldfield, Nevada

This report describes the geology and ore deposits of Goldfield, Nevada.
Date: 1909
Creator: Ransome, Frederick Leslie
System: The UNT Digital Library
Geology and Ore Deposits of the Park City District, Utah (open access)

Geology and Ore Deposits of the Park City District, Utah

From introduction: This survey was the first systematic work undertaken in this geologic province since the Geological Exploration of the Fortieth Parallel, in 1869, and was the first detailed geologic examination of a wide area in the Wasatch Range. Hence, an unusual amount of general geologic work in the region surrounding the special field was required to establish fundamental geologic facts.
Date: 1912
Creator: Boutwell, John Mason
System: The UNT Digital Library
The Geology of Long Island, New York (open access)

The Geology of Long Island, New York

Report describing the geology of Long Island based on surveys and research conducted 1903-1905, with a particular emphasis on glacial deposits and formations from the Pleistocene epoch. It includes a broad discussion, with tabular summaries.
Date: 1912
Creator: Fuller, Myron L.
System: The UNT Digital Library
Lithologic Studies of Fine-Grained Upper Cretaceous Sedimentary Rocks of the Black Hills Region (open access)

Lithologic Studies of Fine-Grained Upper Cretaceous Sedimentary Rocks of the Black Hills Region

More than nine-tenths of the Upper Cretaceous rocks in northeastern Wyoming are fine-grained shales, mudstones, and calcareous marls. A comparative study of the mineralogy, chemical and mechanical composition, density and porosity, fissility, and lamination of samples of these rocks discloses several relations that throw light on the geologic history and structural deformation of the region, and perhaps on its oil and gas possibilities.
Date: 1930
Creator: Rubey, William Walden
System: The UNT Digital Library
Geology of the Eastern Part of the Santa Monica Mountains, Los Angeles County, California (open access)

Geology of the Eastern Part of the Santa Monica Mountains, Los Angeles County, California

From abstract: The Santa Monica Mountains lie only a few miles northwest of the city of Los Angeles and comprise one of the prominent structural features that adjoin the Los Angeles Basin, one of the most prolific oil-producing districts of California. Even though the eastern part of these mountains may yield no oil, information concerning the rock types, structural character, and detailed geologic history of this area should be of value to petroleum geologists. The area described in this report, which lies between Topanga Canyon on the west and the Los Angeles River on the east, presents a section of varied rock types including coarsely crystalline plutonic rocks, basic and acidic intrusive and pyroclastic rocks, metamorphic slate and schist, and a wide assortment of sedimentary rocks.
Date: 1930
Creator: Hoots, H. W.
System: The UNT Digital Library
Geology of the Big Snowy Mountains, Montana (open access)

Geology of the Big Snowy Mountains, Montana

From introduction: The main purpose of the field investigations on which this paper is based was to determine the structure of the mountains. The geologic formations were therefore studied, and sufficient data were obtained to construct a combined areal and structural map.
Date: 1931
Creator: Reeves, Frank
System: The UNT Digital Library
Glaciation in Alaska (open access)

Glaciation in Alaska

From introduction: The history of glaciation in Alaska offers a fascinating field for study. Because of the remarkable development and easy accessibility of valley and piedmont glaciers in the coastal mountains, Alaska has long been popularly conceived as a land of ice and snow, a concept that is only slowly being corrected. To the student of glaciation, however, Alaska affords a unique opportunity to observe the formation, movement, and dissipation of the many living glaciers, to examine the results of glacial erosion on a gigantic scale, and to discover and work out the sequence of Pleistocene events as shown by the topographic forms in both glaciated and unglaciated areas and by the deposits left by ice and water during earlier stages of glaciation.
Date: 1931
Creator: Capps, Stephen R.
System: The UNT Digital Library
The Upper Cretaceous Ammonite Genus Barroisiceras in the United States (open access)

