Sökning: "oxygen isotope"
Visar resultat 16 - 20 av 54 avhandlingar innehållade orden oxygen isotope.
16. The functional potential of methane producing and consuming microorganisms in a changing world : Den funktionella potentialen hos mikroorganismer som producerar och förbrukar metan i en föränderlig värld
Sammanfattning : It’s clear that human activities have heated our climate via the release of anthropogenic greenhouse gases. Recent changes within the earth climate are rapid, intensifying, and unprecedented. LÄS MER
17. Geochemical and sedimentary signatures of Phanerozoic events
Sammanfattning : Geological and biological catastrophic events have occurred repeatedly in the Earth's history, leaving traces in the global stratigraphical record in the form of sedimentary features, geochemical anomalies and biotic turnovers. This thesis focuses on the sedimentological and geochemical signatures of several key events in the Phanerozoic stratigraphical record, and aims to interpret the different signals and the causal mechanisms behind each of these events. LÄS MER
18. Holocene climate and environmental change in high latitudes as recorded by stable isotopes in peat deposits
Sammanfattning : In this thesis, stable carbon and oxygen isotopes in α-cellulose isolated from Sphagnum fuscum moss remains were used as climate proxies. The main focus was to implement the methods in records from high latitude peatlands in the Northern Hemisphere (west-central Canada and north-eastern European Russia), reconstruct palaeoclimate of the studied regions during the Holocene, and evaluate the compatibility of results with other proxy records, especially tree-ring isotope time-series. LÄS MER
19. Holocene climate change in high latitudes recorded by stable isotopes in peat
Sammanfattning : A key to the understanding of natural and human induced climate variations is to reconstruct past changes from different environments. No outstanding method for general use has been pinpointed, instead, a need of multi-proxy studies is often stressed and the reconstructions are under constant improvement by new techniques. LÄS MER
20. Reclamation of acid-generating waste rock by in-pit backfilling and sealing : An evaluation of the Kimheden mine site, northern Sweden
Sammanfattning : The notion of mine site reclamation is very recent compared to the history of mining. In thepast, mine sites were left as is following termination of the operations, but modern regulationsrequire anticipation of long-term contamination of the surrounding environment and return ofthe land to a sustainable use. LÄS MER
