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Articles 1981 - 2010 of 2470

Full-Text Articles in Earth Sciences

Important Geological Features And Localities Of Maine, Maine Geological Survey Dec 1982

Important Geological Features And Localities Of Maine, Maine Geological Survey

Maine Collection

Important Geological Features and Localities of Maine

Executive Department, Maine Geological Survey : Maine State Planning Office

(December, 1982).

Contents: Introduction / Purpose of this Study / The Geology of Maine / Important Publications / Catalogue of the Critical Geologic Features of Maine / Recommendations for Further Research / Publications / Conclusions / Acknowledgements / References Cited / Critical Areas Program List of Geological Planning Reports


Preface, Paul Dean Proctor, John W. Koenig Dec 1982

Preface, Paul Dean Proctor, John W. Koenig

UMR Journal -- V. H. McNutt Colloquium Series

The UMR Journal has had an interesting but somewhat sporadic history. The topics of papers that appeared in UMR Journal 1 in 1968 under the general title of “A Coast to Coast Tectonic Study of the United States” covered the major tectonic features of the contiguous United States from the margin of the Atlantic continental shelf to the Pacific coast. Each paper was authored by a recognized expert for the specific province reviewed. UMR Journal 2, which was published in 1971, related to “Alaska—Its Mineral Potentials and Environmental Challenges”. This UMR Journal 3 emphasizes the geology, genesis, and energy resources …


Geological Evolution And Energy Resources Of The Williston Basin, Lee C. Gerhard Dec 1982

Geological Evolution And Energy Resources Of The Williston Basin, Lee C. Gerhard

UMR Journal -- V. H. McNutt Colloquium Series

The Williston basin of North Dakota, Montana, South Dakota, and south-central Canada (Manitoba and Saskatchewan) is a major producer of oil and gas, lignite, and potash. Located on the western periphery of the Phanerozoic North American craton, the Williston basin has undergone only relatively mild tectonic distortion during Phanerozoic time. This distortion is largely related to movement of Precambrian basement blocks.

Sedimentary rocks of cratonic sequences Sauk through Tejas are present in the basin. Sauk, Tippecanoe, and Kaskaskia Sequence rocks are largely carbonate, as are the major oil and gas producing formations. Absaroka and Zuni rocks have more clastic content, …


The Michigan Basin, L. L. Sloss Dec 1982

The Michigan Basin, L. L. Sloss

UMR Journal -- V. H. McNutt Colloquium Series

The Michigan basin is widely acknowledged to be the archetype among those basins of cratonic interiors whose subsidence is dominated by flexure rather than faulting. Broadly ovate in plan over an area of some hundreds of thousands of square kilometers, with a preserved Phanerozoic sediment thickness exceeding 4 km accumulated during distinct episodes of subsidence over a 500-million year span, the basin is endowed with significant fossil-fuel resources.

The basin area is crossed, from north-northwest, by a rift zone filled with mafic igneous rock and great thickness of sedimentary rock resting on Archean and Middle Proterozoic crystallines. Rifting is presumably …


Umr Journal: Selected Structural Basins Of The Mid-Continent, U.S.A., University Of Missouri--Rolla Dec 1982

Umr Journal: Selected Structural Basins Of The Mid-Continent, U.S.A., University Of Missouri--Rolla

UMR Journal -- V. H. McNutt Colloquium Series

No abstract provided.


Geologic-Tectonic History Of The Area Surrounding The Northern End Of The Mississippi Embayment, H. R. Schwalb Dec 1982

Geologic-Tectonic History Of The Area Surrounding The Northern End Of The Mississippi Embayment, H. R. Schwalb

UMR Journal -- V. H. McNutt Colloquium Series

Since Precambrian time, zones of weakness have been repeatedly but infrequently reactivated in the Mississippi Embayment area. All of the major folds and many of the minor anticlines caused by this activity are associated with faults in the basement rocks. The latest occurrence of major tectonic activity (perhaps Early Cretaceous), however, not only affected the old fault zones but also created a vast new feature, the Pascola arch, which has no Paleozoic antecedent. Severe erosion and subsequent Tertiary subsidence associated with the Pascola arch indicate that this structure alone is the locus of present-day major earthquake activity. Until the time …


