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Development and application of speleothem-based proxies for past climate changeOwen, Robert January 2017 (has links)
This thesis develops and applies new techniques for reconstructing past environments from the speleothem archive. Chapter 3 introduces Ca isotopes as a novel palaeo-aridity proxy. Recent dripwater, farmed calcite and bedrock data show that, in the modern environment, 36% of initial dripwater Ca is removed by prior calcite precipitation at the HS4 dripsite (Heshang Cave, Central China). A speleothem record spanning the 8.2kyr event suggests this value increased to 60% during the event, in response to a decrease in effective rainfall of approximately a third. Modern Ca isotope systematics, and the cycling of other Group II metals, are studied further in Chapter 4. Data from Heshang Cave monitoring samples explore the temporal and spatial controls on these proxy systems. Results highlight the importance of secondary calcite as a potential source of dripwater metals, as well as the significant contribution of particulate calcite to bulk dripwater chemistry. At the HS4 dripsite, over a third of bulk dripwater Ca is present as particulate calcite. This influences bulk dripwater Ca concentrations and isotopes, as well as potentially impacting speleothem growth and chemistry. Chapters 5 introduces CaveCalc, a new numerical model for dripwater and speleothem chemistry and isotopes based on PHREEQC. Key strengths of CaveCalc include its ability to model multiple proxy systems in a single framework, the ability to quantify the extent of open-system dissolution, and the extensible nature of its design. Chapter 6 applies CaveCalc to disentangling the controls on dripwater and speleothem δ<sup>13</sup>C values. Model results are compared with speleothem data. At Heshang Cave, anomalously high δ<sup>13</sup>C is quantitatively explained as the result of CO<sub>2</sub> degassing and prior calcite precipitation, an interpretation made possible by the availability of coupled δ<sup>13</sup>C, a<sup>14</sup>C and Ca isotope data. This approach provides a powerful tool to help researchers better interpret dripwater and speleothem δ<sup>13</sup>C data.
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Stable isotope geochemistry of nitrogen in marine particulates /Libes, Susan M. January 1983 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth and Planetary Sciences, 1983. / Vita. Includes bibliographical references (p. 268-279).
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Geochemical and isotopic study of a core of the Tipton shale member of the Green River Formation, Wyoming /Rao, Pejavar Lata. January 1900 (has links)
Thesis (M.S.)--Ohio State University, 1984. / Includes bibliographical references (leaves 134-138). Available online via OhioLINK's ETD Center
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Isotopic geochemical evidence concerning the origin of Georgia kaolin depositsHassanipak, Ali Asghar 08 1900 (has links)
No description available.
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Carbon isotope stratigraphy of the interglacial Umberatana Group, Adelaide, Fold Belt, South Australia / by Jamie M. Burgess.Burgess, Jamie M. (Jamie Matthew). January 1999 (has links)
Includes bibliographical references (10 leaves). / x, 116, [27] leaves, [40] p. : ill. (chiefly col.), maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study demonstrates the need for refinement of the established approach to interbasin stratigraphic correlation based on C-isotope geochemistry. High data resolution is desirable and correlation should take into account lithostratigraphy and sequence stratigraphy rather than soley relying on data trends or absolute [delta]13C values. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology, 2000
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Carbon isotope stratigraphy of the interglacial Umberatana Group, Adelaide, Fold Belt, South Australia / by Jamie M. Burgess.Burgess, Jamie M. (Jamie Matthew). January 1999 (has links)
Includes bibliographical references (10 leaves). / x, 116, [27] leaves, [40] p. : ill. (chiefly col.), maps ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / This study demonstrates the need for refinement of the established approach to interbasin stratigraphic correlation based on C-isotope geochemistry. High data resolution is desirable and correlation should take into account lithostratigraphy and sequence stratigraphy rather than soley relying on data trends or absolute [delta]13C values. / Thesis (Ph.D.)--University of Adelaide, Dept. of Geology, 2000
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Carbon isotope stratigraphy of the interglacial Umberatana Group, Adelaide, Fold Belt, South Australia /Burgess, Jamie M. January 1999 (has links) (PDF)
Thesis (Ph.D.) -- University of Adelaide, Dept. of Geology, 2000. / Includes bibliographical references (10 leaves).
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An isotopic investigation of some sequential extraction schemes /Tangumonkem, Eric Tayem, January 2008 (has links)
Thesis (Ph.D.)--University of Texas at Dallas, 2008. / Includes vita. Includes bibliographical references (leaves 251-275)
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Oxygen isotopes in geologyBottinga, Jan. January 1963 (has links)
Thesis (M.S.)--University of British Columbia, 1963. / Includes bibliographical references (leaves 127-139).
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Helium and lead isotope geochemistry of oceanic volcanic rocks from the East Pacific and South AtlanticGraham, David W. January 1987 (has links)
Thesis (Ph. D.)--Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution, 1987. / Funding was provided by the National Science Foundation under grants OCE 15270 and OCE 16082.
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