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 10 of 10 for “"high Mg calcite"”.
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Cement types and cementation patterns of Middle Ordovician ramp- to-basin carbonates, Virginia
… basin bordered on the southeast by tectonic highlands. Marine, turbid cements include neospar, bladed and turbid rim cements; they are associated with synsedimentary hardgrounds and erosional surfaces. Neospar cement is isopachous and locally botryoidal, and is neomorphic after acicular and …
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Investigating the Fate of Mg-bearing Calcium Carbonates During Early Diagenesis
… and if the presence of COM further facilitates Mg incorporation into calcium 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 …
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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
… changes, marine early syn-depositional cements (high-Mg calcite), with particular fabrics (e.g. fibrous), gradually contributed to the early lithification of rocks, favoring a steepening of the platform relief. The major controls for the shift of the depositional geometry was triggered by the …
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Cementation and dolomitization of Mississippian limestones, Kentucky and Virginia
… in more distal parts of the aquifer caused high-Mg calcite and aragonite grains to be leached, while isotopically light, fine dolomite (δ¹⁸O -1.7 to -6.7 per mil; δ¹³C 2.7 to -5.3 per mil) replaced muddy carbonates in a paleomixing zone. As the aquifer evolved, low-iron, dully luminescent …
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Establishing the Physical Basis for Calcification by Amorphous Pathways
… for the "classical" step-growth process. The Mg content of ACC and calcite is of particular interest as a minor element that is frequently found in ACC and the final crystalline products of calcified skeletons or sediments at significant concentrations. Previous studies of ACC have provided …
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Tracing Carbon Dynamics in the Southern Ocean and Great Barrier Reef Using Strontium and Calcium
… coral reefs, followed by a description of the high-precision Ca and Sr analysis method. The main chapters explore three objectives: examining Ca and Sr cycling in the Southern Ocean (Chapters 3 and 4) and the Great Barrier Reef (Chapter 5). Chapter 3 investigates CaCO3 cycling in the Southern …
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Tracing Carbon Dynamics in the Southern Ocean and Great Barrier Reef Using Strontium and Calcium
… coral reefs, followed by a description of the high-precision Ca and Sr analysis method. The main chapters explore three objectives: examining Ca and Sr cycling in the Southern Ocean (Chapters 3 and 4) and the Great Barrier Reef (Chapter 5). Chapter 3 investigates CaCO3 cycling in the Southern …
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Rhodoliths as environmental archives in the tropics
… live hundreds of years and continuously form a high-Mg calcite skeleton that presents periodical growth bands. Recent coralline red algae studies show that the variations of specific trace elements along these growth bands can reflect secular changes in various environmental parameters. This …
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Rhodoliths as environmental archives in the tropics
… live hundreds of years and continuously form a high-Mg calcite skeleton that presents periodical growth bands. Recent coralline red algae studies show that the variations of specific trace elements along these growth bands can reflect secular changes in various environmental parameters. This …
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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)
… model for many fossil carbonate settings ("calcite-sea" carbonates) than the photozoan model used before. This study deals with the determination of the diagenetic pathways and environments in such shallow-water heterozoan carbonate assemblages. Special emphasis is put on the identification …