Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Hydrology (1905)
- Geomorphology (1756)
- Sedimentology (1561)
- Stratigraphy (1428)
- Environmental Sciences (1352)
-
- Paleontology (1259)
- Geophysics and Seismology (1168)
- Soil Science (1118)
- Other Earth Sciences (918)
- Oceanography and Atmospheric Sciences and Meteorology (862)
- Geochemistry (851)
- Engineering (808)
- Other Environmental Sciences (575)
- Life Sciences (555)
- Civil and Environmental Engineering (530)
- Other Engineering (469)
- Tectonics and Structure (463)
- Environmental Engineering (456)
- Materials Science and Engineering (434)
- Social and Behavioral Sciences (420)
- Metallurgy (413)
- Other Materials Science and Engineering (412)
- Ceramic Materials (405)
- Geography (290)
- Environmental Monitoring (212)
- Plant Sciences (205)
- Ecology and Evolutionary Biology (204)
- Institution
-
- Western Michigan University (19354)
- University of Nebraska - Lincoln (1807)
- Missouri University of Science and Technology (676)
- University of Kentucky (577)
- Utah State University (507)
-
- University of South Florida (491)
- Montana Tech Library (460)
- Portland State University (447)
- University of North Dakota (407)
- Western Kentucky University (365)
- University of New Mexico (325)
- University of Nevada, Las Vegas (264)
- University of Arkansas, Fayetteville (250)
- Smith College (219)
- Central Washington University (217)
- University of Texas at El Paso (189)
- Brigham Young University (183)
- Old Dominion University (170)
- Michigan Technological University (157)
- Louisiana State University (129)
- University of Dar es Salaam (127)
- University of Alabama at Birmingham (124)
- University at Albany, State University of New York (112)
- Stephen F. Austin State University (109)
- West Virginia University (109)
- Illinois State University (104)
- City University of New York (CUNY) (103)
- Fort Hays State University (84)
- University of South Carolina (75)
- Wayne State University (73)
- Keyword
-
- Geology (730)
- Nebraska (496)
- Montana (275)
- Groundwater (267)
- Geochemistry (198)
-
- Kentucky (196)
- Karst (166)
- Stratigraphy (149)
- Rock (127)
- Tectonics (123)
- Butte (120)
- Utah (120)
- 3d model (116)
- Water (116)
- Geomorphology (115)
- Geophysics (113)
- Hydrogeology (105)
- Physical Sciences (99)
- Limestone (91)
- Hydrology (90)
- Copper (87)
- Petrology (82)
- Seismology (79)
- Shale (76)
- Test (75)
- Logs (73)
- Earth sciences (72)
- Hole (72)
- Map (71)
- Sedimentology (69)
- Publication Year
- Publication
-
- Legacy Scout Tickets from Pure Oil Company (11044)
- Thin Sections (6677)
- Legacy Color Lithology Strip Logs (1152)
- Conservation and Survey Division: Faculty and Staff Publications (897)
- Theses and Dissertations (626)
-
- United States Geological Survey: Staff Publications (507)
- Masters Theses (475)
- Bachelors Theses and Reports, 1928 - 1970 (423)
- Earth and Planetary Sciences ETDs (318)
- All Graduate Theses and Dissertations, Spring 1920 to Summer 2023 (276)
- Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works (265)
- Map and Chart--KGS (234)
- Dissertations and Theses (233)
- Geosciences: Faculty Publications (215)
- International Journal of Speleology (212)
- Geology Faculty Publications and Presentations (193)
- USF Tampa Graduate Theses and Dissertations (181)
- UNLV Theses, Dissertations, Professional Papers, and Capstones (178)
- Open Access Theses & Dissertations (175)
- Geolographs (174)
- Graduate Theses and Dissertations (145)
- Geosciences Faculty Publications (138)
- Mammoth Cave Research Symposia (133)
- Electronic Theses and Dissertations (130)
- Tanzania Journal of Science (127)
- All 3D Rock Models (116)
- Bulletin of the University of Nebraska State Museum (1924–2023) (112)
- Geology Theses and Dissertations (111)
- Robert F. Diffendal, Jr., Publications (103)
- OES Theses and Dissertations (101)
- Publication Type
- File Type
Articles 27541 - 27570 of 29955
Full-Text Articles in Geology
A Seismic Refraction Study Of A Portion Of The Northeastern Margin Of The Tualatin Valley, Oregon, David John Nazy
A Seismic Refraction Study Of A Portion Of The Northeastern Margin Of The Tualatin Valley, Oregon, David John Nazy
Dissertations and Theses
The Tualatin Valley is a well defined elliptical basin centered at Hillsboro, with a major axis trending roughly N65°W. The valley is bordered on the northeast by the Tualatin Mountains (Portland Hills) which are a faulted, northwest-trending asymmetrical anticline. Topographic and geophysical evidence have defined the Portland Hills fault, which occurs along the northeast side of the Tualatin Mountains. The possibility that a fault or fault zone occurs along the southwest side of the Tualatin Mountains was investigated in this study.
