Curtin University
The research, published in the leading journal Nature Communications, used isotopic analysis of minerals to calculate the precise age of the Yarrabubba crater for the first time, putting it at 2.229 billion years old – making it 200 million years older than the next oldest impact.
Lead author Dr Timmons Erickson, from Curtin’s School of Earth and Planetary Sciences and NASA’s Johnson Space Center, together with a team including Professor Chris Kirkland, Associate Professor Nicholas Timms and Senior Research Fellow Dr Aaron Cavosie, all from Curtin’s School of Earth and Planetary Sciences, analysed the minerals zircon and monazite that were ‘shock recrystallized’ by the asteroid strike, at the base of the eroded crater to determine the exact age of Yarrabubba.
The team inferred that the impact may have occurred into an ice-covered landscape, vaporised a large volume of ice into the atmosphere, and produced a 70km diameter crater in the rocks beneath.
Professor Kirkland said the timing raised the possibility that the Earth’s oldest asteroid impact may have helped lift the planet out of a deep freeze.
“Yarrabubba, which sits between Sandstone and Meekatharra in central WA, had been recognised as an impact structure for many years, but its age wasn’t well determined,” Professor Kirkland said.
“Now we know the Yarrabubba crater was made right at the end of what’s commonly referred to as the early Snowball Earth – a time when the atmosphere and oceans were evolving and becoming more oxygenated and when rocks deposited on many continents recorded glacial conditions”.
Associate Professor Nicholas Timms noted the precise coincidence between the Yarrabubba impact and the disappearance of glacial deposits.
“The age of the Yarrabubba impact matches the demise of a series of ancient glaciations. After the impact, glacial deposits are absent in the rock record for 400 million years. This twist of fate suggests that the large meteorite impact may have influenced global climate,” Associate Professor Timms said.
“Numerical modelling further supports the connection between the effects of large impacts into ice and global climate change. Calculations indicated that an impact into an ice-covered continent could have sent half a trillion tons of water vapour – an important greenhouse gas – into the atmosphere. This finding raises the question whether this impact may have tipped the scales enough to end glacial conditions.”
Dr Aaron Cavosie said the Yarrabubba study may have potentially significant implications for future impact crater discoveries.
“Our findings highlight that acquiring precise ages of known craters is important – this one sat in plain sight for nearly two decades before its significance was realised. Yarrabubba is about half the age of the Earth and it raises the question of whether all older impact craters have been eroded or if they are still out there waiting to be discovered,” Dr Cavosie said.
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The full research paper, ‘Precise radiometric age establishes Yarrabubba, Western Australia, as Earth’s oldest recognized meteorite impact structure,’ can be found online at https://www.nature.com/articles/s41467-019-13985-7
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There is abundant evidence of multiple ice ages in the past (i.e. before the Pleistocene glaciation), and some of them seem to have covered large areas (as did the LGM) but the current fashion is to assume that most of the “old” glaciations were global glaciations or “snowball earth” periods.
The snowball earth theory is that the oceans were frozen to the bottom all around the globe. The theory appears to have been first concocted by Paul Hoffman in 1999, as an outgrowth of the “CO2 controls climate” hypothesis. It has a few weak spots:
Because the continents move around, split apart and join together, and this has been going for about 4 billion years, it’s not immediately obvious that a historic glaciation extended into tropical regions. This depends on paleo-latitude estimates, measuring the inclination of remanent magnetism in rocks that show evidence of glaciation, and were formed at the time. Of course, this is a magnetic latitude. We know how much the poles have moved in the last 250 years, so there should be uncertainty in paleo-latitudes.
The snowball earth theory posits that frozen oceans led to a high albedo, so solar radiation could not warm the surface, which perpetuated the frozen conditions. Well, if there was no open water, there would no evaporation and no precipitation. But volcanic activity still went on, and it’s asking a lot to maintain a high albedo for hundreds of millions of years of airborne volcanic ash falling, and no fresh snow to cover it.
If the theory is correct and snowball earth could maintain its albedo for hundreds of millions of years, then how could the earth get out of its snowball condition? The theory posits that CO2 from a major volcanic event warmed the planet enough to start melting, which released CO2 from the frozen oceans, which warmed the planet more, which … and so on. Hmm …
The idea that a single injection of a large quantity of water vapour could cause enough greenhouse effect to de-snowballize a plant is even weaker. Water vapour condenses. Its presence in the atmosphere depends on a continual supply by evaporation.
Non-anthropogenic global warming! Now that’s what I’m talking about!!
As I read through these comments, I had not previously heard of the “Carolina Bays” and found the subject fascinating. I must admit when I first saw the images I thought “has to be impacts from debris”, but luckily I was born with something called “curiosity” and kept digging. Wow…really? Wind? In a low sandy flood plain?
