Bob Bamberg, Postgraduate Researcher

The physical and mechanical properties of natural fault zones in basaltic volcanic rocks

Contact DetailsBob Bamberg

Project Overview

My research focusses on the mechanical significance of inherited structure and alteration in basaltic fault zones as well as their evolution through time. Better understanding these fault zones could greatly benefit geothermal applications and subsurface carbon storage (CCS), for which basaltic rocks are a prime target lithology. Fault zones in basalt show extensive evidence of fluid channelling and associated chemical weakening in the form of alteration from primary plagioclase, pyroxene, and volcanic glass to a zeolite and clay dominated assemblage. My aim is to understand how and when this weakening takes place and how it is linked to the structural evolution and activity of the faults.

Answering these questions requires a multiscale and multidisciplinary approach of:

  1. Developing a 4D structural model of the fault zone from (micro-) structural analysis.
  2. Chemical/petrological characterisation using optical and electron microscopy, XRD, and XRF.
  3. Dry and wet rock deformation experiments under crustal pressure and temperature conditions, potentially including fluid flow simulation.

Research Questions

  • What is the geometry and internal organisation of a basalt-hosted fault zone?
  • What is the mineralogic and chemical alteration sequence during fault zone evolution, and which parts of the fault are affected?
  • How strong are the individual fault rock types and what are the effects of inherited structures and alteration from previous tectonic activity?
  • How is strain distributed in a fault zone with respect to pre-existing structures and mineral assemblage during reactivation?
  • How do these structures evolve during reactivation?
  • How does permeability evolve during deformation?

Publications

Research Theme

Solid Earth

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