Ancient Exploding Comet Likely Source of Vast Glassy Rock Patches in Chilean Desert

Deposits of dark silicate glass are strewn across a 75-kilometer corridor in the Atacama Desert in northern Chile. New research shows that those glasses were likely formed by the heat of an ancient comet exploding above the surface. Credit: P.H. Schultz/Brown University

Heat from a comet exploding just above the ground fused the sandy soil into patches of glass stretching 75 kilometers, a study led by Brown University researchers found.

Around 12,000 years ago, something scorched a vast swath of the Atacama Desert in Chile with heat so intense that it turned the sandy soil into widespread slabs of silicate glass. Now, a research team studying the distribution and composition of those glasses has come to a conclusion about what caused the inferno.

In a study published in the journal Geology, researchers show that samples of the desert glass contain tiny fragments with minerals often found in rocks of extraterrestrial origin. Those minerals closely match the composition of material returned to Earth by NASA’s Stardust mission, which sampled the particles from a comet called Wild 2. The team concludes that those mineral assemblages are likely the remains of an extraterrestrial object — most likely a comet with a composition similar to Wild 2 — that streamed down after the explosion that melted the sandy surface below.

Deposits of dark silicate glass are strewn across a 75-kilometer corridor in the Atacama Desert in northern Chile. New research shows that those glasses were likely formed by the heat of an ancient comet exploding above the surface. Credit: P.H. Schultz/Brown University

“This is the first time we have clear evidence of glasses on Earth that were created by the thermal radiation and winds from a fireball exploding just above the surface,” said Pete Schultz, a professor emeritus in Brown University’s Department of Earth, Environmental and Planetary Sciences. “To have such a dramatic effect on such a large area, this was a truly massive explosion. Lots of us have seen bolide fireballs streaking across the sky, but those are tiny blips compared to this.”

The glasses are concentrated in patches across the Atacama Desert east of Pampa del Tamarugal, a plateau in northern Chile nestled between the Andes Mountains to the east and the Chilean Coastal Range to the west. Fields of dark green or black glass occur within a corridor stretching about 75 kilometers. There’s no evidence that the glasses could have been created by volcanic activity, Schultz says, so their origin has been a mystery.

Some researchers have posited that the glass resulted from ancient grass fires, as the region wasn’t always desert. During the Pleistocene epoch, there were oases with trees and grassy wetlands created by rivers extending from mountains to the east, and it’s been suggested that widespread fires may have burned hot enough to melt the sandy soil into large glassy slabs.

Analysis of the glass samples revealed a mineralogy that was consistent with a cometary origin. Credit: P.H. Schultz/Brown University

But the amount of glass present along with several key physical characteristics make simple fires an impossible formation mechanism, the new research found. The glasses show evidence of having been twisted, folded, rolled, and even thrown while still in molten form. That’s consistent with a large incoming meteor and airburst explosion, which would have been accompanied by tornado-force winds. The mineralogy of the glass casts further serious doubt on the grassfire idea, Schultz says. Along with researchers from the Fernbank Science Center in Georgia, Chile’s Universidad Santo Tomás and the Chilean Geology and Mining Service, Schultz and colleagues performed a detailed chemical analysis of dozens of samples taken from glass deposits across the region.

The analysis found minerals called zircons that had thermally decomposed to form baddeleyite. That mineral transition typically happens in temperatures in excess of 3,000 degrees Fahrenheit — far hotter than what could be generated by grass fires, Schultz says.

The analysis also turned up assemblages of exotic minerals only found in meteorites and other extraterrestrial rocks, the researchers say. Specific minerals like cubanite, troilite, and calcium-aluminum-rich inclusions matched mineral signatures from comet samples retrieved from NASA’s Stardust mission.

“Those minerals are what tell us that this object has all the markings of a comet,” said Scott Harris, a planetary geologist at the Fernbank Science Center and study co-author. “To have the same mineralogy we saw in the Stardust samples entrained in these glasses is really powerful evidence that what we’re seeing is the result of a cometary airburst.”

More work needs to be done to establish the exact ages of the glass, which would determine exactly when the event took place, Schultz says. But the tentative dating puts the impact right around the time that large mammals disappeared from the region.

“It’s too soon to say if there was a causal connection or not, but what we can say is that this event did happen around the same time as when we think the megafauna disappeared, which is intriguing,” Schultz said. “There’s also a chance that this was actually witnessed by early inhabitants, who had just arrived in the region. It would have been quite a show.”

