Question

When igneous rocks form, they can record the orientation of the Earth's magnetic field at that time. Analysis of rocks on the seafloor show that

a. the Earth's magnetic field has never reversed polarity

b. periods of reversed polarity occur in random, irregular patterns across the seafloor

c. periods of reversed polarity occur n symmetric stripes across mid-ocean ridges

d. periods of reversed polarity occur only at the north and south poles

Answer 1

b.periods of reversed polarity occur in random, irregular patterns across the seafloor

Explanation:

Magnetostratigraphy uses the polarity reversal history of the Earth's magnetic field recorded in rocks to determine the age of those rocks. Reversals have occurred at irregular intervals throughout Earth history. The age and pattern of these reversals is known from the study of sea floor spreading zones and the dating of volcanic rocks.