SEAFLOOR MAGNETIC ANOMALIES

1963 – VINE & MATTHEWS PROPOSED THAT MAGNETIC ANOMALIES RESULT AS NEW CRUST FORMED BY MAGMATISM AT THE RIDGE, ACQUIRING THE POLARITY OF THE EARTH’S MAGNETIC FIELD AT THE TIME, AND THEN MOVED APART

THE CRUST THUS FUNCTIONS AS A TAPE RECORDER

(Press & Siever)

THE HISTORY OF MAGNETIC REVERSALS GIVES THE AGE OF A PIECE OF CRUST, AND THE DISTANCE OF THAT CRUST FROM THE RIDGE SHOWS HOW FAST THE RIDGE IS SPREADING