On the other hand unlike puzzle pieces some plates are being pushed underneath other plates usually oceanic under continental and new crust is being formed at spreading rifts.
In sea floor spreading pieces of oceanic crust.
This idea played a pivotal role in the development of the theory of plate tectonics which revolutionized geologic thought during the last quarter of the 20th century.
Seafloor spreading theory that oceanic crust forms along submarine mountain zones and spreads out laterally away from them.
Move apart along a divergent plate boundary.
Basalt the once molten rock that makes up most new oceanic crust is a fairly magnetic substance and scientists began using magnetometers to measure the magnetism of the ocean floor in the 1950s what they discovered was that the magnetism of the ocean floor around.
Move down in a subduction zone.
The process of sea floor spreading.
These age data also allow the rate of seafloor spreading to be determined and they show that rates.
The magnetism of mid ocean ridges helped scientists first identify the process of seafloor spreading in the early 20th century.
Youngest red is along spreading centers.
As upwelling of magma continues the plates continue to diverge a process known as seafloor spreading samples collected from the ocean floor show that the age of oceanic crust increases with distance from the spreading centre important evidence in favour of this process.
In sea floor spreading pieces of oceanic crust.
Age of oceanic lithosphere.
The oceanic crust is composed of rocks that move away from the ridge as new crust is being formed.
Move sideways against each other along a transform plate boundary.
Move together along a convergent plate boundary.
The formation of the new crust is due to the rising of the molten material magma from the mantle by convection current.