Hydrothermal inputs to global geochemical cycles: a novel high resolution approach to quantifying hydrothermal exchange

To apply please use the online application form, simply search for PhD Geological Science and clearly state that you are applying for an ARIES PhD studentship and name the project SOGEES-1022-S1-P2 (ARIES, Harris), at the top of your personal statement.

Online application

Whilst you can apply for up to three ARIES projects, you must submit a separate application for each.

Take a look at the Doctoral College information on applying for a research degree.

Supervisors

Dr Michelle Harris

Professor Antony Morris

Dr Rebecca Greenberger (California Institute of Technology)


Competition Funded PhD Project (Students Worldwide)

 

Project details

Scientific background

Global geochemical cycles are fundamental to the Earth system; where, when, and how much elements are cycled through the Earth underpins a broad range of science, including our understanding of ocean chemistry and how the oceans will be impacted by future climate change. Geochemical fluxes from deep sea hydrothermal systems, where seawater circulates through the seafloor and exits back into oceans via hydrothermal vents, are a key component of global geochemical cycles. The ocean crust preserves this fluid/rock interaction (“hydrothermal alteration”) and by analysing these crustal rocks we can estimate the hydrothermal geochemical flux. However, such studies are limited by poor core recovery by scientific ocean drilling and the time-limitations of mineralogical and geochemical studies.

To advance our understanding of hydrothermal budgets, we need higher resolution characterisation of the distribution and composition of hydrothermal alteration throughout the ocean crust. To achieve this, micro-imaging infrared spectroscopy datasets can be collected on recovered drill core, where mineral specific spectral fingerprints can identify the minerals present at sub-mm resolution. This novel project aims to redefine our geochemical budgets by using preserved hydrothermal alteration sampled by drill cores from the Oman Drilling Project and from the International Ocean Discovery Program to calculate geologically robust estimates of hydrothermal geochemical fluxes.

 

Research methodology

The individual will (1) use micro-imaging spectroscopy datasets to define a set of hydrothermal alteration types in the drill-cores and interpret their abundance and distribution; (2) use representative samples of the different alteration types to characterise the geochemical (major and trace elements and isotopic compositions) variability, and (3) integrate the abundance of alteration types with their geochemical variability to calculate geologically robust geochemical fluxes.

 

Training

The individual will develop a range of industry and academia relevant skills, with specialist training in micro-imaging spectroscopy and a range of analytical geochemistry (including XRF, ICP-MS and isotopic analysis). The successful candidate will join an international team of researchers including the broader Oman Drilling Project Science team and the ocean drilling community.

 

Person specification

This PhD is suitable for individuals with degrees in Geology/Earth Sciences with interests in petrology, geochemistry and big-picture Earth Science questions.

 

Funding notes

This project has been shortlisted for funding by the ARIES NERC DTP and will start on 1 October 2022.

Successful candidates who meet UKRI’s eligibility criteria will be awarded a NERC studentship for 3.5 years, covering fees, stipend (£15,609 p.a. for 2021-22) and research funding. International applicants (EU and non-EU) are eligible for fully-funded UKRI studentships.

ARIES students benefit from bespoke graduate training and £2,500 for external training, travel and conferences.

ARIES is committed to equality, diversity, widening participation and inclusion. Academic qualifications are considered alongside non-academic experience. Our recruitment process considers potential with the same weighting as past experience.

For information and full eligibility visit https://www.aries-dtp.ac.uk/

References

Greenberger, RN., Harris, M., Ehlmann, BE., Crotteau, M.,Kelemen, PB., Manning, CE., Teagle, DAH., and the Oman Drilling Project ScienceTeam (inc. Antony Morris) (2021) Hydrothermal Alteration of the Ocean Crust andPatterns in Mineralization with Depth as Measured by Micro-Imaging InfraredSpectroscopy. JGR Solid Earth. doi.org/10.1029/2021JB021976

2) Harris M, Coggon RM, Wood M, Smith-Duque CE, HenstockTJ, Teagle DAH (2017) Hydrothermal cooling of the ocean crust: Insights fromODP Hole 1256D. Earth and Planetary Science Letters, 462:110–121. https://doi.org/10.1016/j.epsl.2017.01.010

3) Vance D, Teagle DAH, Foster GL (2009) VariableQuaternary chemical weathering fluxes and imbalances in marine geochemicalbudgets. Nature, 458(7237):493–496. https://doi.org/10.1038/nature07828

4) Coggon RM, Teagle DAH, Harris M, Davidson GJ, Alt JC,Brewer TS (2016) Hydrothermal contributions to global biogeochemical cycles:Insights from the Macquarie Island ophiolite. Lithos, 264:329–347. https://doi.org/10.1016/j.lithos.2016.08.024

5) Greenberger RN, Mustard JF, Ehlmann BL, Blaney DL,Cloutis EA, Wilson JH, Green RO, Fraeman AA (2015) Imaging spectroscopy ofgeological samples and outcrops: Novel insights from microns to meters. GSAToday, 25(12):4–10. https://doi.org/10.1130/GSATG252A.1