Bucher investigated the pattern of deformation of a spherical crust in tension. A thin spherical glass shell was filled with water and cooled slowly until it expanded on freezing and cracked the glass producing two fractures from a point that we call the North Pole (the “FOCAL BAR” in Figure 1) to the Equator.
Two Hundred Million Years ago the Earth had a spherical crust overlying a plastic interior and expansion induced tension in the Crust and opened two fractures, The 40 W Meridian fracture widened to become the North Atlantic Ocean, and the East Asian fracture, about 140E Meridian, was associated with volcanism as North America to move away from Asia.
In the Southern Hemisphere expansion moved the continents radially away from Antarctica as shown in Figure 2
EGW 21/05/2015
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