Magma mingling textures within the Los Martires pluton of the Cretaceous (~110 Ma) Alisitos Arc, Baja California. This image displays the mingling between mafic magma (darker elongate blebs) and the main phase felsic magma (lighter matrix). Exceptional 3D paleo-arc exposures in this extensional arc system allow the study of the physical and chemical links between the units that comprise this arc, and constrain the petrologic processes active during the growth and evolution of juvenile arc crust. Similar processes are interpreted to occur at depth within active extensional arcs, such as the Izu Bonin Arc in the western Pacific. Photo Credit: Rebecca Morris