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Articles 28171 - 28200 of 29717

Full-Text Articles in Physical Sciences and Mathematics

Guidebook To The Geology Along Portions Of The Lower Platte River Valley And Weeping Water Valley Of Eastern Nebraska, R. R. Burchett Apr 1971

Guidebook To The Geology Along Portions Of The Lower Platte River Valley And Weeping Water Valley Of Eastern Nebraska, R. R. Burchett

Conservation and Survey Division

No abstract provided.


Guidebook To The Late Pliocene And Early Pleistocene Of Nebraska, T. M. Stout, H. M. Degraw, L. G. Tanner, K. O. Stanley, W. J. Wayne, J. B. Swinehart Apr 1971

Guidebook To The Late Pliocene And Early Pleistocene Of Nebraska, T. M. Stout, H. M. Degraw, L. G. Tanner, K. O. Stanley, W. J. Wayne, J. B. Swinehart

Conservation and Survey Division

No abstract provided.


A Generic Revision Of The Pterodedinae, A New Subfamily Of Feather Mites (Sarcoptiformes: Analgoidea), Chong K. Park, Warren T. Atyeo Mar 1971

A Generic Revision Of The Pterodedinae, A New Subfamily Of Feather Mites (Sarcoptiformes: Analgoidea), Chong K. Park, Warren T. Atyeo

Bulletin of the University of Nebraska State Museum

The generic rev1s1on of the Pterodectinae, new subfamily of the Proctophyllodidae, is based on 88 named and over 160 new species. Included are morphology, host-parasite relationships, diagnoses of four named and eight new genera, and illustrations of each type species. The named genera are:

Anisodiscus Gaud and Mouchet, 1957; Montesauria Oudemans, 1905; Proterothrix Gaud, 1968; Pterodectes Robin, 1877. The new genera and their type species are: Dolichodectes, Proctophyllodes (Pterocolus) edwardsi Trouessart, 1885; Megalodectes, Proctophyllodes (Pterodectes) major Trouessart, 1885; Neodectes, Proctophyl/odes (Pterodectes) securiclatus Trouessart and Neumann, 1888; Pedanodectes, Pterodectes hologaster Gaud, 1953; Syntomodectes, Proctophyllodes (Pterodectes) selenurus Trouessart, 1885; Toxerodectes, Pterodectes gladiger …


Use Of Groundwater For Irrigation In Hamilton And York Counties, Nebraska, Eugene K. Steele Jr. Feb 1971

Use Of Groundwater For Irrigation In Hamilton And York Counties, Nebraska, Eugene K. Steele Jr.

Conservation and Survey Division

No abstract provided.


Geophysical And Geological Analysis Of A Fault-Like Linearity In The Lower Clackamas River Area, Clackamas County, Oregon, Ronald Jay Schmela Jan 1971

Geophysical And Geological Analysis Of A Fault-Like Linearity In The Lower Clackamas River Area, Clackamas County, Oregon, Ronald Jay Schmela

Dissertations and Theses

A fault-like linearity along the lower Clackamas River is evaluated by analysis of physiographic and structural alignments, geological relationships, and by gravity and magnetic data. The study has resulted in the verification of a structural feature extending along the Clackamas River and the eastern front of the Portland Hills. Physiographic alignments were examined in twelve 15 minute and two 7-1/2 minute quadrangle maps. A significant northeasterly morphologic trend, N. 20⁰ W. and N. 40° W., and other secondary trends, namely, the N-S, E-W, and N. 50-60° E., has developed in the Portland area. The consistent northwest trend is observed throughout …


Sediment Properties And Depositional Environment Of The Minnelusa Formation (Permo-Pennsylvanian), Northern Black Hills, South Dakota And Wyoming, El-Magtuf Taleb Taleb Jan 1971

Sediment Properties And Depositional Environment Of The Minnelusa Formation (Permo-Pennsylvanian), Northern Black Hills, South Dakota And Wyoming, El-Magtuf Taleb Taleb

Masters Theses

"Permo-Pennsylvanian sedimentary rocks of the Minnelusa Formation of the Black Hills uplift, South Dakota and Wyoming, can be divided into upper, middle and lower divisions on the basis of lithology. The upper portion of 150 to 200 feet consists of gray and yellow sandstone, with some carbonates and shales in some sections. The middle portion, about 200 to 220 feet thick consists of gray and red sandstone with carbonate members including the prominent dolomite member at the base; some of the carbonates are cherty. The lower portion, 20 to 60 feet thick, consists of pink sandstone, arenaceous dolomite and thin …


