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Articles 391 - 420 of 423
Full-Text Articles in Earth Sciences
Barium And Lithium In Foraminifera: Glacial-Interglacial Changes In The North Atlantic, Jenney M. Hall
Barium And Lithium In Foraminifera: Glacial-Interglacial Changes In The North Atlantic, Jenney M. Hall
LSU Doctoral Dissertations
The trace element content of calcareous foraminifera provides a powerful tool to the study of glacial-interglacial changes in the physical and chemical properties of the ocean. Foraminifera incorporate barium in direct proportion to its concentration in seawater. Using barium as a nutrient proxy, Ba/Ca in benthic Planulina wuellerstorfi is used to reconstruct changes in thermocline ventilation and mid-depth circulation in the North Atlantic during the last glacial and deglacial time. Rivers are concentrated in barium compared to surface seawater. Therefore, barium in planktonic Neogloboquadrina pachyderma is used to identify deglacial meltwater in the Arctic Ocean. Foraminiferal Li/Ca was analyzed to …
Outcrop To Subsurface Stratigraphy Of The Pennsylvanian Hermosa Group Southern Paradox Basin U.S.A., Alan Lee Brown
Outcrop To Subsurface Stratigraphy Of The Pennsylvanian Hermosa Group Southern Paradox Basin U.S.A., Alan Lee Brown
LSU Doctoral Dissertations
Pennsylvanian (Desmoinesian) sedimentary rocks within the Paradox Basin Four Corners area of the western United States afford a unique opportunity to study the development of sedimentary successions in a complex marine to nonmarine depositional setting. The close association of thick intervals of nonmarine fan-delta facies adjacent to and in time equivalent position to marine carbonate-evaporite facies suggests complex relationships between the factors affecting deposition. Development of an effective scheme to differentiate the depositional signatures from within these sedimentary successions is the primary goal of this study. To achieve this goal, two objectives were pursued. The first was to calibrate the …
A Palynological Study Of Two Upland Bogs In The Gulf Coastal Plain, Alabama And Mississippi, Linda C. Pace
A Palynological Study Of Two Upland Bogs In The Gulf Coastal Plain, Alabama And Mississippi, Linda C. Pace
LSU Historical Dissertations and Theses
Fewer Quaternary palynological studies have been conducted in the Gulf Coastal Plain of the southeastern United States than In the northern United States and Canada, resulting in major gaps in the pollen record of this region. The existing studies display discrepancies in the chronology of the pine rise, appearance of the modem climatic regime and vegetation, and timing of the Hypsithermal. In order to fill a gap in the paleoecological data network of the Gulf Coastal Plain, pollen analysis, charcoal analysis, and sediment stratigraphic techniques were used to reconstruct the last 6500 years of Sweetbay Bog, Mississippi, and Minamac Bog, …
The Petrology Of The Precambrian Roof Pendants Thompson Peak, Sawtooth Mountains, Idaho, Susan Denise Anderson
The Petrology Of The Precambrian Roof Pendants Thompson Peak, Sawtooth Mountains, Idaho, Susan Denise Anderson
Honors Capstones
No abstract provided.
Role Of Acetic Acid In Siliciclastic Diagenesis: An Experimental Study, Gina Marian Bagnetto Waters
Role Of Acetic Acid In Siliciclastic Diagenesis: An Experimental Study, Gina Marian Bagnetto Waters
Honors Capstones
No abstract provided.
Role Of Acetic Acid In Siliciclastic Diagenesis: An Experimental Study, Gina Bagnetto Waters
Role Of Acetic Acid In Siliciclastic Diagenesis: An Experimental Study, Gina Bagnetto Waters
Honors Capstones
No abstract provided.
