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Timing Of Thermal Overprints In The Silvermines Granite And Associated Diabase Intrusions, St. Francois Mountains, Missouri, Renee C. Rohs

The Compass: Earth Science Journal of Sigma Gamma Epsilon

Igneous rocks exposed in the St. Francois Mountains record the geologic history of volcanic activity and plutonic intrusions contributing to the growth and stabilization of the continental crust during the Precambrian. These igneous rocks also contain evidence of thermal overprinting both in the isotope chemistry and the crystalline structures. This study presents new isotopic, mineral and petrologic data to support the timing of dike emplacement and thermal overprinting in the host rock. The study area for this research is along the East Fork of the St. Francis River at the Silver Mines Recreation Area where diabase dikes intrude the surrounding …