What element is responsible for creating the magnetic stripes on the ocean floor?

Magnetic stripes on the ocean floor is due to iron content of the rocks of the ocean floor.

Explanation:

The rock of the ocean floor contains iron, which stated initially as molten material that cooled and hardened after a period of time. As the rock cooled, the iron bits inside it aligns in the direction of Earth's magnetic poles due to its influence.

The magnetic pattern develops as oceanic crust pulls apart and the flip of the  planet's magnetic field. The magnetic stripes is an hallmark of sea floors.

the area between the graph and the t axis