<Li> Latent heat released as the liquid outer core crystallizes at the inner core boundary . </Li> <Li> Heat may be generated by tidal force on the Earth as it rotates; since rock cannot flow as readily as water it compresses and distorts, generating heat . </Li> <Li> There is no reputable science to suggest that any significant heat may be created by electromagnetic effects of the magnetic fields involved in Earth's magnetic field, as suggested by some contemporary folk theories . </Li> <P> In Earth's continental crust, the decay of natural radioactive isotopes has had significant involvement in the origin of geothermal heat . The continental crust is abundant in lower density minerals but also contains significant concentrations of heavier lithophilic minerals such as uranium . Because of this, it holds the largest global reservoir of radioactive elements found in the Earth . Especially in layers closer to Earth's surface, naturally occurring isotopes are enriched in the granite and basaltic rocks . These high levels of radioactive elements are largely excluded from the Earth's mantle due to their inability to substitute in mantle minerals and consequent enrichment in partial melts . The mantle is mostly made up of high density minerals with high contents of atoms that have relatively small atomic radii such as magnesium (Mg), titanium (Ti), and calcium (Ca). </P>

Which type of heat transfer has the largest impact on the lithosphere