Guest ” If it looks like a delta, walks like a delta and quacks like a delta, it might just be… ” by David Middleton
It looked like a delta from orbit…
Jezero’s Window to the Past
Jezero Crater sits within the Isidis Planitia region of Mars, where an ancient meteorite impact left behind a large crater some 750 miles (1,200 kilometers) across. This event is known as Isidis impact, and it forever changed the rock at the base of the crater. A later, smaller meteorite impact created the Jezero Crater within the Isidis impact basin. Scientists believe that these events likely created environments friendly to life. There is evidence of ancient river flow into Jezero, forming a delta that has long since been dry.
Jezero Crater is thus likely to have been habitable in the distant past. The Mars Reconnaissance Orbiter’s CRISM instrument has revealed that the crater contains clays, which only form in the presence of water. On Earth, scientists have found such clays in the Mississippi river delta, where microbial life has been found embedded in the rock itself. This makes Jezero Crater a great place to fulfill the Mars 2020 mission’s science goal of studying a potentially habitable environment that may still preserve signs of past life.
At Jezero Crater, Perseverance should be able to access rocks that are as old as 3.6 billion years. There are many ideas about what early Mars was like, and how it came to be what it is today. Accessing the ancient rock at Jezero should help answer some of these questions, and tell us more about the formation of rocky planets. It is also a great location for the rover to collect a variety of samples of Martian rock and soil.
How Features are Named at Jezero Crater
Naming things is a great way to remember them. As Perseverance explores the Martian surface, the science team will assign unofficial names to especially interesting regions and features.
The team informally named the rover’s touchdown site “Octavia E. Butler Landing,” after the groundbreaking science fiction author. Butler grew up in Pasadena, California near the Jet Propulsion Laboratory. The first African American woman to win both the Hugo and Nebula awards, and the first science fiction writer to be honored with a MacArthur Fellowship, her writing inspired many in the planetary science community and beyond.
Throughout the mission, the science team will use a naming system similar to the one used to name the locations that the Curiosity rover has explored on Mars. Before Perseverance launched, the team mapped the entire landing site in Jezero Crater, dividing it into squares about 0.75 miles (1.2 kilometers) on each side. These quadrangles were named for various national parks and preserves on Earth. As a nod to the diversity of its international science partners, the team used names from parks in countries that have contributed to the mission.
As the rover explores Jezero Crater, any time the team sees an interesting feature, they will name it for a corresponding location here on Earth. For example, when the Curiosity team named one of its sites “Yellowknife Bay” after a location in Canada, individual rocks and targets within that area were named after features in Canada’s Yellowknife Bay.
The Perseverance team uses a modified version of this approach for some of their earliest exploration. The rover landed in a part of Jezero Crater that the team had named for Canyon de Chelly National Monument (“Tséyi’” in Navajo) in Arizona. Since Canyon de Chelly is the heart of Navajo Nation lands, the mission team worked directly with the Navajo Nation, who is sharing their language to help the team informally name features on Mars. Among the initial list of 50 candidate names are “Máaz” (Mars), “bidziil” (strength), “hoł nilį́” (respect), and “tséwózí bee hazhmeezh” (rolling rows of pebbles, like waves).
NASA
Now, it looks like a delta from ground level…
Long distance images of exposed scarps taken by the Perseverance Mastcam-Z now have provided strong evidence that this is indeed a lacustrine deltaic feature…
Perseverance Finds Ancient Delta-Lake System, Flood Deposits in Martian Jezero Crater
Oct 8, 2021 by News Staff / SourcePlanetary scientists have analyzed images taken by the Mastcam-Z camera and the Remote Micro-Imager of the SuperCam instrument on NASA’s Perseverance rover — which landed in Jezero crater in February 2021 — in the three months after landing. The images show the geologic layers of an ancient river delta, which formed when Jezero crater was filled by a lake. Named Lake Jezero, the paleolake could have been up to 40 km (25 miles) wide and tens of meters deep.