The Upper Cretaceous Ammonite Genus Barroisiceras in the United States

From introduction: The ammonite genus Barroisiceras Grossouvre is noteworthy because of its wide geographic distribution and its apparently small stratigraphic range. It is reported from deposits of Coniacian age in Europe, Africa, South America, and North America. In the North American Upper Cretaceous it is rather rare, authentic species having been recognized hitherto only in the Austin chalk of Texas, in the Coniacian beds of Zumpango del Rio, Guerrero, Mexico, and, with doubt as to the source, in New Jersey. The Texan species, B. dentatocarinatum (Roemer), is by no means an abundant form, though among those described in early work in the region. The Mexican representatives of the genus thus far described include only fragmentary specimens not specifically named. The occurrence ascribed to New Jersey is based on a fragment that seems to belong to Barroisiceras but whose source is very doubtful.
Date: 1931
Creator: Reeside, John B., Jr.
System: The UNT Digital Library
Pliocene Fossils From Limestone in Southern Florida (open access)

Pliocene Fossils From Limestone in Southern Florida

Abstract: This paper describes the mollusks and echinoids found in limestone dredged from ditches along the Tamiami Trail in southern Florida, in the area mapped as "Lostmans River limestone (Quaternary)" by Sanford but included in the Pliocene Caloosahatchee formation by Cooke and Mossom on the evidence of these fossils as identified by Mansfield. The matrix of the fossils is unlike the typical Caloosahatchee formation, which is sandy, but the fauna is closely related to that of the upper part of the Caloosahatchee formation and is regarded as a facies of the Caloosahatchee. The fauna shows considerable resemblance to that of the Imperial formation of California but may not be contemporaneous with it.
Date: 1931
Creator: Mansfield, Wendell C.
System: The UNT Digital Library
A Miocene Flora From Grand Coulee, Washington (open access)

A Miocene Flora From Grand Coulee, Washington

From introduction: The fossil plants described in the present report were collected at the north end of Grand Coulee during the summer of 1927 by Messrs. T. A. Bonser, F. A. Roberts, and Walter Bruce, of Spokane, and F. W. McCann, of Coulee City. The locality is in the big bend of the Columbia River near the northern boundary of Grant County, Wash., about 85 miles west of the plant-bearing Latah sediments around Spokane. The outcrop in Grand Coulee is about the same distance east of the crest of the Cascade Mountains, about 100 miles northeast of the plant beds at Ellensburg, which are of approximately the same age, and some 200 miles west of beds in Idaho yielding a similar flora and assigned to the Payette formation by Knowlton and others.
Date: 1931
Creator: Berry, Edward Wilber
System: The UNT Digital Library
Stratigraphy of Outcropping Permian Rocks in Parts of Northeastern Arizona and Adjacent Areas (open access)

Stratigraphy of Outcropping Permian Rocks in Parts of Northeastern Arizona and Adjacent Areas

From introduction: In the spring and early summer of 1950 the writers undertook an investigation of the outcropping Permian rocks in northeastern Arizona, northwestern New Mexico, and parts of southern Utah. This work had as its specific objective the establishing of correlations of Permian rocks in the Zuni uplift, Defiance uplift, and Monument Valley upwarp. The determination of these relations, it is believed, will be of aid in the current activities of the Geological Survey in the Navajo Reservation which have as objectives the investigation of the mineral fuels and water resources of the area.
Date: 1961
Creator: Read, C. B. & Wanek, Alexander A.
System: The UNT Digital Library
Yampa Canyon in the Uinta Mountains Colorado (open access)

Yampa Canyon in the Uinta Mountains Colorado

From purpose of the report: A detailed office study of modern topographic and geologic maps and aerial photographs of Yampa Canyon and its environs in the Uinta Mountains.
Date: 1962
Creator: Sears, Julian D.
System: The UNT Digital Library
A Descriptive Catalog of Selected Aerial Photographs of Geologic Features in the United States (open access)

A Descriptive Catalog of Selected Aerial Photographs of Geologic Features in the United States

From introduction: The U.S. Geological Survey has selected and assembled sets of photographs that illustrate numerous types of geologic features in the United States. This catalog lists these special sets of photographs that are available for purchase and describes the features illustrated. One reduced photograph from each set is shown on the back pages of this catalog to assist the purchaser in his selection.
Date: 1968
Creator: Geological Survey (U.S.)
System: The UNT Digital Library
Quaternary Geology of Minnesota and Parts of Adjacent States (open access)

