Primary and non-tectonic structures
Force and Stress
Deformation and Strain
Rheology
Brittle Deformation
100
Any Definable shape or fabric in a rock body
What is Geology Structure
100
What type of stress is perpendicular to the plane?
What is Normal Stress
100
Deformation is the total transformation from the initial to the finlal geometry in a body. deformation is described by these four things?
1. rigid body translation (translation) 2. rigid body rotation (spin) 3. strain 4. volume change (dilation)
100
Plasticity vs. elasticity?
Plasticity - deformation mechanism that involves progressive breaking of atomic bonds without the material losing coherency elasticity - recoverable(non-permanent) = instantaneous strain
100
Brittle deformation is _______ (i.e. distortion remains when the stress is removed)
What is nonrecoverable
200
Define penecontemporatneous and give an example.
1. Occured after sedimentation, but before lithificaiton ex. The faults and folds that occur during a debris flow, slumping
200
What is the difference between Newtonian and Continuum mechanics
Newtonian - studies the action of forces on rigid bodies (breaks down when we consider interactions that involve movement and distortion) Continuum - material is treated as a continuous medium (provides us with a straight forward mathematical description of deformation
200
The material lines that remain perpendicular before and after strain are called?
Principle strain axes
200
the ability of a material to shorten parallel to the compression direction without thickening in the perpendicular direction.
What is Poisson's ratio.
200
What is the difference between a joint and a fracture
joint - a natural fracture which forms by tensile loading (extension the walls move apart slightly and the joint develops) Fracture - a surface in a material across which there has been a loss of continuity and therefore strength
300
Name and describe the four types of unconformities. (there are five, but the book only covers four)
1. disconformity - period of non deposition and or erosion 2. Angular uncon - bedding below the unconformity has a different attitude(angled) than the above strata 3. nonconformity - sedimentary on top of crystalline rock 4. buttress unconformity - when younger bedding is deposited against older strata thus influencing its bedding structure.
300
______ is what allows deformation to occur(sigma1-sigma 2)
What is Differential stress
300
The component that describes the rotation of material lines with resprect ot he principal strain axes is called what?
What is internal vorticity
300
If I have a low strain rate, the ductility _______, and strength reduces.
What is increases.
300
A.W. Griffith resolved the strength paradox by postulating what?
all materials contain preexisting microcracks or flaws at which stress concentrations naturally develop
400
if gravity is the only reason for salt movement, the deformation resulting from its movement is called ______ and the resulting body of salt is called a _____ ________.
Halokinesis and salt structure
400
You are looking at a face that is normal to the x-axis, what are the stress(normal stress) and shear axis? *
Normal = sigma xx Shear = Sigma xy and sigma xz
400
In homogenous strain how do the following things change? originally straight lines become ____. Circles become _____.
Straigh lines remain Straight Cirlces become ellipses
400
What is the relation ship between pore-fluid pressure and confining pressure?
Inverse (the higher the pore-fluid pressure the lower the confining pressure)
400
initiation of brittle deformation involves three phenomena. Name them in order.
1. Tensile crack growth(think of Griffith cracks) 2. Shear-fracture development 3. frictional sliding
500
Volcanic ash that settles into a hot layer welds together to form an ______
ignimbrite
500
_____ stress results in a volume change.
What is isotropic stress.
500
In longitudinal strain, elongation results in a ______ value. In volumetric strain, a volume gain results in a _______ value.
What is Positive
500
Draw a generalized (standard) creep curve, which shows primary, secondary, and tertiary creep.
See figure 5.2 a on page 93.
500
There are 3 ways that brittle fault movement occurs(after it has been formed) Name 2 of these.
1. frictional sliding 2. slip by growth of fault-surface veins 3. cataclasis and cataclastic flow (cataclasis refers to the movement of a fault in a combination of microcracking, friction sliding of fragments past one another, and rotation and transport of grains)
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