I recently enjoyed a visit to Oklahoma State University to give a presentation to Dr. James Knapp’s “Wichita Mountains Task Force” – a group of like minded geoscientists and geophysicists curious about the geology of the Wichita Mountains. My presentation title “Conversations with a Rhyolite Dike” was well received with many questions during and after the presentation. I was rewarded with a lovely sandwich from a local favorite “Mike’s”. This is the abstract of the talk.
Conversations with a Rhyolite Dike
Abstract
The results of a quantitative petrographic study of a porphyritic alkali feldspar “rhyolite-dike” from the bimodal Wichita Mountains Igneous Province, part of the Cambrian southern Oklahoma aulacogen (USA), when combined with geochemical and phase equilibria analysis in the system SiO2-NaAlSi3O8-KAlSi3O8-H2O places constraints on 1) the source depth of the magma, 2) the emplacement depth of the dike, 3) the development of monomineralic clusters of quartz and alkali feldspar, a texture intrinsic to granites, during ascent, 4) a time integrated magmatic ascent rate of 0.037 m/s for the rhyolite dike magma as it traversed 15 vertical kilometers of crust, and 5) the implications for uplift and erosion, presumably by faulting, during formation of the Wichita Mountains Igneous Province.