Ailsa Roper

Ailsa Roper


I am a PhD student in the Earth Surface Science Institute (ESSI), part of the School of Earth and Environment at the University of Leeds. I previously graduated with a Masters in Chemistry at the University of York, with a focus on analytical and archaeological chemistry. My research examines changes in nutrient and oxygen availability in the water column from just before the Triassic-Jurassic (T-J) boundary extinction through the Early Jurassic. This period is known for shifts in the climate and carbon cycle but little is known about the interactions of these with other nutrient cycles, such as phosphorous, and their relationship to water column oxygenation. 


Research interests

This project examines changes in nutrient and oxygen availability across an extended period of Earth history from just before the Triassic-Jurassic (T-J) boundary extinction, through its recovery interval and into the environmental changes that characterised the early Jurassic. This time period contains major shifts in climate and the carbon cycle (Hesselbo et al., 2000; Korte and Hesselbo, 2011; Korte et al., 2015) but little is known about the interacting cycles of nutrients such as phosphorus and carbon, and their relationship to water column oxygenation during these time periods. 

The T-J extinction is one of the ‘big five’ extinction events of the Phanerozoic, but perhaps one of the most enigmatic, whilst the early Jurassic contains the well-known early Toarcian anoxic event, transitions in and out of an icehouse climate in the Pliensbachian, and less well understood environmental changes such as those at the Sinemurian-Pliensbachian boundary and the late Pliensbachian. 

Multiple cores from Sirius Minerals operations in Yorkshire, coupled with pre-existing cores stored at the British Geological Survey and coastal outcrops, represent a transect of the shallow sea that covered much of Europe at this time and offers a unique opportunity to evaluate how the events of this time interval unfolded. 

This project applies a range of techniques to understand the cycling of nutrients and their interaction with the oxygenation state of the water column, including sediment phosphorus speciation (analysis of the phosphorus present in different associations in the sediment), oxygenation quantification (e.g. by biofaces schemes, iron speciation and framboid size measurements) and belemnite phosphate analysis. 

I am funded by the North York Moors National Park (NYMNP) and their ‘Section 106’ planning agreement with Sirius Minerals (SM). 



  • MChem, Chemistry, University of York

Research groups and institutes

  • Earth Surface Science Institute
  • Cohen Geochemistry
  • Palaeo@Leeds