Mid-Ocean ridge
asnthenosphere mantle raises up, creating “pillow basalt”. Sulphide small crabs f
outer core
Outer core is liquid
inner core
Inner core is solid
Three Types of Plate Boundaries
Divergent Boundaries
“Hot Plumbs push crust apart”
- hot plumb below the from the asnthenosphere
- normal faults start forming
- earth crust splits apart, became balsaltic material
- sinks down
- seafloor spread!
Convergent Boundaries
Ocean-Ocean case
- Older, colder, denser plate plunges into younger hotter plate
- Older plate (hard and dense) submerges below the younger plate
This is also why over convergent boundaries the diving plate becomes “deeper” during collisions
Ocean-Continental Case
Ocean goes under continual plate. This creates an “accetionary prism”, which is like a bulldozer which pull things
Continent-Continent Collision
Giant mountain belts since both are “light and fluffy” and hence nothing dives down
Transform Faults
Plates never most past each other very cleanly (i.e., in a normal direction.) and so they crap and move up material with fault trace, pulverizing the material in the mdidle and the rock erode away
Types of Faults
normal faults
Extension of the crust: hanging wall moves down. (i.e. some kind of plaboundary causes left/right stretch, and then the ground breaks open)
reverse faults
left and right squeese, creating a more than 60deg fault
thrust fault
shortening, like reverse fault squeeze, but the slope is more gendle (< 30%)
strike-slip fault
sliding laterally across each other
epicerter
we can find by comparing p and s wave arrival times