Vine–Matthews–Morley hypothesis

The Vine–Matthews–Morley hypothesis, also known as the Morley–Vine–Matthews hypothesis, was the first key scientific test of the seafloor spreading theory of continental drift and plate tectonics.

Harry Hess proposed the sea-floor spreading hypothesis in 1960 (published in 1962). According to Hess, seafloor was created at mid-oceanic ridges by the convection of the earth's mantle, pushing and spreading the older crust away from the ridge. Geophysicist Frederick John Vine and the Canadian geologist Lawrence W. Morley independently realized that if Hess’s seafloor spreading theory was correct, then the rocks surrounding the mid-oceanic ridges should show symmetric patterns of magnetization reversals using newly collected magnetic surveys. Both of Morley's letters to Nature (February 1963) and Journal of Geophysical Research (April 1963) were rejected, hence Vine and his PhD adviser at Cambridge University, Drummond Hoyle Matthews, were first to publish the theory in 1963. Some colleagues were skeptical of the hypothesis because of the numerous assumptions made—seafloor spreading, geomagnetic reversals, and remnant magnetism—all hypotheses that were still not widely accepted. The Vine-Matthews hypothesis describes the magnetic reversals of oceanic crust. Further evidence for this hypothesis came from Cox et al. (1967) when he measured the remnant magnetization of lavas from land sites.Walter C. Pitman offered further evidence with a remarkably symmetric profile from the Pacific-Antarctic Ridge.

The Vine-Matthews hypothesis correlates the symmetric magnetic patterns seen on the seafloor with geomagnetic field reversals. At mid-ocean ridges, new crust is created by the injection, extrusion, and solidification of magma. After the magma has cooled through the Curie point, ferromagnetism becomes possible and the magnetic minerals in the newly formed crust orient themselves with the current background geomagnetic field. Lithospheric creation at the ridge is considered continuous and symmetrical as the new crust pushes the old crust laterally and equally on either side of the ridge. Therefore, as geomagnetic reversal occur, the crust on either side of the ridge will contain a record of remnant magnetizations of normal or reversed magnetizations in comparison to the current geomagnetic field. The ridge crest is analogous to “twin-headed tape recorder”, recording the Earth’s magnetic history.

...
Wikipedia