Textural And Mineralogical Characteristics Of Altered Grande Ronde Basalt, Northeastern Oregon : A Natural Analog For A Nuclear Waste Repository In Basalt, Paul M. Trone
Dissertations and Theses
Altered flows that are low-MgO chemical types of the Grande Ronde Basalt crop out in the steep walls of the Grande Ronde River canyon near Troy, Wallowa County, Oregon. The alteration effects in these flows are being investigated as a natural analog system to a high level nuclear waste repository in basalt. The flows within the study are referred to as the analog flow, in which the alteration effects are the strongest, and the superjacent flow. The analog flow crops out at Grande Ronde River level and a roadcut-outcrop is developed in the flow-top breccia of this flow. The two …
A Groundwater Flow Model Of The Aquifer Intercommunication Area, Hanford Site, Washington, Elizabeth G. Simkover
A Groundwater Flow Model Of The Aquifer Intercommunication Area, Hanford Site, Washington, Elizabeth G. Simkover
Dissertations and Theses
Intercommunication has been identified between the unconfined and uppermost confined aquifer systems underlying a portion of the U.S. Department of Energy's Hanford Site. Erosional thinning and fracturing of the basalt confining layer within the study area allows physical contact between the two aquifers, but the vertical hydraulic gradient (a required driving force) is small. To better conceptualize the distribution and volume of the leakage occurring between the aquifer systems, this study investigates the confined Rattlesnake Ridge Aquifer flow system, which appears to be more sensitive to the vertical leakage than the overlying unconfined aquifer.
The flow system of the Rattlesnake …
Mechanisms Responsible For Sinkhole Flooding On An Urbanized Karst Terrain: South Sunrise / Media Drive, Bowling Green, Kentucky, Thomas Feeney
Mechanisms Responsible For Sinkhole Flooding On An Urbanized Karst Terrain: South Sunrise / Media Drive, Bowling Green, Kentucky, Thomas Feeney
Masters Theses & Specialist Projects
Sinkhole flooding on the urban karst area of Bowling Green, Kentucky, was studied by investigating past flood events in the South Sunrise/Media Drive Sinkhole. The actual flood levels of four floods were compared to levels calculated by an empirical runoff determination method. Outflow capacity tests and dye tracing revealed the nature of drainage within the karst depression.
The Soil Conservation Service runoff determination method and the three-hour maximum rainfall event were used to estimate the level of flooding. Three of the four flood events studied provided deviations between the actual and calculated flood levels of less than 0.26 feet (0.08 …
Geology Newsletter- 1986, Department Of Geology
Geology Newsletter- 1986, Department Of Geology
Geological and Environmental Sciences News
Vol. 1, No. 11
- Dear Alumni and Friends
- Core Research Library
- Advisory Council
- Geology Development Fund
- Faculty Briefs
- Awards and Scholarships
- Alumni Lines
A Hydrogeologic Investigation Of The Balkema Wetland, Daniel V. Fronczek
A Hydrogeologic Investigation Of The Balkema Wetland, Daniel V. Fronczek
Masters Theses
The Balkema wetland, located In southwestern Kalamazoo County, Michigan, represents complex biological and hydrologic Interaction between surface water and a two-aquifer hydrologic system. Situated on the southeastern flank of the Kalamazoo moraine, the glacial geology of the area plays a key role in the understanding of the hydrogeologic function of the wetland. A two-aquifer system, an upper unconfined, and a lower confined, Interact In the vicin ity of the wetland where the c la y /till aqulclude dividing the two systems 1s absent. Various parameters, both hydrologic and geochemical, were measured In the study area, Including specific conductance values of …
Structural, Remote Sensing And Multivariate Correlation Methods As Aids To Mineral Exploration, Central Ireland, D.W. Coller, M.F. Critchley, J.M. Dolan, Ciaran Mcdonnell, C.J. Murphy, W.E.A. Phillips, D.J. Sanderson
Structural, Remote Sensing And Multivariate Correlation Methods As Aids To Mineral Exploration, Central Ireland, D.W. Coller, M.F. Critchley, J.M. Dolan, Ciaran Mcdonnell, C.J. Murphy, W.E.A. Phillips, D.J. Sanderson
Books/Book chapters
This work discusses structural, remote sensing and multivariate correlation methods as aids to mineral exploration in West Central Ireland. The work was performed as part of the EU-funded CREST project.
