Physical and Chemical Variations Along the Central American Volcanic Arc part of MARGINS Data in the Classroom:MARGINS Mini-Lessons
Kent Ratajeski, Calvin University
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.

How Slab Dip Affects the Location of Volcanoes part of MARGINS Data in the Classroom:MARGINS Mini-Lessons
Erin Beutel, College of Charleston
Students will plot the locations of earthquakes on the top of subducting slabs to determine slab dip and will then develop hypotheses regarding the relationship between slab dip, the depth of the slab, and volcanic activity on the surface.