These two things were the magnetic striping on the ocean floor and the age of seafloor rocks.
Magnetic stripes on sea floor.
Magnetic striping magnetic minerals are found in rocks.
The theory of plate tectonics states that the lithosphere which is the earth s outer layer is divided up into a dozens of irregularly shaped plates.
In the 20th century the magnetic survey was conducted in the mid ocean ridge in order to investigate evidence of sea floor spreading.
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.
Magnetic striping of the sea floor after mid ocean ridges and trenches were discovered more evidence was discovered that helped to support the theory that the continents had moved around.
When scientists studied patterns in the rocks of the ocean floor they found more support for sea floor spreading.
By using the magnetometer the magnetic polarity will be shown through a timescale that contains the normal and a reverse polarity.
The discovery of magnetic stripes on the seafloor in the 1950s validated the plate tectonics theory for the geological community.
Evidence from magnetic stripes.
You read earlier that earth behaves like a giant magnet with a north pole and a south pole.
These patterns were unlike any seen for continental rocks.
Surprisingly earth s magnetic poles have reversed themselves many times during earth s history.