Fracture Detection In A Volcanic Oil Reservoir Using Discriminant Analysis Of Well Log Data, Joseph William Cross
Fracture Detection In A Volcanic Oil Reservoir Using Discriminant Analysis Of Well Log Data, Joseph William Cross
OES Theses and Dissertations
A new method of detecting fractures using well logs is presented. The technique uses discriminant analysis to distinguish fractured from unfractured reservoir rock and was developed for the volcanic pay zone of Jatibarang oilfield, West Java, Indonesia.
The a priori information required to derive the discriminant function was provided by 22 wells known to penetrate intervals of either fractured or unfractured volcanics. The samples consisted of these 22 intervals digitized in one-meter increments (1256 meters total thickness). The discriminating variables were the petrophysical measurements made by 10 different types of well logs.
Discriminant analysis correctly classified 94.2% of the total …
Late Pleistocene Sciurids From Kokoweef Cave, H. Thomas Goodwin
Late Pleistocene Sciurids From Kokoweef Cave, H. Thomas Goodwin
Loma Linda University Electronic Theses, Dissertations & Projects
Three local (Tamias panamintinus, Ammospermophilus leucurus and Spermophilus variegatus) and five extralocal (Tamias minimus, Tamias palmeri, Marmota flaviventris, Spermophilus townsendii, and Spermophilus lateralis) sciurid species (Sciuridae) were identified from the late Pleistocene-early Holocene Kokoweef Cave paleofauna. This fauna was the first documentation of T. minimus, T. palmeri and S. townsendii from the Pleistocene of the Mohave Desert. The 30-ft sedimentary sequence apparently recorded the mid-to late-Wisconsian introduction of S. lateralis into the Kokweef fauna but otherwise documented general taxonomic stability. The ecological diversity of the fauna was consistent with--but did not require--the hypothesis of more equable late Pleistocene climates, and …
Geology Of The Willamette Pass Area, Cascade Range, Oregon, Neil M. Woller
Geology Of The Willamette Pass Area, Cascade Range, Oregon, Neil M. Woller
Dissertations and Theses
The Willamette Pass area is situated at the intersection of two hypothesized structural features, the Western Cascade-High Cascade boundary and the Eugene-Denio lineament. It is of interest due to its designation by the U.S. Department of the Interior as a Known Geothermal Resource Area.
Volcanic rocks of Oligocene to Pleistocene age are exposed in the study area. The oldest rocks are the Oligocene-Miocene lavas, undifferentiated, which are a diverse unit of ignimbrites and intermediate to silicic flows. The Oligocene-Miocene rhyodacites are a stratigraphically equivalent unit which is predominantly composed of aphyric rhyodacite flows. Middle Miocene volcanism produced the basaltic lavas …
Karstification Of The Pennyroyal Plain Behind The Retreating Chester Escarpment: Warren, Simpson & Logan Counties, Kentucky, Anthony Able
Karstification Of The Pennyroyal Plain Behind The Retreating Chester Escarpment: Warren, Simpson & Logan Counties, Kentucky, Anthony Able
Masters Theses & Specialist Projects
Hydrogeologic investigations were conducted on the drainage systems of an area of the Pennyroyal sinkhole plain of south central Kentucky. The degree of karstification of five area streams was studied to develop an understanding of the evolution of drainage as the landscape changes from a sandstone caprock plateau to a limestone sinkhole plain. The Chester Upland, capped by the Big Clifty Sandstone, possesses predominantly surface drainage and the Pennyroyal Plain, formed on Mississippian limestones, possesses considerable subsurface drainage. As the Chester Upland Escarpment retreats and surface streams are onto the limestones, the streams evolve to become subsurface streams. The five …
Slack-Water Deposits And The Magnitude And Frequency Of Flash Floods, Eastern Kentucky, Russell G. Shepherd, Lisa K. Bienkowski
Slack-Water Deposits And The Magnitude And Frequency Of Flash Floods, Eastern Kentucky, Russell G. Shepherd, Lisa K. Bienkowski
KWRRI Research Reports
The potential for predicting flood magnitude and frequency using sediments deposited in backwater areas during flash floods was investigated on the Cumberland Plateau of eastern Kentucky, a region n9torious for flash flooding. Slack-water deposits are abundant in the area at tributary mouths and bedrock channel expansions. They are identifiable on geologic quandrangle maps, and are locally good potential indicators of maximum flood-crest elevations. However, in this humid region, flash floods could not be distinguished from non-flash floods using slack-water sedimentology.
