Abstract

This analysis postulates that subduction is a direct function of the momentum associated with the moving continental plates (CP) as they break away from a ‘halted’ supercontinent and start to accelerate from zero velocity (Vo) to plate velocity (Vp) c15mm/year. The developed Momentum = M(weight CP) x Vp will continue to keep the CP moving until collision at a convergent margin. The massive weight of the lower density CP will push down the oceanic lithosphere over which it is moving, against the upward buoyancy and the viscous drag forces. It is this action that starts the subduction cycle and slab pull process. Slab breakaway into the mantle with the loss of the slab pull force, will not stop or impede the continuous movement of the CP. It is thus possible to illustrate that seduction is a direct consequence of tectonic movements as distinct from being the cause. By implication, it is considered that the complex circulatory system of heated convection currents within the mantle has a passive rather than an active role in tectonic plate movements.

In addition, this paper also postulates that the initial break-up of Pangea starting in the early Jurassic period c.200 Mya ago can be explained as a function of the circumferential and centripetal forces associated with the rotating unbalanced planet Earth. To date, the magnitude of these often incorrectly termed ‘inertial forces’ have been generally considered to be negligible in the context of tectonic movements on the basis that the Earth is a freely rotating body about its centre of mass (COM).

This approach allowed the development of the equation F = MRω2Eπ/4 relating the circumferential tensile forces (F) to the offset (E) centre of mass (taken as 1km) and the rotational velocity (R) of the Earth. The circumferential forces developed within the lithosphere due to the rotating ‘unbalanced’ or ‘wobbly’ planet are considered primarily responsible for the perpetual movement of the tectonic plates. It is this continuous action that allows for an alternative cycle of lithosphere regeneration to the Wilson cycle to be proposed and illustrated.

The analysis given in this paper further shows that the Earth alongside the other planets require an ‘offset centre of mass’ to allow the mutually gravitational pull between the Sun and the planets to establish an N-S axis around which the planets are caused to rotate. This, in turn, gives rise to a rational explanation of the reason for the rotation of planets (except Venus unless considered as being upside down) in the same anti-clockwise direction as the Sun itself. This is in keeping with Kepler’s Laws of orbital motion in which the Sun rotates the planets.