Quaternary Geology of Minnesota and Parts of Adjacent States

Description of geology in Minnesota and explanations of glacial drift within the state an immediate surroundings (Wisconsin, Iowa, North Dakota and South Dakota) with sections detailing the movement of each glacier and relevant geological notes. Index starts on page 147.
Date: 1930
Creator: Leverett, Frank, 1859-1943
System: The UNT Digital Library
The Significance of Geologic Conditions in Naval Petroleum Reserves No. 3, Wyoming (open access)

The Significance of Geologic Conditions in Naval Petroleum Reserves No. 3, Wyoming

From Introduction: The work on which this report is based consisted of detailed field and office studies which occupied the greater part of the summer of 1927. During this period mapping was done with plane table and telescopic alidade on a scale of 1 inch to 1,000 feet, and wells, faults, and outcrops within the productive part of the Teapot field were located in detail.
Date: 1931
Creator: Thom, W. T., Jr. & Spieker, Edmund M.
System: The UNT Digital Library
The Kaiparowits Region: A Geographic and Geologic Reconnaissance of Part of Utah and Arizona (open access)

The Kaiparowits Region: A Geographic and Geologic Reconnaissance of Part of Utah and Arizona

From introduction: The purposes of this exploration are to determine routes, to locate water holes, and to select areas where detailed geologic study could profitably be undertaken.
Date: 1931
Creator: Gregory, Herbert E. & Moore, Raymond C.
System: The UNT Digital Library
The Copper Deposits of Ray and Miami, Arizona (open access)

The Copper Deposits of Ray and Miami, Arizona

This is a report on the copper deposits of Ray and Miami, Arizona.
Date: 1919
Creator: Ransome, Frederick Leslie
System: The UNT Digital Library
The Sunset-Midway Oil Field, California: Part 1. Geology and Oil Resources (open access)

The Sunset-Midway Oil Field, California: Part 1. Geology and Oil Resources

This is a report on the Sunset-Midway oil field in Kern County, California, including the geology and production of oil.
Date: 1920
Creator: Pack, Robert W.
System: The UNT Digital Library
Geologic History of the Yosemite Valley (open access)

Geologic History of the Yosemite Valley

The principal result of the investigations upon which this report is based is the determination within narrow limits of the preglacial depth of the Yosemite Valley and of other facts concerning its preglacial development which permit fairly definite estimates of the proportionate shares of work performed by stream and by glacier. The investigations comprise a detailed survey of the glacial and geomorphologic features of the Yosemite region and an equally intensive study of its rock formations, supplemented by reconnaissance work of both kinds in adjoining parts of the Sierra Nevada.
Date: 1930
Creator: Matthes, François E.
System: The UNT Digital Library
Stratigraphy of the Star Peak Group (Triassic) and Overlying Lower Mesozoic Rocks: Humboldt Range, Nevada (open access)

Stratigraphy of the Star Peak Group (Triassic) and Overlying Lower Mesozoic Rocks: Humboldt Range, Nevada

This is a report on the stratigraphy of the Star Peak Group an overlying lower Mesozoic rocks Humboldt Range in Nevada.
Date: 1969
Creator: Silberling, N. J. & Wallace, Robert E.
System: The UNT Digital Library
Geologic Studies, Project Gnome, Eddy County, New Mexico (open access)

Geologic Studies, Project Gnome, Eddy County, New Mexico

From abstract: For Project Gnome, part of the Plowshare Program to develop peaceful uses for nuclear energy, a nuclear device was detonated December 10, 1961, underground in rack salt of the Permian Salado Formation southeast of Carlsbad, New Mexico. The Geological Survey's investigations on behalf of the U.S. Atomic Energy Commission provided basic geologic and geophysical information needed to define preshot and postshot geologic and hydrologic conditions at and near the site. This report describes the geology of the site, some physical and chemical properties of the rocks, and the known effects of the nuclear detonation on the rocks of the site.
Date: 1968
Creator: Gard, Leonard Meade, Jr.
System: The UNT Digital Library