Scuba diver taking coral samples
Geochemistry

About our research

Learn about the 5 research themes we focus on.

Research themes

Our 5 specific research themes are:

  • Past to future climate change
  • Environmental geochemistry and radioactivity
  • Volcanic and magmatic processes
  • Critical elements and metal deposits
  • Carbon dioxide removal and storage

Past to future climate change

Since the industrial revolution the concentration of atmospheric CO2 and other greenhouse gasses have increased. This has already caused demonstrable climate change. We gain insights into how the climate will change in the future by looking into past time periods.

Key research questions

  • What is the sensitivity of the climate system to CO2 forcing?
  • What is the relationship between CO2, ice-volume and sea level? 
  • What processes drive natural CO2 variability? 
  • How can we improve the methods of reconstructing past climate? 
  • How can our reconstructions of the past be used to better predict the future? 

Methods

We use analytical techniques to measure the chemical and isotopic composition of ancient organisms such as microbes, foraminifera and corals. We then reconstruct::

  • ocean pH and hence atmospheric CO2
  • ice volume and hence sea-level
  • water temperature and hence global climate

Environmental geochemistry and radioactivity

We need to understand the sources, pathways and fluxes of contaminants, and find improved ways to measure, monitor and manage contaminants. We can then mitigate their environmental and human health impacts. 

Key research questions

  • Can we develop improved methods of characterising and managing nuclear wastes, particularly for difficult to measure (DTM) radionuclides and sites undergoing nuclear decommissioning?
  • What are the sources and impacts of urban air pollution, particularly in port cities such as Southampton?
  • Can we develop more sustainable methods for managing toxic “forever chemicals” such as perfluorinated compounds, and other contaminants and contaminated sites?
  • To what extent can we use nuclear fallout as a basal marker for the stratigraphic Anthropocene?
  • What processes moderate the inputs of contaminants from land to sea, through estuaries?

Methods

Our geochemistry and radiochemistry facilities allow us to:

  • determine concentrations and environmental fingerprints of a range of contaminants down to ultra low levels in geological and oceanographic materials
  • study and radiometrically date sediment cores to look at recent environmental and anthropogenic changes
  • develop new techniques for characterising environmental and waste materials
  • ensuring their effective clean-up or risk management

Volcanic and magmatic processes

We investigate the processes occurring during magma production and crustal development to learn how they shape the physical, chemical and biological evolution of our planet.

Key research questions

  • How does the ocean crust form? 
  • How does the ocean crust mature? 
  • What are the dynamics of mantle plumes? 
  • How is crust created by arc volcanism? 
  • What is the role of Sub-aerial volcanism in the burial of organic carbon? 

Methods

We use chemical tracers and isotopic measurements of all types of volcanic materials to:

  • investigate fluid and magma interaction with crustal materials
  • analyse Pb isotopes to provide a toolbox of parameters to track mantle recycling
  • conduct microscopic examination of samples to deduce the processes generating the rock fabrics, crystallisation processes and fluid-rock reactions

Critical elements and metal deposits

The global ambition to build a greener, sustainable economy requires an increased supply of critical elements. These elements include cobalt and lithium for use in batteries and rare earth elements (REE) for production of light weight powerful magnets. Future projections suggest current sources of these elements may not be sufficient to meet increased demand. Some available sources are in geopolitically sensitive areas. 

Key research question

  • Are lithium resources linked to a particular period in continental-collision orogenic events? 
  • Within tectonic settings, what are the key geologic processes resulting in concentrated resources? 
  • What is the fundamental geodynamic and geological context for the development of exceptionally endowed sedimentary basins and how are they best identified? 
  • What are the mechanisms and extent of fluid-rock interaction in developing critical element deposits? 

Methods

We have a fieldwork and sampling programme in areas with proven and potential reserves of critical elements. These include Namibia, Serbia, Turkey, Zambia and Argentina. 

Using samples of whole rock and minerals we:

  • measure chemical and isotopic composition using sample dissolution and in-situ laser ablation
  • analyse samples to determine the petrological, tectonic and hydrothermal processes that enrich critical metals in the resources
  • build models to aid refining exploration targets for critical elements 

Carbon dioxide removal and storage

It is clear that reducing emissions of CO2 won’t be enough to achieve the Paris Agreement goal to limit the increase in global average temperature to 1.5 °C.  We need to remove and store approximately 800 Gt of residual atmospheric CO2 emissions by the end of the century. We research carbon capture and storage in geological reservoirs and greenhouse gas removal from the atmosphere. 

Key research questions

  • What is the efficacy of enhanced rock weathering for CO2 removal? 
  • How quickly does mineral carbonation occur? 
  • Can mine waste be used as a feedstock for enhanced rock weathering? 
  • How can we detect and quantify CO2 leakage from geologic sub-seafloor storage reservoirs? 
  • How can we emulate natural carbon mineralisation in peridotites for engineered CO2 removal from air?
  • What are the fundamental feedback mechanisms between in situ mineralisation and reservoir permeability?

Methods

We are: 

  • conducting large scale field trials to demonstrate the efficacy of enhanced rock weathering by application of finely-crushed basalt to agricultural crops 
  • using stable and radiogenic isotope analysis to verify and quantify CO2 removal
  • using natural and artificial tracers to monitor and quantify transport and transformation of CO2 in the environment
  • developing new techniques to couple direct air capture of CO2 with mineralisation
  • developing reactive transport models to simulate CO2 migration in different geologic storage reservoirs 
  • evaluating potential leakage from sub-seafloor CO2 storage sites in the North Sea to reassure the public that CO2 storage is secure