The results from the slack-water deposits studied indicate that they offer limited potential for predicting flash floods because 1) intense …
Pinuxylon Woolardii Sp. Nov., A New Petrified Taxon Of Pinaceae From The Miocene Basalts Of Eastern Oregon, William D. Tidwell, Lee R. Parker, Vaughn K. Folkman
Pinuxylon Woolardii Sp. Nov., A New Petrified Taxon Of Pinaceae From The Miocene Basalts Of Eastern Oregon, William D. Tidwell, Lee R. Parker, Vaughn K. Folkman
Faculty Publications
Specimens of the new species Pinuxylon wollardii have been collected from Miocene strata near Kurkee, OR. These petrified specimens are unique in that, due to weathering, individual tracheids and ray cells can be separated for detailed SEM studies. This species is characterized by its high number of ray cells; numerous rays; large resin ducts which are commonly paired; primarily uniseriate pitting, two to five (usually three) small, oval or cirular pinoid pits per crossfield; and smooth walls on its transverse (ray) tracheids. The latter character relates this species to taxa in the subgenus Haploxylon of Pinus. Pinuxylon woolardii is most …
Cliff-Height And Slope-Angle Relationships In A Chronosequence Of Quaternary Marine Terraces, San Clemente Island, California, Russell Crittenden, Daniel R. Muhs
Cliff-Height And Slope-Angle Relationships In A Chronosequence Of Quaternary Marine Terraces, San Clemente Island, California, Russell Crittenden, Daniel R. Muhs
United States Geological Survey: Staff Publications
Zusammenfassung. Eine Abfolge quartarer Strandterrassen auf ~an Clemente Island, Kalifornien, liefert einen Rahmen fur die quantitative Analyse der Anderungen an vom Meer verlassenen Kustenkliffen als Funktion der Zeit. Es wurde eine Abschatzung der Anwendbarkeit von BUCKNAM & ANDERSON (1979) log-lin~arer Beziehung zwischen Wandhohe und Hangwinkel durchgefuhrt, indem Brandungskliffhohe und maximale Hangwinkel verwendet wurden. Die Ergebnisse zeigen eine regelhafte Zunahme des Hangwinkels mit dem Logarithmus der Kliffhohe, und Kliffe einer bestimmten Hohe zeigen m,it der Zeit eine Abnahmedes maximalen Hangwinkels. 1m ganzen waren die Relationen schwacher als fur FluBterrassen und Bruchstufen in unverfestigten Materialen, aber die Methode kann wahrscheinlich verwendet werden, …
A Structural Investigation Of A Basement-Involved Thrust System In Southern Sphinx Mountain Quadrangle (Madison Range) Southwestern Montana, Jeffrey Scott Brown
A Structural Investigation Of A Basement-Involved Thrust System In Southern Sphinx Mountain Quadrangle (Madison Range) Southwestern Montana, Jeffrey Scott Brown
Masters Theses
The Madison Range is the eastern limb of the Laramide Rocky Mountain foreland Madison-Gravelly Arch. The main segment of the Madison thrust system in the map area is the basement-involved Scarface thrust which dips westward, trends north-northwest, and places Archean rocks onto an overturned footwall of Cambrian through Cretaceous rocks. Foliation of Archean rocks in the footwall is folded with overlying sedimentary rocks.
