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Articles 28081 - 28110 of 29955
Full-Text Articles in Geology
Petrology Of The Cenozoic Igneous Rocks Of The Lytle Creek Area, Bear Lodge Mountains, Wyoming, Stanely F. White
Petrology Of The Cenozoic Igneous Rocks Of The Lytle Creek Area, Bear Lodge Mountains, Wyoming, Stanely F. White
Theses and Dissertations
The purpose of this study was to map and study the petrology of the Cenozoic igneous rocks that crop out in the Lytle Creek area located in the southwestern Bear Lodge Mountains of northeastern Wyoming. Petro graphic and chemical data is used to interpret the Cenozoic phonolite trachyte rock association.
Cenozoic igneous activity in the Lytle Creek area appears to have been a response to the Laramide orogeny 80-40 m.y. B.P. The majority of the rocks were emplaced as laccoliths and sills at the Pahasapa Formation-Minnelusa Formation contact or at the Spearfish Formation Sundance Formation contact. Porphyritic volcanic textures are …
Molluscan Paleontology Of The Pliocene Peace Valley "Beds" And Ridge Route "Formation" (Ridge Basin Group), Ridge Basin, Southern California, Daniel R. Young
Molluscan Paleontology Of The Pliocene Peace Valley "Beds" And Ridge Route "Formation" (Ridge Basin Group), Ridge Basin, Southern California, Daniel R. Young
Theses and Dissertations
The Ridge Basin, 90 km northwest of Los Angeles, California, lies within the San Gabriel, San Andreas, Liebre, and Clearwater fault zones. The basin is an elongated, wedge-shaped, intermontane, Miocene-Pliocene basin filled with about 12 000 m of marine, lacustrine, fluvial, and alluvial sediment. More than half of the thickness of the Ridge Route "formation" and about one fifth of the Peace Valley "beds" was examined for molluscs along the northeastern side of the basin and more than 600 m of section were measured.
The nonmarine molluscs of the Ridge Route "formation" and Peace Valley "beds" consist of ten species: …
Periglacial Landforms And Processes In The Southern Kenai Mountains, Alaska, Palmer K. Bailey
Periglacial Landforms And Processes In The Southern Kenai Mountains, Alaska, Palmer K. Bailey
Theses and Dissertations
The distribution and characteristics of periglacial landforms in the southern Kenai Mountains, Alaska, were investigated during the summer of 1979. The principal area of study was a 1300-metre high mountain mass which stood as a nunatak during the last general glaciation. Periglacial features in the area include gelifluction lobes, nivation hollows, cryoplanation terraces, tors, a string bog, and various for111S of patterned ground such as sorted circles, sorted polygons, earth hummocks, sorted steps, sorted stripes, and small ice-wedge polygons.
Ground temperature measurements indicate that permafrost recently existed in the area but is no longer present. The sorted polygons, cryoplsnation terraces, …
Preliminary Investigation Of The Ground-Water Resources Of Northern Searcy County, Arkansas, Wyndal M. Goodman, Albert E. Ogden
Preliminary Investigation Of The Ground-Water Resources Of Northern Searcy County, Arkansas, Wyndal M. Goodman, Albert E. Ogden
Journal of the Arkansas Academy of Science
Two aquifers are extensively used by residents of small communities and rural areas in northern Searcy County, Arkansas. The Mississippian Boone-St. Joe aquifer is generally the less productive and the shallower of the two. Ground-water yields for the Boone-St. Joe range from 0.5 to 75 gpm with a median yield of 5 and a mean of 9.8 gpm. Well depths range from 100 to 754 feet with a median depth of 350 feet and a mean of 360 feet. Confined conditions are indicated by the greater depths, whereas the Boone-St. Joe aquifer is unconfined when exposed at the surface. Underlying …
Preliminary Investigation Of The Ground-Water Resources Of Baxter, Fulton, Izard And Sharp Counties, Arkansas, Mike Liebelt, Gerald Lundy, Albert E. Ogden
Preliminary Investigation Of The Ground-Water Resources Of Baxter, Fulton, Izard And Sharp Counties, Arkansas, Mike Liebelt, Gerald Lundy, Albert E. Ogden
Journal of the Arkansas Academy of Science
One hundred and seventy-seven drillers' well reports were used to investigate the groundwater resources of Baxter, Fulton, Izard, and Sharp counties. The most widely utilized aquifer zone is composed of the Cotter and Jefferson City dolomites. The well depths range from 30 to 740 ft. with a mean and median of 264 and 225 ft., respectively. The drillers' yield estimates range from 1 to 50 gpm with a mean of 12.0 gpm and a median of 10 gpm. The piezometric surface has an average hydraulic gradient of 9 ft./mile with groundwater discharge occurring along the Spring and White Rivers. Overlying …
