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SEDIMENTATION RATE DETERMINATIONS ON OCEAN BOTTOM CORES BY GAMMA-RAY SPECTROMETRYUnknown Date (has links)
Source: Dissertation Abstracts International, Volume: 28-07, Section: B, page: 2904. / Thesis (Ph.D.)--The Florida State University, 1967.
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STRATIGRAPHY AND PETROLOGY OF THE BASAL CAMBRIAN CHILHOWEE GROUP IN CENTRAL-EASTERN AND SOUTHEASTERN TENNESSEEUnknown Date (has links)
Source: Dissertation Abstracts International, Volume: 28-07, Section: B, page: 2909. / Thesis (Ph.D.)--The Florida State University, 1967.
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ATTEMPTED CORRELATION OF BOND NATURE WITH ANISOTROPIC ANION POLARIZABILITY IN RUTILE-TYPE MINERALSUnknown Date (has links)
Source: Dissertation Abstracts International, Volume: 28-07, Section: B, page: 2903. / Thesis (Ph.D.)--The Florida State University, 1967.
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GEOCHEMISTRY, MINERALOGY AND ORIGIN OF MESOZOIC DIABASE DIKES OF VIRGINIAUnknown Date (has links)
Mesozoic diabase dikes of Virginia, part of the Eastern North America dike swarm, display a wide variety of mineralogical and chemical characteristics, representative of most mineralogical and chemical groups described from other portions of the swarm. The large sample population is used for this study (nearly 200 samples total) has revealed that the previously described diabase groups (excepting HTQ) actually belong to part of a continuum of compositions generated predominantly by a low-pressure fractionation sequence. / Petrographically, the diabases can be classified into three groups, which also display some geochemical distinctions. The OSB group is characterized by abundant olivine as a phenocryst and/or groundmass component and the presence of a Cr-Al spinel as inclusions in olivine or as part of the groundmass assemblage. Chemically this group is the most primitive. The GRB-group samples have the most evolved chemistries and are recognized by the presence of interstitial granophyre and a phenocryst assemblage of plagioclase + clinopyroxene +/- olivine. The chemically intermediate SGA group lacks granophyre and spinel and is dominated by plagioclase and olivine phenocrysts. / Major- and compatible trace-element geochemical trends show that typical SGA-group samples can be derived by crystallization of approximately 17-20% olivine with minor spinel from a magma similar in composition to primitive OSB-group samples. Additional crystallization of 60-70% olivine + plagioclase + clinopyroxene (15:60:24) can yield the most evolved GRB-group compositions. / OSB-group samples with compositions that are primitive with respect to major- and compatible trace-element chemistries display a wide and continuous range of incompatible trace-element (ITE) contents and ratios. While some of this variation may be the result of varying degrees of partial melting of the source region, the range of observed ITE ratios requires a source region that is heterogeneous with respect to these elements. / Source: Dissertation Abstracts International, Volume: 48-03, Section: B, page: 0682. / Thesis (Ph.D.)--The Florida State University, 1987.
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The Late Holocene development of St. Joseph SpitUnknown Date (has links)
Reconstruction of the supratidal history of St. Joseph peninsula was approached on a granulometric, geometric, and internal-structure basis. / Textural and geomorphic evidences supports the hypothesis that the peninsula was integrated from two former barrier islands through subtidal aggradation as well as seaward and lateral progradation. The granulometric characteristics of the platform and subaerial sediment suite suggest a previous history of river and then beach transport. / Salinity-biotopes from benthic foraminifera in the sampled core connote a gradual sea level rise accompanying platform aggradation in the Late Holocene. The terminal stages of this sea level rise were characterized by small-scale fluctuations. / The pre-Holocene topography suggests that the Cape San Blas area represents the site of the earliest stages of platform aggradation. The oldest areas on the spit appear to have emerged at least 1,500 years ago. The Cape San Blas tombolo first emerged and hence linked up with Cape Can Blas about 1,000 years ago. Beach ridge growth rates in ridge set "nf" suggest 700 years of progradation history north of Eagle Harbor. / Two sediment sources were inferred from this study: Cape San Blas and Bell shoal. / Transverse transport was more important earlier in the history of the spit, but littoral drift later became dominant. North of Eagle Harbor, the spit developed under decreasing wave energy conditions. / Beach ridge origin on St. Joseph spit based on internal structure alone is equivocal. Both eolian and non-eolian strata were observed although the latter were more widespread. / Certain previous work has also shown the internal structure of ridges can form by vegetative trapping. / On the backshore of prograding beaches where the subaerial stages of beach ridge history begins, eolian and swash strata are inseparable. Beach ridges are therefore considered to be examples of convergent landforms, evolving initially from swash overtopping during elevated water levels. / Some of the eolian traits appear to come from pulses of eolian settling of "dust" as indicated by the tail-of-fines. / The standard deviation and the tail-of-fines were the most diagnostic criteria recognizing eolian traits. / In general, sediment in the study area revealed an environmental succession from fluvial to beach and (finally) to dune. / Source: Dissertation Abstracts International, Volume: 52-08, Section: B, page: 4088. / Major Professor: William Tanner. / Thesis (Ph.D.)--The Florida State University, 1991.
