Tectonic evolution of the West-Pacific region: formation of lithospheric vortexes

Using the example of the West Pacific Segment of the Earth, the interrelation of vertical and horizontal tectonic movements is considered - the most important and far from being solved at present problem of geotectonics. An overview of the concept of the global ordering of various forms of the earth's surface as an end result of the action of geodynamic forces is given. The author's developments concern the issues of the origin of structures associated with the interaction and influence of endogenous forces on the formation of a regional relief. The main tools for its study were structural-geomorphological methods and lineament analysis. It has been established that: 1) all tectonic dislocations contain both horizontal and vertical components of the velocity of movement, and the former dominate in the structure formation of the region; 2) the end result of their interaction is vortex and other nonlinear (ring, spiral, arc, etc.) deformations of the lithosphere, which constitute the main type of structural elements of the region; 3) they are often accompanied by magmatic activation of the tectonosphere in the form of convective movements and / or «floating» of plumes; 4) the sea and oceanic depressions of the Western Pacific are, in essence, funnels of convective cells, which, under the conditions of shear velocities of the movement of interacting geoblocks of the lithosphere, were structured into the form of tectonospheric eddies. A model of convection of a three-layer tectonosphere is proposed, the movement of which in the gravity field is caused by local decompaction and a decrease in the viscosity of a piecewise inhomogeneous medium. The outlined concepts allow us to consider the tectonic evolution of the West Pacific region as the formation of a lithospheric mega-vortex in the continent-ocean junction zone. Its development is associated with the energy interaction of the mantle and the upper shells (tectonospheres) of the Earth, which is due to the unstable regime of the planet's rotational dynamics.