Subduction zones are places on Earth where one of Earth?s tectonic plates slides beneath another. They are locations of intense geologic activity that pose hazards to humans, including earthquakes and volcanoes. Understanding subduction zones is critical to developing our understanding of global geochemical cycles; the formation, evolution, and composition of the Earth?s crust; global-scale mantle dynamics; the distribution of valuable natural resources in ore deposits; and numerous geological hazards including volcanic eruptions, earthquakes, and tsunamis. Processes occurring deep within subduction zones are impossible to observe directly, but there are a wide variety of rocks that have been exhumed to the Earth?s surface from deep within subduction zones. Those who study these exhumed rocks have the unique ability to inform studies of active subduction zones by ?ground-truthing? the assumptions that go into models, experiments, and interpretive geophysics and geochemistry. ExTerra represents the community of scientists involved in studies of these exhumed rocks from the subduction system.
The goal of the workshop ExTerra 2013: Understanding Subduction through Studies of Exhumed Terranes is to organize disparate studies of subduction-related metamorphic and igneous rocks around a common set of scientific targets in order to move the discipline forward more efficiently as a community. In order to accomplish this goal, we will gather the communities of researchers investigating three categories of exhumed rocks from subduction zones: 1) high-pressure rocks of the subducted slab, 2) middle and lower arc crust, and 3) the mantle wedge. ExTerra 2013 will focus on research themes of common interest to these groups, provide a forum for communication and interaction among scientists, promote participation in the 2013 international Goldschmidt conference, and foster collaboration among participating scientists. We will lay the groundwork for the long-term structure of ExTerra, plan and organize future field trips, and develop an infrastructure for shared sample and data collection, archiving, and distribution. The proposed workshop will incorporate scientific presentations (talks and posters) on current research in exhumed terranes, an update on database and archiving progress, and will identify localities and organizers for field forums to be held over the next few years.
