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