Nebraska Groundwater Level (Decline & Rise) And Location Of Registered Wells, 1980
Nebraska Groundwater Level (Decline & Rise) And Location Of Registered Wells, 1980
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Nebraska County Map
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Geology And Groundwater Supplies Of Box Butte County, Nebraska, 1979, V. L. Souders, F. A. Smith, J. B. Swinehart
Geology And Groundwater Supplies Of Box Butte County, Nebraska, 1979, V. L. Souders, F. A. Smith, J. B. Swinehart
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Collecting In Nebraska's Glacial Deposit, John Boellstorff
Collecting In Nebraska's Glacial Deposit, John Boellstorff
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Geology Along The Republican River Valley Near Red Cloud, Nebraska, R. K. Pabian, J. B. Swinehart
Geology Along The Republican River Valley Near Red Cloud, Nebraska, R. K. Pabian, J. B. Swinehart
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
The Effect Of Dissolution Of Volcanic Glass On The Water Chemistry In A Tuffaceous Aquifer, Rainier Mesa, Nevada, Art F. White, Hans C. Claassen, Larry Benson
The Effect Of Dissolution Of Volcanic Glass On The Water Chemistry In A Tuffaceous Aquifer, Rainier Mesa, Nevada, Art F. White, Hans C. Claassen, Larry Benson
United States Geological Survey: Staff Publications
Geochemistry of ground water associated with the Tertiary tuffs within Rainier Mesa, southern Nevada, was investigated to determine the relative importance of glass dissolution in controlling water chemistry. Water samples were obtained both from interstitial pores in core sections and from free-flowing fractures. Cation compositions showed that calcium and magnesium decreased as a function of depth in the mesa, as sodium increased. The maximum effect occurs within alteration zones containing clinoptilolite and montmorillonite, suggesting these minerals effectively remove bivalent cations from the system.
Comparisons are made between compositions of ground waters found within Rainier Mesa that apparently have not reacted …
Authigenic Kaolinite In The Bear Den Member (Paleocene) Of The Golden Valley Formation, In Southwestern North Dakota, Gordon H. Prichard
Authigenic Kaolinite In The Bear Den Member (Paleocene) Of The Golden Valley Formation, In Southwestern North Dakota, Gordon H. Prichard
Theses and Dissertations
The Golden Valley Formation of North Dakota crops out in isolated remnants over a large area of southwestern North Dakota. The formation has two members, the lower Bear Den Member, which is characterized by kaolin and bright colors and the upper Camels Butte Member, which is characterized by micaceous sand and clay.
Two different theories, either in place weathering or detrital deposition, have developed as to the origin of the kaolinite in the lower member. Early workers suggest that the kaolinite of the member is detrital in origin for the following reasons:
1. No unconformity is present at the top …
Stratigraphy, Sedimentology, And Depositional Environments Of The Hell Creek Formation (Late Cretaceous) And Adjacent Strata, Glendive Area, Montana, Raymond D. Butler
Stratigraphy, Sedimentology, And Depositional Environments Of The Hell Creek Formation (Late Cretaceous) And Adjacent Strata, Glendive Area, Montana, Raymond D. Butler
Theses and Dissertations
The Colgate Member (Fox Hills Formation), Little Beaver Creek, Marmarth, Bacon Creek, Huff, and Pretty Butte Members (Hell Creek Formation), and lower Ludlow Formation in the Glendive area, Montana consist of sandstone, sandy siltstone, shale, and lignite. The Colgate is 24 m thick and consists of mostly sandstone, The Hell Creek Formation (Late Cretaceous) is 120 m thick, The basal member, the Little Beaver Creek, is up to 12 m thick and consists of about half sandstone and half shale. The Marmarth is 24 to 30 m thick and consists of mostly sandstone. The Bacon Creek is 36 m thick …
Paleoenvironmental Analysis Of A Late Holocene Deposit : Stanton Site, West-Central North Dakota, David W. Fischer
Paleoenvironmental Analysis Of A Late Holocene Deposit : Stanton Site, West-Central North Dakota, David W. Fischer
Theses and Dissertations
The Stanton Site (W1/2NE1/4 sec. 16, T. 144 N., R. 85W.), eastern Mercer County, North Dakota, contains a late Holocene organic deposit in the cutbank of an ephemeral stream on the Missouri Plateau. Strati graphic units of the 104-cm section are, in ascending order: (l) gravel; (2) silty, organic, sandy clay; (3) organic silt; (4) silty, sandy, organic clay; (5) organic silt; (6) sandy, silt, organic clay; and (7) sand. A radiocarbon date of wood from the base of unit 2 indicates initiation of deposition at 325±_115 radiocarbon years B.P.
