IAP-24-029

The origin of life at ancient alkaline hydrothermal vents

The steep chemical gradients generated by the mixing of alkaline hydrothermal vents with seawater are regarded as one of the most likely sources of organic molecules and energy for the origin of life on the early Earth. Modern day alkaline hydrothermal vents, such as the Lost City hydrothermal field in the Atlantic Ocean or Prony hydrothermal field in southern New Caledonia, are fed by the recirculating of seawater or freshwater through an up-thrust segment of lower crust unearthing the unstable olivine-rich rock peridotite. Heated water that permeates down into the peridotite reacts with olivine, splitting water to form mM dissolved hydrogen gas in highly alkaline fluids (typically <100 °C) that are emitted at hydrothermal chimneys up to 60 m high.

In this studentship you will use a set of state-of-the-art pressurised continuous flow hydrothermal reactors to mimic the mixing of hydrogen-rich alkaline hydrothermal vent fluids with carbon dioxide-rich seawater or freshwater over a range of different mineral substrates. You will extend exciting recent work in our laboratory where we have successfully generated organic molecules using this apparatus and assess the potential for generating a range of further biological relevant organic molecules. You will also test the conditions under which adsorbed organic molecules can desorb (‘lift off’) from mineral surfaces, and their potential to self-assemble into cell-like vesicles. This studentship aims to make a step change in our understanding of how life originated on our planet, and the potential for life to have started on other worlds.

You will design experiments using pressurised continuous flow hydrothermal reactors to mimic ancient Earth alkaline hydrothermal vent chemistry in the laboratory. You will quantify the evolving inorganic and organic molecular compositions of the fluids and solid minerals (both bulk and surface) using a wide range of complimentary analytical techniques. Key methods will include ion chromatography, gas and liquid chromatography-mass spectrometry, x-ray photoelectron emission spectrometry, and electron, confocal and light microscopy. You will compare analytical results to thermodynamic geochemical models.

Year 1

Time series hydrothermal experiments using a range of Fe/other transition element minerals. Presentation of initial results at a UK workshop/conference.

Year 2

Further experiments focused on quantifying the rates and mechanisms of the desorption of organic molecules from mineral surfaces, and potential formation of vesicles. Preparation of first manuscript, presentation of results at a UK or international conference (e.g. Goldschmidt).

Year 3

Final experiments focused on characterising the properties and functions of vesicles, including their stability. Preparation of second manuscript, and presentation of results at a UK or international conference (e.g. AGU).

Year 3.5

Completion of final thesis/further manuscripts.

At the start of your studies an analysis of your training requirements will be undertaken and a tailored programme of training and support developed by yourself and their supervisory team. Project specific training will include experimental design, analytical inorganic and organic geochemistry, and thermodynamic modelling.