Physical and Chemical Variations Along the Central American Volcanic Arc
The Central American volcanic arc displays large arc-parallel variations in chemical composition that yield important clues concerning the complex origin of magmas in subduction zones. In this exercise, students use data compiled for the NSF MARGINS program to compare heights, volumes, and whole-rock compositions of 39 Quaternary volcanic centers along the Central American arc, together with crustal thicknesses, to assess the possible sources of the magmas and the petrologic processes that have modified them prior to eruption.