Discussion of “Shear patterns of the Earth's crust”

The crustal shear pattern proves the existence of a rigid, elastic crust of considerable strength in which distortional forces of importance must have occurred. As no handy terms exists for these distortional geotectonic forces, the writer proposes to use the expression “regmagenic forces.” Such forces can be created in the crust by a polar drift of the crust over the core, by great fluctuations of the elastic compression in the presence of sensible elastic anisotropics or by unequal tangential stresses (orogenic forces). The writer agrees with Vening Meincsz that polar drifts played a part in the making of the regmatic shear pattern of the crust. He does not think however that this was the only cause and attributes great importance to the other two mentioned reactions. The writer does not believe in the existence of subcrustal currents sufficient to create crustal tectonics and rejects also the idea of such currents in source of a polar drifting. Even if they existed, their total drift moment on the whole crust would be inadequate to overcome the strong elastic counterforces within the crust. Polar drifts can be explained in harmony with the mechanical principles admitting the presence of a sensible general elastic compression and additional regmagenic forces in the tangential plane of the crust. This mechanical, deduction and the proved polar displacements of the past point out that an Earth contraction stands behind the tectonical unrest. A revision of this old concept on the ground of modern knowledge seems highly promising. The origin of the continents is discussed under such an assumption as well as the regmatic pattern of the Earth's crust. The continents are explained as the scars of the past tectonic surface reductions. Some related problems are discussed, especially the significance of the drowned islands of tho Pacific lately described by Hess [see “References” at end of discussion, 1940] as metering cones of tho progressing contraction of the Earth of the past.