Eruption Dynamics And Petrology Of The Most Recent Eruptions Of Nevado Del Ruiz Volcano, Colombia, South America, Richard Henry Young
Eruption Dynamics And Petrology Of The Most Recent Eruptions Of Nevado Del Ruiz Volcano, Colombia, South America, Richard Henry Young
LSU Historical Dissertations and Theses
Field measurements and petrographic analyses of pumices from the most recent tephra deposits of Nevado del Ruiz volcano provide a context in which to view the disastrous eruption of 13 November, 1985 (R0). The pumices are all crystal-rich, two-pyroxene andesites to dacites with whole rock SiO2 contents of 62 - 66 wt.%, and magma water contents estimated to be between 1 - 4 wt.%. The 1985 tephra has greater petrologic diversity than earlier deposits which may be related to an input of a hotter, more basic magma into the Ruiz system, as suggested by xenocrystic olivine which is most …
Geology, Volcanology, And Petrology Of Cerro Bravo, A Young, Dactic, Stratovolcano In West-Central Colombia, David Tondl Lescinsky
Geology, Volcanology, And Petrology Of Cerro Bravo, A Young, Dactic, Stratovolcano In West-Central Colombia, David Tondl Lescinsky
LSU Historical Dissertations and Theses
The northernmost active Andean volcano, Cerro Bravo is a small, young, and very explosive stratovolcano. Cerro Bravo has produced voluminous tephra deposits, that are found> 30 km away, as well as, pumice flow deposits, block and ash flow deposits, and high-aspect lava flows, which are found proximally to the volcano. There have been eight episodes of activity during the past 6250±110 years (Herd, 1982), with the most recent <200 years ago and the present being a period of quiescence with no visible activity or thermal manifestations. Stratigraphic relationships suggest the occurrence of an initial explosive phase and a concluding effusive phase of activity during individual episodes. The products of volcanic activity at Cerro Bravo are a chemically and mineralogically monotonous suite of medium-K dacite and high-silica andesite (59.2- 67.5% SiO2 pumices and lavas. The dominant phenocrysts present are plagioclase and hornblende (oxyhomblende in lavas) with lesser quantities of orthopyroxene, titanomagnetite, and rare augite and biotite also present. Petrology and eruption dynamics …200>
Benthic Foraminiferal Assemblages From Mexican Continental Shelves, Maria De La Luz Mata
Benthic Foraminiferal Assemblages From Mexican Continental Shelves, Maria De La Luz Mata
LSU Historical Dissertations and Theses
The recent benthic foraminifera 1 fauna of the continental margins of Mexico (Gulf of Campeche and Gulf of Tehuantepec) was studied. Surficial sediment samples (lOcc) were collected using a Shipeck dredge and were stained with Sudan Black "B" in order to differentiate the living fauna from the death assemblage. In the 41 samples from the Gulf of Campeche, 279 species were found in the total assemblage in water depths ranging from 9 to 586 m. In the 22 samples in the Gulf of Tehuantepec, 132 species were identified from the total assemblage in water depths of 20 to 180 m. …
Stratigraphy, Sedimentary Petrology, And Depositional Environments Of Tillite In The Upper Precambrian Mount Rogers Formation, Virginia, Richard L. Rexroad
Stratigraphy, Sedimentary Petrology, And Depositional Environments Of Tillite In The Upper Precambrian Mount Rogers Formation, Virginia, Richard L. Rexroad
LSU Historical Dissertations and Theses
The upper member of the upper Precambrian Mount Rogers Formation of southwestern Virginia includes thick units of massive conglomeratic mudstone Interpreted as tillite (Rankin, 1970; Blondeau and Lowe, 1972; Blondeau, 1975; Schwab, 1976). The tillite is composed of unsorted angular plutonic, metamorphic, volcanic, and sedimentary rock fragments enclosed within a matrix of sandy hematitic mudstone. The tillite is interbedded with arkosic sandstone, argillite, and conglomerate. Sedimentary structures and textures of these units suggest deposition by glaciers which protruded from land into a standing body of water as floating ice. Glacial drift was deposited in a large body of water, probably …
Sedimentation And Stratigraphy Of The Mount Rogers Formation, Virginia, Kenneth Morris Blondeau
Sedimentation And Stratigraphy Of The Mount Rogers Formation, Virginia, Kenneth Morris Blondeau
LSU Historical Dissertations and Theses
The Mount Rogers Formation of southwestern Virginia is a thick, upper Precambrian sequence of interbedded conglomeratic mudstones, rhythmically layered argillites, arkosic sandstones and conglomerates, polymict conglomerates, and associated rhyolitic and latitic flows and pyroclastics. The conglomeratic mudstone consists of unsorted, angular to sub rounded grains, ranging in size from silt up to boulders one meter in diameter, enclosed within a fine-grained hematitic matrix or cement. The rhythmically layered argillite is made up of thin, alternating couplets of light, very fine-grained sandstone or siltstone grading upward into dark red argillite. Many of the couplets contain "outsized" exotic clasts which penetrate and …
Facies Analysis; Fredericksburg Limestones; Callahan Divide, Texas, Andre Louis Boutte
Facies Analysis; Fredericksburg Limestones; Callahan Divide, Texas, Andre Louis Boutte
LSU Historical Dissertations and Theses
During Fredericksburg (Early Cretaceous) time the entire Callahan Divide area of west-central Texas was the site of clayey, lime-mud accumulation in a normal-marine, shallow-shelf environment. Lateral homogeneity of the quiet-water environment was soon interrupted locally by the deposition of bioclastic lime-sands in a linear, highly agitated shoal-zone coinciding with a portion of the axis of a regional, positive, Paleozoic structural feature known as the Concho Arch. Localized shoal conditions persisted throughout most of Fredericksburg time and resulted in the deposition of a thick sequence of grainstones and packstones collectively referred to in this paper as the Callahan Complex. Numerous diastems …
The Spotted Horse Coal Field, Sheridan And Campbell Counties, Wyoming., Wilds W. Olive
The Spotted Horse Coal Field, Sheridan And Campbell Counties, Wyoming., Wilds W. Olive
LSU Historical Dissertations and Theses
No abstract provided.
