R.A. Daly’s early model of seafloor generation 40 years before the Vine–Matthews hypothesis: an outstanding theoretical achievement inspired by field work on St. Helena in 1921–1922
Large-scale lateral mobility of the Earth’s lithosphere (mobilism) was a hotly debated issue in Earth Sciences during some two decades following publication of Wegener’s (1912) theory of continental displacement. The final acceptance of lithospheric mobility was brought about with the plate tectonics revolution during the late 1960s. Support for mobilism was rather popular in certain European countries during the 1920s, whereas the reactions in North America were mostly hostile. One of the very few influential mobilists in the New World was Reginald Aldworth Daly of Harvard University. The present paper discusses his model of continental displacement which is very remarkable in many aspects. We focus on the hitherto neglected fact that Daly proposed in the mid-1920s a mechanism to create oceanic crust which would have been totally consistent with the Vine–Matthews hypothesis of seafloor generation published in 1963. It is furthermore suggested that Daly’s geotectonic proposals were inspired by small-scale...