Schultz and his team hope that further research may help to constrain the timing and shed light on the size of the impactor. For now, Schultz hopes this study may help researchers identify similar blast sites elsewhere and reveal the potential risk posed by such events.

“There may be lots of these blast scars out there, but until now we haven’t had enough evidence to make us believe they were truly related to airburst events,” Schultz said. “I think this site provides a template to help refine our impact models and will help to identify similar sites elsewhere.”

Reference: “Widespread glasses generated by cometary fireballs during the late Pleistocene in the Atacama Desert, Chile” by Peter H. Schultz, R. Scott Harris, Sebastián Perroud, Nicolas Blanco and Andrew J. Tomlinson, 2 November 2021, Geology.
DOI: 10.1130/G49426.1

Other authors of the study were Sebastian Perroud, Nicolas Blanco, and Andrew Tomlinson.

Atacama DesertBrown UniversityCometGeologyPopular
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  • mullach abu

    ya could be right ya know
    possible three events that could have caused this event
    13,699,987,200 anno universo = 12,800 annual years ago 10800bc the younger dryas boundary the encounter with a dying disintergrating comet causing a meteor debris hurricane throw out and our blue ball planet will snowplough through the boulder hailstorm wrecking havoc on earth and caused a devastating apocalypse fragments of boulder rocks of ice and stone and metal will rain down on earth starting fires and the middle east plunges into the dark age as soot is thrown up in the air that the sun is blocked out the demise of several ancient civilizations collapse and crumble as the dust fallout dumps huge gas and dust veils through the upper middle and lower atmosphere which destroys photosynthesis and the food chain supply is broken ad life giving light in blotted out reducing temperatures early societies
    And platinum rich dust and glassy beads scattered around the world sparking huge global wildfires burning up to 10% of the planets biomass and causing mass extinctions around the world enough smoke may generate sudden cooling
    And the disintergrating celestical object ends up looking like comet encke an object whose debris caused the taurids meteor shower
    13,699,987,200 anno universo = 12,800 annual years ago 10800bc younger dryas climate event from a wildflower dryas octopetala can tolerate cold conditions and suddenly become common in parts of Europe now
    Southeastern north America south Carolina elgin lake white pond younger dryas impact hypothesis under water core samples large platinum anomaly spikes associated with cosmic objects like asteroids or comets global airbursts plus global multiple impact craters cascading events and a large soot anomaly was also found in the core from the site indicating large scale regional wildfires
    Similar discoveries outwash sediments of platinum and iridium at Greenland
    Northern hemisphere North America Europe
    Southern hemisphere
    Chile pilauco South Africa western asia
    It’s a global event whatever it is further evidence meltglass microscopic spherical particles and nanodiamonds iridium
    Or is it a freshwater flood from the ice dams melting and releasing into north atlantic ocean affecting oceanic circulation was this pulse caused by the cosmic impact or not
    Whatever it is it caused a period of extreme cooling
    Believed to have caused massive wild fires that could have blocked sunlight causing an impact winter near the end of the Pleistocene epoch
    that contributed to extinctions of more than 35 species of megafauna including giant sloths sabre toothed cats mastodons and mammoths it also coincides with a serious decline in early human populations such as clovis culture
    13,699,987,200 anno universo = 12,800 annual years ago 10,800bc
    13000 12800 annual years ago 10800bc usa arizona distinctive black layer impact debris at its base maybe a cluster of comet fragments
    13,699,987,200 anno universo = 12,800 annual years ago 10,800bc
    12,800 years ago fragments of a disintegrating comet or ancient asteroid strike or an hour long hailstorm struck the earth and cosmic impact bombarded
    or ancient volcanic eruptions
    north america europe western asia south america and these impactors generated a thin layer of detritus containing platinum meltglass and nano diamonds causing large scale biomass burning extinction of mega fauna and onset of winter like conditions triggering and plunging the planet into the
    mini ice age lasted 1000 years 12800 11800
    younger dryas cooling event lasting 1500 years 12800 11300
    more than 12000 years ago central north america central saskatchewan southern manitoba ancient glacial ice dammed lake agassiz all the way up to the alberta border drained a meltwater flood roughly the equivalent of all the great lakes combined over a 6 to 9 month period into the surrounding artic ocean and may have affected ocean circulation and cooled the northern hemisphere climate
    57n 111 w alberta
    fort hills
    fort mcmurray quaternaray material on top
    athabasca river clearwater lower athabasca spillway clas
    alberta
    110w
    saskatchewan
    clearwater river
    regions expansive oil sands a region of loose sand water and clay that also has a form of petroleum essentially within the channel that this flood formed
