Chemical Inputs and Outputs at Subduction Zones In this activity
the student analyzes global geochemistry data to create
hypotheses regarding possible geochemical inputs at subduction
zones, and the range of compositions associated with this type
of convergent boundary. The exercise utilizes the EarthChem
federation of online geochemical databases, GeoMapApp and Excel.
The activity focuses on Central America, an NSF-MARGINS Focus
Site, and Cascadia, an NSF-MARGINS allied study site. 2. The
intent is introduce to students to the chemical similarities and
differences between MORB and arc volcanism and begin to explore
ways in which magmatic sources can be traced. Context for Use
Students should perform the task on Mac or PC computers loaded
with the following software: a web browser, Excel or text
editor, and GeoMapApp. The assignment can be modified for an
upper-level undergraduate petrology class by including
additional sites and having the students create hypotheses
regarding magma source components by exami