Gastropoda Of The Fox Hills Formation (Maestrichtian) Of North Dakota, J. Mark Erickson Jan 1971

Gastropoda Of The Fox Hills Formation (Maestrichtian) Of North Dakota, J. Mark Erickson

Theses and Dissertations

The Fox Hills Formation (Maestrichtian, Upper Cretaceous) in North Dakota contains a gastropod fauna of thirty-seven species. Five species, loganensis n. sp., Piestochilus feldmanni n. sp., Hercorhyncus (Hercorhyncus) hollandi n. sp., cvancarai n. sp., and Cancellaria siouxensis n. sp. , and genus, Dakotia, are newly described. Twenty-four genera in eighteen families representing four orders and two subclasses of Gastropoda are present. Eleven species in a like number of genera are newly reported from the Fox Hills For mation. Goniocylichna bisculnturata and rectilabrum occur in common with the gastropod fauna of the Ripley Formation of the Mississippi Embayment, which has the …


Distribution, Petrology, And Environment Of The St. Louis-Ste. Genevieve Transition Zone In Missouri, Donald Howerton Fielding Jan 1971

Distribution, Petrology, And Environment Of The St. Louis-Ste. Genevieve Transition Zone In Missouri, Donald Howerton Fielding

Masters Theses

"In eastern Missouri, southeastern Iowa, and western Illinois - a transition zone, a body of rock consisting of several lithosomes which has a geographic extent measured in scores to hundreds of miles and which lies between a single overlying formation and a single underlying formation and which has lithologic and/or paleontologic properties common to both the overlying and the underlying formations, was found to exist between the St. Louis and the Ste. Genevieve formations. This transition zone is called the St. Louis-Ste. Genevieve Transition Zone, and is shown to possibly be due to continuous deposition between these two times and …


Trace Base Metals, Petrography, Rock Alteration Of The Productive Tres Hermanas Stock, Luna County, New Mexico, Peethambaram Doraibabu Jan 1971

Trace Base Metals, Petrography, Rock Alteration Of The Productive Tres Hermanas Stock, Luna County, New Mexico, Peethambaram Doraibabu

Doctoral Dissertations

"Zinc, lead and minor copper-bearing manto-type and vein- type deposits occur in Paleozoic sedimentary rocks adjoining the Tres Hermanas quartz monzonite stock, Luna County, New Mexico. In an attempt to prove or disprove a possible genetic relationship between these mineral deposits and the stock, 99 half-mile or closer orthogonal grid samples from the stock and 22 soil samples from a connecting alluvial area to the north were analysed by atomic absorption technique for trace contents of zinc, lead and copper. Thirty-two of the rock samples were selected on a wider grid and petrographically studied and modal analyses calculated. Argillic, sericitic …


Ground Water Of The Uncompahgre Valley Montrose County, Colorado, Ted William Craig Jan 1971

Ground Water Of The Uncompahgre Valley Montrose County, Colorado, Ted William Craig

Masters Theses

"Data from water quality tests of 50 wells and from general well information of 309 wells registered with the Colorado Division of Water Resources are presented for the area of Montrose County, Colorado, drained by the Uncompahgre River. This information, along with other pertinent information such as water laws and costs, is evaluated to determine the feasibility of increasing the use of ground water in the area. The drainage basin of the Uncompahgre River within the Montrose area bas three main geologic structures: the Uncompahgre uplift, the Montrose syncline, and the Gunnison uplift. All formations exposed in the area are …


Pleistocene Aquifers In Coles County, Illinois, James D. Hopkins Jan 1971

Pleistocene Aquifers In Coles County, Illinois, James D. Hopkins

Masters Theses

No abstract provided.


