- This event has passed.
Seminar Series: Dr Laura Waters
September 17, 2020 @ 12:00 pm - 1:00 pm
Title: Why doesn’t continental crust evolve to its fullest potential?
The paucity of high-silica rhyolite in volcanic arcs and its restricted occurrence as scattered aplite dikes throughout arc granitoid batholiths suggests there is a mechanism that prevents high-silica (near-eutectic) rhyolite melts from coalescing and erupting as discrete liquids at subduction zones. In contrast, large volumes (≥100 km^3) of high-silica rhyolite, including those that are relatively cold (700–750 °C) and hydrous, erupt in extensional tectonic settings. The emerging question is: What controls the eruption of high-silica rhyolite? In this talk, I use results of several experimental and petrologic studies on silica-rich magmas (rhyolites) from the Sierra Nevada Batholith and Long Valley to provide a crystallization (kinetic) perspective on what it takes to efficiently extract, move and erupt a eutectic melt and, thus, stratify continents.