Dr. Tassos disagrees with accretion as the mechanism and here is his proposal: An Integrated Alternative Conceptual Framework to Heat Engine Earth
An Integrated Alternative Conceptual Framework to Heat Engine Earth, Plate Tectonics, and Elastic ReboundPDF full text of article is: here.
Starvros T. Tassos Institute of Geodynamics, National Observatory of Athens, P.O. Box 200 48, 118 10 Athens, Greece & David J. Ford 2/22 Mitchell St.,Townsville, N.Q., Australia 4810
Abstract -- Physical evidence indicates that a thermally driven Earth, plate tectonics, and elastic rebound theory violate fundamental physical principles, and that Earth is a quantified solid body, the size of which possibly increases with time. Earth's core is considered as a low-temperature, high-energy/high-frequency, high-tension material, wherein new elements form, constituting the Excess Mass (EM), which is then added atom-by-atom to the overlying mantle. Iron, with the highest nuclear binding energy of 8.8 MeV, should be the last element to form. Due ultimately to cosmic stretching, the internal pressure gradient is from the center, toward the surface; so EM ascends as solid state "wedges," which upon encountering an anisotropic obstacle, then accumulates due to its blockage. Iron ascends in the from of reduced high pressure Fe 2- , to a depth of about 700 km. At shallower depths it then releases 4-5 electrons whilst oxidizing and decompressing at reducing confining pressures. Some of the released excess mass electrons travel as free electrons, and thereby cause microcracks to form when the electron concentration exceeds the threshold of >10 18 electrons/m 2 ; these microcracks enlarge as their concentration increases and their cumulative internal electron pressure builds up; via this self-repulsive electron pressure a great mass of rock is uplifted over time. Microcracks serve both as resonant cavities for "old" metallic bond electrons from Fe 2,3+ and "new" electrons from Fe 2- , radiating at the infrared, and as electrical capacitors, producing effective semiconductor behavior. If and when the concentration of electrons in the microcavity and of p-holes at the rock-microcrack interface surpasses the necessary electro-motive force potential, the electrical impedance to electron flow is attrited and dielectric breakdown occurs, i.e., the transient discharging of electrons very rapidly empties the network of cavities, causing an implosive collapse of the regional network of parallel microcavities. This high-energy implosion coerces the otherwise plastic surrounding rocks to repond instantaneously elastically, and an earthquake is thus generated. The same implosion that caused the earthquake can also produce a fault rupture of the rocks if its transient dynamic shock pressure exceeds the rock's bonded strength. The magnitude of an earthquake depends on the size of the active volume of almost concurrently discharging microcavities. Hence, we are referring to an electromagnetic self-organized criticality, a direct implication of whch is the inherent non-predictability of any earthquake's timing or energy release. ...