The Shedhorn Mountain thrust splays from the Scarface thrust. It is exposed north and south of the Shedhorn Mountain anticline, but is blind beneath it. The Taylor fault, an east-dipping back thrust, is inferred to be associated …
Stratigraphic And Sedimentologic Analysis Of The Middle Devonian Filer Sandstone, John Charles Rodwan
Stratigraphic And Sedimentologic Analysis Of The Middle Devonian Filer Sandstone, John Charles Rodwan
Masters Theses
The Filer Sandstone, a multistory assemblage o£ lenticular sand bodies, is a member of the Middle Devonian Amherstburg Formation of the Detroit River Group in the subsurface of the western and central portion of the Michigan Basin. It is distinguished from the reworked eolian and nearshore marine sand facies of the underlying Sylvania Sandstone by recognition of its barrier island facies relationships and stratigraphic position within enclosing carbonates unique to the Amherstburg Formation. Lithologically, the Filer ranges from a fine-grained, carbonate-cemented, supermature quartzarenite at its upper shoreface facies, to a texturally-inverted sandy carbonate at its lagoonal facies. Facies distribution was …
Geology And Petroleum Potential Of The Hay Creek Anticline, North-Central Oregon, Stephen I. Wareham
Geology And Petroleum Potential Of The Hay Creek Anticline, North-Central Oregon, Stephen I. Wareham
Loma Linda University Electronic Theses, Dissertations & Projects
For many years it has been reported that the core of the Hay Creek Anticline exposes metamorphic rocks of Paleozoic or Mesozoic age. On closer study it was found that these rocks consist of only slightly metamorphosed black to dark grey siltstones and sandstones with less abundant chert pebble conglomerate and recrystallized limestone. The sequence is here informally named "Hay Creek Formation." Calcareous nannofossils recovered and identified from the limestone yielded an age of early to middle Eocene.
The depositional environment of the "Hay Creek Formation" is interpreted to be a submarine turbidite fan. Siltstones were deposited as pelagic rain …
Tephrostratigraphy Of The Middle Eocene Chumstick Formation, Cascade Range, Douglas County, Washington, Matthew John Mcclincy
Tephrostratigraphy Of The Middle Eocene Chumstick Formation, Cascade Range, Douglas County, Washington, Matthew John Mcclincy
Dissertations and Theses
This study outlines the ash (tuff) bed stratigraphy (tephrostratigraphy) in the middle Eocene Chumstick Formation of central Washington. The tuff beds provide local marker beds enabling interpretation of the stratigraphy and structure of the formation. The chemical signature of these units provides the basis on which the units can be traced over broad areas in the basin of deposition. Correlations of tuff beds were obtained over distances of 41 km.
The tephrostratigraphy of the Chumstick Formation consists of nineteen tuff marker beds. Seventeen of these units are chemically characterized in this study. Ten elements were used to fingerprint these tuff …
Long-Term Tributary Adjustments To Base-Level Lowering, Northern Rio Grande Rift, New Mexico, Keith Irvin Kelson
Long-Term Tributary Adjustments To Base-Level Lowering, Northern Rio Grande Rift, New Mexico, Keith Irvin Kelson
Earth and Planetary Sciences ETDs
ABSTRACT
Late Cenozoic (post-3.6 Ma) entrenchment of the Rio Grande in northern New Mexico formed a gorge over 200 m deep and induced different types of fluvial adjustments on two adjacent tributaries. Rio Hondo (drainage area 181 km2 ) has a concave-up long-profile and flows in a narrow valley containing six Quaternary strath terraces with parallel long-profiles grading to the Rio Grande. In contrast, Rio Pueblo de Taos (drainage area 1080 km2 ) has a convex-up long-profile and flows in a wide valley containing four strath terraces which do not grade to the Rio Grande. Although smaller in drainage area, …
A Model For Assessing The Visual Resources Of River Basins As An Aid To Making Landuse Planning Decisions, Thomas J. Nieman, Diane S. Meshako, David Walters, Molly M. Davis, Cindy C. Elliot
