april 19th Flashcards
what makes rocks ductile? what do ductile rocks do?
ductile rocks bend instead of break! they make synclines and anticlines and overall change shape. rocks are ductile under hotter temperatures, more pressure, slower strain rates/movement, and when they are deep in the earth.
what makes rocks brittle? what do brittle rocks do?
brittle rocks break and fracture. form faults. they are brittle under lower temperatures, less pressure, faster movement, and closer to the surface.
compression?
when something is squished together. makes folds like anticlines.
tension
when something is pulled apart. makes rocks long and skinny.
shear
sliding side to side in opposite directions. makes faults- sort of.
strike and dip??
Strike follows the horizontal line/plane. dip follows the tilt. Dip angle is the difference between the angle the plane moves at and a flat surface.
hinge and limbs
hinge is the spine of the book. limbs are the pages. axial surface goes straight through.
normal fault
pulling apart, result of brittle tension, hanging wall goes down
disconformity
layers are eroded so there is a chronological gap between layers. something deposited after erosion.
angular unconformity
a set of layers got tilted, and then something got put on top.
nonconformity
an invader!! something comes from below…
porosity
amount of water it can hold
permeability
how easy it is for water to seep through
aquifer
rock or sediment that holds and moves water easily
aquitard
slows or stops groundwater
