Alternating parallel bands of normal and reversed magnetic polarity are found in the basaltic bedrock on either side of 1. the mid-atlantic ridge 2. yellowstone hot spot 3. san andreas fault 4. peru-chile trench

1. the Mid-Atlantic Ridge

Explanation:

The Mid-Atlantic Ridge is a mid-ocean ridge that extends into the South Atlantic Ocean between the South American and African Plates.

Alternating parallel bands of normal and reversed magnetic polarity is found here because basalt contains little magnetic particles that take on the direction of the Earth’s magnetic field at the time of eruption.

These bands are like stripes which shows up on the ocean floor when these variations are mapped.