Geology And Energy Resources Of The Arkoma Basin, Oklahoma And Arkansas, Boyd R. Haley Dec 1982

Geology And Energy Resources Of The Arkoma Basin, Oklahoma And Arkansas, Boyd R. Haley

UMR Journal -- V. H. McNutt Colloquium Series

The Arkoma basin is a structurally defined basin that underlies an area of about 13,000 sq. mi. It extends from Little Rock, Arkansas, to Atoka, Oklahoma. The rocks in the basin grade upward from dolomite, some limestone, sandstone (Upper Cambrian to Upper Devonian) to shale and limestone (Upper Devonian to Lower Pennsylvanian) to shale, limestone, and sandstone (Lower Pennsylvanian) to shale and sandstone (Middle Pennsylvanian). The sediments that formed rocks in the lower part of the Atoka formation on the south side of the basin were deposited in a deep-water environment. All other sediments in the basin were deposited in …


Mineralogical, Textural, And Paragenetic Studies Of Selected Ore Deposits Of The Southeast Missouri Lead-Zinc-Copper District And Their Genetic Implications, Kenneth Bruce Horrall Jan 1982

Mineralogical, Textural, And Paragenetic Studies Of Selected Ore Deposits Of The Southeast Missouri Lead-Zinc-Copper District And Their Genetic Implications, Kenneth Bruce Horrall

Doctoral Dissertations

“A detailed paragenetic study of Pb-Zn-Cu ores from the Viburnum Number 28, Brushy Creek, and Goose Creek mines in the Southeast Missouri lead district indicates a complicated paragenesis characterized by repeated periods of mineral deposition. The sequence is composed of nineteen minerals including abundant galena, sphalerite, chalcopyrite, pyrite, marcasite, dolomite, calcite, and quartz and minor siegenite, bornite, bravoite, blaubleibender covellite, covellite, gersdorffite, digenite, enargite, tennantite, dickite, and malachite.

The paragenesis indicates that the ore solutions evolved in the following order: (1) Cu-rich, (2) Co-Ni-rich, (3) Pb-Zn-rich, and (4) Fe-rich. Subsequent repeated generations include cubic galena, later sphalerite, and minor crystalline …


Radiometric And Petrochemical Characteristics Of The Dells Granite, Yavapai County, Arizona, Kenneth Stewart Fleck Jan 1982

Radiometric And Petrochemical Characteristics Of The Dells Granite, Yavapai County, Arizona, Kenneth Stewart Fleck

Masters Theses

"The Dells granite of central Arizona, an alkaline granite containing accessory fluorite and tourmaline, contains anomalously high amounts of uranium. Gamma-ray spectrometry, x-ray fluorescence, petrographic, and autoradiographic methods were used to determine the contents and distribution of equivalent U, Th, K, and ten major element oxides within the granite pluton. The range of uranium content is 0 to 39.7 parts per million (ppm) with the mean equivalent U content 8.8 ppm; eTh, 26.8 ppm; and K, 4.8%. The average uranium content is about twice the average of western United States granites, the thorium content slightly less than average. The Th/U …


Proximal Air-Fall Deposits Of Eruptions Between May 24 And August 7, 1980 -- Stratigraphy And Field Sedimentology. U.S. Department Of The Interior, Geological Survey, Richard B. Waitt Jr., Vicki L. Hansen, Andrei M. Sarna-Wojcicki, Spencer H. Wood Jan 1981

Proximal Air-Fall Deposits Of Eruptions Between May 24 And August 7, 1980 -- Stratigraphy And Field Sedimentology. U.S. Department Of The Interior, Geological Survey, Richard B. Waitt Jr., Vicki L. Hansen, Andrei M. Sarna-Wojcicki, Spencer H. Wood