[…]
Sci-News
The full text of the paper, Mangold et al., 2021 is available. Here’s the abstract and one of the images of the outcrop:
Perseverance rover reveals an ancient delta-lake system and flood deposits at Jezero crater, Mars
Abstract
Observations from orbital spacecraft have shown that Jezero crater, Mars, contains a prominent fan-shaped body of sedimentary rock deposited at its western margin. The Perseverance rover landed in Jezero crater in February 2021. We analyze images taken by the rover in the three months after landing. The fan has outcrop faces that were invisible from orbit, which record the hydrological evolution of Jezero crater. We interpret the presence of inclined strata in these outcrops as evidence of deltas that advanced into a lake. In contrast, the uppermost fan strata are composed of boulder conglomerates, which imply deposition by episodic high-energy floods. This sedimentary succession indicates a transition, from a sustained hydrologic activity in a persistent lake environment, to highly energetic short-duration fluvial flows.
Mangold et al., 2021



For comparison, here is a schematic diagram of a Gilbert-type delta depositional sequence:
Diagram of Gilbert Delta Characteristics.
Cuyahoga Valley National ParkDESCRIPTION
Deltaic deposits are characterized by the presence of topset, foreset, and bottomset beds. Topset and foreset beds develop when high energy flows enter a lower–energy water environment. As the water’s velocity drops, the sand and gravel that were transported along the bed of the channel as bedload come to a stop, resulting in deposition. The deposits accumulate in layers at an incline along the floor of the lake or sea. As time passes, subsequent deposition occurs on top of the previous foreset beds, creating topset beds. Fine-grained material such as mud and silt remains in suspension longer, and settles out in nearly horizontal layers farther from shore in the lower energy environment, creating bottomset beds. At Cuyahoga Valley National Park, glacial lakes accumulated thick deltaic deposits that are exposed in the valley walls today.
NPS
The Cuyahoga Valley National Park deltaic features are decent analogies, since they are also lacustrine features.
Now they just need to drive Perseverance over there, pick up a suite of rock samples and drill a few cores and see if it quacks like a delta.
I just love field geology!
Reference
Mangold, N. et al. Perseverance rover reveals an ancient delta-lake system and flood deposits at Jezero crater, Mars. Science, published online October 7, 2021; doi: 10.1126/science.abl4051
Excellent!
It looks like it would be a bit difficult to date.
Without rock samples, it can only be roughly dated by cratering density. When rock samples are returned, radiometric dating of the igneous rocks will enable more accurate age estimates.
There is a sample return mission in the cards. But igneous rocks mean tectonics, right? Has Perseverance any chance of sampling such (dispersed by impact)?
Mars was tectonically active in the distant past… I think Olympus Mons is the largest volcano in the solar system. There are a lot of basaltic rocks on Mars. There are also ancient lava flows, related to impact events.
I was thinking more of granite, needing subduction and water. Has anything like that been imaged or sampled on Mars?
https://www.researchgate.net/figure/Tectonic-map-of-Mars-with-emphasis-on-local-subduction-zones-Two-subduction-systems-are_fig5_258994947
Mars may have some granitic rocks… https://themis.asu.edu/node/5395
Indeed there is. Currently it is being referred to as Mars Sample Return (MSR). Perseverance has already picked up at least one sample intended to be delivered back to Earth. The launch date is, I believe, sometime in 2026 with a return in 2030. It is an extremely complex mission with multiple agencies involved including the European Space Agency. IMHO, the cost is going to balloon as the project moves through the various phases leading up to launch. Lots of points of failure on the way. Will be very interesting to see if this can be pulled off successfully.
The evidence keeps piling up that Mars once had plenty of surface water but what we need to sustain human exploration is to find water there now that is accessible.
That is exactly how things started with Columbus. Luckily there is a new environmental NGO on the scene to stop Martian exploitation in its tracks. It is called RED PEACE, which is dedicated to preserving Mars in its current state, for future generations of deindustrialized people to enjoy.
The preservation of Mars should be humanity’s number one concern right now. And as I write this, millions of dollars are being raised from concerned progressives to make this project a reality. And the same methods pioneered by Green Peace, our sister planet NGO, can be used in these efforts: for example, gluing one’s self to a rocket nose cone, flying over launch pads to disrupt launches, and most importantly, voting for political candidates and political parties that will preserve Mars.
Join the Twitter discussion now at hashtag: #LeaveItInTheSky !!!
You forgot to use the sarcasm font…
Red Peace sounds like a good idea(no matter how phony) to stop a massive waste of money by sending a handful of sociopaths to die on a red piece of rock 100 millions mile away
while the money could be used for infrastructure and to hunt the AGW cult down.
We don’t need another huge money wasting scam that benefits a handful of scientists – not even those in spacesuits – until mars travel gets at least 80% cheaper.