A Model For Assessing The Visual Resources Of River Basins As An Aid To Making Landuse Planning Decisions, Thomas J. Nieman, Diane S. Meshako, David Walters, Molly M. Davis, Cindy C. Elliot
KWRRI Research Reports
The visual quality of a river basin and its associated properties can be identified, evaluated and integrated into the landscape planning process. The model developed provides a quantitative methodology for determining visual quality on the basis of available Geographic Information System factors. These factors are utilized to develop the preference attributes, COLOR, FORM, TEXTURE and LINE, which are associated with the assessment of visual quality. The preference attributes are then combined through a decision making process into a continuum of DISTINCTIVE, GOOD, AVERAGE and MINIMAL visual quality and is expressed digitally in map format. By providing visual quality information in …
Benthic Foraminifera And Paleoenvironments Of The Arcola Limestone Member Mooreville Formation (Campanian) In Eastern Mississippi And Western Alabama, Julia K. Palmer
Benthic Foraminifera And Paleoenvironments Of The Arcola Limestone Member Mooreville Formation (Campanian) In Eastern Mississippi And Western Alabama, Julia K. Palmer
OES Theses and Dissertations
Eighty-one species of benthic foraminifera have been recovered from chalky marls of the upper Mooreville Formation including the Arcola Limestone Member, and the basal Demopolis Formation located in five sections in east-central Mississippi and west-central Alabama. These species have been described and seventy-nine illustrated. Analysis of the environmental or depth preferences of abundant species together with planktonic percentages and benthic species diversity, indicates that the chalky marls were deposited in a broad shallow shelf sea (subtidal conditions less than 100m) greatly influenced by open ocean conditions. The benthic assemblage is composed of a mixture of typically neritic and bathyal species …
Groundwater Levels In Nebraska, 1985, Michael J. Ellis, Darryll T. Pederson
Groundwater Levels In Nebraska, 1985, Michael J. Ellis, Darryll T. Pederson
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Factors Affecting Epithecal Growth Lines In Four Coral Species, With Paleontological Implications, Jean-Luc Liénard
Factors Affecting Epithecal Growth Lines In Four Coral Species, With Paleontological Implications, Jean-Luc Liénard
Loma Linda University Electronic Theses, Dissertations & Projects
The number of epithecal (external) growth lines was surveyed over 124 days for Montastrea annularis growing at different depths (3.5 m to 61 m). There was a significant (P< .01) decrease in the number of lines with depth. Although the linear regression is significant, there is evidence for a logarithmic or quadratic relationship, and more data from greater depths are needed to determine which of these gives a better fit.
The number of growth lines formed during light-dark cycles of 16, 24 and 32 hours were compared for M. annularis, M. cavernosa, Porites astreoides and Tubastrea aurea. The variability among colonies from the same species was in many cases more significant than that among light treatments. This is a serious problem for anyone counting lines in corals, especially from a few specimens; therefore conclusions based on such counts seem hazardous on …
Arnoldia Kuesii, A New Juvenile Fernlike Plant From The Lower Permian Of New Mexico, William D. Tidwell, Sidney Ash
Arnoldia Kuesii, A New Juvenile Fernlike Plant From The Lower Permian Of New Mexico, William D. Tidwell, Sidney Ash
Faculty Publications
A nearly complete juvenile fernlike plant is described here from Lower Permian rocks of New Mexico. The fossil consists of a horizontal rhizome with roots, a short thick upright aerial branch, and a tuft of dimorphic leaves. It is assigned to Arnodia kuesii gen. et sp. n. and appears to be the first juvenile fernlike plant known from the Upper Paleozoic. Abundant palynomorphs and other plant fossils associated with the fossil indicate that it is Early Permian in age.
