Paper No. 8
Presentation Time: 10:00 AM
GEOCHEMICAL DATABASE FOR LAVAS FROM THE CENTRAL AMERICAN AND IZU-BONIN-MARIANA ARC SYSTEMS
We have developed a publicly accessible database of high-quality geochemical data collected over the last two decades from magmatic arcs of the two MARGINS Subduction Factory focus sites, the Central American (CentAm) arc system, including Costa Rica and Nicaragua, and the Izu-Bonin-Mariana (IBM) arc system, reaching from Japan to Guam. The CentAm and IBM arc systems were chosen for this project because they represent two end members of subduction factories: the CentAm has a high sediment input and a young, hot, dry subducting slab; and the IBM system has a low sediment input and an old, cold, wet subducting slab. We filtered and compiled this data to explore the magma characteristics of the respective arcs and to interpret their magmagenetic conditions such as sediment input, fluid-flux, and mantle and altered oceanic crustal components. To create the database used to compare the two arcs, we used two publically accessible online data portals: EarthChem (managed by the Lamont-Doherty Earth Observatory) and GANSEKI (Geochemistry and Archives of ocean floor rocks on Networks for Solid Earth Knowledge Integration maintained by the Japan Agency for Marine-Earth Science and Technology). This dataset includes whole rock data collected from the magmatic front of each arc system. The data were first filtered for completeness. To ensure high-quality and uniformity, only samples of Quaternary age or younger published since 1980 with trace element concentrations analyzed by ICP-MS were included in the dataset. We will compare and contrast the magmagenetic conditions of the two arc systems using the geochemical data available in our database, which may serve as an example for those interested in researching the systems or teaching about Subduction Factories.