Common Martian Mineral Found in Antarctic Ice Core

Guest “geologizing” by David Middleton

Geology rocks!

Substance found in Antarctic ice may solve a martian mystery
By Tess Joosse Jan. 26, 2021

Researchers have discovered a common martian mineral deep within an ice core from Antarctica. The find suggests the mineral—a brittle, yellow-brown substance known as jarosite—was forged the same way on both Earth and Mars: from dust trapped within ancient ice deposits. It also reveals how important these glaciers were on the Red Planet: Not only did they carve valleys, the researchers say, but they also helped create the very stuff Mars is made of.

Jarosite was first spotted on Mars in 2004, when the NASA Opportunity rover rolled over fine-grained layers of it. The discovery made headlines because jarosite needs water to form, along with iron, sulfate, potassium, and acidic conditions.


Another idea was that the jarosite was born within massive ice deposits that might have blanketed the planet billions of years ago. As ice sheets grew over time, dust would have accumulated within the ice—and may have been transformed into jarosite within slushy pockets between ice crystals. But the process had never been observed anywhere in the Solar System.

On Earth, jarosite can be found in piles of mining waste that have been exposed to air and rain, but it’s not common. No one expected to find it in Antarctica, and Baccolo wasn’t hunting for it. Instead, he was searching for minerals that might indicate ice age cycles within the layers of a 1620-meter-long ice core, which record thousands of years of Earth’s history. But in the core’s deepest ice, he came across strange dust particles that he thought might be jarosite.


The work suggests jarosite forms the same way on Mars, says Megan Elwood Madden, a geochemist at the University of Oklahoma who was not involved with the research. But she wonders whether the process can explain the huge abundance of jarosite on Mars. “On Mars, this is not just some thin film,” she says. “These are meters-thick deposits.”



The terrestrial jarosite was discovered in an ice core from Talos Dome, Antarctica:


Many interpretations have been proposed to explain the presence of jarosite within Martian surficial sediments, including the possibility that it precipitated within paleo-ice deposits owing to englacial weathering of dust. However, until now a similar geochemical process was not observed on Earth nor in other planetary settings. We report a multi-analytical indication of jarosite formation within deep ice. Below 1000 m depth, jarosite crystals adhering on residual silica-rich particles have been identified in the Talos Dome ice core (East Antarctica) and interpreted as products of weathering involving aeolian dust and acidic atmospheric aerosols. The progressive increase of ice metamorphism and re-crystallization with depth, favours the relocation and concentration of dust and the formation of acidic brines in isolated environments, allowing chemical reactions and mineral neo-formation to occur. This is the first described englacial diagenetic mechanism occurring in deep Antarctic ice and supports the ice-weathering model for jarosite formation on Mars, highlighting the geologic importance of paleo ice-related processes on this planet. Additional implications concern the preservation of dust-related signals in deep ice cores with respect to paleoclimatic reconstructions and the englacial history of meteorites from Antarctic blue ice fields.

Baccolo et al., 2021
Baccolo et al., 2021


Baccolo, G., Delmonte, B., Niles, P.B. et al. Jarosite formation in deep Antarctic ice provides a window into acidic, water-limited weathering on Mars. Nat Commun 12, 436 (2021).

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Abolition Man
January 28, 2021 2:39 am

Oh, to be a rock scientist on Mars!
If only we had a government that encouraged freedom and prosperity so that a robust space program would be seen as a justifiable expense for developing human knowledge and achievement!
Oh, wait! We did have one like that; seems like only yesterday!

Reply to  Abolition Man
January 28, 2021 6:17 am

Ah, sublimely put.

Dare I make a prediction that another government will cancel the Space Force? (My coffee hasn’t kicked in. That’s as sublime as I could think of.)

January 28, 2021 2:48 am

Very Interesting!
Lots of ice on early Mars.
Cold Sun, Ice covered Planet.
So, Mars was then like the Galilean moons of Jupiter are now?

Reply to  David Middleton
January 28, 2021 6:20 am

How exactly did all those changes occur and the Solar System stay in sync?

Wouldn’t such massive changes in the Sun and the composition of the planets cause significant changes in their orbits? As this and that got ejected and hit stuff, wouldn’t that rip the Solar System apart?