Abundant well-preserved fossils are present in the organic sediments of …
Surface Geology For Land Use Planning, Minot, North Dakota Area, Garth S. Anderson
Surface Geology For Land Use Planning, Minot, North Dakota Area, Garth S. Anderson
Theses and Dissertations
The Minot area includes about 330 square kilometres along both sides of the Souris River in north-central North Dakota. The area can be divided into the flat Souris River floodplain, the steeply sloping sides of the Souris and Des Lacs meltwater channels and larger tributaries, and the gently undulating uplands dissected by small streams. Surficial geologic units include Early Tertiary sand, silt, clay, and sandstone of the Bullion Creek Formation, Pleistocene glacial till, ice contact fluvial deposits, and other fluvial deposits of the Coleharbor Group, and Holocene fluvial and eolian deposits of the Oahe Formation.
Expansion of the Minot metropolitan …
Geology Of The Columbia River Basalt In Silver Falls State Park, Oregon, Elizabeth Storm Norman
Geology Of The Columbia River Basalt In Silver Falls State Park, Oregon, Elizabeth Storm Norman
University Honors Theses
Silver Falls State Park is near the southern extent of the Columbia River Basalt Group as mapped in western Oregon. The flows in the park were identified as belonging to subdivisions of the Columbia River Basalt Group on the basis of physical characteristics and trace element geochemistry. The sequence of flows present is as follows: 3-4 flows of the Low-Mg chemical type of the Grande Ronde Basalt, 2 flows of the High-Mg chemical type of the Grande Ronde Basalt, 3 flows of the Frenchman Springs Member of the Wanapum Basalt, and one flow of anomolous geochemistry. The flows dip west …
Provenance Study Of The Westwater Canyon And Brushy Basin Members Of The Morrison Formation Between Gallup And Laguna, New Mexico, Ruben Martinez
Provenance Study Of The Westwater Canyon And Brushy Basin Members Of The Morrison Formation Between Gallup And Laguna, New Mexico, Ruben Martinez
Earth and Planetary Sciences ETDs
The objective of this investigation is to study the provenance of the Westwater Canyon and Brushy Basin Members of the Morrison Formation between Gallup and Laguna, New Mexico. The coarse, subarkosic Westwater Canyon Member is separated from the quartzitic sandstones of the underlying Recapture Member by an unconformity that provides a recognizable datum for correlation and a definite base for the Westwater Canyon Member.
The very pale orange, cliff-forming Westwater Canyon Member consists of Oto 137 m of very coarse- to very fine-grained, poorly sorted, subrounded to angular, arkosic to quartzitic sandstone with numerous lenses of arkosic granules and pebbles …
Petrogenesis Of Orbicular Rock, Tijeras Canyon, Sandia Mountains, New Mexico, Kathleen Affholter
Petrogenesis Of Orbicular Rock, Tijeras Canyon, Sandia Mountains, New Mexico, Kathleen Affholter
Earth and Planetary Sciences ETDs
A new occurrence of orbicular rock is located in the Sandia Granite at W. long. 106° 25' 30", N. lat. 35° 04' 55" close to the granite-gneiss contact near Tijeras Canyon, Sandia Mountains, New Mexico. The orbicules, set in an aplite-pegmatite granitic matrix, have magmatic and metamorphic cores surrounded by a white plagioclase shell and one or two salmon-colored potassium feldspar shells. The outcrop occurs in two dike-like masses with thicknesses of 1 to 4 m trending N. 5° W. and N. 35° E. for exposed lengths of 16m and 46 m, and is surrounded by biotite syenodiorite and biotite …
Geology Newsletter- 1979, Department Of Geology
Geology Newsletter- 1979, Department Of Geology
Geological and Environmental Sciences News
Includes a list of short news items from the chair, Lloyd Schmaltz, addressed to alumni and friends.
