sgr ms thesis - University of Maine

approximately 140m thinner. The Shatter Zone thickness is 300m thinner.
Unfortunately, there is not enough data on the depth geometry of the Shatter
Zone, and there is no proof for a tilted section on the eastern side of the Cadillac
Mountain intrusive complex.
4.4. Evidence for an Actively Mixing Chamber
The maximum temperature achieved by this model does not explain the
existence of a pyroxene zone. The assumptions used for this model are therefore
unrealistic for the Cadillac Mountain intrusive complex, proving that magma
reservoir convection and replenishment were active components of heat transfer.
Additionally, wall-rock groundwater convection from 2-5km depth likely played a
part in contact metamorphism. The Cadillac Mountain intrusive complex was part
of a volcanically active region, which experienced several eruptive sequences
(Chapman, 1962; Berry and Osberg, 1989; Seaman et al., 1995; Seaman et al.,
1999). Widespread presence of enclaves (Wiebe et al., 1997b), evidence of
magma mixing (Chapman, 1962), and the presence of interlayered gabbro and
diorite sheets at the chamber base prove that the Cadillac Mountain Granite was
host to magma replenishment and actively mixing before eruption. Bimodal
chamber systems can often undergo several sequences of reactivation from
mafic dike “entrapment” (e.g. Wiebe, 1994, Wiebe et al., 2004), and chamber
replenishment can lead to overpressurization and potential eruption (e.g. Folch
and Marti, 1998). The thermal input after wall rock brecciation, discussed in
Chapter 7, would have been substantial. The Cadillac Mountain Granite likely
42