sgr ms thesis - University of Maine

(Furlong et al., 1991; Johnson et al., 2011). These discrepancies can give
information about the balance between convection and conduction, and may lead
to a conclusion on the dominant mode of heat transfer. One may also consider
the dynamic heat input from incremental pluton emplacement, chamber
convection, and recharge events (e.g. Hanson and Barton, 1989; Bergantz,
1991; Pignotta et al., 2010), which would all effectively elevate the maximum
temperature achieved in the wall rock and drastically change the spatial range of
metamorphism (e.g. Turcotte and Schubert, 1982; Furlong et al., 1991; Stuwe,
2002). Regardless, it is most beneficial to use conduction modeling for initial
observations because 1) dependent variables for conduction are easily
constrained, 2) using conduction modeling will give an end-member constraint on
the rate of heating and possible isograd trends, and 3) it provides a simple yet
realistic thermal behavior for a contact metamorphic zone (Bergantz, 1991).
For precise modeling, where a solution is required near the contact
between magma reservoir and wall rock, it is beneficial to correct for latent heat
of fusion for the crystallizing magma body (e.g. Jaeger, 1961). A crystallizing
granite can produce 400kJ Kg -1 °K -1 before the solidus is reached (e.g. Burnham
and Nekvasil, 1986; Furlong et al., 1991). Additionally, endothermic metamorphic
reactions, such as dehydration in pelites, can absorb 60 to 110kJ mol -1
of
released H 2 O or CO 2 , depending on the particular reaction (e.g. Furlong et al.,
1991). Applications of these components are discussed below and in Chapter 7.
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