What goes down must come up: Changing oxidation conditions in the Santorini magmatic system as a tracer of subduction components through time

The redox state of volcanic arc systems is highly variable globally, although arcmagmas are generally recognized to be more oxidized than those of mid-ocean ridges. The origins of these oxidation differences are complex; they may represent primary source region differences, potentially related to variations in slab-derived sediments, melts, or fluids, or they may form through secondary means, such as interactions with the overlying mantle wedge or crust during storage and ascent. In this talk I will present new data from drill cores collected during IODP Expedition 398 that has implications for the origin and evolution of the primary redox signature of Santorini magmas through arc history. Trace element geochemistry is used to determine magmatic oxidation state and provide evidence of correlation with fluid infiltration, suggesting slab-derived fluids have had a primary role in determining magmatic redox in the Santorini magmatic system throughout its evolution.

Speaker: Molly McCanta, University of Tennessee, Knoxville

Attend in person or via Zoom (see weblink)