The impact of faults and dykes on fluid flow in the Mercia Mudstone Group

Project Overview

The Mercia Mudstone Group (MMG) is a key target to host a geological disposal facility in the UK. The low porosity and permeability of the MMG indicate it is likely to form an effective seal to fluid flow around radioactive waste. However, heterogeneities exist such as lithological variations, tectonic discontinuities (e.g., faults), and igneous intrusions (e.g., dykes). It is necessary to investigate whether the mechanical and thermal damage on the host rock associated with fault propagation and dyke emplacement results in these features acting as barriers (compartmentalising or inhibiting fluid flow) or providing pathways (facilitating fluid flow, possibly due to their segmentation). This project aims to determine the geometries of the faults and dykes, their influence on the petrophysical properties of the MMG, and any implications for fluid flow, using integrated high-resolution mapping, petrographic microanalysis, and rock deformation experiments.