Please choose the correct answer to the question: A geologist finds a layer of shale near the surface from a certain time period. Nearby, the geologist finds the same layer of shale, but it is deeper underground than the first layer. What might have caused the difference in the depth of the shale layer?

Answer1: a meteorite Answer2: a fault Answer3: ancient fossils Answer4: animal life

Answer format: answer1/answer2/answer3/answer4
Answer: answer2