    more than 12000 years ago ancient glacial ice dammed lake agassiz starts to spillout to the northwest in a channel known as the clearwater athabasca spillway drained a meltwater flood may have pushed earth back into an ice age younger dryas cooling event
    13,699,987,200 anno universo = 12,800 annual years ago 10,800bc 12800 years ago Syria abu hureyra evidence of cosmic blast that caused the destruction of one of the earth worlds earliest settlements
    10,800 12,800bc syria destruction of the village of abu hureyra by a cosmic impact event the first in history
    The transition to agriculture one of the most significant events in our earths cultural and environmental history
    Then a fragmented comet on a human settlement
    The largest cometary debris cluster are proposed to be capable of causing thousands of airbursts within a span of minutes across one entire hemisphere of earth
    The impact contributed to the extinction of most large animals including mammoths and American horses and camels the disappearance of the north American clovis culture and to the abrupt onset of the end glacial younger dryas cooling episode
    Abu hureyra lies at the easternmost sector of what is known as the younger dryas boundary ydr strewnfield which encompasses about thirty other sites in the Americas Europe and parts of middle east these sites hold evidence of massive burning including a widespread carbon rich black mat layer that contains millions of nanodiamonds high concentration of platinum and tiny metallic spherules formed at very high temperatures
    A young 31 kilometre impact crater beneath the Hiawatha glacier of the Greenland icesheet
    Southern chile pilauco black mat layer high temperature meltglass human butchering of large animals up to but not younger than the ydb impact burn layer and disappearance of south American Pleistocene megafauna fossils an abrupt shift in regional vegetation and a disappearance of human artifacts the layer containing the spherules show peak concentrations of platinum and gold and native iron particles rarely found in nature and some of the most important are chromium rich and it turns out that the volcanic rocks in the southern andes can be rich in chromium and a large biomass burning event and may have contributed to the extinction of the local south American Pleistocene megafauna including giant ground sloths sabretooth cats mammoths and elephant like gomphotheres as well as the termination of the local indigenous south American culture peoples
    The abu hureyra village would have been abruptly destroyed as it shows direct evidence of the disaster on this early human settlement an impact or an airburst must have occurred sufficiently close to send massive heat and molten glass over the entire early village
    Archaeological site bore witness to the moment ancient nomadic people first settled down and started cultivating crops parts of houses food and tools cereals grains splashed on early building material and animal bones was melt glass some features of which suggest it was formed at extremely high temperatures far higher than what humans could achieve at that time or that could be attributed to fire lightning or volcanism
    Such intensity could only have resulted from a extremely violent high energy high velocity phenomenon something on the order of cosmic impact these fragments are all part of the same comet that likely slammed into earth and exploded in the atmosphere at the end of the Pleistocene epoch
    The glass was analysed for geochemical composition shape structure formation temperature magnetic characteristics and water content results from the analysis showed that it formed at very high temperatures and included minerals rich in chromium iron nickle sulfides titanium and even platinum and iridium rich melted iron all of which formed at temperatures higher than 2200 degrees Celsius the critical materials are extremely rare under normal temperatures but are commonly found during impact events the meltglass was formed from the nearly instantaneous melting and vaporization of regional biomass soils and floodplain deposits followed by instantaneous cooling additionally because the material found are consistent with those found in the ydb layers at other sites across the world globe its likely that they resulted from a fragmented comet as opposed to impacts caused by individual comets or asteroids
    The ydb hypothesis would then account for the widely dispersed coeval materials across more than 14,000 kilometres of the northern and southern hemispheres
    Then the site was flooded
    1970s The taqba dam impounded the euphrates river in northern Syria a large mound marks the settlement which now lies under lake assad
    Breaking news 08/03/2020 11.00 thus we know how eire lost its glacier mass and the meltdown and bounce back starts to occur

    • Elon Musk

      Riiiiight. Coo-Coo.

    • Tectonic Funk

      Can you please go back and edit this using some form of punctuation? Would make a lot more sense.

  • Cynthia Binder

    Something happened, just looked at Chili n the south America cont. Great this has been discovered or rediscovered.

  • AZWarrior

    Right. We have known this for years. Does someone have a research grant renewal coming up?

    • mullach abu

      how long have you known
      and told noone
      that we had to hear it from here