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 31 for “"Multiproxy"”.
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Paleoclimate and paleoecology of Miocene Eastern African primate habitats : a multiproxy approach.
… the value of regionally based datasets and multiproxy integration, providing refined site‑ to basin‑scale environmental frameworks for Early–Middle Miocene primate habitats.
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A multiproxy investigation of oceanic redox conditions during the Cambrian SPICE event
The research presented here is an effort to characterize changes in marine oxygen availability across a portion of the later Cambrian noted for unique evolutionary dynamics and which includes a significant global oceanographic event known as the SPICE event (Steptoean Positive Carbon Isotope …
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Multiproxy Analyses of Past Vegetation, Climate, and Sediment Dynamics in Hudson River Wetlands
… changes of the Hudson Estuary: 1) Long-term multiproxy paleoecological reconstruction at two important freshwater National Estuarine Research Reserve marshes; and 2) pre and post industrialization sediment composition analysis across a North-South transect of the river. Knowledge about past …
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Palaeoenvironments and Palaeoclimates During The Late Holocene in Lake Siscunsi (Colombia), A Multiproxy Perspective
This thesis provides a palaeolimnological and environmental reconstruction of the last ~2,800 years of Lake Siscunsí, located in the Eastern Cordillera of Colombia. This study is mainly based on a high-resolution diatom record in combination with Chlorophyll 𝑎 and other analyses previously done in …
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A multiproxy paleoenvironmental reconstruction of Late Quaternary marine sediments: Sunda Shelf, Southern South China Sea
Two gravity cores were collected from 43 km and 90 km offshore of Kuala Terengganu (western Sunda Shelf, southern South China Sea) at ~60 m water depth to characterize late Quaternary paleoenvironments by using bulk sediment magnetic susceptibility (BMS), elemental analysis via X-ray fluorescence …
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Palaeoenvironmental reconstruction in South Africa's year-round rainfall zone using multiproxy geochemical analyses on lake sediments from Swartvlei
Coastal lakes in the south coast of South Africa contain sediments with good records of palaeoenvironmental changes. Swartvlei is the largest of the lakes in the Wilderness Embayment and is connected to the Indian Ocean via an estuary. The lake is believed to have been formed during sea-level …
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Using a multiproxy analysis of springbok fossils to track 2 million years of vegetation changes experienced by hominins in southern Africa.
A causal link between climatic changes and hominin evolution is an established one, yet the exact dynamics of this relationship is debated. Key climatic changes, such as the intensification of the Northern Hemisphere Glaciation, the onset of the Walker Circulation and the Mid-Pleistocene …
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Antarctic phytoplankton and climate change using Holocene sedimentary DNA, fossils and chemical proxies.
… food webs. This thesis applies a high-resolution multiproxy strategy, including sediment geochemistry, diatom assemblages and sedaDNA, to reconstruct late-Holocene environmental change and ecosystem response at Maxwell and Börgen bays. The study interval (~1.5 ka) spans the Neoglacial, the …
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A late quaternary history of Agulhas-Benguela interactions from two sediment cores on the western continental slope of South Africa
… the last 850 kyr are investigated through the multiproxy study of two giant piston cores, MD962080 and MD962084, retrieved from the Agulhas Bank and Olifants River continental slopes of South Africa. The stable oxygen isotope record of the benthic foraminifer, Cibicidoides wuellerstorfi, and …
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Palaeoceanographic conditions and palaeoproductivity changes from the sub-Antarctic island South Georgia since the late deglacial, using marine micropalaeontology and geochemistry
This thesis presents a high-resolution multiproxy reconstruction of palaeoceanographic conditions and palaeoproductivity on the South Georgia shelf spanning the late deglacial through the Holocene. South Georgia lies within the path of the Antarctic Circumpolar Current (ACC) and the Southern …
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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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Aggregate potential of Irish south coast offshore palaeovalleys
… coast. Qualitative data was processed using a multiproxy geophysical and sedimentological approach, creating detailed seabed maps using bathymetric data supported by ground truthing sedimentsamples. Surficial sediment deposits display a close fit to industry standard aggregates but considerable …
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Understanding good ecological status: a palaeolimnological approach
The current study uses multiproxy palaeolimnological analysis of sediment cores to reconstruct the long-term (10² to 10³ years) nutrient status of Upper Talley and Llyn Pencarreg, two closely adjacent, moderately nutrient-enriched lakes in Carmarthenshire, South Wales. The use of diatoms, …
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Stratigraphic and Geochemical Expression of Early Cretaceous Environmental Change in Arctic Svalbard
… Cretaceous (palaeo-latitude of c. 65 °N), via a multiproxy sedimentological, geochemical, sequence- and chemo- stratigraphic study of Berriasian–Albian strata from the Central Basin of Svalbard. The “outsized clasts” recorded on Spitsbergen do not show evidence that they were rafted by glacial …
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Relative sea level, sediment supply and barrier dynamics as driving mechanisms of Holocene coastal change.
… and temporal differences in sedimentation. A multiproxy approach, comprising lithostratigraphic, sedimentological, bio- and chronostratigraphic methods, identified and constrained the timing of major phases of coastal change. New sea-level index points (11 intercalated peat and 6 basal peat …
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A multi-technique provenance study of the Oligocene : recent Nile cone sediments and River Nile hinterland
This thesis presents the first detailed multiproxy provenance study of the modern Nile catchment, together with Oligocene-Recent sediments of the offshore Nile cone, and demonstrates for the first time that the palaeodrainage of the Nile has remained relatively stable over the last 30 Ma. Detrital …
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Holocene sea-level changes in the Falkland Islands: new insights into accelerated sea-level rise in the 20th Century
… was Northern Hemisphere land-based ice melt. Multiproxy sea-level reconstructions were established for the Falkland Islands, a location where models suggest sea-level rise from Northern Hemisphere ice melt produces the largest signal. The Falklands reconstruction indicated sea levels in the …
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Speleothem Palaeoclimatology in the Maya Lowlands of Northwestern Yucatán, Mexico
… at Uxmal and Chichén Itzá. Secondly, I provide a multiproxy palaeoclimate record from the stalagmite HOBO-5, spanning the last 1,500 years. I use combination of the traditional stable isotopes δ<sup>18</sup>O and δ<sup>13</sup>C, and calcium isotopes (δ<sup>44</sup>Ca), a novel speleothem proxy …
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Characterising the Namaqualand Mudbelt: Chronology, Palynology and Palaeoenvironments
This multiproxy study explores the palaeoenvironmental record of two cores, H2 and H7, from the Namaqualand Mudbelt representing an arid and highly variable landscape. As bulk organic radiocarbon ages previously proved problematic, with anomalous reversals, the primary objective was to improve …
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Refining tsunami inundation limits for the 1700 CE Cascadia earthquake: detailed mapping of fine-grained deposits and diatom biostratigraphy at the Salmon River estuary, central Oregon
… of tsunami inundation, we use a high-resolution, multiproxy approach to more precisely map the true inland extent of 1700 CE tsunami inundation at the Salmon River estuary, Oregon. We identify fine-grained tsunami deposits in sediment cores collected across the previously mapped tsunami sand …
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