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PALEOGENE ABYSSAL ENVIRONMENTS OF THE EASTERN SOUTH ATLANTIC: A FORAMINIFERAL STUDYUnknown Date (has links)
Paleogene abyssal environments in the eastern South Atlantic were analyzed with respect to stable isotopes, population dynamics, and patterns of dissolution. Combined results of these studies indicate three times of change in the abyssal environment: the Paleocene-Eocene boundary, the middle-late Eocene boundary, and the Eocene-Oligocene boundary. / An extinction event occurred at the end of the Paleocene which removed many species from the benthic foraminiferal population. This event was cosmopolitan and may have been the result of altered circulation patterns due to the separation of Australia and Antarctica or the initiation of subsequent climate cooling. / In the middle Eocene the benthic fauna oscillated between opportunist taxa typical of the early Paleogene and generalist species which were dominant in the late Eocene. The middle Eocene shifts in assemblage components appear to be due to pulses of cold, dense bottom water from polar regions. / A decisive shift from opportunist taxa toward a generalist assemblage occurs in the late Eocene. Species originations are high in the late Eocene which results in high species diversity prior to the Eocene-Oligocene boundary. In the early late Eocene a 5(DEGREES)C drop in bottom water temperature is interpreted from a (delta)('18)O shift of 1.2('o)/oo. This temperature decline may have been the result of the continuous flow of polar bottom water. / An additional shift in ('18)O values occurred at the Eocene-Oligocene boundary indicating a temperature drop of 4(DEGREES)C. This may be a result of the full development of a psychrospheric ocean and initiation of intensification of AABW flow. The extinction rate rose sharply at the Eocene-Oligocene boundary causing lowered diversity values in the earliest Oligocene. All significant originations or migrations into the Angola Basin abyssal environment cease at the end of the Eocene; this condition, which persists until the end of the Oligocene, indicates unfavorable conditions in the deep sea during this time. / Dissolution studies suggest high CCD and lysocline positions for the late Eocene and Miocene. The Oligocene CCD is depressed possibly due to increased productivity in a well mixed ocean. / Source: Dissertation Abstracts International, Volume: 44-01, Section: B, page: 0085. / Thesis (Ph.D.)--The Florida State University, 1983.
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Mobilization of the radionuclides radon, thorium and radium in groundwater by the alpha-recoil mechanismUnknown Date (has links)
Ion motions, involving atomic collisions within the solid and fluid phases are simulated using a three-dimensional Monte Carlo algorithm, which is based on the principles of ion scattering and electronic interactions with the moving ion. The recoil range distributions of radon, thorium and radium are calculated from this algorithm, which are then used to compute the emanating powers of these elements for synthetic porous media. The synthetic porous media are generated using the turning bands method, from which a fractal dimension of the recoil surface area can be obtained. The depletions of thorium and radium from the solid phase are calculated based on the effective recoil surface area, and expressions describing emanation of daughter ions through successive recoil, from $\rm\sp{238}U$ to $\rm\sp{222}Rn$ and from $\rm\sp{232}Th$ to $\rm\sp{220}Rn$ are developed. The recoil emanation-rate ratios under conditions of zero adsorption and complete adsorption of radon, thorium and radium are calculated for a saturated medium. For the isotopes within the same decay chain, it is predicted that the daughters usually should have higher measured radioactivities than the parents. It is found that the recoil supply rates and emanation rates increase slightly with porosities because the effective recoil surface area increase with porosities. Recoil release rates under varying degrees of saturation are also examined. It is found that the recoil emanation rate under saturated conditions is much larger than the emanation rate under dry conditions due to the intense embedding in a dry sample. For a moisture content of 10% or more, the recoil emanation rates quickly approach the emanation rate associated with saturated conditions, and with 30$\sim$40% moisture content, the emanation rate essentially equals that under saturated conditions. A recoil experiment was conducted to / demonstrate that the recoil effect does occur in a natural sample, and could cause radioactive depletion on the sample surface. / Source: Dissertation Abstracts International, Volume: 56-07, Section: B, page: 3658. / Major Professor: David J. Furbish. / Thesis (Ph.D.)--The Florida State University, 1995.
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FACTORS INFLUENCING OCCURRENCE OF PHOSPHORITE IN GEORGIA'S COASTAL PLAIN SEDIMENTSUnknown Date (has links)
Source: Dissertation Abstracts International, Volume: 32-01, Section: B, page: 0378. / Thesis (Ph.D.)--The Florida State University, 1970.
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THE ARAGONITE-CALCITE TRANSFORMATIONUnknown Date (has links)
Source: Dissertation Abstracts International, Volume: 30-12, Section: B, page: 5555. / Thesis (Ph.D.)--The Florida State University, 1969.
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THE SEDIMENTS AND SEDIMENTARY PROCESSES OF THE EASTERN MISSISSIPPI CONE, GULF OF MEXICOUnknown Date (has links)
Source: Dissertation Abstracts International, Volume: 31-05, Section: B, page: 2764. / Thesis (Ph.D.)--The Florida State University, 1970.
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