Granitic Pegmatites

June 7 (Tuesday), 6 p.m., Teton Co. Library Auditorium – Open to Public. Presentation: “ Granitic pegmatites – formation and mining”. Presented by Mark Jacobson, Retired Chevron Corporation.

Pegmatites, formed in the last stages of magma crystallization, have long been prominent, often beautiful parts of igneous and metamorphic rock environments – they can be found in the Teton Range, the Winds, the Gros Ventres, and indeed around the world. Beautiful mineral specimens and elements important to a wide range of industrial uses.

This talk will provide a brief review of how pegmatites  form – something that involved a major paradigm change circa 1988, and then will include an overview of why they are mined today. An overview of a worldwide selection of pegmatites will be examined, including some examples from Wyoming and Colorado, showing quarry pits, geologic cross sections, miners, photogenic scenery, and interesting minerals that are found in pegmatites.