EAST TENNESSEE GEOLOGICAL SOCIETY
May 2019 Meeting
Monday,
May 13, 2019
6:00 - 7:30 pm
Pellissippi State Technical Community College
10915 Hardin Valley
Road, Knoxville
J.L Goins Administration Building
Faculty/Staff Dining Room
Award Winning Student Presentations
Viscosity of the Mercurian Magma Ocean: Implications for
Crystal Fractionations and Crustal Petrogenesis
Presented By
Megan D. Mouser
Graduate Teaching Assistant
Department of Earth and Planetary Sciences
University of Tennessee, Knoxville
Abstract
Differentiation of terrestrial planets is often ascribed to magma oceans, as the formation and crystallization of magma oceans can produce a core, mantle, and crust, and sets the stage for subsequent evolution of planetary mantles. Here we present new measurements of a Mercurian magma ocean analogue and use them to evaluate the efficiency of crystal fractionation from its magma ocean. We conducted falling sphere viscometry experiments at the Advanced Photon Source, Argonne National Laboratory to test the viscosity of a composition resembling Mercury's composition, with and without sulfur. We found that the composition (with and without S) had low viscosities at the conditions tested (1700-2000 deg C and 2.7-6.2 GPa). Using the viscosity results we can calculate crystal grain sizes and viscosity ranges for crystal entrainment in the magma ocean to hypothesize if the mantle formed a more heterogeneous or homogeneous composition. Using these results and calculations we can begin to interpret the interior of the planet and how that influences what we see on the surface of the planet today.
Biography
Megan is currently a Master's candidate at
the University of Tennessee studying early formation processes of the planet
Mercury. Prior to attending the University of Tennessee, Megan received her
Bachelor of Science in Earth and Planetary Sciences from the University of New
Mexico. She then went on to intern and work full time as an experimental
petrologist at NASA Johnson Space Center, where she participated in a project
studying the petrology of Apollo lunar samples, and doing experimental work on a
variety of projects studying the lunar mantle and meteorite petrogenesis.
A Global Perspective on
Martian Alluvial Fans
Presented By
Claire Mondro
PhD Student
Department of Earth and Planetary Sciences
University of Tennessee Knoxville
Abstract
Alluvial fans that form in Martian craters have been studied in localized context across the equatorial latitudes in the Noachian-Hesperian Highlands. Because alluvial fan sediment generally experiences relatively short transport distances, these features provide a record of bedrock weathering, sediment transport, and deposition within a small region which has been of interest to modelers reconstructing sediment flux and water accumulation in and around craters. This record of weathering, transport, and deposition also provides an important link between climatic and geologic history which can be analyzed in the rock record. Previous analysis of alluvial fans on Earth suggest that the style of sediment deposition depends on the balance of chemical versus physical weathering, which in turn is controlled in part by water temperature during runoff events. By analyzing the morphology and sedimentary characteristics of Martian alluvial fans, it is possible to reconstruct the sediment transport and bedrock weathering history. My work suggests that analysis of a global population of alluvial fans on Mars may reveal large-scale trends in the style of sediment deposition which can be linked to global climate.
Biography
Claire Mondro is a PhD student at
The University of Tennessee in Knoxville, studying regional
compositional trends of alluvial fans on Mars. She got a Bachelor of
Science from Ohio State in geology and a Bachelor of Arts in
English. She did a Masters at Penn State in geology where her
research was investigating the tectonic history of Taiwan by
measuring the strain history recorded in curved pressure shadows.
After graduating from Penn State, Claire moved to Houston to work
for Chevron as an Exploration Geologist on their New Ventures Teams,
evaluating new exploration opportunities in Africa and the Middle
East. When the oil price crashed and layoffs loomed, Claire decided
she had had her fill of corporate America and came back to the
academic world, making the jump into planetary geology along the
way. Her current research interests are focused on exploring how
interactions between climate, geology, and hydrology are preserved
in the rock record, specifically in alluvial fans. She uses a
combination of morphology, spectral composition, and thermal inertia
measurements to analyze the sediment depositional history of
alluvial fan features across the surface of Mars. Claire is also
interested in investigating Earth analogs for Mars alluvial fans and
developing drone-based remote sensing methodology that lets us
explore earth analogs in a method similar to how we perform
planetary exploration.
The future of lunar
exploration and the role of the Lunar Reconnaissance Orbiter in
improving our geologic understanding of the Moon
Presented By
Cole Nypaver
MS Student
Department of Earth and Planetary Sciences
University of Tennessee Knoxville
Abstract
Apollo 11 and the subsequent
manned missions to Earth's Moon provided a wealth of data and
geologic information that helped us to understand our closest
celestial neighbor. In the 50th anniversary year of this ground
breaking mission, a renewed interest in lunar exploration and lunar
geology has taken hold. Indeed, NASA has stated, publicly, that the
ambitious goal of a manned mission reaching Earth's Moon by 2024 is
achievable. The scientists, engineers, and administrators which
participate in the Lunar Reconnaissance Orbiter (LRO) mission are
working to enable this goal in the time-frame proposed. Scientists
at LRO use combinations of radar data, thermal measurements, optical
images, ultraviolet starlight, and many other techniques in order to
unravel lunar geochemistry, establish targets of geologic interest,
and propose future landing sites for manned or robotic missions to
the Moon. This talk will summarize the near-future plans for lunar
exploration and the types of work done by lunar scientists at LRO in
order to facilitate future lunar exploration.
Biography
Cole Nypaver is a Master's
candidate at the University of Tennessee, Knoxville Department of
Earth and Planetary Sciences with research interests in long-term
regolith evolution on the Moon and radar remote sensing techniques.
Prior to his studies at the University of Tennessee, Cole received a
Bachelor of Science degree in Geology from Mercyhurst University in
Erie, Pennsylvania. Cole's research at Mercyhurst University
involved a global analysis of shield volcanoes and effusive
volcanism on the surface of Venus. Concurrent with his master's
research, Cole is an active science team affiliate of the Lunar
Reconnaissance Orbiter Mini-RF instrument where his duties include
data management and public data usability.
Cole's MS research is focused on long term erosion of lunar impact
craters, which is a new method of obtaining ages of the lunar
surface. The surface of Earth's Moon is mottled with small impact
craters which are formed via the collision of an asteroid of comet
with the lunar surface. Over time, these impact craters and the
rocks that are thrown out upon their formation are eroded by
subsequent impact events and constantly fluctuating temperatures at
the lunar surface. In this work, we assess the degree to which
impact craters have been eroded by characterizing them in both radar
and thermal data. These two datasets grant us the ability to
determine exactly how rocky and rough the impact craters are at the
lunar surface and near surface. We then compare the thermal and
radar signatures of the craters to previously modeled ages in order
to establish a rate at which rocks break down and impact craters on
the Moon erode. These rates provide a new metric of age-dating the
lunar surface in which the age of a given impact crater can be
obtained directly from the radar of thermal signature of that
crater. A presentation of this research is tentatively planned at an ETGS
meeting in the Fall of 2019!
Page updated May 14, 2019 |