thermoremanent magnetization

/ thûr′mō-rĕm′ə-nənt /

1. The magnetization that an igneous rock acquires as the temperature of the magma or lava from which it forms falls below the Curie point during the cooling and solidification process. The thermoremanent magnetization bears the signature of the magnetic field (usually the Earth's magnetic field) in which the rock is located as it forms.
2. See Note at magnetic reversal