Precambrian palaeomagnetic results compatible with contemporary operation of the Wilson cycle

Abstract

Sutures marking zones along which continental blocks have collided can be recognized on geological evidence in rocks with ages from Archaean onward. The existence of these sutures leads to the conclusion that the Wilson cycle of ocean opening and closing has been in operation since early Precambrian times. We have used published palaeomagnetic pole positions to test the validity of this conclusion by plotting APW (apparent polar wander) paths for suture-bounded blocks. We find that APW paths produced in this way fit the palaeomagnetic data better than APW paths for present-day continents or Pangea. Previous suggestions based on the interpretation of palaeomagnetic data that plate tectonics did not operate between about 2500 and 600 m.y. ago therefore appear invalid.