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Full-Text Articles in Physical Sciences and Mathematics
Contact Zone Mineralogy And Geochemistry Of The Mt. Mica Pegmatite, Oxford County, Maine, Kimberly T. Clark
Contact Zone Mineralogy And Geochemistry Of The Mt. Mica Pegmatite, Oxford County, Maine, Kimberly T. Clark
University of New Orleans Theses and Dissertations
This study focuses on exocontact mineral assemblages to determine composition, thermal signatures, and the extent of exomorphism that occurred between the Mt. Mica pegmatite and the migmatite host rock at the contact. Biotite-garnet thermometry of country rock samples resulted in an average temperature estimate of 630 °C. Measured biotite Fe/(Fe+Mg) ratios were used to calculate an fO2 of -18. The results indicate that the country rock and pegmatite formed under similar oxidizing conditions near the quartz-fayalite-magnetite (QFM) equilibria buffer. Whole rock (REE) analysis indicates an interaction trend between the country rock and pegmatite. Exomorphism does not appear to have …
Mineralogy And Geochemistry Of The Erongo Granite And Interior Quartz-Tourmaline Orbicules And Nyf-Type Miarolitic Pegmatites, Namibia, Andrew P. Boudreaux
Mineralogy And Geochemistry Of The Erongo Granite And Interior Quartz-Tourmaline Orbicules And Nyf-Type Miarolitic Pegmatites, Namibia, Andrew P. Boudreaux
University of New Orleans Theses and Dissertations
The early Cretaceous anorogenic Erongo Granite of Namibia is known to host abundant boron mineralization in rounded, quartz-tourmaline clusters and in NYF-type miarolitic, pegmatitic cavities. Rock and mineral samples were taken from the bulk granite, tourmaline nests, and miarolitic cavities and analyzed using a variety of modern analytical techniques. Geochemical and mineralogical data suggest substantial input from the metasedimentary rocks of the Damara orogen was important in the genesis of the Erongo Granite magma. The geochemical signature of the Damara orogen is most evident in the tourmaline clusters and miarolitic cavities, where fractional crystallization accumulated volatile and incompatible elements enough …