OK, so if it happened in North Carolina in the past, it must be happening somewhere else today, and I thought of Alaska and when scanning along the river channels in the far north. It didn’t take long to find a startling image: “70°16’46.27″ N 158°56’06.62″ W”
Well that sort of settled it for me…Geologists 7, YDIH 0; end of first quarter.
I had no idea shallow lakes could look so entirely weird.
As for the point of this article, you hit a planet with a big enough rock it is going to release a lot of energy. Things are going to catch on fire. The air is going to have a lot of soot in it. The albedo is going to take a nose dive. You hit the Earth with a big enough rock and it will vibrate like a bell and continental plates are going to shift allowing magma to get loose and build new volcanoes (which might or might not add to warming or cooling). So I find the idea credible, but I am not taking any sides (yet) on whether it happened.
I find the idea of a “snowball Earth” far harder to believe than a big asteroid could warm up the planet. Yeah, the planet could be colder and glaciers could have grown to incredible depth and area – but I do not buy the oceans freezing over. There is a lot of heat in the ocean, and more heat being released into it all the time at especially at continental plate boundaries – more so 200 million years ago, not less. I find the term “snowball Earth” an unfortunate one…unless they convince me that the oceans really *did* freeze over.
According to wiki the average geothermal heat flux is 0.1MW/km**2, which I think is 0.1W/m**2. I don’t think that would be enough to maintain liquid oceans absent the sun. Perhaps some ice volcanoes.
The lunar and solar tides might have some effect at keeping the oceans liquid.
There’s a series of similar lakes in Bolivia, for 500 km along the Rio Mamore by the town of Trinidad. My best bet for a meteor breakup. S15° W65°
Another bunch of lakes at S14° W67°, same orientation.
Same here.
Few years ago while looking at the google Earth I stumbled across something I thought it was a fascinating impact crater, but the WUWT geologist explained what it was.
Link to image shows coordinates so anyone interested can easily find it.
In eastern Siberia, a perfect circle of rock contrasts with the surrounding topography. The 6-kilometer- (3.7-mile-) wide ring looks like an impact crater, or the caldera of an extinct volcano, but it is neither. Kondyor Massif was formed by the intrusion of igneous, or volcanic, rock that pushed up through overlying layers of sedimentary rock, some of them laid down more than a billion years ago.
https://earthobservatory.nasa.gov/images/8773/kondyor-massif-russian-far-east
That they identified a crater that old is pretty impressive. What the impact event may or may not have done is something else entirely.
A 70 km crater is not particularly large as known craters go. And for it to have some sort of global climate significance is an interesting conclusion.
A more recent example for your consideration: The Chesapeake Bay impact dates around 35 Ma and left a 85 km crater. The Popigai impact crater dates around 35 Ma and left a 100 km crater. Final large structure is Tom’s Canyon off NJ which also dates around 35 Ma and left a 22 km crater. Related? Perhaps. Perhaps not, though the timing is interesting.
Only climatic event around that time is a moderate extinction event at the end of the Eocene and an overall global temp fall after then. Was the cool down due to the impact events or isolation of Antarctica from the other continents or the creation of the Himalayas disrupting global wind patterns? The closest LIP in time was one at the Afar around 30 Ma.
Kind of cool they identified a crater that old. Interesting timing with the end of a snowball glaciation. Of course we haven’t a clue about possible ocean impacts near that time. Cheers –
Half a trillion tons of water vapor from one impact sounds like a lot, but if this spread over the entire atmosphere of the earth, it would increase the water vapor content of the atmosphere by 157 ppm, or 0.0157%.
For sake of comparison, at 20 C and 100% relative humidity, the water vapor content of the atmosphere would be 2.3 vol%, or 23,000 ppm. So we are asked to believe that some prehistoric incident from over 2 billion years ago, which increased the water vapor content of the atmosphere by less than 1% could trap enough heat to melt ice covering the entire earth?
The whole “snowball earth” theory seems preposterous, that all the world’s oceans would freeze over, and all the continents would be covered in ice, particularly if the sun’s radiation output and the earth’s orbital distance from the sun were similar to what they are now.
Climate change skeptics frequently make the argument that even if CO2 in the atmosphere trapped a small amount of additional heat, it would take thousands of years to melt the Greenland or Antarctic ice caps due to the large amount of heat needed to melt ice, compared to that needed to heat air.
The same argument can be made in reverse regarding the possibility of a “snowball earth”–so much heat needs to be removed to freeze water (particularly salt water), that the heat transferred to the surroundings would inhibit further freezing, particularly in the tropics which receive strong solar radiation year-round.
