Date of Award
Earth & Environmental Science
Earth and Environmental Sciences
William B. Simmons, Jr.
Alexander U. Falster
Karen L. Webber
Investigation of phosphate assemblages selectively collected at the Fletcher Mine pegmatite, North Groton, New Hampshire, yielded eighteen discrete secondary phosphate species. Secondary phases were formed via metasomatic (high temperature) and hydrothermal (low temperature) alteration of primary triphylite and fluorapatite. Mineral associations bear proximal phases known to occur under contrasting conditions, both oxidizing and reducing, suggesting the formation of microenvironments during concomitant mineral generation. Late-stage hydrothermal fluids provide ions taken up in low temperature secondary phases with calcium and magnesium most prevalent in these suites. High iron to manganese ratios in analyzed specimens establish the relative evolution of the pegmatite host. Ubiquitous presence of Huréaulite in all associations suggests trend in late-stage cooling. An unidentified aluminum rich phase requires further investigation. Updated standards of pegmatite classification allow for more precise categorization of the Fletcher Pegmatite based on mineralogy and complexity.
Kreinik, Susanna T., "Phosphate Mineralogy and Paragenesis of the Fletcher Pegmatite, North Groton, New Hampshire" (2022). University of New Orleans Theses and Dissertations. 3039.