Research Opportunities for Undergraduates

Years ago I performed a series of experiments of varying duration in order to measure crystal growth rates. While successful for some minerals, I was unable to accurately measure the size of quartz crystals in meta-quartzites I had synthesized at high pressure and temperature because the grain boundaries were not always visible in standard SEM images. With our new Electron Backscatter Detector we should be able to collect images with orientation contrast, i.e., adjacent quartz crystals will have different brightness levels in greyscale images, so we will be able to use image analysis to measure the size of each quartz crystal. Doing this for all of the experiments of varying duration, we should be able to estimate the crystal growth rate.

Identifying the source of soil in Nashville

This project aims to use a novel technique to answer the question of whetherNashville’s soil is residual (formed by weathering of bedrock) or transported. We will separate zircon and monazite grains from samples of local soil and limestone bedrock and image them using our new environmental SEM. Then we will use LA-ICP-MS to measure their ages and compositions. We will judge the soil to be residual if the ages and compositions of grains from soil and bedrock are similar. If we find the soil is residual, we will estimate how much rock weathered to form the soil by comparing the concentrations of zircon and monazite in soil and bedrock.

Larisa R. G. DeSantis 

Assessing mammalian paleoecology, paleobiology, and responses to climate change during the Cenozoic

Multiple opportunities are available in the lab to work on existing projects or independently develop new questions.  Currently, potential projects broadly include, the following:

• Assessing the paleoecology, paleobiology, and potential effects of climate change on Australian marsupials (e.g., kangaroos, extinct giant wombats, etc.) during the Pleistocene
• Assessing the paleoecology, paleobiology, and potential effects of climate change on North American mammals (e.g., ungulates, carnivores, sloths and armadillos, etc.) in the southeastern US during the Cenozoic
• Improving paleoecological and palebiological proxies including the integration of geochemical tools (stable isotope analyses), dental mesowear, Dental Microwear Texture Analysis, and morphology
• Macroecological research that involve assessing deep time responses to climate change and/or understanding the underlying patterns and mechanisms responsible for species diversity gradients, globally.

These projects integrate biological and geological disciplines to ask questions of relevance to current climate change.  The majority of paleoecological questions involve stable isotope analyses to assess past climate change and subsequent dietary/floral responses.  Additionally, 3-D dental microwear (microscopic wear left due to the processing of food), mesowear (macroscopic wear), and morphological tools are integrated to assess the paleobiology of extinct organisms.  Opportunities primarily include independently and collaboratively working in the laboratory her at Vanderbilt, but do include potential museum visits and field work.  Please contact DeSantis to further discuss potential projects and/or research opportunities.

Dan Morgan

Geo-archeological investigations at Mawchu Llacta, Colca Valley, Peru

I am looking for 1-2 students who are interested in working on summer research projects that will involve field work inPeru. The goals of this project are to investigate the environmental history of the area to see how it may relate to the creation and abandonment of the archeological site Mawchu Llacta in theColcaValleyin southernPeru. There are a number of opportunities to work on paleoenvironmental geology projects related to these goals. Research opportunities include: dating glacial moraines, climate analysis from glacial history, dating landslides, investigating the activity of an alluvial fan, paleoenvironmental history from lake sediments, igneous petrology, and dating archeological sites. Students who are interested in geomorphology, paleoclimate/paleoenvironment, and archeology are encouraged to apply.

Interested students will need to apply for summer funding through the Vanderbilt Undergraduate Summer Research Program (VUSRP), which is a competitive funding opportunity. Applications for the VUSRP are usually due before spring break. Students interested in the field work should have significant camping and wilderness experience. Students should be physically fit and willing to endure a significant amount of physical discomfort in strenuous conditions. We will be camping at high elevation (14,000-16,000 ft), hiking 6-10 miles a day with heavy packs (30-40 lbs), be exposed to cold temperatures, and not have access to running water or means of communication for weeks at a time. Conversational Spanish language skills, while not necessary, would be beneficial.

Laboratory techniques for cosmogenic isotope dating of rock samples

I am looking for 1-2 students who are interested in learning laboratory techniques for how to physically prepare rock and soil samples for cosmogenic isotope analysis. Interested students can earn credit for EES 289A/B – Directed Study for this work. This work will involve crushing, sieving, and utilizing a number of chemical and physical mineral separation techniques to isolate quartz, apatite, and zircon minerals from the rock and soil samples. Students will learn general lab skills that will translate to any future lab experience. I expect students to work 5-8 hours per week on a project for 1-2 hours of credit. Additional work may include learning numerical techniques to cosmogenic isotope analysis depending on the students’ interest.

General geomorphology, geochronology, paleoclimate projects

As a geomorphologist, I seek to understand how landscapes change through time and how environmental changes are reflected across a landscape. To address these questions, I utilize a variety of geochronologic techniques, including exposure dating with cosmogenic isotopes (such as ¹⁰Be, ²⁶Al, and ²¹Ne) and lichenometry, which allow me to study questions about landscape evolution, the timing of geologic events, and the rates at which geomorphic processes occur. Much of my work focuses on interpreting glacial terrains to determine the timing and extent of past ice ages. My work involves a mixture of field-based studies in alpine areas andAntarctica, laboratory analysis, and numerical modeling. Additionally, I study the sustainable use of natural resources, quantifying environmental impacts using life cycle assessments, and the role of science in environmental decision making.

I am always interested in doing independent (EES291A/B) or directed studies (EES 289A/B) with students who are interested in anything that relates to my general research program. Students who are interested in glacial geology, paleoclimate, paleoenvironment, natural resource use, environmental impacts, sustainability, wilderness issues, and environmental decision making are encouraged to contact me to discuss a research opportunity.