Research

My research is underpinned by a strong desire to understand the origin and evolution of atmospheres, which means I need to understand the nature of the volatile elements (primarily C-N-Noble gases) in the interior of planets to ascertain how they behave during accretion, differentiation, and during plate-tectonic cycling. The details provided below outline some details of on-going projects. Please get in touch if you want to collaborate.

The Nature of Magmatic Carbon on Mars (funded by the UK Space Agency)

PhD Student: Mr Michele Rinaldi (BSc Milan; MSc Milan)

The genesis of the atmospheric methane and solid organic carbon are enigmatic. The existing hypotheses include: [i] an extant subsurface biosphere, [ii] hydrothermal activity, [iii] the melting of clathrates or [iv] present-day effusive volcanism. This means the sources of any complex hydrocarbons in the Martian atmosphere (by ESA’s Trace Gas Orbiter) or in the crust (by ESA’s Exomars Rover) cannot be identified without a significant ambiguity (at present). To assist in the determination for the sources of any complex hydrocarbons we will combine high-pressure and -temperature experiments with thermodynamic modelling to chart the pathway followed by magmatic carbon, and to constrain whether their isotopic signature can be used to rule out or affirm a possible volcanic origin. We will replicate the conditions thought to be representative of Martian magma chambers to gain understanding of the speciation of carbon during differentiation of magma in the Martian lithosphere. Then we can examine the nature carbonaceous gases that shouldbe degassed and detected by the Nadir and Occultation for Mars Discovery (NOMAD) instrument on the TGO.

The Nature of Earth’s Deep Nitrogen Cycle (funded by NERC – link)

PostdocDr Eleanor Mare (BSc Hons, Monash; PhD, ANU)

We are working to determine the controls on the equilibrium exchange coefficient between potassium and ammonium from 1-10 GPa. This programme of research is being done in collaboration with Drs Geoff Bromiley, Cees-Jan de Hoog (Edinburgh), Prof Simon Redfern (Cambridge), and Dr Colin Jackson (Smithsonian Institution).

Alternative Anions and the Negative Side of Geochemistry (funded by St Leonard College, St Andrews)

PhD student: Mr Filippo Formoso (BSc, Milan; MSc, Milan)

This project focuses on the incorporation mechanics of fluorine and nitrogen in silicate minerals. We have hired a PhD student to work under the guidance of myself alongside Ms Fawn Holland (Undergraduate research intern). The supervisory team also includes Dr Elarnor Mare (Earth Sci, St Andrews), Prof Sharon Ashbrook & Dr Dan Dawson (Chemistry, St Andrews). Some of this work is being done in collaboration with Drs Geoff Bromiley (Edinburgh), Francis McCubbin (NASA), and Bastian Joachim (Innsbruk).

The evolution of Earth’s atmosphere as recorded by continental crust (funded by NERC via the IAPETUS DTP)

PhD student: Mr Toby Boocock (BSc, Edge Hill; MSc, St Andrews)

We are exploring the possibility that granitic rocks can be used to trace the nitrogen abundance of the crust, and by proxy, the surface environment, through time. Toby is based at St Andy’s jointly with Dr Eva Stueeken (St Andrews), and works in collaboration with Dr Julie Prytulak (Durham). This work is carried in our Gas-Source Mass Spectrometry Laboratory (Thermo MAT-253 attached to a bespoke gas-line) where we are establishing a protocol for the isotopic analysis of trace amounts of nitrogen in geological materials.

New constraints on the volcanic history of Earth’s sibling planet, Venus (Royal Society-Funded)

Volcanism is a primary input to the chemistry of planetary surfaces. This project will derive an experimental framework (diffusion experiments) with which to interpret preexisting argon isotope data and aims to constrain the volcanic history of Earth’s sibling, Venus. This project is being conducted in collaboration with Prof Darren Mark (SUERC).

Diamond-formation in Earth’s mantle

We primarily apply stable isotope geochemistry (C-N mostly, but recently using O and Noble gases) to address the origin of diamond-forming carbon in Earth’s silicate mantle. This programme of Research is being done in collaboration Prof Fin Stuart (SUERC), Mr James Crosby (former MSc student, now at Cambridge), Drs Sahsa Verchovsky, Frances Jenner, Feargus Abernethy (Open University), Steve Shirey (Carnegie Institution for Science), and Francis McCubbin (NASA).

Exoplanets

We have established the St Andrews Centre for Exoplanet Science, a collaborative endeavour between astronomers and geoscientists. Furthermore, because there are huge societal ramifications to the answer of the question (are we alone?), we have broadened the centre away from purely physical sciences and includes members from the School of Philosophy. For more information follow this linkWe are very excited about our future, and we greatly look forward to working with the many other groups around the world who share our passion for understanding where we come from, and whether or not we are alone in the cosmos.