Page 27 - GeoPRISMS_Newsletter_Spring2018_Neat

and participated in the educational videos. The field
work also set the stage for monthly video conferences
among the graduate students, which helps to maintain
coordination between individual thesis projects and the
project as a whole.
Moving forward, we will collect a suite of data that will
provide the foundation for a novel approach using two
primary lines of investigation:
1. Constraints on the thermal history of pre-eruptive
magma storage by coupling absolute ages for plagioclase
crystal populations derived from U-series measurements
with trace element diffusion models to constrain
the maximum residence time of crystals at a given
temperature; and

2. Quantification of the compositional heterogeneity
of crystals and melt components, through in-situ
measurements of trace-element and isotopic compositions in
primary and accessory minerals and in melt inclusions (δ O in
18
zircon, ε in zircon; Pb isotopes in plagioclase and melt inclusions),
Hf
which will provide a measure of the degree
to which the magma system is mixed across
time and space within the reservoir as well
as variations in the contributions of mantle
and crustal sources to this reservoir.
The unique strength of this approach is that
it will allow simultaneous characterization
of the thermal, compositional, and physical
evolution of these silicic reservoirs.
Therefore, the results of this study should
be broadly relevant to other silicic volcanic
systems and will represent an important
step forward in improving our ability to
interpret volcano monitoring data. Large
silicic systems represent an end-member
for volcanic activity globally, and more
general models of the controls on the
thermal conditions of magma storage
beneath volcanoes will be developed by
linking the results of this study with those
from other ongoing projects. ■

NSF GeoPRISMS Awards # 1654506,
1654275, 1654128

From top to bottom: Members of the field team in front of a fumarole
on White Island. Left to right: Adam Kent, Nicole Rocco, Kari Cooper,
Jordan Lubbers, Damien Cranney, Sara Moilanen, Olivia Barbee, Tyler
Schlieder; Darren Gravley sampling a tephra unit in the Mangaone
sequence, Okataina Volcanic Center; Graduate students in front of Lake
Taupo. Left to right, Jordan Lubbers, Elizabeth Grant, Lydia Harmon,
Nicole Rocco, Olivia Barbee, Tyler Schlieder; Tephra sequence from
Okataina Caldera Center (including Rotorua eruption, ~15 ka) in quarry
section. Left to right, Tyler Schlieder, Lydia Harmon, Elizabeth Grant,
Damien Cranney. Photos credit: Kari Cooper

Spring 2018 Issue No. 40 GeoPRISMS Newsletter • 27