Vine-Matthews-Morley Hypothesis

The Vine-Matthews-Morley hypothesis explains the striped pattern of alternating magnetic polarity found in rock on the ocean floor as direct physical evidence that new oceanic crust forms continuously at mid-ocean ridges and spreads outward over time. British geophysicists Fred Vine and Drummond Matthews at the University of Cambridge proposed the hypothesis in a 1963 paper, and Canadian geophysicist Lawrence Morley independently reached the same conclusion the same year, though his own paper on the idea was initially rejected by two journals before being published in 1964. The hypothesis holds that as molten rock rises and cools into new crust along a mid-ocean ridge, magnetic minerals within it align with Earth's magnetic field at the time and lock in that orientation permanently, so that as the field periodically reverses polarity over geological time, the spreading crust records a symmetric sequence of magnetized stripes running parallel to the ridge on both sides. The hypothesis provided crucial, independently verifiable supporting evidence for seafloor spreading and, through it, for plate tectonics, once oceanographic surveys in the mid-1960s confirmed the predicted symmetric stripe pattern across several ocean ridges.