Correlation Of The Miocene Of The Florida Panhandle With The Western And Central Gulf States., Harbans Singh Puri
Correlation Of The Miocene Of The Florida Panhandle With The Western And Central Gulf States., Harbans Singh Puri
LSU Historical Dissertations and Theses
No abstract provided.
Pleistocene Terraces Along The Brazos And Wichita Rivers, Central And North-Central Texas., Fred Lee Stricklin
Pleistocene Terraces Along The Brazos And Wichita Rivers, Central And North-Central Texas., Fred Lee Stricklin
LSU Historical Dissertations and Theses
No abstract provided.
Geology Of Ouachita Parish, Louisiana., Kia Kang Wang
Geology Of Ouachita Parish, Louisiana., Kia Kang Wang
LSU Historical Dissertations and Theses
No abstract provided.
Recent Foraminiferal Faunules From The Louisiana Gulf Coast., Harold Veral Andersen
Recent Foraminiferal Faunules From The Louisiana Gulf Coast., Harold Veral Andersen
LSU Historical Dissertations and Theses
No abstract provided.
Mudlumps At The Mouths Of The Mississippi River., James P. Morgan
Mudlumps At The Mouths Of The Mississippi River., James P. Morgan
LSU Historical Dissertations and Theses
No abstract provided.
A Petrographic Study Of The Eocene Jackson Group Of Mississippi And Adjacent Areas., Ming-Shan Sun
A Petrographic Study Of The Eocene Jackson Group Of Mississippi And Adjacent Areas., Ming-Shan Sun
LSU Historical Dissertations and Theses
No abstract provided.
Some Physical And Chemical Properties Of Loess Deposits In The Lower Mississippi Valley., Ellis Louis Krinitzsky
Some Physical And Chemical Properties Of Loess Deposits In The Lower Mississippi Valley., Ellis Louis Krinitzsky
LSU Historical Dissertations and Theses
This study presents a general picture of loess in the Lower Mississippi Valley. Loess is recognized as unstratified, calcareous, slightly plastic, porous loam with an average grain size distribution between 0.05 and 0.01mm. diameter. Materials meeting this definition but lacking in calcium carbonate are termed "leached loess" when in association with loess and "brown loam" when not in association with loess.
Loess has been found to occur chiefly as pseudo-anticlinal caps on hills. It is mapped as occurring within an area averaging 10 to 15 miles in width extending from southern Illinois southward along the eastern walls of the Lower …
Quaternary Geology Of Southeast Texas., Hugh Allen Bernard
Quaternary Geology Of Southeast Texas., Hugh Allen Bernard
LSU Historical Dissertations and Theses
No abstract provided.
Piedmont Interstream Surfaces Of The Colorado Springs Region., Benjamin Almon Tator
Piedmont Interstream Surfaces Of The Colorado Springs Region., Benjamin Almon Tator
LSU Historical Dissertations and Theses
No abstract provided.
Pennsylvanian Stratigraphy Of The Colorado Springs Quadrangle, Colorado., Kenneth Phelps Mclaughlin
Pennsylvanian Stratigraphy Of The Colorado Springs Quadrangle, Colorado., Kenneth Phelps Mclaughlin
LSU Historical Dissertations and Theses
No abstract provided.
A Study Of Deep-Seated Domes Of South Louisiana., William Edwin Wallace
A Study Of Deep-Seated Domes Of South Louisiana., William Edwin Wallace
LSU Historical Dissertations and Theses
No abstract provided.
Geology Of Webster Parish., James Littell Martin
Geology Of Webster Parish., James Littell Martin
LSU Historical Dissertations and Theses
No abstract provided.
The Physiography Of Beauregard And Allen Parishes., Wilbur Charles Holland
The Physiography Of Beauregard And Allen Parishes., Wilbur Charles Holland
LSU Historical Dissertations and Theses
No abstract provided.
The Geology Of The Claiborne (Eocene) Group Of Mississippi As Far North As Grenada County., Emil Paul Thomas
The Geology Of The Claiborne (Eocene) Group Of Mississippi As Far North As Grenada County., Emil Paul Thomas
LSU Historical Dissertations and Theses
No abstract provided.
Geology Of Desoto And Red River Parishes, Louisiana., Grover E. Murray
Geology Of Desoto And Red River Parishes, Louisiana., Grover E. Murray
LSU Historical Dissertations and Theses
No abstract provided.
Geology Of Holmes And Washington Counties, Florida., Robert O. Vernon
Geology Of Holmes And Washington Counties, Florida., Robert O. Vernon
LSU Historical Dissertations and Theses
No abstract provided.
Louisiana Cane River Eocene Foraminifera., Keith Morgan Hussey
Louisiana Cane River Eocene Foraminifera., Keith Morgan Hussey
LSU Historical Dissertations and Theses
No abstract provided.