Can crystallization of olivine tholeiite give rise to potassic rhyolites?—an experimental investigation

Experiments were conducted to determine whether the rhyolites and basalts of the intraplate silica-saturated potassic suites could be genetically related through crystallization. Extreme crystallization (96–97%) of a high-MgO (10.62 wt%) olivine tholeiite from the Snake River Plain with an initial bulk water content of 0.4 wt% at a mid-crustal pressure of 4.3 kbar generated potassic rhyolitic liquids similar in major element chemistry to those found in the Quaternary rhyolite domes of the Snake River Plain and their plutonic equivalents in the Proterozoic Laramie Anorthosite Complex. Residual liquids comparable in composition to the bulk rock compositions of intermediate rocks found at the Craters of the Moon and Cedar Butte eruptive centers in the Snake River Plain are also generated along this crystallization path. This paper constitutes part of a special issue dedicated to Bill Bonnichsen on the petrogenesis and volcanology of anorogenic rhyolites.