sgr ms thesis - University of Maine

contact (Figure 4.1). The metamorphic intensity increases from the biotite-chlorite
assemblage found in the undeformed Bar Harbor Formation to the cordieritegarnet
assemblage that dominates most of the Shatter Zone, finally increasing
grade to orthopyroxene-cordierite hornfels facies proximal to the Cadillac
Mountain Granite contact. Isograds (Figure 4.2) were determined by a set of 11
samples taken along a traverse of the Shatter Zone. The samples from this
traverse represent all known facies within the contact metamorphic aureole. Most
mineral identification was done optically and some with electron microprobe.
4.3. Methods for Contact Metamorphic Thermal Modeling
Many attempts have been made to calculate the cooling history of igneous
intrusions. The problem is described as a volume of magma with known shape
and initial temperature that intrudes the wall rocks with known temperature, and
the subsequent variation in thermal gradient caused by the contact is to be
calculated (Jaeger, 1961, 1964; Hart, 1964; Parmentier and Schedl, 1981; Attoh
and van der Meulen, 1984; Hanson and Barton, 1989; Bowers, 1990; Annen and
Sparks, 2006; Johnson et al., 2011).
Conduction models can serve as a baseline observation to better
constrain some first order variables, including the dominant mode of heat
transfer. For example, if the thermal gradient produced by the model does not
match the isograds identified in the field, it could be that convection and/or
advection played a large part in heat distribution. If isograd and model data
match well, heat transfer was more likely dominated by conductive heat transfer
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