The shell resulted from external aggregation of solids and gases and internal segregation about a molten core. The fault blocks came from shrinkage of the shell over a liquid core, adjusted by luni-solar gravitation and rotation through the pre-geologic ages. The continental and oceanic boundaries of the fault blocks were determined by elevated and sunken blocks with core volcanism of escaping gas melting walls and laying down an exterior siliceous armorplate on the earliest solidified globe. This in continents is the seismologists’ lighter exterior layer underlaid by denser rock at the armorplate bottom. Continental volcanism (VOLC.-CONT.) became differentiated from oceanic volcanism, by light atmospheric pressure over the raised blocks and much greater water pressure over three-quarters of the earth, the sunken blocks. The subdivision is represented in the diagrammatic section on the globe by three-quarters of the section being ocean, namely twelve-sixteenths. The section shows twelve-sixteenths as sunken blocks, four-sixteenths as raised blocks. The four sixteenths by the tetrahedral hypothesis of Lowthian Green and Michel-Lévy make the four continental protuberances. Twelve-sixteenths of the surface is broken by fundamental rifts of irregular shapes, some of them north-south, controlled by centrifugal stresses and corresponding to the north-south deeps and heaps and known rifts. These have persisted since the first volcanism of primitive time. Circum-continental volcanism is represented on the diagram by VOLC.-CONT., oceanic volcanism is represented by VOLC.-OCEAN. Both are shown as interblock rifts, adjusted through the ages (exaggerated on the drawing) and always tensional over expansional core pressure, with exothermal heating agencies.