School of GeoSciences

School of GeoSciences

Earth and Planetary Science : Geochemical Research

Carbonates in Namibia To understand the fundamental mechanisms and physico-chemical processes of Earth Materials and Fluids, and their interaction, often at the small scale, in order to provide a more fundamental of larger-scale solid Earth processes and evolution. The research employs a range of skills spanning: experimental simulation; numerical and thermodynamic modelling; geochemical analysis of solids and fluids; mineralogical, petrological and textural studies; geophysical detection and monitoring; and field-based geochemical and structural investigation

Processes and mechanisms of fluid (including melt) generation, segregation, transport and reaction at all depths and scales within the earth from the deep mantle to the near-surface are studied, using a range of modern theoretical, experimental and analytical techniques. On the larger scale we address the relationship of fluid flow to deformation, hydrocarbon migration and reservoir quality, mantle plume formation, crustal dehydration and melting, groundwater movement and contaminant transport.

Research Themes

Neoproterozoic Chemostratigraphy : Aqueous Geochemistry : Carbonate Processes : Carbon Storage Research : Diagenesis : Experimental Geochemistry : Igneous Petrology : Metamorphic Petrology


Khowarib capsequence

Neoproterozoic Chemostratigraphy : Simone Kasemann

Isotope geochemical analyses of Neoproterozoic carbonate rocks provide valuable information for ancient ocean conditions during a period of extreme climate change. Recent studies have focused on establishing a detailed record of four stable isotopic systems, B, Ca, and O, in the classic pre- and postglacial Neoproterozoic carbonates in Namibia. The aim is to elucidate the environmental factors governing carbonate precipitation, oceanic pH and atmospheric CO2 concentrations during the initiation, zenith and ultimate demise of severe climate change events. This will further our understanding of the isotope geochemistry of B and Ca as records of seawater compositions. It will also provide fundamental new insights into the methodologies we use to determine and assess levels of atmospheric CO2 through periods of dramatic global climate changes.

Carbon Storage Research : Stuart Hazeldine, Andrew Cavanagh, Stuart Gilfillan, Mark Wilkinson & Jiemen Lu

Emissions of CO2 from the industrialised world are linked to increasing world temperatures and climate change. This problem will become worse, with continued combustion of fossil fuels - including developing economies such as India, China, and SE Asia. It is possible to capture CO2 at point sources, such as fossil fuel power stations, liquify the gas and inject into the deeply-buried porespace of depleted hydrocarbon fields and saline aquifers. Edinburgh and Heriot-Watt Universities have formed the UK's largest expert group to research the geological, geo-engineering and geophysical aspects of ensuring safe storage fro tens of thousands of years. More information, links to our UK networks and publications at SCCS.
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Experimental Geochemistry : Colin Graham & Stephan Klemme

Experimental geochemical research at Edinburgh University investigates fundamental processes that govern the deep interior of the Earth. Modern research in geochemistry is process orientated and in our modern laboratories we aim to simulate a wide range of geochemical processes ranging from partial melting of mantle rock to high grade metamorphism of crustal rocks.

Research topics include aspects of melt generation in the Earth's mantle and the Moon, experimental simulation of recycling of crustal material at subduction zones, phase transitions in the deep Earth, and experimental simulation of metamorphic reactions in the lower crust. To tackle these problems, we use a number of modern and innovative analytical and experimental techniques which include piston-cylinders, multi-anvil apparatus, diamond anvil cells and state-of-the-art analytical equipment such as ion- and electron microprobes, scanning electron microscopes, and several high-resolution mass spectrometers.

In conjunction with experimental studies, we employ numerical modelling approaches to compliment our experimental results and demonstrate the implications of our results for natural systems.


Carbonates

Carbonate Processes : Rachel Wood

Carbonate research uses outcrop data, petrography, geochemistry, and various modelling techniques to understand and quantify both production and diagenetic processes. Recent studies have focused on wireline interpretation and early diagenesis in hydrocarbon reservoirs from the Middle East, particularly Cretaceous ramp systems. A further aim is to understand the changing role of biological processes in carbonate deposition and in the global carbon cycle.

Current PhD projects are:

  • Shallow marine carbonate geological process modelling
  • Statistical interpretation and reconstruction of heterogeneity on image-log data

Aqueous Geochemistry : Bryne Ngwenya

  • Thermodynamics of metal adsorption and mechanisms of metal uptake onto bacterial cells
  • Metal pollution and biogeochemistry in constructed wetlands and in coastal settings
  • Fluid-rock interactions, time-depedent failure and fluid flow in the brittle crust

Diagenesis : Stuart Hazeldine & Mark Wilkinson

Our aims are to reconstruct the porosity and permeability changes in hydrocarbon reservoir sandstones during burial. This requires examination of the pore-fluid history of sedimentary basins, as an aid to understanding where the ions came from, where the ions went to, and how the pore-water moved or did not move.

Other areas of research :

Igneous Petrology : Godfrey Fitton

Metamorphic Petrology : Ben Harte