THE INTERNAL STRUCTURE: ROCK BEHAVIOR AND SEAFLOOR SPREADING Flashcards
(28 cards)
Is the force that pushed and pulled plates that acts on the rocks which create different behavior or characteristics
geological stress
Rocks responds to stress by deforming elastically
elastic deformation
2 kinds of elastic deformation:
ductile deformation
brittle deformation
it either flows
ductile deformation
It fractures in
brittle deformation
is the process by which the crust is deformed along tectonic plate margins.
DEFORMATION
produces a variety of geologic structures such as folds and faults, joints and foliation.
DEFORMATION
a bend in rock that is response to compressional force. It can be linked to the waves in the ocean
Folding of the crust
most visible in rocks that contained layering
Folding of the crust
a convex up fold in rock that resembles an arch like structure with the rocks beds (or limbs) dipping away from center of the structure.
Anticline
the rock layers are warped downward
Syncline
when the stress overcome the internal strength of the rock resulting in a fracture.
Faulting of the crust
Faulting of the crust is the __________ of once connected blocks of rocks along a fault plane.
displacement
is a geologic process in which tectonic plates split apart from each other as a result of mantle convection.
SEAFLOOR SPREADING
is the slow, churning motion of the earth’s mantle.
Mantle Convection
currents carry heat from the lower mantle and core to the lithosphere
Convection
a German geophysicist, and meteorologist
he theorized that all of Earth’s continents had once existed as a single land mass
ALFRED WEGENER
continent of single land mass
pangea
between 275 and 175 million years ago Pangaea began to separate.
between 275 and 175 million years ago Pangaea began to separate.
a professor of geology and former US Navy
HARRY HESS
Used SONAR (also called echo sounding)
HARRY HESS
Hess believed that ocean trenches were the locations where the ocean floor was _______ and _____
destroyed and recycled
books made by harry hess
The History of Ocean Basins’ in 1962 & ‘Sea Floor Spreading’
3 Evidence for seafloor spreading
Molten material
Magnetic stripes
Drilling samples