Reply to  BlueCat57
January 28, 2021 8:22 am

Mars didn’t move, it’s atmosphere did.
Mars’ magnetic field failed as a result of it’s cooling core. Once the magnetic field was gone, the solar wind started to strip the atmosphere away.

Reply to  BlueCat57
January 28, 2021 9:41 am

If I’m understanding your question (not sure what “in sync” means), no, it would not significantly affect the solar system. Planetary orbits are mostly dependent on the mass (and therefore gravitational attraction) of the Sun, which has not changed significantly. (The solar wind and coronal mass ejections makes what I assume are minor changes over eons. And the gravitational attraction of other planets, particularly Jupiter, also has an effect, although far smaller than the Sun’s.) Ice vs. liquid water of course has no effect.

Impacts would of course have an effect, although the impacting bodies–while huge–seem to have been much smaller than the planets we have today, and even their larger moons. The hypothesized impact of a Mars-size planet with the Earth, creating the Moon, is a partial exception to this: the mass of Mars is just over 1/10 that of Earth. Who knows what orbit we were in before that, but the present orbit seems pretty good.

Reply to  mcswell
January 28, 2021 10:11 am

The keyword in all of that: assume

They are just making guesses to fit their presuppositions.

If what they find doesn’t fit their previous guesses, they just change the math so it works.

I’m guessing a similar list to this one could be made for all sorts of discoveries on Mars.

Reply to  BlueCat57
January 29, 2021 9:08 am

You’re describing “climate science”.

Reply to  beng135
January 29, 2021 9:54 am

Unfortunately, in my opinion, I am describing almost all science that does not rely on verifiable, repeatable experiments.

The “science” used to build things such as bridges and spacecraft fits that description.

Then there is “historical” science which assumes that what we see today has been happening for billions of years. I believe that is called “Uniformitarianism”.

What happened on Mars cannot be “repeated” but only guessed at. And since the base assumption is that the universe is billions of years old, “scientists” “fit” what they observe into that timeframe.

You might tell me all of that is “settled science” and I will tell you it is not because despite it being repeatedly “falsified” they simply shrug it off and say, “We need to ‘rewrite’ (fill in the blank)” instead of what they should say, “We were wrong and we need to figure out why.” To which I say, “change your assumptions which appear to be causing all these falsifications”. (there is a part 2 as well, even a part 3)

Michael S. Kelly
Reply to  David Middleton
January 30, 2021 4:16 am

I certainly hope that Perseverance finds no evidence of the mineral extensively used in buildings in the capital city of France: parisite. It’s the only known mineral invasive species (though it’s more often invaded than it invades, at least successfully). If Perseverance does find it, then that explains a lot…

Reply to  Philip Mulholland
January 28, 2021 4:31 am

Just curious, has anyone checked Terra’s ice at that epoch? I know there were ~3 snowball Earth epochs, at least one caused by a gamma-ray-burst .

John Tillman
Reply to  bonbon
January 28, 2021 8:53 am

A gamma ray burst is just one of many hypotheses about the causes of Snowball Earth episodes.

There was at least one in the Paleoproterozoic Era, 2.1-2.4 Ga, and two, briefly separated in the Neoproterozoic, ~717-635 Ma, plus a later more limited glaciation in that era. There wasn’t one three billion years ago, in the Archean Eon.

Abolition Man
January 28, 2021 3:12 am

Any thoughts on Graph section b)? The percentage of jarosite at the top of the ice core seems a little strange. Is it just an anomaly?

Abolition Man
Reply to  David Middleton
January 28, 2021 8:28 am

I was wondering how there could be jarosite at the top of the ice core, in fairly recent dust deposits, where the high pressure and acidic brines that produce it deep in the core would not be available. I’m assuming it would have to wind borne from elsewhere on Antarctica, South America or Australia.
Thanks for a fascinating post that takes our minds off the latest installment of Fall of the American Empire!

January 28, 2021 3:49 am

The progressive increase of ice metamorphism and re-crystallization with depth, favours the relocation and concentration of dust and the formation of acidic brines in isolated environments”

Ok, if we accept ‘ice metamorphism’ as a mechanism, doesn’t that throw all interpretations of historic CO2 levels (based on captured and somehow pristine bubbles) straight out into fantasy land??

Especially if at some point there are “acidic brines” formed??

