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 21 for “"early diagenesis"”.
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Seagrass-Mediated Carbonate Dissolution and Early Diagenesis in Bahamas Bank Sediments
… seagrasses play in carbonate dissolution and early diagenesis of Bahamas Bank sediments. Three aspects of this problem are addressed: (1) stable carbon isotopes as an indicator of early diagenesis of carbonates, using results of a field study; (2) carbonate dissolution stoichiometry and …
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Investigating the Fate of Mg-bearing Calcium Carbonates During Early Diagenesis
… carbonates under conditions that approximate early diagenesis and burial. The study compares Mg-incorporation in carbonate precipitated from a solution with the composition of an idealized Silurian seawater in the presence of functionalized (-COOH) organic matter followed by moderate increases …
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Stratigraphy, Sedimentology and Early Diagenesis of Pennsylvanian-Permian Mixed Carbonate-Siliciclastic Cyclothems, SW Ellesmere Island, Nunavut
… evidence of subaerial exposure and meteoric diagenesis, which played a role in secondary porosity development, thus contributing to the economic potential of this succession.
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Investigations on sedimentology and early diagenesis in shallow-water warm-temperate to tropical miocene carbonates : a case study from Northern Sardinia, Italy
… and document the existence and significance of early diagenesis in this carbonate system, especially the diagenetic history, which reflects the diagenetic potential in terms of skeletal mineralogy. The motivation behind the present study was to investigate the role that early cementation has …
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The Lower Carboniferous (Chadian-Brigantian) geology of shallow marine carbonate rocks in the central and southeast Irish Midlands and the Wexford Outlier
… reveals that the style of sedimentation and early diagenesis substantially influenced the late diagenesis, and the characteristics of Zn-Pb mineralization in the Rathdowney Trend. The study also demonstrates the fundamental difference in the style of sedimentation and tectonic history between …
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Diagenesis of the B chalk, B marl, and Fort Hays member of the Niobrara Formation, Denver Basin, Colorado
… (δ18O) values as the system became more closed. Early diagenesis of the Fort Hays Member was supported by little evidence of compaction or pressure solution, as well as early lithification of the carbonate mud. As a result, the Fort Hays presented more enriched δ18O values than were seen in the …
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Controls on mineralisation in the Cadeby formation (lower magnesian linestone)
… in voids resultant from evaporite dissolution. Diagenesis is complex with different mechanisms of dolomitization, evaporite replacement and dedolomitization; mineralization is related to early diagenesis at some localities. The spatial occurrences of mineralized localities suggests an underlying …
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Provenance, redox conditions, and diagenesis of shales in Chang 7 member of Upper Triassic Yanchang Formation, Ordos Basin, China
… cracks in the shales. Results show that in early diagenesis, unconsolidated mud was expanded open by escaping gases produced during organic matter maturation under hydrothermal influences. Calcite initially filled the cracks; bitumen and pyrite came in later and occupied the cracks in …
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High-resolution sequence stratigraphy and diagenesis of mixed carbonate/siliciclastic successions.
… successions, using facies and early diagenetic analyses. These are the Upper Jurassic Corallian Group of south Dorset and the Lower Cretaceous lower to middle Ericeira Group of west central Portugal. Early diagenetic analyses (including petrographic, CL, XRD and stable isotope …
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Sequence Stratigraphy and Chemostratigraphy Across the Permo-Triassic Extinction Event, Upper Khuff Carbonates, Ghawar Field, Saudi Arabia
… include the Late Permian upper Khuff C, the Early Triassic Khuff B and the Khuff A sequences, which corrrelate with global cycles. Seven high frequency sequences (HFSs) make up the Changhsingian upper Khuff C. These HFSs are ~400 k.y. duration and probably driven by long term eccentricity. …
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The role of biological production in pleistocene atmospheric carbon dioxide variations and the nitrogen isotope dynamics of the southern ocean
… to the diatoms, that it is invulnerable to early diagenesis, and that its isotopic compositon varies with that of the sinking flux. Paleoceanographic records of diatom-bound N isotopic composition corroborate the conclusion, previously based on bulk sediment isotopic data, that nitrate …
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Paleontology and stratigraphy of the Niobrara Formation (Upper Cretaceous) of eastern North Dakota with emphasis on the calcareous nannoplankton
… to paleobiogeography, the age of the strata, and early diagenesis. Macrofossils include Lingula, ammonites, and four bivalve taxa, including the abundant oyster, Pseudoperna congesta, and fragments and prisms of inoceramids. Trace fossils include non-pyritized burrows (Chondrites) and pyritized …
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Geochemical Analysis of Ironstone Preserved Molluscan Fossils of the Hell Creek Formation (Cretaceous) and Ludlow Member of the Fort Union Formation (Paleogene) of Southwestern North Dakota
… water conditions that may have existed during early diagenesis of the Hell Creek Formation and Ludlow Member. </p>
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Production and preservation of the Arctic sea ice diatom biomarker IP25
… parameters provided new evidence for the early diagenesis of this biomarker. Statistical correlations between some IP25 and Mn/Ti profiles (Station 405b; r = 0.89), that aid determination of the oxygen penetration depth, provided novel evidence for the partial degradation of IP25 (and …
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Investigations on the importance of early diagenetic processes for the mineralogical stabilisation and lithification of heterozoan carbonate assemblages : (Oligo-Miocene, Maltese Islands and Sicily)
… Special emphasis is put on the identification of early, near-seafloor diagenetic processes and on the evaluation of the amount of constructive diagenesis in form of cementation in this diagenetic environment. As study area the Central Mediterranean, the Maltese Islands and Sicily, was chosen. Here …
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Unravelling the impacts of palaeoecology, palaeoenvironment and lithofacies on sedimentary organic NSO compounds
… on the solvent extracts of immature–early mature rock samples from the marine Dynow, Schöneck, Posidonia formations, the lacustrine Wealden Formation, and the terrestrial Waikato and Brunner coal measures. Coals, being the in-situ deposits of terrestrial plant remains, primarily …
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Interaction between ferric hydroxides and dissolved sulfide in anoxic aquifers: Pathway and kinetics of iron and sulfur products formation
… is pyrite. Pyrite formation, as a significant early diagenesis process, plays an undeniable role as a global sink for the elements Fe and S. Therefore, the interaction of ferric iron and sulfide, especially pyrite formation, has been studied for quite a long time. However, questions remain …
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Transport of trace metals in nearshore sediments
… the sediment column of nearshore sediments. The early diagenesis of several first-row transition metals exhibiting a variety of behaviors in the ocean -- Mn, Fe, Co, Ni, and Cu -- has been studied intensively at a site in Buzzards Bay, Mass. By limiting the study to a single site, independent …
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