From the Colorado Plateau to beyond Earth: using magmatic intrusions into sulphate-rich sediments as analogue for planetary habitable environments

The Open University

PhD 3 years Milton Keynes, UK

Uploaded 25 Nov 2018

Job Description


Rocks of basaltic composition dominate the Earth’s oceanic crust, they dominated the Early Earth’s surface and they are ubiquitous on Mars and even Venus. This PhD project will investigate a focused problem of basaltic magma–sediment–water interaction on Earth and extrapolate the findings to the Early Earth and potentially other planetary environments.

This project is designed to investigate a focused aspect of water–magma–sediment interaction: what are the effects of magma intrusion into sulfate bearing soils? For this, the NASA funded consortium team (see ‘Partners’ below) will carry out fieldwork at the San Rafael Swell on the Colorado Plateau, where we have previously identified the interaction of magmatic intrusions with such sulfate veins. The overall project will thereby cover all aspects of mineralogy and petrology, reaction pathways of magma-water-sediment interaction and the effect on the habitability of the site. The main hypothesis that the consortium study will be testing is that the subsurface was a habitable environment that would have contained both the water and the energy necessary to support microbial life, and that the introduction of magma might have briefly sterilized metamorphic aureoles, but the introduction of fluids would have stimulated habitability by introducing new nutrient and energy sources. The OU team thereby focuses on two aspects: 1) thermochemical modelling of the reaction pathways between the original host rock and the resulting alteration phases, and 2) assessing the habitability potential of the resulting environments. The successful candidate will be able to take part in the consortium fieldwork and assist with the in-situ investigations.

The main task of the PhD will focus on thermochemical modelling of the reaction pathways at the San Rafael Swell. This work will be based on expertise gained from previous modelling of Ca-sulfate transport in martian environments, but will be unique in the accuracy achievable when working with detailed ground truth data. The results from the modelling will be the basis of the habitability assessment of this planetary analogue, which can - depending on the interests of the student - include testing of the modelled conditions through microbiological experiments.

Person Specification

Students should have a strong background in Earth sciences or biology and enthusiasm for data analysis and thermochemical modelling (alternatively microbiological work). Experience of thermochemical modeling or microbiological culturing is desirable. The student will join a well-established team researching into fluid rock interaction on Earth and Mars and will be working within an international consortium.

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