Geophysics S-waves in the outer core. This indicates that the outer core is liquid, because liquids cannot support shear. The outer core is liquid, and the motion of this highly conductive fluid generates the Earth's field. The inner core, however, is solid because of the enormous pressure. Reconstruction of seismic reflections in the deep interior indicate some major discontinuities in seismic velocities that demarcate the major zones of the Earth: inner core, outer core, mantle, lithosphere and crust. The mantle itself is divided into the upper mantle, transition zone, lower mantle and "D′′" layer. Between the crust and the mantle is
Chaotian (geology) the Mundrabilla iron meteorite of Western Australia using the argon method determined an age of 4,570 ± 60 million years ago. The proposed collision with Theia, leading to the formation of the Moon, is estimated to have occurred 4.527 billion years ago. Outgassing and differentiation of the earth in an iron-rich core and mantle may have been completed 4.45 billion years ago. Chaotian (geology) In the geologic record the Chaotian eon or era is unofficially proposed to denote the time preceding the solidification of the Earth's crust and the formation of Earth's moon, it is the earliest era within the