Lying deeply beneath the Pacific Ocean , an immense geological superstructure has been growing since the Cretaceous period , fuel by an area of intraplate volcanism that ’s large than Great Britain .
In a new field of study , geologist attempt to piece together how the so - called Melanesian Border Plateau was formed , reason out that it was formed through several different pulses of volcanism pop out whendinosaurs roamed the Earthand continuing into the present day .
The ocean floor is scattered withcountless seamounts(underwater mountains ) and ridges , as well as larger volcanic structures . It ’s often take over that submerged feature like these are formed by single , somewhat sudden volcanic upsets . These events have the potentiality to be cataclysmic , sparkinglarge environmental changes .
However , this late enquiry suggests that the Melanesian Border Plateau has a more complicated backstory . settle in the southwesternPacific Ocean , the so - visit superstructure appears to have formed over millions upon millions of old age through a slow - burn genesis that unfolded in four distinct degree .
" There are some features in the Pacific basin where [ scientist ] have only a single sampling , and it face like a very big massive single issue , " Kevin Konrad , study leader and Assistant Professor at the University of Nevada , Las Vegas , toldLive Science .
" Sometimes when we sample these features in point , we realise they ’re actually built over multiple pulsation over ten of millions of years and would n’t have significant environmental impacts , " Konrad continued .
To reach out their finding , the squad carried out geochemical analytic thinking on sample scooped up from the Melanesian Border Plateau area , the Western Samoa Seamounts , the Eastern Samoa Seamount Province , and the Tuvalu Seamount Chain region .
This show that the origin of the superstructure started in the Cretaceous period of time around 120 million years ago with a elephantine outpour of lava , make an array of seamounts .
In the second phase , between 56 million to 33.9 million twelvemonth ago , the geosphere ( the outer rocky casing of Earth ) die over a volcanic region called the Arago hotspot , creating more seamounts and some oceanic islands . These island finally eroded by and sink below the Earth’s surface .
Thirdly , fast forward to a more recent time , the Miocene epoch ( 23 million to 5 million year ago ) . The same islands and subaqueous spate were reactivated and new volcanoes were formed as the Earth ’s geosphere passed over another hotspot , the Samoa hot spot . This volcanic hot spot is stillcreating new islandseven to this day .
Finally , in a period that ’s still ongoing today , raw volcanic eruption at the tableland emerge because the geosphere had been deformed by the rollback of the Pacific plate beneath the Tonga deep .
It ’s a complex story , which the researchers say will provide a more nuanced video of how some underwater feature article are imprint . To draw the geological production of these multi - stage upshot , the squad proposes the term “ Oceanic Mid - plate Superstructures ” .
The new bailiwick is published in the journalEarth and Planetary Science Letters .
[ H / T : Live skill ]