For now just send Mann, Hansen, et al.
If wealthy people want to spend their own money to go to Mars, then IMHO it’s nobody’s business but their own. You, of course, are free to spend your money however you choose, so happy hunting.
Unless I choose to spend my money on a small gasoline engine in California, you mean.
“If wealthy people want to spend their own money to go to Mars, then IMHO it’s nobody’s business but their own.”
That’s my opinion, too.
If Bezos or Musk want to fund their trips around the solar system, more power to them.
And they are just the tip of the iceberg when it comes to space development. Private space entrepreneurs are coming out of the woodwork now.
Musk is getting ready to launch a new company’s “Fuel Depot” into orbit. This space-going fuel depot is going to be used to refuel satellites in orbit, including in geosynchronous orbit.
As long they do i don’t care.
As soon it’s taxpayers money it’s a different song.
/to stop a massive waste of money/
Unless the NGO takes in more money than the cause it is up against. (lol)
Vice Commander Harris, the nearly invisible No. 2 in the Bai Den Regime, was seen recently gushing about “Space!” to a bunch of well-paid child actors! Perhaps she would like to set another first, and be the first woman to walk on the surface of the Moon, or even Mars!
I believe that we could easily find money for a one-way ticket to either destination; in a few more months the public might demand it!
@Anon
You should have quoted The Restaurant at the End of the Universe by Douglas Adams
+42×1042
This seems reasonable, this at least is based on observations, so why does Nasa insist on going stupid?
Climate Modeling Suggests Venus May Have Been Habitable
Venus may have had a shallow liquid-water ocean and habitable surface temperatures for up to 2 billion years of its early history, according to computer modeling of the planet’s ancient climate by scientists at NASA’s Goddard Institute for Space Studies (GISS) in New York.
The findings, published this week in the journal Geophysical Research Letters, were obtained with a model similar to the type used to predict future climate change on Earth.
https://www.nasa.gov/feature/goddard/2016/nasa-climate-modeling-suggests-venus-may-have-been-habitable
Nasa GISS I suppose that explains it. The curse of Schmidt
Because it fits the fantasy of runaway CO2 heating.
The only way Venus could ever had surface liquid water would be if it originally turned much more slowly than now. Its dense atmosphere would have permitted liquid water at higher temperature, indeed too hot for life, but no one presently knows what its primordial rotation rate was.
Most (76%) sunlight is reflected back to space high in Venus’ atmosphere. Only about 10% reaches the surface, three percent directly and seven percent after scattering. The rest is absorbed in the air.
Venus is hot because it turns so slowly (and backwards), and, due to its thick air and high winds, doesn’t cool off during its months-long night, unlike also slowly rotating Mercury.
The features on Mars, the atmosphere of Venus (which is more like an early version of Earth not the other way round) and Earth do all seem to form a vague pattern. It’s an odd question but could planet’s have a sort of ‘sequence’ like stars? Could Venus be an early sequence planet, Earth a middle sequence and Mars a late sequence one? Mars shares similar features to Earth and Venus shares similar characteristics with a very early Earth, so could all 3 planet’s be on a similar sequence with Mars being something like our planet’s future? Might never get an answer to that but it’s an intriguing idea.
Maybe they know how to use plurals and possessives on those other planets. 🙂
All right, calm down – I was slightly distracted this evening and at the mercy of the autocorrect on my phone. Normally I’m better than this but wasn’t thinking entirely clearly. Do you want to comment on the rest of it, or not?
maybe, but for sure they knew how to use pronouns.
Your argument is not valid for all planets.
But let’s assume you meant the goldilocks region and focus only on our solar system.
Then ,planets made of identical elements may indeed go through identical stages in terms of atmosphere.
Problem is that this does not explain the delay of a billion years in terms of sequence as mars is a bit older than earth but said to have lost liquids and dense atmosphere more than 3 billion years ago.
Another thing may be : why does the planet that suffers the most from sunwinds has the most gas?
Well, of the 3 planet’s in the habitable zone, Mars is the furthest out and receives less energy per m2 whilst Venus is the closest and receives more energy per m2 – I am assuming here that solar energy is a big driver of atmospheric changes but maybe not so unreasonable.
Bright Venus’ high albedo (.76) means that only about ten percent of sunlight incident at the top of its thick atmosphere reaches the surface. Another 14% is absorbed by the dense air.
