If you have ever been to the golden dome of Mount Emei in Sichuan, you may be shocked by the grand view of the sunrise of the sea of clouds on Mount Emei.
For geologists, however, what is more shocking than the sunrise is the rock that makes up the cliffs of the Golden Dome , the Emei Mountain Basalt.
Emei Mountain basalt cliff
About 10 million years after the basalt eruption of Mount Emei, the Earth ushered in the largest volcanic eruption event in the history of earth evolution, the Siberian Shield Event, which spewed out magma in a million years and covered more than 7 million square kilometers of land.
If you put all this magma in China, can you imagine most of China in fiery lava?
From this, you can imagine how magnificent the volcanic eruption at the end of the Permian was 250 million years ago, with half a continent of magma, no grass on the surface, dust covering the sky, animals fleeing in a hurry, and hundreds of millions of corpses lying in the ocean. In the face of such continental overflowing basalt volcanic events, other volcanoes such as Yellowstone and Tonga appear eclipsed.
It was this million-year-long volcanic eruption that caused the worst extinction event in Earth's evolutionary history, the end-Permian mass extinction, in which about 96 percent of the planet's species became extinct within a million years, including 90 percent of marine life and 70 percent of land vertebrates.
The scale of its eruptions and the devastating catastrophe it caused to life on Earth eclipsed all future catastrophes, and now let's step into the distant Permian to explore the beginning and end of this mass extinction.
Permian past
The Permian is the last epoch of the Paleozoic Era, the continental plate closed to the end, the world formed a super Pangea continent, the earth has a vast land area, and the central Pangu Mountains in the middle of the continent run through the north and south Pan continents, looking at the mountains and rivers.
In the ocean, the trilobite is trembling on the bottom of the sea, on the verge of extinction, and the hornstones that once ran through the ocean have lost their former prestige and have shrunk into ammonites, all of which mean that the era of invertebrates has gone, marine vertebrates have developed to a new height, fish have won the position of ocean hegemony, and tens of meters long sharks are making waves in the ocean.
Spiny tooth shark
On land, due to the warm and humid climate of the Permian, the flora and fauna of the land grew savagely, the naked fern plant began to decline, and the gymnosperms of pine, cycad and ginkgo biloba took to the stage of life, forming dense forests.
In the middle of the jungle, there are many dangers. The largest insect in the history of the earth travels through the jungle, a large variety of amphibians are hidden under the dense leaves, and reptiles begin to develop, waiting for the opportunity, calculating the status of the next generation of earth overlords.
At this moment, the supremacy of the earth belongs to a group of mammals with canine teeth - the lidonts, they are one of the most powerful predators on the land before the emergence of dinosaurs, and their existence is also a highlight moment of mammals, who have died and pinched the ancestors of dinosaurs.
In the Permian Earth, from ocean to land, life is thriving. However, the earth will never give the creatures too long a comfortable time, and under the prosperity, the disaster of destroying the world is being conceived.
Latter-day volcano
Volcanoes are an extreme means by which a planet releases internal nuclear heat on a large scale in a very short period of time, and it outputs the deepest thermal energy directly to the surface. So what happens when a rift valley inside a continent encounters a volcano?
251 million years ago, the ground on which Siberia was located cracked open a large crack tens of kilometers long. Under the huge high pressure of the continental crust, the mantle magma rises along the cracks of the rift valley, gushing out from the cracks in the continental surface at the same time, like a flood that opens the floodgates, flowing to the Siberian rift valley, where the magma goes, the earth is red, and the scene is spectacular.
Perhaps compared to the Tonga volcanoes, the volcanoes at the end of the Permian did not have a soot-filled mushroom cloud scene, because the magma from deep in the mantle did not have a high viscosity and did not explode, they only overflowed the surface along the crustal fissures, forming large continuous basalt layers.
Since then, however, a large amount of magma has been spewing out continuously, and the main eruption has lasted for millions of years, and the magma spewed out covers seven million square kilometers of land, close to the area of one Australia, and it can be said that half of the Pangea continent at that time was burning.
Although it has been erupting for millions of years, the mere burning of magma and the gases it spews out may not be enough to cause such a tragic mass extinction, but when the magma encounters the Tunguska Basin, it is different.
Earth Purgatory
After a time of dense jungle in the Carboniferous and Permian periods, Siberia formed the largest coal seam in the history of the earth.
When scorching magma intrudes into a basin with a large number of coal seams, the magma scorches the hydrocarbons beneath the surface, making it the world's largest fossil fuel plant, with the Siberian Shield volcano potentially spewing up to 100 trillion tons of carbon into the air within a million years.
Methane, carbon dioxide and other greenhouse gases evaporated by magma are constantly filled into the air, and the heat of volcanic eruptions cannot be dissipated, so the temperature of the earth begins to soar, the average temperature rises by more than ten degrees, the high temperature evaporates a large amount of seawater, the large-scale seabed is exposed, and the desertification is aggravated, and the average depth of the ocean at that time was only one-third of the current level.
At this time, the atmosphere is not only carbon dioxide, methane and other greenhouse gases, but also a large amount of sulfur dioxide gas wafting out of the magma, when sulfur dioxide and water vapor react, it forms tens of thousands of years of acid rain, animals cry under acid rain, plants wither under acid rain.
The state of the ocean is worse than on land.
Acid rain directly destroys the bottom of the ocean's food chain, plankton, and when sulfur dioxide is combined with seawater, the ocean acidifies, some animals that cannot adapt to acidic seawater die directly, and corpses float above the sea surface, so the ocean becomes a pool of sulfuric acid filled with mud and dead bodies.
In addition, magma burning coal seams and marine carcass decay consume a lot of oxygen in the atmosphere, the earth's oxygen content drops below 10%, oxygen in the ocean is even more scarce, and the lack of oxygen makes a large number of marine organisms extinct.
At this time, there are new killers appearing, after a large number of marine organisms die, so anaerobic bacteria multiply on a large scale, and in the process of reproduction, a large amount of hydrogen sulfide is released, and this strange smelly toxic gas can even block some organisms, calling this era the most smelly era on the earth.
A series of extreme environmental events caused by the eruption of overflow basalt on the Siberian continent, including persistent hypoxia in the ancient ocean, rapid warming of the earth and ocean acidification events, together made the earth's surface present a miserable scene of everything withering and lifeless, creating the largest mass extinction in the history of earth's evolution.
Born to die
The mass extinction at the end of the Permian was a milestone in the transition of Earth's history from the Paleozoic to the Mesozoic, upending the entire Paleozoic ecosystem. Most of the vast number of ferns became extinct, only some herbaceous plants remained, a large number of insects disappeared, and 63% of the tetrapods, including the toothless vertebrates, that rose in the Permian Period became extinct in this event.
In the ocean, this extinction has completely destroyed the Paleozoic biota that occupied the ocean for nearly 300 million years, forever frozen in the historical record, and since the explosion of life, the "era of ancient creatures" that lasted for 300 million years has ended.
However, not all living things will disappear, everything will become wasteland, and everything will be reborn after the wasteland.
After the Permian crisis, new species emerged rapidly and the ecosystem underwent a most thorough renewal. The "modern evolutionary fauna" in the ocean, which is dominated by molluscs, etc., has rapidly replaced the vacant ecological niche of the "Paleozoic evolutionary fauna", the reptiles represented by dinosaurs on land have begun to rise, and the history of the earth has entered a new era in the Middle Ages.