Petrology And Petrography Of The Croweburg Coal, North-Central Missouri, William Keith Wedge Jan 1971

Petrology And Petrography Of The Croweburg Coal, North-Central Missouri, William Keith Wedge

Masters Theses

"Under a grant from the National Air Pollution Control Administration, the Missouri Geological Survey undertook a core drilling program of coals in north-central Missouri. The chemical and petrographic characteristics of five complete samples of the Croweburg coal recovered from this drilling project are major contributions of this study. Detailed lithologic logs of the drill cores are an additional contribution of the investigation. Megascopic lithotypes of vitrain, fusain, clarain, and durain as well as areas of mineral matter are described from polished column samples of the Croweburg coal for the first time in Missouri. Measured Croweburg coal sections from five drill …


Dolomitized Pahasapa Limestone (Mississippian), Northeastern Sector Of The Black Hills, South Dakota, Petrography And Geological Setting, Abdullatif Najjar Jan 1971

Dolomitized Pahasapa Limestone (Mississippian), Northeastern Sector Of The Black Hills, South Dakota, Petrography And Geological Setting, Abdullatif Najjar

Masters Theses

"The carbonates of the Mississippian Pahasapa Limestone in the northeastern sector of the Black Hills outcrops were examined in order to ascertain specific characters of the lithology in this area where the formation is predominantly a dolomite in contrast to adjacent areas where it is mainly a limestone. The Pahasapa seems to be uniform in thickness at the study areas and maintains a thickness of about 550 feet. Because of poor exposures, usually at the base or top, complete sections could not be measured. Much of the Pahasapa consists of coarsely crystalline dolomite containing varying proportions of crinoid plates, gastropods, …


Distribution Of Trace Elements In Olivines And Proxenes - An Experimental Study, Melvin Leroy Bird Jan 1971

Distribution Of Trace Elements In Olivines And Proxenes - An Experimental Study, Melvin Leroy Bird

Doctoral Dissertations

"Olivine, pyroxene,and spinel were crystallized in the ternary system anorthite-forsterite-silica to which trace amounts of the transition metal ions Cr³⁺, Fe²⁺, Mn²⁺, Co²⁺, Ni²⁺, and Cu²⁺ had been added. The resulting concentrations of the transition metal ions in the liquid and crystalline phases were determined using the electron microprobe. The results, given as free energies and partition functions, indicate the order of substitution of the dipositive ions in all crystals to be Ni²⁺, Co²⁺, Mn²⁺, Cu²⁺, and Fe²⁺ according to the predictions of crystal field theory. The ion Cr³⁺ substituted in greater or lesser quantities depending on the crystalline phase. …


Hydrothermal Alteration Of Ash-Flow Tuffs In The Indian Peak District Of Southwestern Utah, Michael Allan Tolley Jan 1971

Hydrothermal Alteration Of Ash-Flow Tuffs In The Indian Peak District Of Southwestern Utah, Michael Allan Tolley

Masters Theses

"Careful petrographic study of the ash-flow tuffs in the Indian Peak District of southwestern Utah reveals hydrothermal alteration around the fluorite veins. The alteration minerals themselves and the intensity of alteration vary with distance from the veins. Primary plagioclase has altered to secondary feldspar, calcite, sericite, and traces of epidote and zoisite. Hornblende and biotite have altered to chlorite, calcite, and secondary iron oxide, and traces of epidote and zoisite. Diopside has changed to calcite and secondary iron oxide. An overall picture of the mining district shows that certain minerals increase and others decrease as one nears the veins. Hydrothermal …


Shaded Topographic Map Of Nebraska Jan 1971

Shaded Topographic Map Of Nebraska

Conservation and Survey Division

No abstract provided.


Shaded Topographic Map Of Nebraska, Conservation And Survey Division Jan 1971

Shaded Topographic Map Of Nebraska, Conservation And Survey Division

Conservation and Survey Division

No abstract provided.


Nebraska Groundwater Level (Decline & Rise), 1971 Jan 1971

Nebraska Groundwater Level (Decline & Rise), 1971

Conservation and Survey Division

No abstract provided.


Nebraska Minimum Standards For Artificially Gravel Packed Irrigation Wells, P. E. Fischbach, P. E. Schleusener, V. H. Dreeszen Jan 1971

Nebraska Minimum Standards For Artificially Gravel Packed Irrigation Wells, P. E. Fischbach, P. E. Schleusener, V. H. Dreeszen

Conservation and Survey Division

No abstract provided.