I just love it when 1 article can wipe a whole branch of ‘ established science’ of the table. Didn’t Einstein warn about something like that? Or is there a ‘come on man’ coming up?

stay sane,

M Courtney
Reply to  Willem69
January 28, 2021 4:58 am

I have been saying this for years. On WUWT as well as elsewhere. It completely explains the smoothing that is observed in the concentrations of everything in the ice cores.
And frankly, it’s impossible to see how crystals subject to vibration from the wind wouldn’t have internal cracks in them.

But there’s no interest in wiping out an entire field of science.
Science is the practice of publishing papers to gain kudos in order to raise research funds for the creation of more published papers.

It has nothing to do with any empirical reality.

Reply to  M Courtney
January 28, 2021 9:46 am

it’s impossible to see how crystals subject to vibration from the wind wouldn’t have internal cracks in them.” Actually, it’s quite easy to see, if you have a microscope. Just gather some dust and sand from any wind-blown sand dune. You’ll find rounding, but not cracking. Or use a rock tumbler, although the mechanism is different.

M Courtney
Reply to  mcswell
January 28, 2021 10:53 am

Please remember to continue this process for 100,000 years and be sure that no cracks occur for longer than 30 seconds at a time.

Clyde Spencer
Reply to  David Middleton
January 28, 2021 9:49 am

“Very common” is in the eye of the beholder. Jarosite is typically associated with the oxidation of iron sulfides like pyrite, marcasite, and pyrrhotite, in what are expressed as gossans. That is, it can be the result of hydrothermal alterations, which are responsible for ore deposits, and then subsequently exposed to slightly acidic meteoric water at the surface, when exposed by erosion. While not as common as ‘dirt,’ were it not for the abundance of gossans, many precious-metal mines would not have been discovered.

January 28, 2021 4:06 am

Jarosite is a very common mineral on earth, often formed through the alteration (weathering) of iron sulphur complexes, like pyrite. Without detail on grainsize, I might hazard a guess that it could well have blown in.

Ron Long
Reply to  Gordo
January 28, 2021 5:49 am

Gordo, you get a fat “A” for your comment about jarosite being common on earth. The main reflectance peak of jarosite is at 710 nanometers, and those of us that pr4ocess and utilize multi-spectral imagery always watch for jarosite reflectance peaks when we are searching for hydrothermal mineral deposits, which virtually always have jarosite as the weathered surface product. Utilizing jarosite in ice cores from Antarctica to talk about Mars is not correct.

Abolition Man
Reply to  Gordo
January 28, 2021 8:35 am

So the long gap between the small amount at the top of the core and the varying amounts deep in the core would be due to a lack of dust particles. Would that indicate a wetter climate with less wind borne dust? Or is the anomaly that there was any dust in the recent section at the top of the ice core?

Peta of Newark
January 28, 2021 4:18 am

I. Am. In. Love.

Just look at that stuff. swoon
And I thought Mars was hell. How wrong can anyone be?
OK, the weather’s a bit ropey but let’s always keep an open mind
Absolutely Epic. Gorgeous. Perfect. Beautiful. – there aren’t the words.

Well yes there are:
One word: want

Just get me 500 Gigatonnes of the that stuff and we’ll have this Planet’s, Oceanic and Land-based Climate sorted in No Time Flat
We’ll make the climate & vegetation of Planet Avatar look like a deserted kiddies sandpit, in Blackpool, in winter.
No kidding
Unobtanium exists. Right next door on Mars!

Every farmer on this Globe would gladly pay $200+ per tonne for it

Seriously. Shirley.
Whaddya reckon gurl, are we together on this…

Alan Robertson
Reply to  Peta of Newark
January 28, 2021 7:38 am

Sounds like a case of geometrical frustration, to me.

January 28, 2021 5:18 am

There is a biological way to make jarosite. link

Clyde Spencer
Reply to  commieBob
January 28, 2021 9:58 am

The assertion of the importance of aerobic bacteria in producing jarosite puts the abundance of jarosite on Mars in a different perspective. Might we be looking at significant evidence for past life on Mars?

Reply to  Clyde Spencer
January 28, 2021 5:16 pm

When I stumbled across that link, my mind boggled and I’m not sure it’s unboggled yet. It’s kind of like struggling with the implications of abiotic methane. link

January 28, 2021 6:08 am

very thin layers in earth ice … meter thick layers on Mars … NOT THE SAME PROCESS of deposit … period … correlation is not causation …

January 28, 2021 6:15 am

Are they sure it isn’t a common EARTH mineral that they found on Mars?

