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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Quantitative studies of porphyroblastic textures

Hirsch, David Marshall, 1969- 28 August 2008 (has links)
Spatial correlation functions, which quantify spatial relationships among porphyroblasts over a range of length scales, can be used in combination with other techniques of quantitative textural analysis to constrain crystallization mechanisms in metamorphic rocks. The utility, reliability, and robustness of these functions, however, depend critically upon correct methods of calculation and application to geological samples. Application of the L' -function, Pair Correlation Function, and Mark Correlation Function (Stoyan and Stoyan, 1994) to artificial arrangements of crystals yields results consistent with their predetermined ordering and clustering qualities. These results serve as a foundation for the interpretation of more complex simulated and natural crystal arrays. Analysis of artificial and simulated crystal arrays in which ordering signals are obscured in various ways (displacing crystals in an ordered array by increasing amounts, reducing the number of crystals, and increasing the sample's aspect ratio) demonstrates that these scale-dependent functions are robust indicators of effects diagnostic of certain crystallization mechanisms, even in complex circumstances. The effects of clustering of nucleation sites, however, can strongly obscure any underlying signal that might reveal crystallization mechanisms. The L' -function and the Pair Correlation Function are sensitive to short-range ordering of crystals, which may reflect suppression of nucleation in the vicinity of growing porphyroblasts. The Mark Correlation Function is sensitive to size-isolation correlations, which may reflect retardation of growth among crystals competing for nutrients. Interpretation of these functions, however, requires careful attention to proper calculation of Monte Carlo simulations, which are used to identify values of the functions that constitute a null-hypothesis region for comparison to samples with unknown ordering and clustering characteristics. To yield functional values commensurate with those calculated for a particular natural rock specimen, each simulation must match as closely as possible several critical features of the natural rock, including the set of crystal radii, limitations on the observability of crystals, and the shape and size of the bounding surface of the sample. Crystallization mechanisms in seven previously studied garnetiferous rocks from three localities (Carlson et al., 1995; Denison and Carlson, 1997) have been re-assessed using both scale-dependent correlation functions and single-valued spatial statistics, both evaluated by comparison to rigorously computed null-hypothesis regions. The results confirm previous inferences that the nucleation and growth rates of the garnet porphyroblasts in these specimens were governed by rates of diffusion through the intergranular medium. / text
42

The structure and metamorphism of the Irindina supracrustal assemblage on the western side of the Entia Dome, Harts Range, central Australia /

Lawrence, Robert William. January 1987 (has links) (PDF)
Thesis (Ph. D.)--University of Adelaide, Dept. of Geology and Geophysics, 1987. / Typescript. Maps in back pocket of v. 1. Microfiches in back pocket of v. 2. Microfiches contain petrographic descriptions, total rock XRF analyses and microprobe analyses. Includes bibliographical references (leaves 160-183 (v. 2)).
43

Metamorphic and geochronologic constraints on Palaeozoic tectonism in the eastern Arunta Inlier /

Mawby, Joanna. January 2000 (has links) (PDF)
Thesis (Ph.D.) -- University of Adelaide, Dept. of Geology & Geophysics, 2000? / Appendix 4 and 5 in pocket on back cover. Bibliography: p. 123-130.
44

Geology of the Southern Campbell Range, Southern Yukon: implications for the tectonic evolution of Yukon-Tanana terrane /

Devine, Fionnuala, January 1900 (has links)
Thesis (M. Sc.)--Carleton University, 2005. / Includes bibliographical references (p. 115-126). Also available in electronic format on the Internet.
45

Metamorphism of graphitic schists from Syros, Greece

Renedo, Roxanne. January 2009 (has links)
Honors Project--Smith College, Northampton, Mass., 2009. / Includes bibliographical references.
46

Numerical modeling of reactive fluid flow in the Notch Peak contact metamorphic aureole, Utah /

Cui, Xiaojun, January 2002 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 174-188). Also available on the Internet.
47

Numerical modeling of reactive fluid flow in the Notch Peak contact metamorphic aureole, Utah

Cui, Xiaojun, January 2002 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 2002. / Typescript. Vita. Includes bibliographical references (leaves 174-188). Also available on the Internet.
48

Fluid-rock interaction in scapolite bearing belt group metasediments, northwest of the Idaho batholith

Mora, Claudia Ines. January 1988 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1988. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 169-188).
49

Metamorphism in the northern Park Range of Colorado : fluid-rock interactions and thermobarometry /

Rougvie, James Russell, January 1999 (has links)
Thesis (Ph. D.)--University of Texas at Austin, 1999. / Vita. Includes bibliographical references (leaves 304-316). Available also in a digital version from Dissertation Abstracts.
50

Tectono-metamorphic evolution of the Grenville Front zone, Smokey archipelago, Labrador /

Owen, John Victor, January 1985 (has links)
Thesis (Ph.D.) -- Memorial University of Newfoundland. / Typescript. Bibliography: leaves 263-283. Also available online.

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