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Articles 28111 - 28140 of 29955
Full-Text Articles in Geology
The Geology And Geochemistry Of The North Fork Stock, Northeastern Oregon, David Joseph Matty
The Geology And Geochemistry Of The North Fork Stock, Northeastern Oregon, David Joseph Matty
Dissertations and Theses
The North Fork stock is a composite intrusive body of Late Jurassic-Early Cretaceous age which outcrops in the Blue Mountains of northeastern Oregon. The upper 600 m of the intrusion are exposed over an area of approximately 36 km2 along the canyon walls of the North Fork of the John Day River in Grant and Umatilla counties. The stock intrudes metasediments, metavolcanics, and metagabbros associated with the Permian-Triassic Elkhorn Ridge Argillite. Contact metamorphism of the Elkhorn Ridge Argillite is developed to the hornblende-hornfels facies throughout most of the exposed area of this unit in the study area. The contact …
Broadwater Ne Quadrangle, Morrill County, Nebraska, Robert F. Diffendal Jr.
Broadwater Ne Quadrangle, Morrill County, Nebraska, Robert F. Diffendal Jr.
Robert F. Diffendal, Jr., Publications
7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.
41° 37'30" — 41° 45'
102° 45' — 102° 52'30"
Scale 1:24,000
Completed June 6, 1979
High resolution .tif file attached below as supplemental file
The Matrix Of Unequilibrated Ordinary Chondrites: Implications For The Origin And Subsequent History Of Chondrites, Gary Robert Huss
The Matrix Of Unequilibrated Ordinary Chondrites: Implications For The Origin And Subsequent History Of Chondrites, Gary Robert Huss
Earth and Planetary Sciences ETDs
The matrices of fourteen unequilibrated (type 3 and 3, 4) ordinary chondrites (all witnessed falls) were analyzed using transmitted and reflected light microscopy, electron microprobe analysis, and instrumental neutron activation analysis. The matrix is defined as the fine-grained silicate material between chondrules, chondrule fragments, other distinct silicate grains, and Fe-Ni and troilite grains. It makes up about 13 percent of each meteorite. Although all meteorites in this study have been altered to some extent since their formation, those with least alteration indicate that the unaltered matrix had submicron grain size, a clastic texture, and was friable even though interstitial pore …
Geology Of The Galisteo Formation, Hagan Basin, New Mexico, Timothy Walker Gorham
Geology Of The Galisteo Formation, Hagan Basin, New Mexico, Timothy Walker Gorham
Earth and Planetary Sciences ETDs
In north-central New Mexico the Hagan basin contains the thickest (261 to 1,295 m) and least deformed section of the Eocene Galisteo Formation. The Galisteo unconformably overlies sandstone and carbonaceous shale of the Mesaverde Group (Upper Cretaceous) and provides a record of late Laramide (Eocene) tectonics in this part of the Rocky Mountains.
The Galisteo Formation contains a complex fluvial sequence of abundant red to green mudstone, with varying amounts of red to white laterally continuous and discontinuous sandstone, and buff to white conglomeratic sandstone. Sedimentary structures and facies relationships in seven coarse-grained Galisteo members indicate that the Galisteo Formation …
The Geology And Blueschist Petrology Of The Western Ambler Schist Belt, Southwestern Brooks Range, Alaska, Craig Joseph Nelsen
The Geology And Blueschist Petrology Of The Western Ambler Schist Belt, Southwestern Brooks Range, Alaska, Craig Joseph Nelsen
Earth and Planetary Sciences ETDs
The western Ambler Schist Belt is located in the southern Brooks Range of Alaska and is defined in this study as that part of the Brooks Range schist belt which contains abundant bimodal volcanic, volcaniclastic and related carbonate sediments. The schist belt appears to be the basinal part of Middle Devonian through Mississippian shelf-slope-basin sequence. To the south of the schist belt are upper Paleozoic-Mesozoic (?) ophiolite overlain by Cretaceous greywackes and calc-alkalic intrusives and related extrusives. These two distinct terrains are juxtaposed along a suspected continental suture, the Angayucham-Cosmos Hills-Jade Mountain belt, on with a minimum of 115 km …
Interpretive Study And Numerical Model Of The Hydrogeology Upper Big Blue Natural Resources District., Ralph E. Cady, Marilyn H. Ginsberg
Interpretive Study And Numerical Model Of The Hydrogeology Upper Big Blue Natural Resources District., Ralph E. Cady, Marilyn H. Ginsberg
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Petrology And Mineralogy Of Quaternary Basalts, Gem Valley And Adjacent Bear River Range, Southeastern Idaho, William D. Perkins
Petrology And Mineralogy Of Quaternary Basalts, Gem Valley And Adjacent Bear River Range, Southeastern Idaho, William D. Perkins
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Quaternary basalts of Gem Valley, Idaho, are present as valley fill (Group 1) and as well defined flows in the Bear River Range (Group 2) east of Gem Valley. Minerals present in both groups of basalts include olivine (Fo73 -Fo39), augite (Wo41 En39 Fs20), plagioclase (An75 -An40), and Fe-Ti oxides. Coexisting pairs of magnetite and ilmenite, and olivine and clinopyroxene in several samples indicate temperatures of crystallization from 958°c to 1167°c. The Group 2 basalts exhibit a cumulate texture with abundant large (2 cm) phenocrysts of plagioclase.