Geosciences Faculty Publications and Presentations

During each of the magmatic eruptions of Mount St. Helens on May 25, June 12, and August 7, a vertical eruptive column rose intermittently to altitudes of 12-15 km, from which pumice, lithic fragments, and crystals settled downwind in lobes that generally become thinner and finer away from the volcano. Each ejecta lobe is asymmetric according to several criteria, including (1) the axes of maximum thickness and of maximum pumice size are not midway between the two margins of the lobe, (2) the axis of maximum pumice size does not correspond to the axis of thickness, and (3) the median …


Areal Distribution, Thickness, Mass, Volume, And Grain Size Of Air-Fall Ash From The Six Major Eruptions Of 1980, Andrei M. Sarna-Wojcicki, Susan Shipley, Richard B. Waitt Jr., Daniel Dzurisin, Spencer H. Wood Jan 1981

Areal Distribution, Thickness, Mass, Volume, And Grain Size Of Air-Fall Ash From The Six Major Eruptions Of 1980, Andrei M. Sarna-Wojcicki, Susan Shipley, Richard B. Waitt Jr., Daniel Dzurisin, Spencer H. Wood

Geosciences Faculty Publications and Presentations

The airborne-ash plume front from the Mount St. Helens eruption of May 18 advanced rapidly to the northeast at an average velocity of about 250 km/hr during the first 13 min after eruption. It then traveled to the east-northeast within a high-velocity wind layer at altitudes of 10-13 km at an average velocity of about 100 km/hr over the first 1,000 km. Beyond about 60 km, the thickest ash fall was east of the volcano in Washington, northern Idaho, and western Montana. A distal thickness maximum near Ritzville, Wash., is due to a combination of factors: (1) crude sorting within …


A Thermochemical Study Of The Ore Deposits Of The Milliken Mine, New Lead Belt, Missouri, Douglas L. Rickman Jan 1981

A Thermochemical Study Of The Ore Deposits Of The Milliken Mine, New Lead Belt, Missouri, Douglas L. Rickman

Doctoral Dissertations

"The ore body at the Milliken mine is a typical Mississippi Valleytype ore deposit. Mineralization is in a dolostone and structures are subtle, but very important ore controls. The major mineralogy is simple, predominately galena, luminescent hydrothermal dolomite, sphalerite and chalcopyrite. Twenty-three additional minerals have been identified in the ores, including barite and Pb-aragonite, bot h of which have not previously been recognized in the district.

Paragenetically, the ores are very complex, with four major, distinct periods of mineralization plus numerous periods of dissolution. The paragenesis provides evidence for the dynamic, evolving nature of the ore system. Galena textures, euhedral …


An Investigation Of The Nickel-Cobalt Occurrence In The Southeast Missouri Mining District, David Ray Jessey Jan 1981

An Investigation Of The Nickel-Cobalt Occurrence In The Southeast Missouri Mining District, David Ray Jessey

Doctoral Dissertations

"A study of the occurrence of nickel and cobalt in the Southeast Missouri Mining District has revealed several significant geochemical trends and mineralogical relationships. Regional geochemical studies indicate that the greatest concentration of nickel and cobalt occurs in the Fredericktown area. Mines in the Viburnum Trend also have significant concentrations of these metals. Studies of the Viburnum Trend have established that both nickel and cobalt decrease in concentration southward from the Magmont mine to the Brushy Creek mine, increase at the Fletcher mine, and decrease again at the Sweetwater mine.

A detailed geochemical study of the Buick mine has shown …


Geophysical And Geochemical Analyses Of Selected Miocene Coastal Basalt Features, Clatsop County, Oregon, Virginia Josette Pfaff Dec 1980

Geophysical And Geochemical Analyses Of Selected Miocene Coastal Basalt Features, Clatsop County, Oregon, Virginia Josette Pfaff

Dissertations and Theses

The proximity of Miocene Columbia River basalts to the "locally-erupted" coastal Miocene basalts in northwestern Oregon, and the compelling similarities between the two groups, suggest that the coastal basalts, rather than being locally erupted, may be the westward extension of plateau basalts derived from eastern Oregon and Washington.

The local-origin hypothesis is based largely on the interpretation of coastal dikes and sills as representing vent areas; however, a complex mechanism, as yet unsatisfactorily defined, would be required to cause the eruption of virtually identical magmas simultaneously from source areas 500 km apart.

