Experimental Petrology

Overview

My research interests include quantifying the processes and timescales that lead to volcanic eruptions, which is crucial information to our ability to monitor such systems and develop effective hazard mitigation plans. I use methods such as mineral and glass geochemistry, diffusion chronometry, experimental petrology, thermodynamic modeling, and statistical modeling. If you are interested in these topics, please peruse this website or contact me!

Using Experimental Petrology to Simulate Magmatic Processes

Conducting high-temperature and pressure experiments allows us to simulate the conditions and processes that occur in a magma chamber. I use experimental petrology in my research to recreate tiny magma chambers in order to examine elemental behavior at magmatic conditions that leave chemical fingerprints on the mineral and rock record.

Cold-seal pressure vessel apparatus in Jim Watkins Experimental Lab at University of Oregon.

In Progress: Testing the Controls on Ba Zoning in Sanidine

Ba zoning in sanidine is commonly observed and is used to make interpretations on the processes and timescales associated with magma storage and eruption. However, little is known on what actually controls Ba (and other trace element) zoning (i.e., partitioning) in sanidine, leaving it unclear on what Ba zoning in sanidine is really recording. My work explores these controls by conducting cold-seal pressure vessel experiments as well as Laser ICP-MS analysis of both natural and experimental sanidine and rhyolites.

Shamloo et al., 2021, GSA Abstracts; NSF EAR Postdoctoral Fellowship Award

Example: Developing a New Geospeedometer

Diffusion chronometry (also known as geospeedometry) has become a popular tool for determining the tempo of magmatic processes. It is especially important to use multiple chronometers in a single phase for differentiating magmatic processes from one another (e.g., Shamloo and Till 2019). Current research uses a 1-atm vertical furnace to determine how and how fast magnesium diffuses in alkali-feldspar, a ubiquitous phase in silicic volcanic rocks. Results suggest Mg diffuses simultaneously by both a fast- and slow-mode, suggesting diffusion in feldspar is more complex than previously understood (Shamloo et al. 2021).

Simple schematic of the experimental design for diffusion experiments (Shamloo et al., 2021).

Arrhenius plot for Mg diffusion in Eifel sanidine Or71 (top panel) and Or82 (bottom panel) showing the two crystallographic orientations investigated (diffusion measured both parallel and perpendicular to c axis). Linear regressions for each dataset are shown by solid black line (Shamloo et al., 2021)

Shamloo, H., Till C. B., Hervig, R. L., (2021) Multi-Mode Magnesium Diffusion in Sanidine: Applications for Geospeedometry in Magmatic Systems. Geochimica et Cosmochimica Acta. https://doi.org/10.1016/j.gca.2021.01.044