Geology Of The Cerro Del Grant Area, Rio Arriba County, North-Central New Mexico, John Richmond Lawrence
Geology Of The Cerro Del Grant Area, Rio Arriba County, North-Central New Mexico, John Richmond Lawrence
Earth and Planetary Sciences ETDs
The present study undertook the geologic mapping and investigation of the stratigraphy, structural geology, igneous petrology and mineral resources of the Cerro del Grant area, a 75- (190 ) region near Coyote, Rio Arriba County, north-central New Mexico. The area is situated at the junction of three geologic provinces: the Chama platform, the Española Basin of the Rio Grande rift, and Jemez volcanic field.
Sedimentary rocks include 2,500 ft (830 m) of sandstone, shale, conglomerate and limestone of Late Triassic to Quaternary age. These strata are unconformably overlain by several hundred feet of mafic, intermediate and rhyolitic lavas which make …
Analysis And Interpretation Of The 5,000 Ft (1,538 M) Red-Bed Sequence Encountered In The Sparks Et Al. #1-8 (Michigan Basin Deep Borehole), John H. Fowler
Analysis And Interpretation Of The 5,000 Ft (1,538 M) Red-Bed Sequence Encountered In The Sparks Et Al. #1-8 (Michigan Basin Deep Borehole), John H. Fowler
Masters Theses
A 5,000 ft (1,538 m) pre-Mt. Simon (Upper Cambrian) red-bed sequence, encountered in the Gratiot County deep borehole (Sparks et al. #1-8) and herein named the North Star Formation, consists of undeformed recurring beds of immature arkosic sandstone 2 to 34 in (5 to 85 cm) thick. These beds grade upward from erosional basal contacts into mudstone units 1 in to 12 ft (3 cm to 3.8 m) thick. Within the sandstones, grading, horizontal lamination, and crossstratification define Bouma intervals "a", "b", and "c", which combine to form incomplete Bouma sequences. Mudstones exhibit abundant horizontal laminations. Secondary sedimentary structures (load …
Structural And Petrologic Comparison Of The Southern Sapphire Range, Montana With The Northeast Border Zone Of The Idaho Batholith, Stacy Lon Clark
Structural And Petrologic Comparison Of The Southern Sapphire Range, Montana With The Northeast Border Zone Of The Idaho Batholith, Stacy Lon Clark
Masters Theses
No abstract provided.
Analysis And Interpretation Of The 5,000 Ft. (1,538 M) Red-Bed Sequence Encountered In The Sparks E̲T̲ A̲L̲. #1-8 (Michigan Basin Deep Borehole), John H. Fowler
Analysis And Interpretation Of The 5,000 Ft. (1,538 M) Red-Bed Sequence Encountered In The Sparks E̲T̲ A̲L̲. #1-8 (Michigan Basin Deep Borehole), John H. Fowler
Masters Theses
A 5,000 ft (1,538 m) pre-Mt. Simon (Upper Cambrian) red-bed sequence, encountered in the Gratiot County deep borehole (Sparks et al. #1-8) and herein na~ed the North Star Formation, consists of undeformed recurring beds of immature arkosic sandstone 2 to 34 in. (5 to 85 cm) thick. These beds grade upward from erosional basal contacts into mudstone units 1 in to 12 ft (3 cm to 3.8.m) thick. Within the sandstones, grading, horizontal lamination, and crossstratification define Bouma intervals "a", "b", and "c", which combine to form incomplete Bouma sequences. Mudstones exhibit abundant horizontal laminations. Secondary sedimentary structures (load . …
Atmospheric Implications Of Studies Of Central American Volcanic Eruption Clouds, R. D. Cadle, A. L. Lazrus, B. J. Huebert, L. E. Heidt, William I. Rose, D. C. Woods, Raymond L. Chuan, Richard E. Stoiber, D. B. Smith, Robert A. Zielinski
Atmospheric Implications Of Studies Of Central American Volcanic Eruption Clouds, R. D. Cadle, A. L. Lazrus, B. J. Huebert, L. E. Heidt, William I. Rose, D. C. Woods, Raymond L. Chuan, Richard E. Stoiber, D. B. Smith, Robert A. Zielinski
Department of Geological and Mining Engineering and Sciences Publications
During February 1978 a group of scientists from the National Center for Atmospheric Research, several colleges and universities, the U.S. Geological Survey, and NASA used a specially equipped Beech Queen Air aircraft to make 11 sampling flights in Guatemala through the eruption clouds from the volcanoes Pacaya, Fuego, and Santiguito. Measurements were made of SO42−, SO2, HCl, HF, and 11 cations that were in water-soluble form, on samples collected by a specially designed filter pack. Particle size distributions were obtained with a piezoelectric cascade impactor, and the particles were identified by energy dispersive X ray …
Petrogenetic Properties Of Chondrules In Unequilibrated H-, L-, And Ll-Group Chondritic Meteorites, James Leslie Gooding
