Volcanic Activity in the Aleutian Arc (open access)

Volcanic Activity in the Aleutian Arc

Including a list of all known volcanoes and a summary of activity betwen 1760 and 1948.
Date: 1950
Creator: Coats, Robert R.
System: The UNT Digital Library
Shorter Contributions to the Stratigraphy and Geochronology of Upper Cretaceous Rocks in the Western Interior of the United States (open access)

Shorter Contributions to the Stratigraphy and Geochronology of Upper Cretaceous Rocks in the Western Interior of the United States

The following report presents measured sections and lithostratigraphic correlations of the units in the order to document a syntectonic unconformity in order to understand the tectonic history of the area.
Date: 1995
Creator: Geological Survey (U.S.)
System: The UNT Digital Library
Geology of the Clark Fork Quadrangle Idaho-Montana (open access)

Geology of the Clark Fork Quadrangle Idaho-Montana

This report gives a brief geological description of the Clark Fork quadrangle on the Idaho-Montana border.
Date: 1963
Creator: Harrison, Jack Edward & Jobin, Daniel A.
System: The UNT Digital Library
Cenozoic Geology in the Mammoth Area Pinal County, Arizona (open access)

Cenozoic Geology in the Mammoth Area Pinal County, Arizona

From introduction: "The purpose of this report is to show how mapping of discrete units of the valley fill may lead to a broadened understanding of Cenozoic history of intermontane basins in Arizona. The area described is in the vicinity of Mammoth Arizona where deep dissection has exposed a complex sequence of terrestrial deposits and related rocks."
Date: 1963
Creator: Heindl, L. A.
System: The UNT Digital Library
Geologic Reconnaissance Along the Alaska Highway, Delta River to Tok Junction, Alaska (open access)

Geologic Reconnaissance Along the Alaska Highway, Delta River to Tok Junction, Alaska

The following report studies results from the bedrock and surficial geologic reconnaissance of the middle section of the Tanana lowland and adjacent parts of the Alaska Range and the Yukon-Tanana upland.
Date: 1965
Creator: Holmes, G. William
System: The UNT Digital Library
Pleistocene and Recent Deposits in the Denver Area, Colorado (open access)

Pleistocene and Recent Deposits in the Denver Area, Colorado

This report describes the stratigraphy of Pleistocene and Recent deposits in the Denver area, Colorado that was conducted intermittently between 1948-52.
Date: 1954
Creator: Hunt, Charles B.
System: The UNT Digital Library
Pecos National Monument, New Mexico: Its Geologic Setting (open access)

Pecos National Monument, New Mexico: Its Geologic Setting

From introduction: The ruins of the pueblos and missions of Pecos lie on the east bank of Glorieta Creek near its junction with the Pecos River at the south end of the Sangre de Cristo Mountains in north-central New Mexico. Here the Pecos River and Glorieta Creek have formed a broad rolling valley in which the red adobe walls of the mission church stand as a striking monument to a historic past.
Date: 1969
Creator: Johnson, Ross B.
System: The UNT Digital Library
Minor Elements in Bedrock Soil, and Vegetation at an Outcrop of the Phosphoria Formation on Snowdrift Mountain Southeastern Idaho (open access)

Minor Elements in Bedrock Soil, and Vegetation at an Outcrop of the Phosphoria Formation on Snowdrift Mountain Southeastern Idaho

This report follows the geochemical study of bedrock soil and vegetation at an outcrop of the Phosphoria Formation of Permian age on Snowdrift Mountain, southeastern Idaho.
Date: 1963
Creator: Lotspeich, Frederick B. & Markward, Ellen L.
System: The UNT Digital Library
Surficial Geology of the Louisville Quadrangle, Colorado (open access)

Surficial Geology of the Louisville Quadrangle, Colorado

This report analyzes surficial deposits in the Louisville quadrangle, Colorado, that are divided into three main groups--pre-Wisconsin, Wisconsin, and Recent.
Date: 1955
Creator: Malde, Harold E.
System: The UNT Digital Library
The Eagle Valley Evaporite, Northwest Colorado--A Regional Synthesis (open access)

The Eagle Valley Evaporite, Northwest Colorado--A Regional Synthesis

The following report presents a regional study of the extent, thickness, lithology, stratigraphic relations, age, depositional environment, and tectonic history of thick sulfate deposits and associated salts of sodium and potassium.
Date: 1971
Creator: Mallory, William W.
System: The UNT Digital Library
Nonopaque Heavy Minerals in Sandstone of Jurassic and Cretaceous Age in the Black Hills, Wyoming and South Dakota (open access)

Nonopaque Heavy Minerals in Sandstone of Jurassic and Cretaceous Age in the Black Hills, Wyoming and South Dakota

The following report describes the examinations of the nonopague heavy minerals in sandstone found in the Black Hills in northeastern Wyoming and western South Dakota. The studies were made to determine if differences in the shapes of the grains and proportions of minerals are sufficiently distinctive to be used in subdividing and correlating formations.
Date: 1964
Creator: Mapel, W. J.; Chisholm, Wayne A. & Bergenback, Richard Edwards
System: The UNT Digital Library
Geology of the Duck Creek Pass Quadrangle, Montana (open access)

Geology of the Duck Creek Pass Quadrangle, Montana

This report follows geological studies of the Duck Creek Pass quadrangle, Montana during the summers of 1956 and 1957.
Date: 1963
Creator: Nelson, Willis H.
System: The UNT Digital Library
Geologic Reconnaissance of the Antelope-Ashwood Area North-central Oregon: With Emphasis on the John Day Formation of Late Oligocene and Early Miocene Age (open access)

Geologic Reconnaissance of the Antelope-Ashwood Area North-central Oregon: With Emphasis on the John Day Formation of Late Oligocene and Early Miocene Age

From introduction: "This report briefly describes the geology of an area of about 750 square miles in Jefferson, Wasco, Crook, and Wheeler Counties, Oregon."
Date: 1964
Creator: Peck, Dallas L.
System: The UNT Digital Library
The Eastern Front of the Bitterroot Range, Montana (open access)

The Eastern Front of the Bitterroot Range, Montana

From abstract: The origin of the gneissic rocks on the eastern border of the Idaho batholith in the Bitterroot Range, near Hamilton, Mont., has long been in dispute. Lindgren regarded these rocks as the product of stresses related to a normal fault along the front of the range with an eastward dip of about 150. He thought both the hanging wall and the footwall had moved, with a total displacement along the fault plane of at least 20,000 feet. The faulting was believed to have been so recent as to be a major factor in the present topography. Langton appears to accept the concept of faulting but to regard the gneissic rocks as formed much earlier from a granitic rock that was more silicic and older than the Idaho batholith.
Date: 1952
Creator: Ross, Clyde P.
System: The UNT Digital Library