The Engineering Geology Of The Fountain Landslide, Hood River County, Oregon, Susanne L. D'Agnese
The Engineering Geology Of The Fountain Landslide, Hood River County, Oregon, Susanne L. D'Agnese
Dissertations and Theses
The Fountain Landslide located along I-84, five kilometers east of Cascade Locks, Oregon has moved periodically for over thirty years. Aerial photographs taken prior to recorded movement of the landslide show the headscarp of a large preexisting landslide. In 1952 a cut was made into the toe of the landslide to straighten Highway 30. The recorded movement history begins at this time. Stabilization procedures in the late 1950's focused on dewatering the slide mass. Movement had nearly stopped by 1957. A deeper cut was made into the toe of the landslide in 1966 to widen the highway to the four-laned …
Dynamic Deformation Of Volcanic Ejecta From The Toba Caldera: Possible Relevance To Cretaceous/Tertiary Boundary Phenomena, Neville L. Carter, Charles B. Officer, Craig A. Chesner, William I. Rose
Dynamic Deformation Of Volcanic Ejecta From The Toba Caldera: Possible Relevance To Cretaceous/Tertiary Boundary Phenomena, Neville L. Carter, Charles B. Officer, Craig A. Chesner, William I. Rose
Department of Geological and Mining Engineering and Sciences Publications
Plagioclase and biotite phenocrysts in ignimbrites erupted from the Toba caldera, Sumatra, show microstructures and textures indicative of shock stress levels higher than 10 GPa. Strong dynamic deformation has resulted in intense kinking in biotite and, with increasing shock intensity, the development in plagioclase of planar features, shock mosaicism, incipient recrystallization, and possible partial melting. Microstructures in quartz indicative of strong shock deformation are rare, however, and many shock lamellae, if formed, may have healed during post-shock residence in the hot ignimbrite; they might be preserved in ash falls. Peak shock stresses from explosive silicic volcanism and other endogenous processes …
Hydrogeology Of Water-Quality Monitoring Transects In An Irrigated Area Of The Eastern Sand Hills, Nebraska, Dennis R. Lawton
Hydrogeology Of Water-Quality Monitoring Transects In An Irrigated Area Of The Eastern Sand Hills, Nebraska, Dennis R. Lawton
Conservation and Survey Division: Faculty and Staff Publications
No abstract provided.
Diagenesis And Water Chemistry Of The Woodbine Group In The East Texas Basin, Helmuth Victor Wuerch
Diagenesis And Water Chemistry Of The Woodbine Group In The East Texas Basin, Helmuth Victor Wuerch
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Petrographic and SEM study of flu vial-deltaic sections of the Woodbine Group in the East Texas Basin indicates that authigenic mineral suites are controlled, in part, by the presence of organic-rich matrix.
During early, precompaction diagenesis, organic matter supplied the metabolic fuel required by sulfate-reducing bacteria to reduce sulfate in depositional waters ultimately to pyrite. With burial the sulfate supply was ultimately exhausted, and bicarbonate activity thereafter controlled the precipitation of siderite and Fe-calcite.
Matrix material supplied the components and reaction sites for the most import ant porosity-occluding reaction: kaolinite --> Fe,M g chlorite. Matrix physically inhibited the growth of …
Petrology Of The Late Proterozoic(?) - Early Cambrian Arumbera Sandstone And The Late Proterozoic Quandong Conglomerate, East-Central Amadeus Basin, Central Australia, Johnnie O. Phillips
Petrology Of The Late Proterozoic(?) - Early Cambrian Arumbera Sandstone And The Late Proterozoic Quandong Conglomerate, East-Central Amadeus Basin, Central Australia, Johnnie O. Phillips
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Throughout the James Ranges and Gardiner Range the Arumbera Sandstone forms prominent strike ridges with distinctive dark reddish slopes and pale red to orange-white cliffs. Because of their lithologic and stratigraphic similarities, the names Eninta and ''Quandong" for these units should be suppressed in favor of the name of Arumbera Sandstone, which has precedence. The stratigraphic and lithologic differences observed between the Quandong Conglomerate in the type locality and the Arumbera Sandstone in the study area suggest that these units are not equivalent. Similarites with the Areyonga Formation suggest the Quandong Conglomerate could be part of the Areyonga Formation.
Lithofacies …
Sedimentological And Foraminiferal Characterization Of A Holocene Island Slope (130-240m), North Jamaica, Craig V. Nelson
Sedimentological And Foraminiferal Characterization Of A Holocene Island Slope (130-240m), North Jamaica, Craig V. Nelson
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Recent carbonate sediments from (133-236m) on the northern Jamaican island slope are significantly different from shallower reef zones (l-70m) in grain constituents, textural parameters, and foraminiferal assemblages. The island slope sediment is dominated by coral fragments, calcareous algae, Halimeda plates, and foraminiferal tests. The sediment is characteristically poorly-sorted, nearly-symmetrically skewed, and mesokurtic, with a mean grain size in the fine sand range. Mineralogically, the sediment is predominantly aragonite (66%) and high-Mg calcite (22%), with some calcite (8%), and minor amounts of clays and other insoluble minerals (4%).
Q-mode cluster analyses of sediment constituents, textural parameters, and foraminiferal species and larger …