Chemically, the Gem …
Structural Geology Of The Northern Part Of Oxford Quadrangle, Idaho, Jerrold N. Mayer
Structural Geology Of The Northern Part Of Oxford Quadrangle, Idaho, Jerrold N. Mayer
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The northern part of the Oxford Quadrangle, Idaho, includes parts of the Bannock Range to the west and the Portneuf Range to the east. These ranges are separated by Marsh Valley to the north and Cache Valley to the south. Red Rock Pass, the outlet of glacial Lake Bonneville, divides the two valleys. The mapped area is north of Preston, Idaho, and south of Downey, Idaho. The north-south dimension of the mapped area is 5.2 miles and the east-west dimension is 6.4 miles.
The stratigraphic units, within the mapped area, are Precambrian, Paleozoic, and Cenozic in age. The oldest rock …
Structural Geology Of Eastern Part Of James Peak Quadrangle And Western Part Of Sharp Mountain Quadrangle, Utah, Steven L. Rauzi
Structural Geology Of Eastern Part Of James Peak Quadrangle And Western Part Of Sharp Mountain Quadrangle, Utah, Steven L. Rauzi
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
A detailed study was made of the James Peak-Sharp Mountain area, in the southern part of the Bear River Range, Utah. The mapped area is located in north-central Utah between lat. 41°22'30" N. and lat. 41°30' N. and long. 111°42'30" W. and long. 111°46' W. It measures about 3.8 miles in the east-west direction and 8.7 miles in the north-south direction. The area is centered about 22 miles south-southeast of Logan, Utah.
Stratigraphic units of late Precambrian to Mississippian age underlie the mapped area. The Precambrian units include the Mutual and Browns Hole Formations. The Brigham, Langston, Ute, Blacksmith, Bloomington, …
Geochemistry Of Andesites And Related Rocks, Central-Northern Rio Grande Rift, New Mexico, Charles J. Zimmerman
Geochemistry Of Andesites And Related Rocks, Central-Northern Rio Grande Rift, New Mexico, Charles J. Zimmerman
Earth and Planetary Sciences ETDs
Similarities in the petrography, whole rock and mineral chemistries, trace element abundances, and initial Sr ratios of 1-5 MY andesitic through rhyolitic rocks erupted in the central-northern Rio Grande rift, New Mexico allow for their study as a single calcalkalic volcanic suite. Ti-rich ferroan pargasites and pargasitic hornblendes found in some of these lavas and their inclusions indicate that hornblende is a stable phase from lower crustal/upper mantle to near-surface pressure conditions and may be important in controlling the generation and fractionation of this andesitic suite. Andesitic rocks from Cerro Tome, Cerro de Los Lunas, Cerros del Rio, and the …
Geology Of North Craters Of The Moon National Monument, Idaho, William C. Sidle
Geology Of North Craters Of The Moon National Monument, Idaho, William C. Sidle
Dissertations and Theses
The purpose of the investigation was to map the geology of the north end of Craters of the Moon National Monument and surrounding area. A stratigraphic sequence of Late Paleozoic sedimentary and Tertiary volcanic rocks was compiles and the structures of these rocks and contact relationships with intrusions were delineated. Grade and facies of contact metamorphism were defined. The Snake River Plain basalts were also mapped. The sources of these flows were determined where possible. Preexisting structures and relationships of vents to earlier faulting were explored in ascertaining extensions of the Great Rift Zone into the Pioneer Mountains. Petrographic descriptions …
Postglacial Environmental History Of A Marl Lake Site In Kalamazoo County, Southwestern Michigan, Valerie A. Naeve
Postglacial Environmental History Of A Marl Lake Site In Kalamazoo County, Southwestern Michigan, Valerie A. Naeve
Masters Theses
The depositional and ecological history of Oakland Bog, a relic Wisconsinan (16,500+300 years B.P.) lake site is interpreted from pollen stratigraphy, molluscan faunal assemblages and sediment facies. The lake basin, which probably formed after the melting of a late Wisconsinan buried ice block in the Kalamazoo Moraine Complex, is irregular, steep-sided and floored by glacial till. The till is overlain by as much as 7.6 meters of lacustrine marls which extend over an area of nearly 0.5 km2. Basal marls are characteristically medium gray, clayey, and contain abundant calcified stem fragments of charophytes; however, the overlying marls display …
Geology Of The Central Peloncillo Mountains, The North Third Of The Pratt Quadrangle, Hidalgo County, New Mexico, Dennis J. Gebben
Geology Of The Central Peloncillo Mountains, The North Third Of The Pratt Quadrangle, Hidalgo County, New Mexico, Dennis J. Gebben
Masters Theses
No abstract provided.
