Role of Microbial Processes in Carbon Storage in Kimberlite Rocks and Tailings

Speakers: 
Dr Evelyn Mervine, Senior Project Geoscientist, Anglo American and Adjunct Fellow, UQ
Thomas Jones, PhD Candidate, UQ
Jordon Poitras, PhD Candidate, UQ

Abstract:  Kimberlite rocks and tailings have the potential to store large amounts of CO2 through carbon mineralisation reactions that convert primary ultramafic minerals to secondary carbonates. Unfortunately, these reactions occur slowly as a natural part of the carbon cycle. However, if weathering can be accelerated, these reactions can offset anthropogenic emissions at diamond mine sites. The challenge, then, is finding ways to cost effectively accelerate these reactions. An exciting pathway for accelerating these reactions at low cost is through use of microbial catalysts, i.e. adding biofilms to tailings facilities.  This talk will provide a brief overview of carbon mineralisation potential at diamond mine sites, including a high-level overview of De Beers’ Project CarbonVault R&D initiative. The talk will also discuss two on-going research collaborations between De Beers and UQ Professor Gordon Southam’s geomicrobiology laboratory, that are focused on understanding the role of microbes in kimberlite alteration reactions. The first collaborative project consists of experiments designed to quantify microbial influences on kimberlite alteration processes, including serpentinisation and carbonation reactions. The second collaborative project consists of lab (~30 g) and field-scale (~800 kg) experiments studying interactions between kimberlite tailings and biofilms. These experiments are currently underway in both Australia and South Africa.

Bio: Dr Mervine currently works as a Senior Project Geoscientist for Anglo American. She is also an Adjunct Fellow at The University of Queensland. Previously, she worked as a Climate Change Specialist and Senior Geologist for De Beers Group. She holds a BA in Earth Sciences and Arabic Language & Literature (double major) from Dartmouth College and a PhD in Geology, which was jointly awarded by the Massachusetts Institute of Technology and Woods Hole Oceanographic Institution. She is currently studying (part-time) for a MSc degree in Carbon Management from The University of Edinburgh.