The ocean plates spread and grow in opposite directions so rocks that are equidistance from the center have the same magnetic polarity and age.
Sea floor spreading ages.
Every so often it has occurred over 170 times over the past 100 million years the poles will suddenly switch.
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.
Spreading rate is the rate at which an ocean basin widens due to seafloor spreading.
As the magma and lava cool at seafloor spreading centers whatever magnetic field is present get ingrained into the rock.
The oldest sediments so far recovered by a variety of methods including coring dredging and deep sea drilling date only to the jurassic period not exceeding about 200 million years in age.
These age data also allow the rate of seafloor spreading to be determined and they show that rates.
Spreading rates determine if the ridge is fast intermediate or slow.
Measurements of the thickness of marine sediments and absolute age determinations of such bottom material have provided additional evidence for seafloor spreading.
Evidence of sea floor spreading.
Seafloor spreading occurs along mid ocean ridges large mountain ranges rising from the ocean floor.
This evidence was from the investigations of the molten material seafloor drilling radiometric age dating and fossil ages and the magnetic stripes.