Sorry folks, Mars is and always was a “dead” piece of space rock.

Scientists are PRESUMING that Mars was something different, and because they are making assumptions and are not objective in any sense of the word, they are missing the truly amazing.

John Tillman
Reply to  David Middleton
January 28, 2021 8:57 am

Present ice has been observed on Mars both above the regolith, at the poles, and below it at lower latitudes by probes.

John Tillman
Reply to  BlueCat57
January 28, 2021 9:16 am

Arguments for Mars as a cradle of life, whether wet or dry four billion years ago:

Even if the wet options include a Snowball Mars, pockets of liquid water exist in all but the hardest ice.

Reply to  John Tillman
January 28, 2021 10:18 am

Have you heard of Population Genetics?

Or why are so many things “too young”?

Note that the keyword in your link is speculation. They simply do not know and are just toss spaghetti against the wall to see what sticks.

John Tillman
Reply to  BlueCat57
January 28, 2021 10:26 am

I taught college population genetics, so unlike you, know enough to laugh at the blatant falsehoods of paid, professional creationist liars.

The scientific method is speculation, ie guessing an hypothesis, then testing by experiment or observation falsifiable predictions made upon it.

Reply to  John Tillman
January 28, 2021 12:59 pm

Ah, so you know that according to population genetics life could not have “evolved” within the timeframe for the age of the universe.

Please provide the specific “blatant falsehoods of paid, professional creationist liars.”

Ah, but surprisingly when “falsified” “scientists” never admit that nor change their hypothesis.

I have yet to read an article that starts off with “Scientists admit they were wrong and are now seeking a new explanation.”

Reply to  BlueCat57
January 28, 2021 9:49 am

Are they sure it isn’t a common EARTH mineral that they found on Mars?” Not sure what you’re asking. Clearly they didn’t bring a few tons of jarosite with them to Mars, so that can’t be what you’re saying. What do you mean?

Reply to  mcswell
January 28, 2021 10:13 am

I’m merely point out that they are assuming that what is on Earth came from Mars instead of the other way around. Or, the more likely reason for finding that on both Earth and Mars is that it is just another mineral in the Solar System.

John Tillman
Reply to  BlueCat57
January 28, 2021 10:28 am

Clearly, you didn’t bother to read the post. They’re not saying that the Antarctic mineral came from Mars, but that the vast deposits of it on Mars could have formed in ice.

Reply to  John Tillman
January 28, 2021 1:00 pm

I did read the article. I am merely pointing out that the bias is that Mars is the starting point.

Why not say: “Rare Earth Mineral Also Found on Mars”?

Reply to  BlueCat57
January 28, 2021 1:48 pm

Mars was very different in the past. Take a look at the Eberswalde delta for example.

Reply to  tty
January 29, 2021 10:00 am

Agreed, but in what timeframe?
“…radiometric dating of the lava dome at Mount St. Helens by Geochron Laboratories of Cambridge, Mass., dates 10-year-old rock as somewhere between 340,000 and 2.8 million years old. With the KNOWN age of this rock, potassium-argon radiometric dating, which is supposed to indicate when a rock solidified, gets the age 99.99999% wrong! That’s REALLY WRONG. See more about the eruption at”

The following introduces Novarupta. Have you ever heard of that volcanic eruption?

I’m expressing my opinions based on the information I have and my worldview.

Hopefully, some of what I am sharing is new information to you. All I ask is that you consider it.

January 28, 2021 9:50 am

My connection is that these things are also minerals:

Robert of Texas
January 28, 2021 12:32 pm

Very interesting find David, where the heck do you find these articles? I want to subscribe to wherever you are finding these.

It really makes you wonder just how much all of the planets have changed over the past 2 or so billion years. Would we even recognize the Earth? Was Venus more hospitable?

Here is a thought for people…we have found chunks of Mars on Earth – they are rare but Mars rocks have made it here. It is easier for a rock to drift inward rather than outward (but not impossible). That makes me wonder if Earth rocks ever made the journey to Venus, and if so, did anything living catch a ride? There is almost zero chance of life surviving there now, but billions of years ago?

Reply to  Robert of Texas
January 28, 2021 1:55 pm

It is easier for a rock to drift inward rather than outward

Not really, unless it is small enough to be affected by the Poynting-Robertson effect.

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