Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 44 for “"geologic time"”.
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HOW DO NOVICE AND EXPERT LEARNERS REPRESENT, UNDERSTAND, AND DISCUSS GEOLOGIC TIME?
… novice and expert learners constructed for the geologic timescale. Learners engaged in a three-part activity. The purpose was to compare novice learners’ representations to those of expert learners. This provided insight into the similarities and differences between their strategies for event …
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The Influence of Root Geometry on Soil Cohesion and Anchoring Ability through Geologic Time
Vegetation has become ubiquitous among most modern landscapes. However, for much of the Earth’s history, land plants were absent. Their rapid diversification throughout the Devonian and Carboniferous brought about a massive shift in geomorphology and landscape evolution. Complex rooting structures …
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Morphometric approaches to systematics and microevolution: Applications from paleozoic bryozoa
Documentation of microevolution through geologic time is a significant paleontologic contribution to evolutionary biology. Paleomicroevolutionary studies require accurate stratigraphic resolution over a large geographic area, through changing environments, over a sustained period of time, with an …
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Spatial variability in modern brachiopod assemblages: paleoecological and geochemical implications
… understanding of global patterns through geologic time depends upon multi-scale analyses of spatial variation within narrow temporal intervals. This work investigates geochemical and paleoecological patterns in modern brachiopod faunas which may serve as analogues for ancient brachiopod …
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Basin Evolution and Slope System Dynamics of the Cretaceous Magallanes Basin, Chilean Patagonia
… transfer from continents to ocean basins over geologic time scales. This isespecially true in basins associated with regions of active tectonism, where loss or alteration ofsediment source terrains leave submarine basin deposits as the only record of the tectonic and cli-matic forcings that …
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Quantitative Models of Fluid Flow, Chemical Reaction, and Stable Isotopic Fractionation and Their Application to Sediment Diagenesis and Hydrothermal Alteration
… transfer. The model is formulated and solved in geologic-time and basin distance scales, and can be therefore applied to study basin-wide diagenesis related to long-distance fluid migration. The model integrates predicted groundwater flow patterns with the reaction path modeling; this approach …
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Molecular characterization and effect of diagenesis and maturation of melanin in the fossil record
… with the high preservation potential over geologic time scales; it is found in virtually all extant organisms, from bacteria to humans.
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Charcoal chemistry : developing a proxy for paleofire regimes.
Wildfires have occurred over geologic time since the evolution of land plants and affect global biogeochemical cycling and ecosystem processes. Charcoal particles in the geological record may contain information on several aspects of paleowildfire regimes. The fire intensity, the energy produced …
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Biomolecular Controls on Calcium Carbonate Formation by Amorphous and Classical Pathways: Insights from Measurements of Nucleation Rates and Isotope Tracers
… changes in climate and seawater chemistry over geologic time and by recent anthropogenic effects. This dissertation presents the findings from experimental studies of the thermodynamics and kinetics of multiple mineral formation processes, including nucleation and transformation from an …
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Human Verses Mountain: Climbing, Language, and the Liveliness of Stone
… one’s breath, and as a key to the legibility of geologic time.</p>
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Testing the ancient marine redox record from oxygenic photosynthesis to photic zone euxina
… and purple sulfur bacteria biomarkers through geologic time is evaluated to test whether these compounds reflect a water column sulfide signal, which is implicit in their utility as PZE paleoredox proxies. Results from a modern case study underscore the need to consider allochthonous and …
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Testing the ancient marine redox record from oxygenic photosynthesis to photic zone euxina
… and purple sulfur bacteria biomarkers through geologic time is evaluated to test whether these compounds reflect a water column sulfide signal, which is implicit in their utility as PZE paleoredox proxies. Results from a modern case study underscore the need to consider allochthonous and …
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ΘΕΡΜΟΜΗΧΑΝΙΚΗ ΣΥΜΠΕΡΙΦΟΡΑ ΤΗΣ ΛΙΘΟΣΦΑΙΡΑΣ ΣΤΟΝ ΕΛΛΗΝΙΚΟ ΧΩΡΟ
… AND THEIR INTERRELATIONSHIP IN THE COURSE OF THE GEOLOGIC TIME. THEMAIN DATA USED ARE NEOTECTONIC ONES, ABSOLUTE VALUES OF THE EFFECTIVE PRINCIPAL STRESSES MEASURED THROUGH HYDROFRACTURING IN OIL WELLS, THE TECTONIC SUBSIDENCE OF NEOGENE SEDIMENTARY BASINS, TEMPERATURE MEASUREMENTS AND ESTIMATED …
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Experiments on biomarker preservation
… becomes fossilized and which persists through geologic time, are continuing challenges. This is because decay begins immediately after senescence and diagenetic transformations typically continue progressively over millions of years. To this end, in this dissertation, I utilize various …
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Geodynamic Modeling Applied to Venus
… change evolving into resurfacing through geologic time, or large-scale overturn and injection of heat deep into the Venusian mantle.
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The geophysical evolution of impact basins and volcanic structures on Mercury and the Moon
<p>The geologic histories of most terrestrial bodies are dominated by two major processes: meteorite bombardment and volcanism. The forms that the resulting impact craters and volcanic structures take can tell us a great deal about the ways in which these processes occur and about the environment …
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Genetic diversity and distribution of the ringed salamander (Ambystoma annulatum) across multiple spatial scales
… movement of individuals and are variable through time and space. These dynamic processes, such as shifts in temperature and precipitation regimes throughout geologic time, in conjunction with the species physiological constraints are strong regulators of local population dynamics, and thus the …
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Determination of sediment provenance at drift sites using hydrogen isotopes in lipids
… best archive for studying these events through geologic time, but such sites in the open ocean are limited to sediment drift deposits such as the Bermuda Rise in the northwest Atlantic. Using multiple climate proxies in a single core is becoming more common in high-resolution paleoclimate …
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Determination of sediment provenance at drift sites using hydrogen isotopes in lipids
… best archive for studying these events through geologic time, but such sites in the open ocean are limited to sediment drift deposits such as the Bermuda Rise in the northwest Atlantic. Using multiple climate proxies in a single core is becoming more common in high-resolution paleoclimate …
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A PETROLEUM SYSTEM STUDY OF THE CRATONIC WILLISTON BASIN IN NORTH DAKOTA, U.S.A.: THE ROLE OF THE LARAMIDE OROGENY
… are found for every source rock. In this same geologic time an increase in temperature is observed in the North Dakota area, as well as the maximum burial period. Subsidence curves show a slow and long tectonic subsidence period across the basin, with rapid subsidence stages during the …
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