They awarded the Earth for almost 200 million years, but at the end, the old poor dinosaurs did not have the opportunity.
About 66 million years ago, a meteorite of 10 to 80 kilometers wide, is likely to be asteroid, hit the planet, creating a Chicxulub crater under the Mexican Yucatan Peninsula.
Even before the collision, extensive lava floods were already growing what is now central in the middle of India, according to two papers published in Science today.
One of which is the extra-earth cut has made these volcanic cuts worse even to be discussed.
According to one study, led by Courtney Sprain, University of Liverpool, the collision triggered higher earthquakes that were disturbed with that volcanic activity, with three quarters of the lava flowing out after the crash.
But the other – by Blair Schoene and University of Princeton University, and colleagues – claim that the lava broke into "ponds", which started independently well before the effect.
Dr Sprain said that the story of what three quarters of plant and animal species, including the non-bird dinosaurs, finished at the end of the Cretaceous era helps us to understand changes that occur to modern ecosystems.
Fostering exactly how much Lava Deccan flows and the asteroid all have contributed to the mass dose has been difficult to do, in part due to the exact date when the lava & # 39; n flowing is hard.
But that's what the two new studies intend to do using different techniques.
Although Dr Sprain and his team used a technique and measuring different types of mineral argon in the name of plagioclase directly taken from layered layers, Dr Schoene crew examined uranium and lead ratio in zircons has combined between the flow.
The two dating techniques work on the same principle – given some time, chemical elements rotate into new elements – but each has its advantages and savings.
Scientists use clink vs. clunk & # 39; hammer …
Parts of the Deccan Tracks were out of date, but argon / argon arguments can be inaccurate as minerality tends to rapidly occur in the tropical environment.
To go around this, Dr Sprain decided that his colleagues concentrate on one ore – plagioclase – often found in basalt.
It also keeps its crystal structure, even when other minerals do not.
So how do you find plagioclase crystals in these ancient ancient lava flow?
"It's very technical," said Dr. Sprain.
"The clinic means that some of those mineral structures are still intact, but the clunk indicates that they have changed to clay."
They calculate that lava flows have dramatically increased almost 600,000 years after the collision, with 75 percent of Deccan Trapiau volume falling after the effect.
But this perception raises new questions.
Previous studies showed that climate change – which is attributed to carbon and sulfur volcanic gas emissions in the millions of years before mass damage – is already deteriorating ecosystems.
The main question for Dr Sprain was: if Deccan's lava flow did not drive that climate change before the big dump, was the gas being released?
"Was gas passively released through cuts [before the collision]? "she said.
"Or was there another source of gas from the volcanic system that we do not even think about?"
Uranium lead dating tells another story
Dr Schoene's crew analyzed layers around the flood layered layers using uranium lead dating – one of the oldest and most precise dating techniques.
It can take advantage of the fact that when zircon forms turn uranium into its crystal structure, but not lead, so any wire in the zircon must be produced by the rotation of radioactive uranium.
But even though astronomy is common in some volcanic ash and rocks, such as granite, it will rarely be a basalt, and what is lava flows.
So, directly dating these flows using uranium lead is quite impossible.
There is also the issue that Zircon can have formed for a long time before it was thrown out of the crust, said Jacqueline Halpin, a geologist at Tasmania University who was not part of another study .
"The sequel could grow early in a magma chamber, hang around for tens to thousands of years, then be lifted and cut out later," said Dr. Halpin.
Therefore, with some mathematical modeling to take that growth phase into account, Dr. Schoene's team found four injections of volcanic activity, each lasting around 100,000 years.
Significantly, they concluded that this volume wastes began tens of thousands of years before the meteorite collision.
Go to the carbon question
Both teams intend to keep drilling into the Deccan Traps timeline and exploring drivers of climate change at the time of the great dizziness.
People think that a volcano causes mass extensions by putting carbon dioxide and sulfur dioxide to the atmosphere, says Dr Schoene.
"But we still have a fairly poor understanding of the amount of carbon dioxide and sulfur dioxide in these pigs.
Some geologists believe that ancient magma did not contain enough carbon to remove as many bats in the climate as it did.
However, he said that magma under the belt might have forced her way up without breaking the surface, and heating sediments that are most carbonate to the place where they are releasing gases greenhouse to the atmosphere.
What sounded a death rotation for dinosaurs?
Fred Jourdan, curtin University geologist, collected Dr. Schoene's collections – that the huge surprises that arose well before the effect on the meteor – were "more logical" in terms of climate change.
Although people are responsible for the sixth mass disappearing, others have come together with volcanage, said Professor Jourdan.
For example, it is believed that the "Great Dying", which marked the end of the period of the Permian and disappeared almost every life on Earth, has been triggered by a huge massive lava called Siberia Drapes in Russia.
"These great igneous states produce a lot of gas in a short time, and that's where the problems start," says Professor Jourdan.
"The atmosphere can not keep up."
If the asteroid had lost the Earth 66 million years ago, could volcanism on its own trigger the event disappear?
Probably, Professor Jourdan said: "Whatever the prophecy began, the effect has finished the business."