Petrogenetic Properties Of Chondrules In Unequilibrated H-, L-, And Ll-Group Chondritic Meteorites, James Leslie Gooding
Earth and Planetary Sciences ETDs
The physical properties (size, shape, mass, density, surface morphology), bulk chemical composition (by nondestructive instrumental neutron activation analysis), texture, and phase compositions (by electron microprobe analysis) have been determined for each of 141 individual chondrules separated from a total of 11 different H-, L-, and LL-group chondritic meteorites of Van Schmus-Wood petrologic types 3 and 4. In addition, physical properties have been determined for 75 other chondrules from the same chondrites. The chondrites studied are comparatively unaltered and unequilibrated and include Tieschitz (H3), Dhajala (H3, 4), Ochansk (H4), Weston (H4), Hallingeberg (L3), Saratov (L4), Tennasilm (L4), Chainpur (LL3), Semarkona (LL3), …
The Origin Of Fine Scale Acoustic Stratigraphy In Deep-Sea Carbonates, Larry A. Mayer
The Origin Of Fine Scale Acoustic Stratigraphy In Deep-Sea Carbonates, Larry A. Mayer
Affiliate Scholarship
In this paper we investigate the origin and geologic significance of the closely spaced high-frequency subbottom acoustic reflectors characteristic of pelagic carbonates. A detailed survey was conducted of a small area in the equatorial Pacific with the Marine Physical Laboratory's Deep-Tow instrument package, providing high-resolution 4-kHz profiles and precise positioning of core samples. The cores were sampled at closely spaced intervals for sound velocity and saturated bulk density. Acoustic impedances were calculated, and a reflection coefficient log determined for the upper 10 m of the sediment column. The reflection coefficient log revealed no interfaces with large reflection coefficients that correlated …
A Geophysical Definition Of A Klamath Falls Graben Fault, Cynthis Ann Veen
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.
Rubidium-Strontium And Related Studies Of The Salado Formation, Southeastern New Mexico, Joseph K. Register Jr.
Rubidium-Strontium And Related Studies Of The Salado Formation, Southeastern New Mexico, Joseph K. Register Jr.
Earth and Planetary Sciences ETDs
The Salado Formation, a member of the Ochoa Series, is a bedded salt deposit which is found in the Delaware Basin southeastern New Mexico and west Texas. It is comprised primarily of halite and sylvite with minor amounts of sulfate minerals. Rubidium-strontium age determinations of the evaporite minerals in the Salado indicate an age of final equilibration of 214 15 m.y. This age is fairly consistent with the geologic age of the formation, precluding substantial alkali-alkaline earth migration since deposition. Polyhalite and anhydrite samples from the Salado give / values of about .7078, which are consistent with reported valued for …
Oxygen Isotopic Analysis Of Silicates And Oxides Using Both Bromine Pentafluoride And Fluorine Gas As Reagents, Harold Roy Northrop
Oxygen Isotopic Analysis Of Silicates And Oxides Using Both Bromine Pentafluoride And Fluorine Gas As Reagents, Harold Roy Northrop
Earth and Planetary Sciences ETDs
In recent years the preferred analytical procedure for the extraction of oxygen from silicates and oxides for oxygen isotope analysis has been the oxidation of the samples with either fluorine (F2) or bromine pentafluoride (BrF5) to produce oxygen. Several standards are available for monitoring the extraction procedure, and one in particular (NBS-28) is used in many laboratories. The oxygen-18 oxygen-16 ratios obtained for NBS-28 vary by as much as one permil between laboratories. The major cause of this variation lies in the extraction procedure used. Extraction of oxygen from iron bearing minerals and whole rocks (and minerals containing certain other …
Agricultural Geology, R. Fenwick
Agricultural Geology, R. Fenwick
Natural resources published reports
WESTERN AUSTRALIA
Precambrian rocks occupy 1.5 million kn2 or roughly 60% of the total land area of the state, to form one of the most extensive and varied precambrian regions of the world. The oldest rocks are the comparatively little altered sediments and volcanics of the Pilbara Diock whose age must exceed that of the 3 000 million year old granites which intrude then
Western Australia is divisable into two broad geological types. The great plateau or Western or Archean Shield and coastal and inland basins.
The Western Shield is the largest area of Archean (Archeozoic era) rocks in Australia, …