How does the ocean floor preserve evidence of past magnetic reversals.
A) Magnetic particles in basalt orient with the magnetic field in force at the time the oceanic lava cooled and hardened.
B) Isotopic analysis of ocean core sediments help determine sea floor age and this can be used to infer past magnetism.
C) The ocean floor is uniformly old, preserving the Earth's 4.6 billion history.
D) Mantle hot spots are always oriented to the magnetic field.

Question

Quizplus · Accepted Answer

Magnetic particles in basalt align with Earth's magnetic field when the lava cools and solidifies, preserving a record of the magnetic field direction at that time. This creates a pattern of magnetic stripes on the ocean floor that records past magnetic reversals.

How Does the Ocean Floor Preserve Evidence of Past Magnetic