Overview: The Subduction Factory Mini-lessons
Chris Kincaid, Bob Stern, Sarah Penniston-Dorland, Ben Edwards

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Modified from Kimura, Jun‐Ichi, Bradley R. Hacker, Peter E. van Keken, Hiroshi Kawabata, Takeyoshi Yoshida, and Robert J. Stern. "Arc Basalt Simulator version 2, a simulation for slab dehydration and fluid‐fluxed mantle melting for arc basalts: Modeling scheme and application." Geochemistry, Geophysics, Geosystems 10, no. 9 (2009).
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The MARGINS Subduction Factory Initiative (SubFac) focused on three sub-themes:
- The relationship of magma output and composition to forcing functions such as convergence rate, plate age, and sedimentary input.
- The cycling of volatiles from the slab to the mantle wedge and ultimately to either the crust and surface reservoir or back into the deep mantle.
- The production rate of arc crust.
The Central American and Izu-Bonin-Mariana magmatic arcs were chosen during open meetings by the geoscientific community to be the foci for a wide range of geochemical and geophysical studies because they represent two different types of factories: one whose input is old oceanic crust (IZB) and the other young oceanic crust (CAVA).
To help integrate important results from SubFac into geoscience curricula, we have developed three mini-lessons intended to guide student exploration of heat and mass inputs and outputs of the Subduction Factory:
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Subfac: Slab temperatures control melting in subduction zones, what controls slab temperature? - this module is a hands-on demonstration of advection and diffusion of heat in subduction zones that uses analog models to investigate their controls on slab thermal evolution and relationships to melting and Metamorphism.
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×Hide CaptionLeft: Photomicrograph of Jenner Beach garnet blueschist in plane-polarized light, width of field of view is 2.7 mm. Right: Thin section photomicrograph illustrating the defining mineral assemblage for eclogite facies: garnet (large yellow-orange crystals) and omphacite pyroxene (green crystals). Field of view is 2.7 mm, image is in plane-polarized light
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Subfac: Central American arc volcanoes, petrology, and geochemistry - this module uses basic concepts in igneous petrology, from hand specimen identification of lavas to major element geochemistry, to teach students how to investigate processes that lead to the production of petrologic diversity in subduction zones using two Central American arc volcanoes as examples.