Tree Root Systems In Eastern Nebraska, John A. Sprackling, Ralph A. Read
Tree Root Systems In Eastern Nebraska, John A. Sprackling, Ralph A. Read
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Geologic History Of Scotts Bluff National Monument, Roger K. Pabian, James B. Swinehart Iii
Geologic History Of Scotts Bluff National Monument, Roger K. Pabian, James B. Swinehart Iii
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Broadwater Nw Quadrangle, Morrill County, Nebraska, Robert F. Diffendal Jr.
Broadwater Nw Quadrangle, Morrill County, Nebraska, Robert F. Diffendal Jr.
Robert F. Diffendal, Jr., Publications
7.5' topgraphic quadrangle showing exposures of bedrock formations and other geologic information.
41° 37'30" — 41° 45'
102° 52'30" — 103° 00'
Scale 1:24,000
Completed June 25, 1979
High resolution .tif file attached below as supplemental file
Stratigraphy And Sedimentary Petrology Of The Northwest Quarter Of The Dutchman Butte Quadrangle, Southwest Oregon, Thomas Edward Koler
Stratigraphy And Sedimentary Petrology Of The Northwest Quarter Of The Dutchman Butte Quadrangle, Southwest Oregon, Thomas Edward Koler
Dissertations and Theses
The study area lies in southwest Douglas County 5 kilometers south from Camas Valley and is accessible by state highway 42. The purpose of the study was to map the geology at a 1:31,250 scale, determine the stratigraphy, study the petrology of the formations, and determine the provenance within a tectonic setting.
The Structure And Stratigraphy Of The Columbia River Basalt In The Hood River Valley, Oregon, Susan Timm
The Structure And Stratigraphy Of The Columbia River Basalt In The Hood River Valley, Oregon, Susan Timm
Dissertations and Theses
The Hood River Valley, located 100 kilometers east of Portland, Oregon, is in the transition zone between two geologic provinces--the High Cascades and the Columbia Plateau. The entire valley is probably underlain by Columbia River Basalt, but it crops out only on steep hillsides and in stream valleys. The base of the basalt is not exposed in the thesis area. The basalt is overlain by Pliocene and Quaternary basalt and andesite, volcanic sediments and glacial debris.
The stratigraphy of the Columbia River Basalt is useful in determining the path of the basalt flows into western Oregon, in mapping the structure …
Structural Geology Of The Southeast Quarter Of The Dutchman Butte Quadrangle, Oregon, Gerald Lee Black
Structural Geology Of The Southeast Quarter Of The Dutchman Butte Quadrangle, Oregon, Gerald Lee Black
Dissertations and Theses
Field work in the southeast quarter of the Dutchman ·Butte Quadrangle, which lies within the Klamath Mountains geomorphic province of southwestern Oregon, was completed during the summers of 1973 and 1974. The objectives of the study were fourfold: (1) to produce a geologic map of the southeast quarter of the Dutchman Butte Quadrangle, (2) to determine the nature of the contact between the Dothan and Rogue formations, (3) to construct a stratigraphic column of the Dothan Formation in the area, and (4) to attempt to determine the nature of the deformation occurring in the area.
Ua66/8/3 Annual Report, Wku Geography & Geology
Ua66/8/3 Annual Report, Wku Geography & Geology
WKU Administration Documents
Annual report of activities of the WKU department of Geography & Geology.
