HR: 11:05h
AN: V12A-04 INVITED     [Abstracts]
TI: Progress towards an integrated computational model of magma genesis and transport in subduction zones
AU: * Katz, R F
EM: katz@ldeo.columbia.edu
AF: Richard F. Katz, Lamont Doherty Earth Observatory 61 Route 9W, Palisades, NY 10964 United States
AU: Spiegelman, M
EM: mspieg@ldeo.columbia.edu
AF: Richard F. Katz, Lamont Doherty Earth Observatory 61 Route 9W, Palisades, NY 10964 United States
AB: We present progress towards an integrated computational model of magma genesis and transport in subduction zones that incorporates variable viscosity mantle creep, hydrous melting and reactive porous flow of magma. These complexities will permit self-consistent prediction of a variety of geophysical and geochemical observables, including the time-scales of melt transport. There now exists an abundance of disparate observations relevant to subduction zones processes and time-scales: from heat flow and gravity profiles to measurements of radiogenic and cosmogenic nucleides, trace elements and volatiles in arc lavas. Taken together, these can provide powerful constraints on an integrated model. The petrological and computational complexity of assembling such a model is significant, however, and requires a component-wise approach. The hydrous melting parameterization that we have developed and published is the first of three basic components. The second is a functioning code to calculate dislocation/diffusion creep flow and thermal structure in subduction zones. Results from these simulations are distinct from those of isoviscous codes; a much hotter wedge corner and upwelling flow are evident. The third component is the calculation of reactive porous flow of hydrous magma through the mantle. Anhydrous reactive flow codes have demonstrated behaviour such as melt channelization with important implications for geochemical transport. Similar results are expected for hydrous reactive flow, however the inverted mantle temperature gradient present in subduction zones may play a modifying role. We will discuss each of these components and the challenges of assembing and interpreting an integrated model of subduction zones.
UR: http://www.ldeo.columbia.edu/~katz/
DE: 8434 Magma migration
DE: 3640 Igneous petrology
DE: 3210 Modeling
DE: 3230 Numerical solutions
DE: 1065 Trace elements (3670)
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2004 AGU Fall Meeting