Distensional Mediterranean and World Orogens - Their Possible Bearing to Mega-Dykes Active Rising

An overview of the modern progresses of the expanding Earth conceptions as
they come out from new data and their possible interpretations is provided in this paper. The
starting point of this review is the new detailed 3D distributions of relocated hypocenters
laying under orogenic belts. The similarity of the hypocentral patterns under the Tethyan
orogenic belts, and under the South American Pacific orogenic margin is considered to be
a major font of information on which to build a more realistic global geodynamic model.
Clusters and filaments of hypocenters are recognizable instead of regular patterns. These
clusters taper downwards, leading to the idea of a deep origin in narrow regions of disturbance,
besides other important facts that witness in favour of surfaceward movements of
deep material along what can be called "mega-dykes". The outpouring of the material on
the surface produces gravitational nappes and their overthrust on the sediments of the preexisting
trough, forcing them on a burial path which emulate the subduction process, but
without reaching depths greater than 50-70 km. Phenomenons like metamorphism, mixing,
migmization, upward transport of fragments of the buried lithosphere etc. are possible at
the boundary between uplifting material and down-pushed crust and lithosphere. Additional
clues can be collected that confirm the new proposed framework. The astronomical indications
of a coseismic displacement of the instantaneous Earth’s rotation axis in the occasion
of the great Sumatra (Mw=9.3) and Honshu (Mw=9.0) earthquakes are especially significant
because in complete disagreement with the plate tectonics modelled axis shift and
in agreement with the shift expected in the new conception. Because of analogous opposite
predictions of the length of day variation following the extreme magnitude earthquakes
(ΔLOD<0 vs ΔLOD>0), future improvements of the time measurement techniques could
allow a final choice between rival geodynamical models.