Coal Resource Occurrence And Coal Development Potential Maps Of The Southeast Quarter Of The Hiawatha 15-Minute Quadrangle Emery County, Utah, United States Geological Survey
Coal Resource Occurrence And Coal Development Potential Maps Of The Southeast Quarter Of The Hiawatha 15-Minute Quadrangle Emery County, Utah, United States Geological Survey
All U.S. Government Documents (Utah Regional Depository)
This report was compiled to support the land planning work of the Bureau of Land Management and to provide a systematic coal resource inventory of Federal coal lands in Known Recoverable Coal Resource Areas (KRCRA's) in the Western United States. It supplements the land planning requirements of the Federal Coal Leasing Amendments Act of 1976 (Public Law 94-377) sec. (3)(B) which states, in part, that "Each land-use plan prepared by the Secretary [of the Interior] (or in the case of lands within the National Forest System, the Secretary of Agriculture pursuant to sub-paragraph (A)(i)) shall include an assessment of the …
Hydrologic And Climatologic Data, Southeastern Uinta Basin, Utah And Colorado Water Year 1977, United States Geological Survey
Hydrologic And Climatologic Data, Southeastern Uinta Basin, Utah And Colorado Water Year 1977, United States Geological Survey
All U.S. Government Documents (Utah Regional Depository)
This report contains hydrologic and climatologic data that were collected as a part of an investigation of the southeastern Uinta Basin, Utah and Colorado, by the U.S. Geological Survey. This report contains data mainly for the 1977 water year, which includes the period October 1976-September 1977. Conroy and Fields (1977) reported data collected mainly for water years 1975 and 1976.
Uranium Transport In The Walker River Basin, California And Nevada, Larry Benson, D. L. Leach
Uranium Transport In The Walker River Basin, California And Nevada, Larry Benson, D. L. Leach
United States Geological Survey: Staff Publications
During the summer of 1976 waters from tributaries, rivers, springs and wells were sampled in the Walker River Basin. Snow and sediments from selected sites were also sampled. All samples were analyzed for uranium and other elements. The resulting data provide an understanding of the transport of uranium within a closed hydrologic basin as well as providing a basis for the design of geochemical reconnaissance studies for the Basin and Range Province of the Western United States. Spring and tributary data are useful in locating areas containing anomalous concentrations of uranium. However, agricultural practices obscure the presence of known uranium …
Inferred Areal Extent Of The Oligocene (White River Group) Chadron Basal Sand, Conservation And Survey Division, University Of Nebraska-Lincoln
Inferred Areal Extent Of The Oligocene (White River Group) Chadron Basal Sand, Conservation And Survey Division, University Of Nebraska-Lincoln
Conservation and Survey Division: Faculty and Staff Publications
Inferred Areal Extent of the Oligocene (White River Group) Chadron Basal Sand. Map. No Scale. Nebraska High Plains-Ogallala Aquifer Study Area series. Lincoln: University of Nebraska. Print. (date unknown, 1979?)
Preliminary Investigation Of Rural-Use Aquifers Of Boone, Carroll, And Madison Counties, Arkansas, Albert E. Ogden, Nancy L. Taylor, Steve D. Thompson
Preliminary Investigation Of Rural-Use Aquifers Of Boone, Carroll, And Madison Counties, Arkansas, Albert E. Ogden, Nancy L. Taylor, Steve D. Thompson
Journal of the Arkansas Academy of Science
Approximately 500 water wells having driller's lithologic logs were plottedin Boone, Carroll, and Madison Counties, Arkansas. Three aquifers were found to be used by the rural residents and smaller communities. The most shallow of these is the Mississippian Boone-St. Joe aquifer. This aquifer is generally the least productive having a range of .25 to 60 gpm but a median productivity of only 5 gpm. Well depths for the Boone-St. Joe range from 46 to 464 ft. and have a median depth of 225 ft. The Boone-St. Joe aquifer is unconfined to semi-confined and yields sufficient quantities of water only when …
Geology Of Igneous Extrusive And Intrusive Rocks In The Sundance Area, Crook County, Wyoming, Earl F. Fashbaugh
Geology Of Igneous Extrusive And Intrusive Rocks In The Sundance Area, Crook County, Wyoming, Earl F. Fashbaugh
Theses and Dissertations
Two major igneous rock types occur in the Sundance, Wyoming area including foyaite of the Bear Lodge Mountain sill and quartz latite of Sundance Mountain and Sugarloaf Mountain. The igneous bodies were mapped on a scale of 1:5000 in an effort to determine petrogenetic relationships between the two rock types.