Erosion And Sedimentation In Lake Ashtabula, Southeastern North Dakota, Darryll T. Pederson Jan 1971

Erosion And Sedimentation In Lake Ashtabula, Southeastern North Dakota, Darryll T. Pederson

Theses and Dissertations

Erosion along the shore of Lake Ashtabula and nearshore and offshore sedimentation were studied from May 1969 to December 1970. The lake, located in the southeastern part of North Dakota, was formed when the Baldhill Dam stopped the flow of the Sheyenne River in 1950. Maximum depth of the lake is 45 feet in the inundated river channel immediately above the dam. The lake is 27 miles long and ranges in width from 1/3 to 1/2 mile.

Shoreline erosion, measured at stations located at 100-foot intervals around the margins of the lake, was found to be a major source of …


Fossil Otoliths Of Some Lower Cenozoic Perciform Fishes Of The Gulf Coast, Mostafa Juma Salem Jan 1971

Fossil Otoliths Of Some Lower Cenozoic Perciform Fishes Of The Gulf Coast, Mostafa Juma Salem

Masters Theses

"Nineteen perciform species from the lower Cenozoic and one Recent species are described, and included under eight genera. The main characters that were considered as generic are the outline of the sagitta and the structure of the sulcus. The other features of the otolith were regarded as secondary in importance. The characters that were believed to be valuable at specific level are almost the same as those for the genus but in more detail. These species are considered to be within the Suborder Percoidei. The fossil species of "Nemipterus" were put in the Family Nemipteridae as they resembled the Recent …


Freshwater Losses To The Sea And Water Level Decline In Northwest Libya, Mohammed Ahmed Attiga Jan 1971

Freshwater Losses To The Sea And Water Level Decline In Northwest Libya, Mohammed Ahmed Attiga

Masters Theses

"The area studied in this investigation, located in Tripolitania, Libya, between 13º and 16º east longitude and 31º and 33º north latitude, covers about 42,000 square kilometers. It is divided topographically into two parts. They are the coastal zone to the north and the Jebel (plateau) zone to the south. Some wadis which rise in the Jebel drain northward across the area to the sea. The temperature in the area ranges from 5ºC to 19ºC in the winter and from 19ºC to 40ºC in the summer. Precipitation in the area ranges from 380 millimeters to less than 100 millimeters. The …


Concretions And Nodules In The Hell Creek Formation, Southwestern North Dakota, Gerald H. Groenwold Jan 1971

Concretions And Nodules In The Hell Creek Formation, Southwestern North Dakota, Gerald H. Groenwold

Theses and Dissertations

The Hell Creek Formation (Upper Cretaceous) in southwestern North Dakota consists of lagoonal and floodplain deposits and contains abundant concretions and nodules. Representative specimens of the concretions and nodules and their corresponding enclosing sediments were analyzed by thin section and by quantitative and qualitative x-ray diffraction methods.

Fourteen types of concretions and three types of nodules, classified according to shape and composition, have thus been defined. Concretionary types include calcareous sandstone lenses, “logs”, and irregular masses; sideritic sandstone lenses and irregular masses; calcareous and sideritic lignitic sandstone lenses; bone-cored rounded masses; coprolite-cored masses; jarosite bodies; pyrite spheres; baritic sandstone lenses; …


Groundwater Flow, Hydrochemistry, And Uranium Deposition In The Powder River Basin, Wyoming, J. Ladd Hagmaier Jan 1971

Groundwater Flow, Hydrochemistry, And Uranium Deposition In The Powder River Basin, Wyoming, J. Ladd Hagmaier

Theses and Dissertations

The relation between regional groundwater flow, hydrochemistry, and uranium distribution in the Powder River Basin indicates that uranium was deposited during the Tertiary Period in groundwater recharge areas where the groundwater changed from a sulfate-bicarbonate water to a bicarbonate-rich water.

The regional recharge and discharge areas of present-day groundwater-flow systems have about the same location as the recharge and discharge areas of the Tertiary groundwater-flow systems. The present-day groundwater is recharged in the eastern, western, and especially in the southern margins of the basin and is discharged in the valley of the Powder River, especially in the north. Flow nets …


The Petroleum Geology Of The Midale Subinterval In North Central North Dakota, Kent A. Johnson Jan 1971

The Petroleum Geology Of The Midale Subinterval In North Central North Dakota, Kent A. Johnson

Theses and Dissertations

The Mississippian Midale subinterval is the basal unit of the Ratcliffe interval of the Madison Group. The Midale subinterval, an important petroleum producing unit in North Dakota, is a dolomitized limestone which is approximately 40 feet thick. A detailed study of 17 oil fields in north central North Dakota was conducted to determine the petroleum geology of the Midale subinterval. The study was done with the use of 563 mechanical well logs and core samples from 10 wells.

