HR: 0800h
AN: ED51A-0013 [Abstracts]
TI: Modeling composition of partial melts in mantle upwellings through Earth history: an example of a 2D
poster
AU: * Sparks, D W
EM: sparks@seaver.tamu.edu
AF: Texas A&M University, Dept. of Geology and Geophysics, TAMU, College Station, TX 77843-3115
United States
AU: Cheadle, M
EM: cheadle@uwyo.edu
AF: University of Wyoming, Dept. of Geology and Geophysics, Laramie, WY 82071-3006
United States
AB:
The composition of magmas created by partial melting of the mantle depend on the interplay of several processes: the mantle
phase diagram, the physics of magma migration through the mantle and crust, the patterns of solid-state mantle and fluid
circulation and heat transfer, to name a few. This modeling study attempts a self-consistent combination of these physical
and chemical processes, to predict the composition of magma created in upwelling mantle over a very broad range of mantle
conditions, with particular emphasis on the deep past in a hot Archean mantle. We utilize 1) high P-T melting experiments to
constrain the composition of melts formed at different depths in the mantle, 2) thermal and compositional solid-state
convection models to constrain the temperature and melting rate and the three-dimensional distribution of these melts, and 3)
simplified models of magma migration to predict the accumulation and mixing of these magmas, for comparison with
mantle-derived primitive melts over time.
An explanation of this study requires a description of details from a number of varied disciplines (Archean geology, trace
element geochemistry, experimental petrology, solid-state convection, magma migration). While most interested poster readers
will want to know the details of one or two aspects of the calculations, few will want to wade through them all. This goal
of this poster design is to present the outline of the story in way that can be scanned quickly at a distance, but with
several independent offshoots containing explanation of parts of the story that can be either read or skipped, and yet
another level containing details for the experts on a particular topic.
DE: 0845 Instructional tools
SC: Education and Human Resourcese [ED]
MN: 2004 AGU Fall Meeting