In today’s location of the continents and oceans, most of the area of the tropics (between 23.5 degrees north and 23.5 degrees south latitude) are covered by water, and daytime evaporation followed by thunderstorms (as pointed out by Willis Eschenbach) tends to prevent the tropics from becoming too hot.
But if there was a period of extensive glaciation of land areas 2.2 billion years ago (outside the tropics), this would lower sea levels, meaning that a greater area of the tropics would become dry land, which absorbs sunlight better than the ocean surface, without heat loss due to evaporation. This land could only become glaciated if it was cold enough for snow to accumulate without melting (which is possible in mountainous areas), but lowland areas in the tropics would not be glaciated. In addition, an extensive area of sea ice away from the tropics would reduce the amount of water that could be evaporated, which would give land areas near the edge of the glaciers a drier climate, which would tend to cause melting.
“precise age”
oh sweet jebus, the false confidence in the accuracy of aging is still going on. Could be +/-500m/yr
Throw in the serious limitations in determining termination and starting of events, means the claims made far more certain than the actual science could ever say…
All areas of science are in real trouble, with gross misrepresentation of the science and the ignorance of the severe limitations, and the complete failure of peer review in modern times..
Unfortunately, many have to pass away before the institution of science globally, changes, the whole enterprise needs to be rethought and safeguards thought up to stop what amounts to probably 50% of all research in all science globally being utter horseshit
A massive comet or meteorite strike would lead to a massive release of
natural gas hydrates, not just methane. The amount of upwelling natural
gas all around the world trapped by the “snow ball” earth would have dwarfed
the amount that we see today.
Natural gas perks up all around the earth continuously, but rises where it is
not blocked by igneous or shield layers. The earth at present, is allowing most,
but not all, to rise, most be oxidized in the topsoil, the remainder, to rise into
the atmosphere, to be oxidized, and support life as we know it.
The zone of stability, a combination of temperature and pressure, limit
the amount which hits the atmosphere. The build up of natural gas
hydrates, like the massive amount off the Carolina coast, act as a stopper,
limiting the rise of more from deep in the earth, just as the cork in a
bottle of Champaign limits the release of gas. When the stopper, the ice, is
vaporized, a massive release of natural gas hits the atmosphere. A serious
green house effect takes place.
The gas would survive the initial atmospheric heat flash, then the cooling effect
of the debris, then the inevitable period of vulcanism and resultant dust occur.
The period immediately after the strike, with all of the ice gone and the ocean
temperature raised, the zone of stability would have been exceeded world wide,
and all the hydrates would flash to a gas. The cork in the bottle, the hydrates,
are the valve which limits the flow of hydrocarbons from deep in the earth,
so the flow of gas from its source, would continue, probably for hundreds
of thousands of years.
As the initial massive burst of released hydrates, exacerbated, by the mechanical
input of heat to the earth’s core, and the massive shock and vibration, the cooling
from the attenuation of the real “global warming” would have taken a long time
to return to the zone of stability which we see today.
For those who think that natural gas is a “fossil” fuel, the continuous rise of
natural gas can be seen as hydrates which accumulate under the areas of the
world which freeze every winter, and thaw every spring, releasing that short
accumulation of gas.
Another example of the rise of natural gas is the richness of topsoil wherever
the flow is not blocked by igneous rock or shield near the surface and there
is enough moisture to support the aerobic microbial life which enrich and
create the topsoil. The microbes use the hydrogen in the gasses for energy,
and the result of this process is the reason that CO2 rises from the soil.
The more natural gas rising through the soil, in the presence of adequate
moisture, the richer and blacker, (higher carbon content) the soil.
Very good examples of this are the deep, rich soils in the US Midwest, the
Ukrainian, and the Tera Preta in the Amazon, which are over plumes of
natural gas.
These areas prove that natural gas rises continuously wherever it is
not blocked by ice or rock.
A simple test for CO2 at the surface of rich topsoil is the residue of
this process. Gas also rises in areas, un oxidized where there is not
enough moisture to support the microbial culture.
Most of this upwelling gas would have accumulated under snowball
earth, save the occasional volcano, and have been the source of
of the massive release I referred to above.
This process, in a much more limited way, explains why CO2 is a
trailing indicator, after each glaciation, in more recent times.
Unlike the carbon balance, used by the USEPA, upland topsoil
is not a sink for natural gas, it is a source. Fortunately most is
oxidized by the soil culture, so the serious greenhouse effect
is mitigated or eliminated by microbes.
There would have been no life on earth without hydrocarbons
and their follow on effect, so David, the vast majority of hydrocarbons
are, in fact abiotic.
A correction on the above timeline which says hundreds of thousands
of years should read tens of thousands of years.
I was pressed for time and didn’t proof read.