Dr Carol Mahoney

Dr Carol Mahoney

Profile

I am a geochemist investigating the effects of past climate change on marine biogeochemistry and nutrient cycling by measuring the elements which accumulate in sediments and by using scanning electron microscopy to investigate short timescale changes.

After an MSc in Petroleum Geochemistry (2012-2013) focussing on organic geochemistry at Newcastle University, I transitioned to using inorganic geochemistry to investigate Cretaceous age organic-rich mudstones from Colombia during my PhD (2014-2018), also at Newcastle. Since March 2018, I have been a member of the Science Party for IODP Expedition 381 hosted at SEE at Leeds. For this project, I am investigating the effects of glacial-interglacial cycles on sediment geochemistry in newly collected samples from the Gulf of Corinth.   

Research interests

  •  Carbon burial in extreme greenhouse periods – The shales of the Eastern Cordillera of Colombia span the majority of the Cretaceous – an extreme period of global warming. During my PhD I used bulk and trace metal contents to investigate how this climate may have led to extreme carbon burial in the basin.
  •  Iron and sulphur dynamics in different water column environments – the type and amount of Fe and S species in sediments can help identify periods where the overlying water column was oxygen depleted – conditions which increase carbon burial in the ocean. During my PhD I was able to identify anoxic conditions in Colombia during the Cretaceous. Iron and sulphur also behave very differently in brackish/freshwater environments and this also effects the bioavailability of P, a key nutrient. The newly collected Gulf of Corinth sediments (IODP Expedition 381) offer the opportunity to investigate these dynamics, as the Gulf became brackish/fresh during glacial low sea level stands in the Quaternary.
  • The effect of pyrite oxidation on the release of Fe and trace metals from shales – The release of S and trace metals from shales exposed at outcrop or during anthropogenic activities is a well-researched phenomenon in terms of water quality and human health as these elements re-enter the surface environment, but it is also a problem for geochemists hoping to reconstruct past environments. The Cretaceous shale samples used in my PhD had been exposed to oxidative weathering in tropical conditions at outcrop. I use statistical techniques and an experimental set-up to investigate the effects of weathering on the bulk and trace metal inventory.
  • Novel applications of Scanning Electron Microscopy to investigate short term changes in geochemistry – in close collaboration with researchers at Heriot-Watt University, I have been involved with projects using novel techniques and procedures to investigate the geochemistry and mineralogy of fine grained rocks.
     
<h4>Research projects</h4> <p>Any research projects I'm currently working on will be listed below. Our list of all <a href="https://environment.leeds.ac.uk/dir/research-projects">research projects</a> allows you to view and search the full list of projects in the faculty.</p>

Qualifications

  • PhD, Earth Sciences, Newcastle University, Geochemical Characterisation of Cretaceous Source Rocks
  • MSc, Petroleum Geochemistry, Newcastle University
  • BSc(Hons), Environmental Geosciences, University of Edinburgh

Professional memberships

  • The Geological Society - Member
  • European Association of Geochemistry - Member