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Comet May Have Hit Earth 56 Million Years Ago, Triggered warm, ice-free period on Earth: Scientists

The researchers said they have not found the location of an impact crater linked to the collision

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A tiny sand-grain-size tektite, thought to be created when vaporized material from an impact solidified while flying through the air, is shown in this image released in New York, Oct. 13, 2016. VOA

October 14, 2016: Droplets of glass dug up in New Jersey and from the Atlantic seabed indicate a comet or some other extraterrestrial object may have smacked Earth 56 million years ago, roughly 10 million years after the asteroid impact that doomed the dinosaurs.

Scientists said on Thursday the collision may have triggered a particularly warm, ice-free period on Earth when important mammalian groups, including the primate lineage that led to humans, appeared for the first time.

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The findings, published in the journal Science, marked the latest evidence of the profound influence that past impacts by celestial bodies have had on life on Earth.

The tiny spherical bits of dark glass, called microtektites, represent strong evidence of a collision with a comet or asteroid, the researchers said. They form when a space rock hits Earth’s surface and vaporises the spot where it lands, ejecting into the air bits of molten rock that solidify into glass.

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The microtektites were excavated from a geological layer marking the start of the Eocene Epoch about 56 million years ago from three sites in southern New Jersey (Millville, Wilson Lake and Medford) and an underwater site east of Florida.

That coincided with the beginning of a warming event, called the Paleocene-Eocene Thermal Maximum, associated with an accumulation of atmospheric carbon dioxide. It lasted more than 100,000 years and drove up global temperatures about 9-14 degrees Fahrenheit (5-8 degrees Celsius).

The impact of an asteroid about six miles wide (10 km) off Mexico’s Yucatan Peninsula 10 million years earlier killed off many marine and terrestrial creatures including the dinosaurs, and enabled mammals to gain supremacy.

No such mass extinction was associated with the event 56 million years ago, although many single-celled ocean-bottom creatures disappeared. During the warming period, primates and two mammal groups — one that includes deer, antelope, sheep and goats and another that includes horses and rhinos — first appear in the fossil record.

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The researchers said they have not found the location of an impact crater linked to the collision. They said geological evidence suggested the object was a comet.

“We can’t really say where it was, or how big, at this point,” said geochemist Morgan Schaller of Rensselaer Polytechnic Institute, who led the study.

While the findings are not proof that the impact caused the warming period, they are “a rather dramatic finding in support of an impact trigger” for the climate changes, said planetary scientist Dennis Kent of Columbia University’s Lamont-Doherty Earth Observatory and Rutgers University. (VOA)

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Dinosaurs Once-in A Lifetime Fossil Saved from Australian Floods

Steve Poropat, a paleontologist at Swinburne University in Melbourne says the footprints were saved from recent monsoonal flooding in Queensland.

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A small dinosaur fossil is seen in this undated handout photo from Australian customs. The largest-ever haul of illegally exported fossils was formally handed back from the Australian Government to the Chinese Government during a ceremony in Perth, Sept. 30, 2005. VOA

A team of Australian paleontologists and volunteers has saved a once-in a lifetime fossil discovery from devastating floods in Queensland state.

The dinosaur tracks give a rare insight into an ancient world. Found on an outback farm near the Queensland town of Winton, 1,100 kms from Brisbane, they are estimated to be almost 100 million years old.

The footprints are stamped into a large slab of sandstone rock, and were made by a sauropod, a giant creature with a long neck and tail, and by two smaller dinosaurs. Some of the footprints are up to a meter wide and come from the Cretaceous period.

Scientists were alerted to the danger posed to this remarkable collection when it was partly damaged by severe flooding last year.

For three weeks scientists and volunteers worked to carefully dig up and relocate the dinosaur tracks.

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Scientists were alerted to the danger posed to this remarkable collection when it was partly damaged by severe flooding last year. Pixabay

They are being stored at the Australian Age of Dinosaurs museum in Winton, where they will eventually go on display.

David Elliott is the museum’s executive chairman.

“We really want to preserve the integrity of the tracks. We do not want to just tear them up and go and lock them on the ground somewhere. You know, they have to be done a certain way. We cannot just leave it here because that is, you know, [a] find of a lifetime.”

Dinosaur tracks are rare in Australia.

Steve Poropat, a paleontologist at Swinburne University in Melbourne says the footprints were saved from recent monsoonal flooding in Queensland.

“The imperative was to get those soft footprints out of the ground because they just would not have lasted in another flood now that they have been fully exposed. To get it all out of the ground, to ma

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The dinosaur tracks give a rare insight into an ancient world. Found on an outback farm near the Queensland town of Winton, 1,100 kms from Brisbane, they are estimated to be almost 100 million years old. Pixabay

ke sure that it is safe from future floods is fantastic,” he said.

 

Monsoonal rains in Queensland have caused chaos, flooding hundreds of homes and drowning several hundred thousand livestock. Officials said it was a one-in-100-year event, and they have warned it could take years to rebuild the local cattle industry.

Also Read: Frequent High-Tide Flooding May Affect Coastal Communities’ Economy

As the floodwaters recede on land, they are polluting parts of the Great Barrier Reef. Experts say plumes of polluted water are stretching up to 60 kms from the coast, putting more pressure on coral that has suffered mass bleaching in recent years. When ocean temperatures increase, corals can expel the algae that live in their tissues causing the coral to turn completely white.

The Great Barrier Reef is Australia’s greatest natural treasure and stretches 2,300 kms down Australia’s northeast coastline. (VOA)