This study will develop and test a model for sublacustrine eruptions based on evaluation of several volcanoes known to have erupted in relatively deep lakes. A selected set of volcanoes erupted into ancient Lake Idaho will be evaluated using the model to test its validity. Precise field observation is critical. The PIs will log eruptive successions in detail, and trace-out lateral relationships on cliffside exposures. Additional information will be obtained by standard thin-section petrography and limited x-ray diffraction and microprobe analysis. The study is expected to demonstrate that eruptive processes analogous to those inferred for Surtseyan volcanoes control the evolution of volcanoes erupted into deep lakes.
