Dr. Christian J. Renggli

Research interests

Metal transport in volcanic gas

Volcanic degassing plays a major role in the global cycling of volatile elements. The volcanic gas emissions predominantly consist of the volatile species H2O, CO2, SO2, H2S, HCl and HF. In addition, volcanic gases can transport significant amounts of heavy metals at high temperatures, which are deposited at the surface as the gases cool. The gases are highly enriched in trace metals, by up to a factor of 105 relative to the magmatic source. At these degrees of enrichment, quiescently degassing volcanoes emit kilograms to tons of metals per day. Metals emitted in volcanic gases form fumarolic deposits at the surface, consisting of highly diverse mineral assemblages, including oxides, silicates, sulfides, sulfates, halides and native metals.

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I also work on questions relating to the behavior of metals degassing from magma oceans and the surfaces from airless bodies and in the early solar system.

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Gas-solid reactions in planetary volcanic systems

Determination of reaction mechanisms and reaction rates between SO2, and reduced S-gas species with silicate glasses, melts and minerals. These gas-solid reactions play a key role in the formation of volcanic ore deposits, scavenge S from the gas phase in explosive eruptions, and enrich planetary surfaces and crusts in sulfur.