The anhydrite and dolomite units of the Rival subinterval, which underlie the Midale, and the Ratcliffe interval, which over lies the Midale, …


Origin And Distribution Of Selenium In The Upper Cretaceous Niobrara And Pierre Formations, Northeastern North Dakota, Robert M. Novak Jan 1971

Origin And Distribution Of Selenium In The Upper Cretaceous Niobrara And Pierre Formations, Northeastern North Dakota, Robert M. Novak

Theses and Dissertations

High concentrations of selenium, often as much as 28 ppm, have been found in the bentonitic zones near the contact of the Niobrara and Pierre Formations of Cretaceous age in northeastern North Dakota. A 64-foot section in the Pembina Hills area reveals that the highest selenium content occurs in shale and marlstone beds adjacent to the bentonite beds which, themselves, contain comparatively little selenium. Higher concentrations of selenium were found in the brown shale than in the black, with a small variation in color making a big difference in selenium content.

The selenium content of the shale and marlstone drops …


Quantitative Geomorphology And Hydrology Of The Cass River Basin, New Zealand, Frank J. Schulte Jan 1971

Quantitative Geomorphology And Hydrology Of The Cass River Basin, New Zealand, Frank J. Schulte

Theses and Dissertations

The Cass River drainage basin is in the Southern Alps in the central part of the South Island of New Zealand. The Alps are composed of complexly folded greywacke which is still actively rising. The basin has been modified by several glacial advances during Pleistocene time.

The Cass basin has a temperate climate characterized by a steep precipitation gradient. Its vegetation includes plants of the forest grassland, shrubland, swamp, rock, and river-bed associations.

The Cass basin may be divided into four geomorphic areas: bedrock areas, high-angle fans, moderate-angle fans, and a low-angle fan. The bedrock areas consist of fractured greywacke; …


Geology Of Mclean County, North Dakota, John P. Bluemle Jan 1971

Geology Of Mclean County, North Dakota, John P. Bluemle

Theses and Dissertations

McLean County, in west-central North Dakota on the east side of the Williston Basin, is covered by 8,500 to 13,000 feet of Paleozoic, Mesozoic, and Cenozoic rocks, which dip to the west at low angles. The Tertiary Tongue River and Sentinel Butte Formations are widely exposed in McLean County, and the Tertiary Cannonball Formation is exposed in a few places. Glacial drift, assigned to a new formation, the Coleharbor Formation, occurs throughout the county and reaches a maximum thickness of at least 400 feet in certain preglacial valleys.

The eastern part of McLean County, part of the Missouri Coteau, is …


Geology, Geochemistry And Lava Tubes In Quaternary Basalts, Northeastern Part Of Zuni Lava Field, Valencia County, New Mexico, James Douglas Causey Nov 1970

Geology, Geochemistry And Lava Tubes In Quaternary Basalts, Northeastern Part Of Zuni Lava Field, Valencia County, New Mexico, James Douglas Causey

Earth and Planetary Sciences ETDs

Basaltic volcanism in the northeastern part of the Zuni lava field is related to a north-northeast trending regional fracture system. This is shown by elongation of centers and their alignment. However, .the fractures do not control the direction of lava tubes.

There are three distinct stages of volcanic activity common to the Zuni lava field:

1) early pyroclastic eruptions,

2) quiescent flows or fissure eruptions􀀅

3) late pyroclastic eruptions.

Evidence for the first stage is sometimes lacking, but the second and third stages can always be seen.

The basalts range from weakly tholeiitic to alkali in nature. Potassium content varies …


Machairodont Cats From The Early Pleistocene Broadwater And Lisco Local Faunas, C. Bertrand Schultz, Larry D. Martin Nov 1970

Machairodont Cats From The Early Pleistocene Broadwater And Lisco Local Faunas, C. Bertrand Schultz, Larry D. Martin

Bulletin of the University of Nebraska State Museum

A new species of Ischyrosmilus (I. crusafonti) is reported from the Early Pleistocene Broadwater Local Fauna of Morrill County, Nebraska. Ischyrosmilus sp. is reported from the Early Pleistocene Lisco Local Fauna. Megantereon is reported from the Broadwater Local Fauna and this is the first record of the genus from North America.