Discuss subduction zones, including the thermal and seismic structure of subduction zones, volatile and geochemical cycling, petrology of the subducting slab, seismicity, mantle wedge dynamics, volcanism, and the start of plate tectonics. Geological Sciences 356S and 371T (Topic: Ins & Outs of Subduction Zones) may not both be counted. Three lecture hours a week for one semester.