Appendix

Appendix

A) Deformation of volcanic arcs

Each volcano forming part of a volcanic arc consists of a main duct and several secondary volcanic ducts formed in the crevices of the friable rim of a crater.

Volcanoes formed under oceans cool themselves in a relatively quick manner after erupting, and because of this main duct structure and lateral cracks being filled up with magma, each undersea forms a compact block, denser than the rest of the terrain around it.

It is the same phenomenon that makes it difficult to remove molding sand from the recesses of complex geometry parts in metal casting processes.

The terrain surrounding each consolidated volcanic block remains friable because it was formed in the crater rim region – the same type of terrain that facilitates the creation of cenotes and karst lakes (evident on Chicxulub/Tarim/the southern Australian coast formerly adjacent to Wilkes Land in Antarctica, all themes of other studies by the author).

This process of infiltration and cooling of the magma ducts creates a “geological bead necklace” that is unable to withstand the pressure of continental drift or significant lava spills inside the crater.

We can compare these volcanic blocks to icebergs, but formed by magmatic rocks, and possessing a central volcanic duct with hardened roots that penetrate deeply into the Earth's crust.

This mechanism explains the deformation of the volcanic arc of the central crater: the pressure from the huge basaltic spills within the Wegener Crater/Wegener B/Philippine Sea Plate/Mariana Plate opened the “bead necklace” and each volcanic block drifted to its present position.

B) Reactivation of hotspots and volcanic arcs

As said above, volcanic blocks are units of individual volcanoes with relative ease to drift in relation to its tectonic plate.

The deep central duct offers a lower resistance passage to the underground magma as the ensemble remains fixed at the impact location, in the case of hotspots, or it follows the tectonic plate drift, in the case of volcanic arcs formed on crater rims.

If there is an increase in pressure on the underlying mantle as a result of collision and subduction processes, the volcanoes that constitute the hotspot or the volcanic arc will again become active by clearing their ducts in a short geologic timeframe, or by creating new magma passages that will generate new volcanoes.

This phenomenon is occurring today at Thwaites Glacier, in Antarctica — a remnant hotspot of Wegener Crater, responsible for the Permian Extinction, and at Mediterranean Sea/Italian Peninsula — a remnant hotspot of Viluy Crater, responsible for the Devonian Extinction, among other hotspots in Atlantic Ocean.[1]

In this way, volcanic arcs and geological hotspots can remain active continuously for hundreds of millions of years, or be reactivated after being inactive for such as many years.

This mechanism may explain the occurrence of hotspots nowadays along the seamount chains such as volcanic islands found along the Pacific Ocean.

However, there is also the possibility that these hotspots distant from the edges of the Pacific tectonic plate could be not reactivation cases, but remnant hotspots of other impact craters previous to the tectonic plate passing over those points.

The eventual craters and their volcanic chains from previous impacts would have been subducted a long time before the passage of the Wegener Crater.


[1] According to other studies by the author.