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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.
1

Characterization of Pb and selected trace elements in amazonitic K-feldspar

Sokolov, Maria, 1969- January 2006 (has links)
No description available.
2

Characterization of Pb and selected trace elements in amazonitic K-feldspar

Sokolov, Maria, 1969- January 2006 (has links)
Amazonitic K-feldspar is characteristic of evolved granitic pegmatites of NYF (niobium-yttrium-fluorine) type, associated with A-type granite emplacement. In this work, I focus on four notable examples of such an association: (1) West Keivy, Kola Peninsula, Russia, (2) Saint-Ludger-de-Milot, Quebec, (3) Lac Sairs, Quebec, and (4) Morefield, Virginia. A fifth locality, the Broken Hill metamorphosed exhalative-type volcanogenic deposits in Australia, is an unusual type of amazonitic K-feldspar formed in an ore environment. A total of nineteen samples of amazonitic K-feldspar were characterized geochemically and mineralogically on the basis of X-ray diffraction, electron-microprobe and laser-ablation ICP-MS analyses. Lead, as an essential requirement for formation of the blue-green amazonitic color, has received particular attention. In every case, the analytical data show elevated amounts of Pb and rare alkalis, which strongly partition into the K-rich phase of the perthite intergrowth. Unusual micrometric grains, highly enriched in Pb, are found in cracks in the material from West Keivy. Some of the grains represent a new mineral species, a Pb-dominant feldspar. The presence of amazonitic K-feldspar in a granitic pegmatite is more than a curiosity. It can shed light on important petrogenetic issues such as metasomatic rejuvenation of crustal rocks prior to regional melting in a period of extension.

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