The Igneous Architecture of Arcs throughout the Crustal Column

Barbara Ratschbacher, Kyle Samperton, Katie Ardill and I will be convening a session on arc magmatism at the 2018 Goldschmidt Conference in Boston (August 12-18th). Abstract submission will begin in early 2018 - read more here

Magmatic arcs are often considered to be a major site of new continental crust formation. However the detailed differentiation mechanisms resulting in typical evolved, oxidized, calc-alkaline magmas are still controversial. In particular, contrasting hypotheses persist regarding the depth of differentiation in the arc crustal column and possible changes thereof throughout the lifespan of arc magmatism. Resolving these contrasting hypotheses requires us to investigate the crust-wide architecture of magma plumbing systems: Where does magma accumulate to form magma reservoirs, how long lived are they, and what is the extent of differentiation at each crustal level? How well do igneous processes connect throughout the crustal column? How does the thermal and rheological behavior of the arc crustal column change throughout the lifespan of arc magmatism and how does this influence the composition of magmas, ascent and eruption of magma? In this session, we seek to bring together a wide range of disciplines that resolve vertical magmatic processes operating in arc crustal columns, and the temporal variability thereof. We encourage submissions working on present-day active arcs as well as extinct and exposed sections of different arc crustal depths using field techniques, geophysical methods, geochronology, volcanic and plutonic studies, numerical modeling and experimental petrology. By combining these diverse fields, we hope to arrive at a better understanding of arc magma plumbing systems and differentiation at all depths throughout the crust.