This study, therefore, has investigated the coastal basalt …


Near-Bottom Seismic Profiling: High Lateral Variability, Anomalous Amplitudes, And Estimates Of Attenuation, R. C. Tyce, Larry A. Mayer, F. N. Spiess Nov 1980

Near-Bottom Seismic Profiling: High Lateral Variability, Anomalous Amplitudes, And Estimates Of Attenuation, R. C. Tyce, Larry A. Mayer, F. N. Spiess

Affiliate Scholarship

For almost a decade the Marine Physical Laboratory of Scripps Institution of Oceanography has been conducting near‐bottom geophysical surveys involving quantitative seismic profiling. Operating initially at 4 kHz and more recently at 6 kHz, this system has provided a wealth of fine scale quantitative data on the acoustic properties of ocean sediments. Over lateral distances of a few meters, 7‐dB changes in overall reflected energy as well as 10‐dB changes from individual reflectors have been observed. Anomalously high amplitudes from deep reflectors have been commonly observed, suggesting that multilayer interference is prevalent in records from such pulsed cw profilers. This …


An Analysis Of Gravity Surveys In The Portland Basin, Oregon, Janice C. Perttu Oct 1980

An Analysis Of Gravity Surveys In The Portland Basin, Oregon, Janice C. Perttu

Dissertations and Theses

The geologic setting of the Portland Basin is ideal for gravity surveys because of the large density contrasts between geologic units. The Portland Basin consists of a north-northwest-trending syncline in the Columbia River basalt overlain by Pliocene to Recent alluvium. This study was undertaken to define structures in the Portland Basin which are obscured by the alluvium.

An areal gravity survey of the Portland Basin covering approximately 450 square kilometers was conducted for this study.


Chemical Trends In The Ice Springs Basalt, Black Rock Desert, Utah, W. C. Lynch, W. P. Nash Jun 1980

Chemical Trends In The Ice Springs Basalt, Black Rock Desert, Utah, W. C. Lynch, W. P. Nash

All U.S. Government Documents (Utah Regional Depository)

The Holocene Ice Springs volcanic field of west-central Utah consists of 0.53 km3 of tholeitic basalts erupted as a sequence of nested cinder cones and associated lava flows. Whole rock x-ray fluorescence and atomic absorption analysis of ninety-six samples of known relative age document statistically significant inter- and intra- eruption chemical variations. Elemental trends include increases in Ti, Fe, Ca, P, and Sr and decreases in Si, K, Rb, Ni, Cr, and Zr with decreasing age. Microprobe analyses of microphenocrysts of olivine, plagioclase, and Fe-Ti oxides and of groundmass olivine, plagioclase, and clinopyroxene indicate limited chemical variation between mineral assemblages …


A Geophysical Definition Of A Klamath Falls Graben Fault, Cynthis Ann Veen Sep 1979

A Geophysical Definition Of A Klamath Falls Graben Fault, Cynthis Ann Veen

Dissertations and Theses

Four geophysical methods, along with well logs and outcrop data, were used in determining the location of a fault situated on the campus of Oregon Institute of Technology, just north of Klamath Falls, Oregon. The fault displaces rocks of the Yonna Formation, of Pliocene age. Wells located northeast of the fault (on the upthrown side) produce cold water, and wells located southwest of the fault (on the downthrown side) produce hot water. The purpose of this investigation was to define the characteristics of the fault exposed behind a large water tank southeast of the OIT campus.


