1. Structures & textures 1

2. Today Updates: Evaluation today at end of class Lecture outline:
Deformation and textures
Timing of crystal growth and deformation

3. Metamorphic Textures Textures are small-scale penetrative features
Relict Textures
Inherited from original rock
Blastoporphyritic (<-> porphyroblastic)
Any degree of preservation
Pseudomorphs of minerals or pre-metamorphic textures/structures
New Textures (following)

4. New Textures

5. Pressure solution

6. Deformation within a crystal

7. Point defect

8. Line defect: edge dislocation
virtual2002.tau.ac.il/users/www/68379/PDF_Papers/2_Micro_Macro/Dislocations.pdf

9. Slip
virtual2002.tau.ac.il/users/www/68379/PDF_Papers/2_Micro_Macro/Dislocations.pdf

10.
Deformation twins

11. Recovery Crystals recover from strain by: Migration of
Vacancies
Dislocations
Annihilation (opposite sense dislocations)
Polygonization- general term for formation of low-strain subgrains: dislocations gather

12. Defect migration

13. Extinctions and subgrains

14. Recrystallization Simple way to reduce lattice strain
Grain boundary migration
Subgrain rotation
Solid-state diffusion creep at higher T
Grain boundary sliding and area reduction
Coalescence- recovery and recrystallization by which large grains form by the addition of smaller strained grains by grain boundary migration

15. Grain boundary migration and sub-grain rotation

16. Coalescence in quartzite

17. Examples of pre, syn, post-kinematic crystals

18. Syn-kinematic crystals
Microboudinage: Growing zones try to keep up with stretching and breaking
Spiral Porphyroblast: in shear zone shear results in crystal rotation: foliation captured, crystal rotates a bit, grows/captures

19. Syn-kinematic garnet