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 63 for “"multi proxy"”.
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Middle Miocene carbon cycle dynamics: A multi-proxy approach
The development of permanent, stable ice sheets in Antarctica happened during the middle Miocene, about 14 million years ago (Flower and Kennett, 1995; Zachos et al., 2001). The middle Miocene therefore represents one of the distinct phases of rapid change in the transition from the “greenhouse” of …
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Multi-proxy palaeoclimate reconstruction of the permian-triassic mass extinction event
The Permian/Triassic (P/Tr) boundary is widely assumed to have been a time of extreme environmental upheaval and change. In the terrestrial realm, a negative anomaly in 813C isotope values has been reported from organic carbon in Antarctica, Australia, India and Madagascar, and from marine …
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Holocene development of Lake Lögurinn and Eyjabakkajökull : a multi-proxy approach
… the northeastern part of Vatnajökull. Using a multi-proxy approach, proxies for glacial meltwater variability and surge periodicities of Eyjabakkajökull have been examined to infer its Holocene development. In addition, changes in sediment transport from a non-glaciated catchment adjacent to …
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A multi-proxy study of the Palaeocene - Eocene Thermal Maximum in northern Spain
At the boundary between the Paleocene and Eocene epochs (ca. 56 Ma) a significant global warming event, termed the Paleocene-Eocene Thermal Maximum (PETM), occurred. Records of this event are characterised by a negative carbon isotope excursion (CIE) which has been associated with the release of …
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Holocene environmental change in the Scottish Highlands: multi-proxy evidence from blanket peats
This thesis seeks to investigate the Holocene environmental history of two areas of Northern Scotland with specific reference to the evidence for pine woodland density variations and tree-line dynamics. The evidence is derived from the biostratigraphy of of peat profiles sampled along altitudinal …
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Multi-Proxy Records of Climate and Carbon Cycle Perturbations in the Paleozoic: Integrating Isotope Geochemistry and Sedimentology
Carbonate rocks are a valuable archive of past environmental conditions. To glean robust information from this archive, we must understand how carbonate sediments form, ensure our analytical techniques are optimized, and consider how inherently local deposition of sediments can communicate …
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A multi-proxy approach to investigating the latest Holocene (~4,500 yrs. BP) vegetational history of Catahoula Lake, Louisiana
<p>A multi-proxy investigation of sediments examined from Catahoula Lake, Louisiana has provided a record of late-Holocene vegetational changes, related to both hydrology and climate. This study integrates data from phytoliths, pollen, stable isotopes, magnetic susceptibility, and core sediment …
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Reconstruction of environmental and climate dynamics using multi-proxy evidence from palaeosols of the Western Cape, South Africa
… have been impacted over centennial to multi-millennial timescales. Palaeosols constitute an important stratigraphic marker for past environments and may provide useful validation of pedogenic and other earth system process models. However, the characterisation and analysis of palaeosols …
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Palaeoenvironmental reconstruction of late Holocene climate dynamics in Southwest Africa using a multi-proxy characterization of Namaqualand mudbelt sediments
… oceanic and terrestrial climate components. A multiproxy analysis was conducted on a west coast mudbelt sediment core, where continuous deposition over the last 2,250 years has aided the production of an uninterrupted age model. Alkenone and isotopic analyses were conducted at a multi-decadal …
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Analysis of deposition, erosion, and landscape stability during the late Quaternary using multi-proxy evidence from Owl Creek, Central Texas, USA.
Episodes of fluvial deposition and incision preserved in Quaternary sediments are valuable archives of environmental change, but have been understudied in low order streams in central Texas, USA. An exposure along Owl Creek a tributary of the Brazos River was examined using geological and …
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A 1400 Year Multi-Proxy Record of Hydrologic Variability in the Gulf Of Mexico: Exploring Ocean-Continent Linkages During the Late Holocene
… spanning the last 1400 years and utilizes a multi-proxy approach incorporating organic and inorganic geochemical analyses to define intervals of varying continental inputs and to assess changes in the moisture balance (E-P) within the Gulf of Mexico.
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A multi-proxy study of the Kalkkop impact Crater Lake deposits in south-central South Africa: implications for late neogene climate evolution
The Kalkkop Crater Lake deposit formed as a result of a meteorite impact, and is situated ~51 km southwest of Graaff-Reinet in the Southern part of South Africa. The structure is about 650 m wide, and contains 90 m of lake deposits that are mainly carbonate precipitates. A 90 m sediment core from …
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Recent extreme events in a tropical stalagmite: Multi-proxy records and analysis of ecosystem delta carbon-13 value sensitivity to weak climate forcing
… demonstrates the potential for developing novel proxy records of past regional environmental extremes, such as tropical cyclones, explosive volcanism, and enhanced seasonal contrasts from speleothems that are sensitive to transient infiltration events through very high-resolution, multi-parameter …
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Late Holocene environmental and climate dynamics along the southern Cape coast of South Africa: high resolution multi-proxy records from the wilderness embayment
… of sedimentary sequences and associated proxy records. The climate along the southern Cape coast is influenced by both tropical and temperate climate systems, and the region hosts highly diverse vegetation including fynbos and thicket elements and includes the Knysna Afrotemperate Region …
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Lateglacial to Holocene climatic and environmental changes in Europe : multi-proxy studies on lake sediments along a transect from northern Italy to northeastern Poland
… quasi-synchronously, major leads and lags in proxy responses characterize the onset of the Lateglacial Interstadial. In particular, the spread of coniferous woodlands and the reduction of detrital flux lagged the initial Lateglacial warming by ca. 500–750 years. Major cooling at the onset of …
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Paleoenvironmental changes in the Black Sea region during the last 26,000 years : a multi-proxy study of lacustrine sediments from the western Black Sea
Paleoenvironmental records provide ample information on the Late Quaternary climatic evolution. Due to the great diversity of continental mid-latitude environments the synthetic picture of the past mid-latitudinal climate changes is, however, far from being complete. Owing to its significant size …
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Social Organisation And Change In Bronze Age South Asia: A multi-proxy approach to urbanisation, deurbanisation and village life through phytolith and macrobotanical analysis
… Contrary to previous suggestions, a range of multi-cropping strategies were seen from the beginning of occupation at all settlements. A slight trend towards increased proportions of millet, which is viewed as being arid-adapted, was seen over time, but no drastic switch to these crops was …
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Testing the late-Holocene climate signal from ombrotrophic bogs in southernmost Chile and the Falkland Islands: a multi-proxy, multi-profile and multi-site approach
… Islands, to form a regional comparison. A multi-proxy approach was used, combining both palaeoecological and stable isotopic methods. At one site, Karukinka, intra-site replicability was tested across three profiles located along a microtopographical gradient. A low number of statistically …
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Reconstruction of the Late and Mid-Pleistocene climate and landscape history in SE-Central Europe - A paleopedological and geochemical multi-proxy approach in loess-paleosol studies.
… the region by a paleopedological – geochemical multi-proxy approach. Furthermore, methodological investigations aim to evaluate the validity of various paleoenvironmental proxies especially geochemically based weathering indices, as well as biomarker and stable isotope approaches in LPSS …
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