Hydrothermal Alteration At The Roosevelt Hot Springs Thermal Area, Utah: Petrographic Characterization Of The Alteration To 2 Kilometers Depth, J. M. Ballantyne, W. T. Parry Apr 1978

Hydrothermal Alteration At The Roosevelt Hot Springs Thermal Area, Utah: Petrographic Characterization Of The Alteration To 2 Kilometers Depth, J. M. Ballantyne, W. T. Parry

All U.S. Government Documents (Utah Regional Depository)

Hydrothermal alteration in drill cuttings from Thermal Power drillhole 14-2, Roosevelt Hot Springs Thermal area, has been studied petrographically. The hole is sited in alluvium approximately 1.6 km southeast of the old Resort and was rotary drilled to a depth of 1866.0 m. The exact hole location is 2310 FNL, 350 FWL, Sec. 2, Twp 27S, Rge 9W, elevation 1908.5 m. Core was extracted from 792.5 to 795.5 m. Thin sections were made from samples 15.2 m intervals of drill cuttings collected at 1.5 or 3.0 m intervals during drilling. Thin sections were made of 1.5 or 3.0 m intervals …


Shear Waves In Glacial Till, Craig Woerpel Aug 1977

Shear Waves In Glacial Till, Craig Woerpel

Masters Theses

No abstract provided.


Geophysical Approaches To Coal Exploration, Gerald B. Rupert Oct 1976

Geophysical Approaches To Coal Exploration, Gerald B. Rupert

UMR-MEC Conference on Energy / UMR-DNR Conference on Energy

The exploration for minerals by geophysical means has been confined largely to the search for hydrocarbons and metallics while applications to coal exploration are somewhat limited. However, the surface reflection seismic technique has been successfully applied not only to delineating coal deposits but also as a tool in mine exploitation. Furthermore, channel waves generated underground have demonstrated potential in detecting the presence of faults in advance of the coal face and Vibroisis* experiments have been conducted whereby abandoned underground workings have been detected by surface seismic arrays. Examples of all of the preceeding are presented and discussed.


Predicción De Terremotos: ¿Cuándo?, Aldemaro Romero Jr. Jan 1976

Predicción De Terremotos: ¿Cuándo?, Aldemaro Romero Jr.

Publications and Research

No abstract provided.


Response Of Saturated Sands To Cyclic Shear At Earthquake Amplitudes, Vincent P. Drnevich, John P. Jent Oct 1975

Response Of Saturated Sands To Cyclic Shear At Earthquake Amplitudes, Vincent P. Drnevich, John P. Jent

KWRRI Research Reports

Both quasi-static and resonant cyclic shear tests were performed on hollow cylindrical specimens of saturated sands at various densities and confining stresses. Shear moduli measured at nondestructive amplitudes were shown to be independent of frequency for the range of 0.1Hz to 50Hz. Application of cyclic shear at larger amplitudes caused effective stresses to decrease and failure. The number of cycles to failure was related to ratio of cyclic shear stress to maximum drained shear stress. Effective confining stress reduces approximately linearly with number of cycles. Shear modulus and shear damping.can be described by the Hardin-Drnevich equations if change in effective …


Structural Studies In The Mafic And Ultramafic Rocks Of The Lewis Hills, Western Newfoundland, Jeffrey A. Karson Jan 1975

Structural Studies In The Mafic And Ultramafic Rocks Of The Lewis Hills, Western Newfoundland, Jeffrey A. Karson

Geology Theses and Dissertations

Table of contents:
CHAPTER I. INTRODUCTION
CHAPTER II. REGIONAL GEOLOGY
CHAPTER III. THE LEWIS HILLS COMPARED TO THE NORTHERN AREAS OF THE BAY OF ISLAND COMPLEX
CHAPTER IV. PETROGRAPHY
CHAPTER V. STRUCTURAL GEOLOGY
CHAPTER VI. SUMMARY, CONCLUSIONS, AND SPECULATIONS
BIBLIOGRAPHY
APPENDIX I. CONTOURED STEREOGRAPHIC PROJECTIONS OF FOLIATIONS AND LINEATIONS IN THE HINES POND AREA


A Comparison Between Direct Waves And Head Waves In A Seismic Refraction Profile., Nelson Jose Aboud Garcia Jan 1975

A Comparison Between Direct Waves And Head Waves In A Seismic Refraction Profile., Nelson Jose Aboud Garcia

Masters Theses

"The purpose of this investigation was to experimentally verify the theoretical prediction that the particle velocity of a head wave is the time integral of the particle velocity of a direct wave.

