Mid ocean ridges
sea floor spreading
Sea floor spreading
As the sea floor spreads, the old ocean floor gets pushed out, which makes the plates move.
Seafloor spreading where new floor is formed. Subduction zone where older floor is pushed back into the mantle.
new rocks form
As plankton die, it sinks to the sea floor, and over many years, a sediment is formed.
one plate is moving under another plate
Sea floor spreading
A rift valley will form
It continues to grow upward
Mapping of magnetic anomalies on the ocean floor shows alternating bands of normal and reversed polarity, indicating that new oceanic crust is continuously forming at mid-ocean ridges and spreading away in opposite directions.
Mid ocean ridges are the direct result of sea floor spreading.