Sundance Mountain and Sugarloaf Mountain are extrusive in origin. Quartz latite occurs as subparallel units of breccia, tuff, and massive flows without any clear cross-cutting relationships. Fragmental types (breccia and cuff) constitute 41 to 76 percent of the rocks, suggesting that Sundance Mountain is a mixed cone. The quartz latite …
Petroleum Potential Of The Tilston Interval (Mississippian) Of Central North Dakota, John P. Himebaugh
Petroleum Potential Of The Tilston Interval (Mississippian) Of Central North Dakota, John P. Himebaugh
Theses and Dissertations
The Tilston interval sediments were deposited on the eastern flank of the Williston basin of North Dakota, Manitoba and Saskatchewan. The interval (Osagian) is composed of a basal carbonate and upper anhy drite in the predominantly carbonate Mississippian Madison Formation. The interval consists of four major facies (subtidal, shoal, tidal flat and supratidal anhydrite), and two geographically restricted facies (lagoonal and elastic) and represents a regressive sequence.
Tilston deposition began with the subtidal facies, deposited on a broad, shallow shelf. As the sea regressed this was followed by deposition of the shoal facies. Further regression resulted in the deposition of …
Applied Geology In The Beulah-Hazen Area, Mercer County, West-Central North Dakota, Gary N. Meyer
Applied Geology In The Beulah-Hazen Area, Mercer County, West-Central North Dakota, Gary N. Meyer
Theses and Dissertations
Increased lignite development around the small towns of Beulah and Hazen, North Dakota, will cause rapid growth and necessitate the develop ment of new subdivisions and expansion of present sewage disposal facili ties. A detailed geologic study of a 9 0-square mile area surrounding the two towns was undertaken to provide information valuable to those concerned with proper management of this growth. A surface and near-surface materials map was prepared at a scale of 1:24, 000 showing relative depths and thicknesses of a maximum of three earth materials to a depth of 9 m. Eleven units were mapped at the …
Petrology Of The Cenozoic Igneous Rocks Of The Tinton District, Black Hills, South Dakota - Wyoming, John T. Ray
Petrology Of The Cenozoic Igneous Rocks Of The Tinton District, Black Hills, South Dakota - Wyoming, John T. Ray
Theses and Dissertations
The Tinton district is located on the northwest flank of the Black Hills uplift, 20 km west of Lead, South Dakota, along the Wyoming South Dakota border. The Tinton or Nigger Hill uplift comprises a central area of domed Precambrian Xstrata with marginal exposures of Paleozoic sedimentary rocks which dip radially outward on all sides. The area was intruded by Cenozoic igneous rocks that include a stock of quartz latite/quartz trachyte porphyry, an alkalic ring dike complex, lamprophyre dikes and intrusive breccia.
Precambrian rocks are represented by a sequence of metapelites thst have been intruded by metabasite and granitic pegmatite …
Geology Of The Mafic/Ultramafic Transition, Table Mountain, Western Newfoundland, Suzanne O'Connell
Geology Of The Mafic/Ultramafic Transition, Table Mountain, Western Newfoundland, Suzanne O'Connell
Geology Theses and Dissertations
A thin (<200 m.) mafic suite and well developed mafic/ultramafic transition zone are exposed above a flat lying peridotite contact on northwestern Table Mountain. The igneous layering and sedimentary features indicate mineral deposition under conditions which promoted adcumulate growth, were capable of minor transport, and were subjected to at least minor tectonic activity during consolidation. Feldspathic,. mafic, and ultramafic dikes and veins cross-cut the layering. Microscopic futures indicate deformation at elevated temperature and/or low strain rates. Deformation is best developed within the transition zone, but cataclastic zones are most common in the hornblende gabbros. Orientations of layering, foliation, and lineation indicate a variable mafic/ultramafic transition and macroscopic folding. Geometric analysis indicates three distinct fold axis orientations: an east-west horizontal fold axis, a northeast trending modestly plunging axis, and a vertical though poorly defined axis. Such features demonstrate that an apparently simple contact relationship may be extremely complex. This has important implications for ocean floor accretion. The relatively simple ocean floor seismic stratigraphy masks very complex petrological and structural processes. Such processes may involve deposition in an actively convecting magma chamber with a differentially subsiding wedge (Dewey and Kidd, 1977), in which folding occurs in response to the steepening angle between the cumulate banding and the base of the magma chamber. The instability is enhanced by the different accumulation rates and densities of the minerals involved. The lineation may originally be a sedimentary feature indicative of transport direction from the convection cell, and perpendicular to the compressive stress which produced. the folding. The different orientations of lineations and fold axes could be produced by rotation of the ocean crustal blocks during lateral transport along the ocean floor and/or obduction. Further detailed study of ophiolite complexes will continue to shed light upon the nature and development of oceanic crust.