The procedure was to use small explosions in the field to generate direct waves and head waves in a surface layer of low compressional velocity overlying a higher velocity medium. The direct waves were distinguished by the ratio of frequencies and by the slopes in a time distance plot.

The result of comparing the particle velocity of the head waves with the integral of the particle velocity of …


Reflected Surface Waves From A Vertical Discontinuity., Jesus Manuel Aboud Jan 1975

Reflected Surface Waves From A Vertical Discontinuity., Jesus Manuel Aboud

Masters Theses

"Surface waves generated in the field by small explosions were observed along lines parallel and perpendicular to a vertical discontinuity in a surface layer. Three types of wave particle motion were observed in waves incident on the discontinuity: retrograde, progressive, and shear (SH). Waves of the last two types were intense enough to observe a reflection, permitting calculation of reflection coefficients. The results demonstrate the feasibility of using reflection measurements to locate a discontinuity such as a fault zone"-- Abstract, p. ii


Seismic Refraction Study Of Post-Pliocene Stratigraphy, Dismal Swamp, Virginia, William Brian Fraser Jan 1973

Seismic Refraction Study Of Post-Pliocene Stratigraphy, Dismal Swamp, Virginia, William Brian Fraser

OES Theses and Dissertations

This study examines Pliocene-Pleistocene lithostratigraphy and the Yorktown unconformity within the Dismal Swamp by means of remote sensing analysis, Wyrobek-Gardner seismic refraction profiling and split-spoon coring. Pre-Sangamon fluvial/tidal channel deposits are not present and the Yorktown unconformity dips irregularly southeastward at 0.35 meters/kilometer (2 feet/mile) from a high at 4 meters above sea level to a low of -1 meter (+12 to -2 ft) below sea level. The marker velocity for the Yorktown Formation is 1600 mps (5250 fps) and regression of seismic depths of the Yorktown Formation with corresponding split-spoon depths yields a high correlation. Short line upper layer …


Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part Ii, Vincent P. Drnevich, D. Raghu Aug 1972

Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part Ii, Vincent P. Drnevich, D. Raghu

KWRRI Research Reports

Four seismic field methods and a laboratory method are used to determine shear wave propagation velocities and shear moduli for two sites. The four seismic methods are: standard seismic refraction survey, down hole shooting refraction survey, transient Rayleigh wave survey, and crosshole shooting survey. A torsional resonant column apparatus was used for the laboratory tests. The cross hole shooting method gave the best results because direct measurements were made. Criteria for using this method are given. Methods which measure compression wave velocity give inconsistent results because the conversion to shear wave velocity is very sensitive to Poisson's ratio. Laboratory tests …


Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part I, Vincent P. Drnevich, S. R. Smith, E. P. Cleveland Aug 1972

Location Of Solution Channels And Sinkholes At Dam Sites And Backwater Areas By Seismic Methods: Part I, Vincent P. Drnevich, S. R. Smith, E. P. Cleveland

KWRRI Research Reports

The basic concepts associated with the sledge hammer seismic refraction survey are reviewed and a modified version called down hole shooting is discussed. The latter method has distinct advantages for rock surface profiling. These include: calibration at the end points of the survey, measurement of vertical wave propagation velocities directly, and having a refracted wave ray path for almost the entire survey length.

The down hole shooting seismic refraction survey has been simulated with the digital computer. The method can handle any shaped rock surface profile and generates corresponding travel time curves for the forward and reverse profile surveys. This …


A Numerical, Time Domain Solution For The Response Of A Gimbal Supported Gyro, Floyd Stanley Hall Jan 1972

A Numerical, Time Domain Solution For The Response Of A Gimbal Supported Gyro, Floyd Stanley Hall

Doctoral Dissertations

"This paper develops an algorithm to generate a numerical solution for the response of a gimbal supported gyro to arbitrary forcing functions and base motion, and includes the normal parasitic effects of bearing friction, viscous pivot damping, and pivot spring constants. There are relatively few restrictions on gyro and gimbal structure geometry. Solution accuracy is limited only by the computing machine accuracy; the algorithm being an explicit function of the input data. The algorithm is fast and requires only a moderate amount of computer memory"--Abstract, page ii.