Which two main archives preserve the historical signature of the Earth's magnetic field orientation?

Answer

Volcanic rocks and sediments

Volcanic rocks preserve the magnetic field direction as they cool below the Curie temperature, while sediments trap the field direction as iron-rich minerals align while settling on the ocean floor.

Which two main archives preserve the historical signature of the Earth's magnetic field orientation?

#Videos

Why Does the Earth's Magnetic Field Keep Flipping? - YouTube

EarthCorereversalmagnetic fieldgeophysics