• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 17
  • 17
  • 1
  • Tagged with
  • 40
  • 40
  • 20
  • 20
  • 15
  • 14
  • 12
  • 11
  • 8
  • 8
  • 5
  • 5
  • 5
  • 5
  • 4
  • 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.
1

The petrology and geochemistry of the Reedy Creek granitoids and migmatites /

Moeller, Thomas. January 1980 (has links) (PDF)
Thesis (B.Sc.(Hons))--University of Adelaide, Department of Geology,1980.
2

Petrography and geochemistry of the Koloula River igneous complex, Guadalcanal, British Solomon Islands

Netzel, Richard Karol. January 1974 (has links)
Thesis (M.S.)--James Cook University of North Queensland, 1974. / Includes bibliographical references (leaves 37-45 (2d group)).
3

A large late-glacial eruption of the Hudson Volcano, Southern Chile

Weller, Derek James 01 July 2015 (has links)
<p> Lakes formed in the Ays&eacute;n region of southern Chile after the retreat of mountain glaciers, beginning by at least ~17,900 cal yrs BP, contain numerous late-glacial and Holocene tephra layers derived from >70 eruptions of the volcanoes in the region, including Hudson, the southernmost in the Andean Southern Volcanic Zone (SVZ). Sediment cores from six of these lakes each contain an unusually thick late-glacial age tephra layer, which based on its distribution and bulk trace-element composition was derived from a large explosive eruption of the Hudson volcano between 17,300 and 17,440 cal yrs BP, and is termed Ho. In these cores, located ~100 km northeast of Hudson, the Ho tephra layers range between 35 to 88 cm in thickness. Comparison with three previously documented large explosive Holocene Hudson eruptions (H1, H2, H3 1991 AD) suggests that Ho was larger, with an estimated tephra volume of >20 km3, the largest post-glacial eruption documented for any volcano in the southern Andes. In total, Hudson has erupted &ge;45 km<sup>3</sup> of pyroclastic material in the last ~17,500 years, making it the most active volcano in the southern Andes in terms of the total volume of pyroclastic material erupted since the beginning of deglaciation in the region. Chemical stratification is not seen in the Ho deposits, but this eruption was bi-modal, with a much greater proportion of dark glassy basaltic-andesite dense fragments and pumice, which range between 55 to 59 wt % SiO<sub>2</sub>, and volumetrically less significant lighter colored dacite pumice with 66 wt % SiO<sub>2</sub>. In contrast, H1 was andesitic in composition, H2 was more felsic than H1, being composed essentially of dacite, and although H3 in 1991 AD was again bi-modal, it erupted a much smaller proportion of mafic compared to felsic material than Ho. Thus, the repetitive large explosive eruptions of Hudson volcano have evolved to progressively less mafic overall compositions from late-glacial to historic times, and their volumes have decreased. All analyzed phases of different Hudson eruptions, have similar Sr-isotopic composition (0.70444 &plusmn; 0.00007), indicating that crystal-liquid fractionation rather than crustal assimilation was the main process responsible for these chemical variations.</p>
4

A stable isotope study of fluid-rock interaction in serpentinites of the Franciscan Complex, San Rafael Mountains, California

Brown, Christine P. 31 October 2014 (has links)
<p> The fluid history of serpentinites from three locations in the Franciscan Complex, San Rafael Mountains, California is evaluated with petrologic and stable isotope data that allow interpretation of the serpentinization history and tectonic origin of these rocks. Petrologic evidence shows that most samples were originally serpentinized in a relatively low temperature seafloor hydrothermal environment, but some rocks underwent subsequent recrystallization. Data obtained from serpentine-magnetite geothermometry indicate that the serpentinization temperatures ranged from 168&deg;C to 306&deg;C. Oxygen isotopic values suggest that the serpentinites may have originated in a forearc setting. Hydrogen isotopic values obtained do not reflect the original conditions of serpentinization, but indicate that the rocks subsequently underwent isotopic exchange with meteoric water once they were emplaced onto the continent.</p>
5

Petrology and geochemistry of Cambrian volcanic rocks from the Avalon zone in Newfoundland and New Brunswick /

Greenough, John David. January 1984 (has links)
Thesis (Ph.D.) -- Memorial University of Newfoundland. / Typescript. Bibliography : leaves 344-373. Also available online.
6

The petrology, geochemistry and petrogenesis of the Riwaka Complex, South Island, New Zealand /

Saunders, Jeffrey Keith, January 1997 (has links)
Thesis (M. Sc.), Memorial University of Newfoundland, 1998. / Bibliography: leaves 138-147. Also available online.
7

The petrology, geochemistry and geochronology of the felsic alkaline suite of the eastern Yilgarn Block, Western Australia /

Johnson, Geoffrey I. January 1991 (has links) (PDF)
Thesis (Ph. D.)--Dept. of Geology and Geophysics, University of Adelaide, 1992. / Typescript (Photocopy). Includes copies of 4 papers by the author as appendix 4 (v. 1). Errata slip inserted. Includes bibliographical references (leaves 170-192 (v. 1)).
8

Compositional and lithological variation of the Platreef on the farm Nonnenwerth, northern lobe of the Bushveld Complex implications for the origin of platinum-group elements (PGE) mineralization /

Manyeruke, Tawanda Darlington. January 2008 (has links)
Thesis (M.Sc.(Geology))--University of Pretoria, 2007. / Abstract in English. Includes bibliographical references (leaves 208-235).
9

The petrography and geochemistry of the Platreef on the farm Townlands near Potgietersrus, northern Bushveld Complex

Manyeruke, Tawanda Darlington. January 2005 (has links)
Thesis (M.Sc.(Geology))--University of Pretoria, 2003. / Summary in English. Includes bibliographical references.
10

Pétrographie et géochimie des roches du secteur environnant de la mine Bruneau Chibougamau, Quebec /

Trudeau, Yvon. January 1981 (has links)
Mémoire (PH.D.Géol.)- Université du Québec à Chicoutimi, 1981. / "Mémoire présenté en vue de l'obtention de la maîtrise en sciences appliquées géologie" 6 cartes dont 1 en coul, en pochette. CaQCU CaQCU Document électronique également accessible en format PDF. CaQCU

Page generated in 0.7732 seconds