To provide an understanding of the principles and mechanisms of rock deformation throughout the crust, including the theory of homogeneous stress in two-dimensions, brittle fracture, rock friction, diffusive mass transfer and intracrystalline plastic flow.

(LO1) 1. Knowledge and UnderstandingStudents should:a. Understand how stress is analysed and how it relates to the deformation of rocks.b. Have a knowledge of the mechanisms by which rocks undergo deformation

(LO2) 2. Intellectual AbilitiesStudents should:a. Have a systematic quantitative understanding of the principal deformation processes in geological materials.b. Have an critical appreciation of how experimental data may be used to quantify the mechanical properties of geological materials.c. Be able to criticaally assess the published literature within the subject area and present this in a concise report format.

(LO3) 3. Subject-based practical skillsStudents should:a. Be able to apply analytical and numerical techniques to the analysis of stress and strain in rocks.b. Be able to apply analytical and numerical techniques to the quantification of the deformationbehaviour of rocks at all levels in the Earth.

(LO4) 4. General transferable skillsa. General numeracyb. The ability to present in a report format the finidngs of a laboratory investigationc. Critical thinking and problem solving through resolution of practical problemsd. ICT through report presentation and data processing and analysis

Lecture 1 Introduction. Aims and objectives, course structure,
applicability.

Lecture 2 Stress. Force, stress. Shear stress, normal stress. Theory of stress in 2D. Stress as a tensor. Mohr
diagram.

Lecture 3 Stress and strain. Hooke’s law, elastic constants, generalized form of Hooke’s law. Stress-strain curves, brittle/ductile behaviour, plastic and viscous behaviour. Methods of stress measurement, World stress map. Methods of strain measurement

Lecture 4 Griffith theory. Theoretical strength of materials. Griffith theory of tensile failure, Energy balance, Obriemoff’s experiment. Griffith cracks.

Lecture 5 Irwin’s fracture mechanics. Crack displacement
modes. Stress field surrounding crack tips. Stress intensity factor and Mechanical energy release rate. Limitations to fracture mechanics approach.

Lecture 6 Fracture and fault growth. Fault growth from model cracks. Axial, circumferential and volumetric stra in. Mohr-Coulomb failure criterion, Griffith failure criterion.

Lecture 7 Pore fluid effects on fracture. Mechanical, chemical effects. Law of effective stress. Dilatancy, compaction. Dilatancy hardening. Subcritical crack growth.

Lecture 8 Rock Friction. Amontons''s law. Effect of surface roughness, Bare surface sliding; stabilizing effect of gouge. Internal, dynamic, static friction coefficient.

Lecture 9 Rate and State Friction. Principles and concepts. Velocity strengthening and weakening. Critical slip distance, unified theory for rock failure.

Lecture 8 Earthquake mechanics. Earthquake energy balance, earthquake moment and moment magnitude. Conditions required for earthquake instability.

Lecture 10 San Andreas fault. Tectonic setting. Stress-heat flow paradox. Fault weakening mechanisms

Lecture 11 Brittle – ductile transitions. Effect of temperature, confining pressure, porosity. Ductility and plasticity. Mode of failure versu s mechanism of failure.

Lecture 13 Defects and diffusion. Stacking faults, vacancies, impurities. Diffusion, water assisted diffusion.

Lecture 14 Dislocation creep. Edge and screw dislocations, Peierls stress. Dislocation glide and climb, dislocation creep.

Lecture 15 Recovery and recrystallization. Subgrains, subgrain walls and dislocation tangles. Subgrain rotation - Subgrain rotation recrystallization. Bulge recrystallization. Strain induced grain boundary migration. Cold and hot working.

Lecture 16 Deformation mechanism maps.

Lecture 17 Palaeopiezometry. Grain size as an indicator of
stress. Calcite twinning.

Lecture 18 Deformation of the principal rock forming minerals. Olivine, quartz, calcite, halite. Hydrolytic weakening.

Lecture 19 Crystallographic Preferred orientation. Methods of Analysis, mechanisms, interpretation.

Lecture 20 Overview of crustal rheology

Lab 1Stress and strain analysis
Lab 2 Intact brittle defor mation
Lab 3 Faults and friction
Lab 4 Fracture mechanics
Lab 5 San Andreas stress-heat flow paradox
Lab 6 Crustal strength profile
Lab 7 Mechanical properties
Lab 8 Flow laws and experiments
Lab 9 Analogue experiments
Lab10 Palaeopiezometry
Lab11 Tectonics and rock deformation

Teaching Method 1 - Lecture
Description: Lecture
Attendance Recorded: Yes

Teaching Method 2 - Laboratory Work
Description: Paper and practical exercises
Attendance Recorded: Yes