-study of faulting and folding of rocks

(effects of deformation)

-magnitude & direction of defroming force on surface

-force applied over an area

(force per unit area)

Confining

(Uniform Stress)

-applied by weight of overlying rocks

-equal in all directions by pressure

-still looks the same in layers

-body to change size not shape

Tensional

(differental stress)

-stress on body that causes stretching and elongation

-pulling apart

-rocks change shape

-streach & thinning faulting

(stress not equal in all directions)

Compressional

(differental stress)

-stress that squeezes and compresses body

-pushes it together

-rocks change shape

-folding or faulting

(stress not equal in all directions)

plate tectonics= subduction

Shear

(differental stress)

-force on body causing slippage or translation

-one direction on top/ opposite direction on buttom

-rock change shape

-shearing & faulting

(stress not equal in all directions)

plate tectonics-transform

measure of changes in

-length

-volume

-shape

in a stressed material

-observable deformation in the rock

-reversible change in change (volume or shape) in rock

-springs back to orginal form

-nonpermanent

(ex. rubberband)

-limiting stress

-solid has permentant deformation

-does not return to orginal size or shape once stressed is removed

-undergoes smooth, plastic deformation

-permentally deform

-flow, no breakage

-irreversable change in shape and/or volume

-stress beyond elastic limit

(butter-bends)

-limits of both elastic and ductile has exceeded

-Brittle substance

-irreversible kind of deformation

(chalk-broke)

higher temp

-increase ductility & less brittle solid becomes

 lower temp

-uniform squeezing of rock, by overlaying strata

-reduction of brittleness

High Confining Pressure

-rocks experience ductile deformation=bend and flowing

-rate a rock is forced to change volume or shape

-measured in volume per unit or second

-fracture or ductile

Rock Composition

 minerals make up rocks properties

-quartz, garnet, olivine=brittle

(fracture easily)

-mica, clay, calcite,gypsum=ductile

(flow easily)

Water content

-reduces brittle, enchances ductile

-weakens chemical bonds

Above 15km rocks are

strong=fracture

Below 15km rocks are

fractures less common=increasing ductile

(bc quartz weakens)

-bearing line definded by intersection of the plane and the horzontal

(waterline marks strike)

-acute angle btw plane and horizontal

-perpinducular to strike

changes in 

-shape

-position

-orientation of a body

-subjected to great stress that exceeds the yield point 

(elastic limit)

-subjected to sudden stress 

(impact

-does not spring back

-keeps deformed shape

-chewing gum

-causes- high temp (near melting or high pressure)