Topical Field I Localization of deformation, chemo-mechanical feedback
Project I.1: Deformation mechanisms and chemical/mineralogical changes around porphyroblasts/clasts
PI’s: B. Grasemann
Marcin Dabrowski (PGP, Oslo)
Rationale: Inclusions in a progressively deforming rock will influence the stress and strain field around these heterogeneities influencing the bulk rheology of the rock. We will combine high resolution analytical data from fault rocks with mechanical numerical models in order to study the stress and pressure distribution in rocks with inclusions and the possible influence of such heterogeneities on the deformation mechanisms in the surrounding matrix.
Methods: Light microscope, SEM/CL/FIB/STEM/EBSD/EDX, EPMA, whole-rock geochemistry
Project I.2: Chemical vs. petrophysical control on strain localization in porous sediments
PI: U. Exner
Int. Coop.: P. Baud (EOST Strasbourg)
Rationale: Deformation bands are fault zones in high-porosity sediments, usually characterized by a reduction of porosity and permeability caused by grain rotation and fracturing. Analyzing natural samples from sediments with a wide range of mineralogical composition, but similar maximum displacement and burial depth, this project aims to quantify the influence of chemical composition, cementation and alterations on the petrophysical properties and deformation mechanisms. Complementary deformation experiments are performed to constrain mechanical properties of rock samples of different composition.
Methods: Light & CL microscopy, SEM/CL, EPMA, whole-rock geochemistry, XRD, experimental rock deformation (EOST Strasbourg)