Research & Projects

Influence of Volatiles on Mantle Melting and Crystallization

Volatile elements such as hydrogen, carbon, nitrogen, and sulfur play a crucial role in planetary evolution, influencing the material properties of planets, atmospheric composition, and serving as essential ingredients for life. One theme of my research is unraveling the transport and processing of volatiles in planetary interiors and exploring the impact of volatiles on the chemical differentiation of planets through high pressure and temperature experiments. I have investigated the effects of subducting slab-derived hydrous silicate melts and H2O-CO2 fluids on partial melting in subduction zones, exploring alternative models of arc magmatism. This line of research has led to several publications which demonstrate that H2O and CO2, in isolation and in mixtures, uniquely influence the major element composition of peridotite partial melts, resulting in a diverse range of primary mantle-derived melt compositions (Lara and Dasgupta, 2020, Geochimica et Cosmochimica Acta, Lara and Dasgupta, 2022, Earth and Planetary Science Letters; Lara and Dasgupta, 2023, Journal of Petrology ). Future research will explore the impact of volatiles on three key areas: (1) major and trace element partitioning during mantle melting, (2) crystallization processes in the lower crust, and (3) melting dynamics within the interiors of other planets.

Oxygen Fugacity of Planetary Interiors

While volatile elements play a pivotal role in the chemical differentiation of Earth and other planets, their behavior is predominantly governed by the oxidation state, or oxygen fugacity (fO2), of the mantle. Variations in fO2 within and between planetary bodies can significantly impact mineral stability, volatile speciation, and atmospheric composition, leading to diverse evolutionary trajectories and habitability potentials. Consequently, quantifying the fO2 of Earth’s interior and those of other planets remains a critical unknown in comparative planetary science. Ongoing projects along this line of research involve: (1) investigating the effects of pressure, temperature and fO2 on spinel/melt partitioning of ferric iron during partial melting and (2) calibrating a new sulfur in apatite oxybarometer for high pressure metamorphic rocks. Future projects will focus on quantifying ferric iron partitioning between minerals such as pyroxene, amphibole and silicate melt and investigating the effects of slab-derived sulfide and sulfate on mantle wedge melting.

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