PUBLICATIONS Geochemistry, Geophysics, Geosystems RESEARCH ARTICLE The role of magmatically driven lithospheric thickening on arc 10.1002/2014GC005355 front migration Key Points: L. Karlstrom1, C.-T. A. Lee2, and M. Manga3 Arc front migration occurs globally in continental and some oceanic 1Department of Geophysics, Stanford University, Stanford, California, USA, 2Department of Earth Science, MS-126 Rice settings University, Houston, Texas, USA, 3Department of Earth and Planetary Science, University of California at Berkeley, Berkeley, Crustal thickening causes arc front California, USA migration and truncates mantle melting Tectonic extension may balance crustal thickening for stationary arc Abstract Volcanic activity at convergent plate margins is localized along lineaments of active volcanoes fronts that focus rising magma generated within the mantle below. In many arcs worldwide, particularly continen- tal arcs, the volcanic front migrates away from the interface of subduction (the trench) over millions of Correspondence to: years, reflecting coevolving surface forcing, tectonics, crustal magma transport, and mantle flow. Here we L. Karlstrom,
[email protected] show that extraction of melt from arc mantle and subsequent magmatic thickening of overlying crust and lithosphere can drive volcanic front migration. These processes are consistent with geochemical trends, Citation: such as increasing La/Yb, which show that increasing depths of differentiation correlate with arc front Karlstrom, L., C.-T. A. Lee, and migration in continental arcs. Such thickening truncates the underlying mantle flow field, squeezing hot M. Manga (2014), The role of mantle wedge and the melting focus away from the trench while progressively decreasing the volume of magmatically driven lithospheric thickening on arc front migration, melt generated.