Verneshot

A verneshot (dt. About Verne emissions , Verne shot or Verne eruption , named after the French author Jules Verne ), according to the hypothesis of a working group of the American geologist Jason Phipps Morgan (then at GEOMAR in Kiel , today at the Cornell University in Ithaca, NY ), a volcanic eruption caused by the massive pressure build-up of gas beneath the earth's crust of a craton . Such an event, according to the theory, could release enough energy to propel large quantities of material from the earth's crust and mantle into a suborbital trajectory .

Connection to massive extinction of species in the history of the earth

Verneshots were suggested by Morgan and his colleagues as a possible cause to the statistically unlikely joint occurrence of flood basalt , mass extinction, and evidence of meteorite impacts (such as deformation of the crystal structure, shock quartz, and anomalies in the concentration of iridium , which have traditionally been considered clear evidence apply an impact ).

The theory of the Verneshots assumes that a mantle plume causes heat and carbon dioxide to form beneath the continental lithosphere . If the overlying crust is weakened, for example through continental rifting , the gas could be released explosively and possibly send a column of material from the earth's crust and mantle to heights above the stratosphere . It is not clear whether such a pillar can remain intact or whether it will disintegrate into smaller pieces before hitting the earth again. The tube in the earth through which the magma and gas escaped would collapse during the process, sending out shock waves at supersonic speeds that deform the surrounding kraton.

The event of a Verneshot would presumably have a connection to a flood basalt event occurring in its vicinity, which occurs before, during or after the Verneshot. This connection would be helpful in finding evidence of the effects of Verneshots. On the other hand, since there is a high probability that the majority of the evidence is buried below the flood basalt, such investigations are difficult. Morgan et al. have suggested that gravity anomalies found below the Dekkan Trapp may suggest the presence of Verneshot tubes possibly related to the Cretaceous-Paleogene (KP) mass extinction .

If the Dekkan-Trapp were the location of a Verneshot on the CP-border, the sudden strong increase in iridium at the time of the CP-border could be explained by the iridium-rich nature of the Réunion-mantle plume , which is currently below the volcano Piton de la Fournaise , which at the end of the Cretaceous Period was below India, in the area of the Dekkan-Trapps. The Verneshot could potentially have spread the iridium worldwide. However, Morgan points out in his article that it is unlikely that a Dekkan-Réunion-Verneshot could have made the route to Chicxulub without breaking into several pieces. In a Verneshot, there should be other smaller craters in addition to the Chicxulub impact crater, but these have not yet been found. The Chicxulub impact and the Deccan flood basalt event did indeed occur coincidentally at the same time.

Verneshots of a smaller size

Smaller Verneshots were named by Phipps Morgan's working group as a possible cause of the formation of kimberlite tubes ( chimneys ), which run along weak zones in the earth's crust, which in turn could be the result of larger Verneshots.

It has been suggested that the Tunguska event in 1908 was indeed the possible location of a more recent Verneshot event. The place where the event took place is in the middle of the Siberian Trapp , a large area of igneous rock that formed at the turn of the Permian / Triassic (at this point the largest known mass extinction in geological history occurred, with 75% of the living on land and 95% of marine invertebrates died out, see Perm-Triassic border ). Interestingly, recent work suggests a circular depression below the trap, just as the Verneshot model would predict. In the Verneshot model, the kratonic crust below this region would remain a weak point, which enabled the formation of a kimberlite tube or a micro-Verneshot, i.e. an eruption of volcanic gas that subsequently ignited. However, this theory is controversial and is only listed as a possible example of a Verneshot.

Less drastic rock eruptions were documented in 2003 after an earthquake that struck central Taiwan in 1999 .

History

In 1865 Jules Verne's novel From Earth to the Moon was published . In this novel, the concept of a ballistic missile that leaves the realm of gravity came up. From this novel Phipps Morgan et al. the name "Verneshot" from and used it in their article, in which they presented the theory of large gas emissions and their connection to events of mass extinction.

References and comments

^ Profiles - Earth and Atmospheric Sciences - Cornell Engineering. Retrieved February 11, 2018 .
↑ ^a ^b ^c ^d ^e J. Phipps Morgan, TJ Reston and CR Ranero: Contemporaneous mass extinctions, continental flood basalts, and 'impact signals': are mantle plume-induced lithospheric gas explosions the causal link? In: Earth and Planetary Science Letters . tape 217 , 2004, pp. 263–284 ( online version; PDF file; 705 kB ).
↑ More information can be found on Professor Jason Phipps Morgan's faculty page at Cornell University from May 2004: “I became interested in the causes of mass-extinctions, in particular worrying about the 'too-many-coincidences' problem that these periods appear to be associated (if we believe what's published in the mainstream literature) with BOTH extremely rare continental flood basalts and continental rifting, and even rarer 'impact signals' commonly presumed to come from large extraterrestrial bolide impacts. Our recently published Verneshot hypothesis is our best guess on how to explain these coincidences in a self-consistent causal manner. "
↑ L. Hryanina: The bouquet of the meteorite craters in the epicenter of Tunguska impact in 1908 year . In: Lunar and Planetary Science Conferences . tape 30 , 1999.
^ Huang et al .: Huge rock eruption caused by the 1999 Chi-Chi earthquake in Taiwan . In: Geophysical Research Letters . tape 30 , 2003 (not publicly available).

Web links

Homepage of J. Phipps Morgan at Cornell University

[1] Profiles - Earth and Atmospheric Sciences - Cornell Engineering. Retrieved February 11, 2018 .

[Morgan_2003-2] J. Phipps Morgan, TJ Reston and CR Ranero: Contemporaneous mass extinctions, continental flood basalts, and 'impact signals': are mantle plume-induced lithospheric gas explosions the causal link? In: Earth and Planetary Science Letters . tape 217 , 2004, pp. 263–284 ( online version; PDF file; 705 kB ).

[3] More information can be found on Professor Jason Phipps Morgan's faculty page at Cornell University from May 2004: “I became interested in the causes of mass-extinctions, in particular worrying about the 'too-many-coincidences' problem that these periods appear to be associated (if we believe what's published in the mainstream literature) with BOTH extremely rare continental flood basalts and continental rifting, and even rarer 'impact signals' commonly presumed to come from large extraterrestrial bolide impacts. Our recently published Verneshot hypothesis is our best guess on how to explain these coincidences in a self-consistent causal manner. "

[4] L. Hryanina: The bouquet of the meteorite craters in the epicenter of Tunguska impact in 1908 year . In: Lunar and Planetary Science Conferences . tape 30 , 1999.

[5] Huang et al .: Huge rock eruption caused by the 1999 Chi-Chi earthquake in Taiwan . In: Geophysical Research Letters . tape 30 , 2003 (not publicly available).