Mesozoic complementary crust in the North Atlantic

Abstract

Detailed surveys of complementary oceanic crustal sections have been carried out over Mesozoic magnetic anomalies M4–M0 (∼116–110 Myr BP) in the North Atlantic Ocean. We report here reconstructions of these crustal sections, one on the North American plate and one on the African plate, as they once existed together at the ridge crest using a statistical least squares technique, as well as by eye. The reconstructions allow a test of plate rigidity and consequently a refinement of the reconstruction of the whole North Atlantic in these times. Previous reconstructions had the uncertainty that the correct sections were being matched; the gentle curvature of the Mesozoic plate boundary provides little constraint along the strike of the boundary. The unique local pattern of the magnetic anomalies and their offsets in the surveyed areas allows an unambiguous match.