Microtectonics Masterclass Part II


The course treats all aspects of microstructures visible in thin sections, and gives information on other possible means to study microstructures such as electron microscopy and tomography. Topics treated during the course, and some examples of content are:

  • What is a microstructure:Principles of microtectonic analysis, overprinting relations, deformation phases and tectonic phases, pitfalls and possibilities
  • Flow and deformation:Theory of flow, deformation, strain, elasticity, vorticity, rheology, deformation mechanisms
  • Intracrystalline deformation:Cataclastic flow, fractures, pressure solution, deformation lamellae, deformation maps, grain boundary sliding, vacancies, interstitials, dislocations, subgrains, recrystallisation mechanisms, twinning
  • Foliations and lineations:Schistosity, primary and secondary foliations, tectonic layering, pencil cleavage, slaty cleavage, crenulation cleavage, chlorite stacks, flame foliation, object and trace lineations, slickensides, lattice preferred orientation patterns
  • Shear zones:Brittle fault rocks: gouge, breccia, pseudotachylyte, mylonite, ductile and brittle shear sense indicators, shear band cleavage, porphyroclasts, mantled clasts, sigmoids, mica fish, flanking folds, asymmetric boudinage, foliation boudins
  • Veins and fringes:Bedding parallel veins, flanking structures, antitaxial and syntaxial structures, strain shadows, strain cap, fringes, fibrous veins, elongate crystals
  • Porphyroblasts:Porphyroblasts and metamorphism, internal and external foliations, spiral garnets, millipede structures, deformation schedules
  • Metamorphic reaction rims:Coronas, double coronas, moats, kelyphitic structure, mimetic growth, myrmekite, interpretation of metamorphic overgrowth
  • Other techniques:SEM, TEM, EBSD, micro-tomography, AVA, analogue modeling, computer modeling, ELLE, FLAC

Topics are treated through an alternation of lectures and microscopy practicals. Each lecture is immediately followed by a practical where the structures treated in the lecture can be investigated in thin sections. We have 20 binocular microscopes, and each participant can use a private microscope during the course.

The practical part of the course is based on our Microtectonics Collection of 300 selected thin sections with clear examples of specific structures. Participants get the opportunity to study the main collection of 300 sections during the 4 day practical. Where relevant, samples of the microstructures seen in this section are shown as examples. We have an additional collection of more complex thin sections which participants can also study if they have enough time.