That can only be answered with exoplanet surveys and ALMA’s nebula scans. To catch planet formation in action.
https://www.eso.org/public/news/eso1436/
Riiight. They can’t even accurately model the freakin’ planet they live on!
My sentiment exactly.
Beautifull picture, interesting spot. I hope to experience the finding of ancient life on Mars, I am born 1939.
I’ve seen articles lately claiming humans should be able to live to 130 years.
I’m going to test that theory. 🙂
People have been claiming water on Mars since they first discovered “canals” through a telescope. Water on Mars is a classic case of observational bias.
Well this one finally settles it. You can’t get that type of cross bedding without water. No observational bias needed here; an open mind will do fine.
Plus… The water that did this has been gone for 2.5-3 billion years.
Jezero Crater has clay minerals, carbonate minerals and a nearly textbook outcrop of deltaic facies. It doesn’t get much more QED than this.
I do not question that the patterns are result of liquids,
but may it be something else than h2o?
Koolaid?
Maybe liquid CO2?
After all, CO2 causes everything!
(Or so we’ve been sold.) 😎
Not entirely true. You need a liquid.
Given the conditions on Mars you [or me anyway] would presume it to be water but there are other possibilities – carbon dioxide, ammonia.
You could get a delta from a pyroclastic flow.
Not sure about cross bedding though.
Clay minerals are hydrous aluminum phylosilicates. They can only form in the presence of water. They either contain water or hydroxyl molecules in their lattices.
https://advances.sciencemag.org/content/4/6/eaar3330
We know that Mars once hosted large bodies of water as well as we know that the Norphlet aeolian sandstone was deposited in an arid desert environment. I don’t need to have lived in the Jurassic Period to know that the Norphlet was deposited as sand dunes. I just need to understand sedimentary geology.
https://www.sciencemag.org/news/2015/10/mars-once-hosted-lakes-flowing-water
Gale Crater has thick layers of mudstone (AKA shale), sandstone and conglomerates. Some of the sandstones clearly appear to be aeolian, others clearly appear to be fluvial deposits. The mudstones are composed of clay minerals that release water when heated.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016JE005055
Mars also appears to have some carbonate rocks.
https://www.nature.com/articles/news.2008.1329
https://eos.org/research-spotlights/detecting-carbonates-on-the-surface-of-mars
Including carbonate rocks identified by the Curiosity Rover in Gale Crater…
https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2016JE005225
Great update on the Mars Rover and the old delta. It will be interesting to see Rover close-up digital photos of the less inclined cobble/pebble beds to see if the finer sediments settle directly above them, in a pseudo-Bouma Cycle texture, showing the flood cycles. You mentioned the finer sediments farther out in the ancient lake, but the flood cycles are where the action is, including trapped ancient life remnants (I’m thinking pond scum).
Turbidites on Mars would be very cool.
How about getting an Exxon Vail sea level curve first just to prove that Exxon knew. Fossils in our deltaic rocks? Dinosaurs or stromatolite mounds?
I’m actually more enthusiastic and certain about huge lava tubes running throughout all altitudes of Olympus Mons. It probably would not take a lot of locally produced aggregates to create massive air locked chambers.
Much more importantly, this is a depositional environment. Things transported into a depositional environment stay there preserved. This is a great place to find fossils, even single cellular life such as stromatolites.
Yep. Curiosity has already imaged features in Gale Crater that morphologically look like stromatolites and other features on Earth associated with primitive, simple lifeforms. Until these rocks can be examined in a laboratory, there’s no way to know for sure… Even then, we might not know for sure.
David, the near-tidal muddy environment in older Paleozoic sedimentary rocks contains zones of stromatolite mounds, commonly mapped as “Dolly Parton Structure”. I personally introduced a size range described as “Little Annie” to Queen Latifah”. Funny what the heat in the field in the summer does to geologists.
Stromatolites have been found from the Archean Eon.
assuming there are any to be found
If we do find life on Mars, then that will mean the universe is teeming with life.
Or, I suppose a case could be put forward that Martian/Earth life are related via meteorites and life is unique to this solar system.
Those are some good pictures of the crater and surrounding area.
I suspect that life arises wherever conditions permit. The main elements of nucleotides, H, C, O and N, abound in the universe. Only P is relatively rare. But each nucleotide needs just one P atom, vs. several each of the other elements.
And of course, life elsewhere might use a different system for storing genetic information.
Researchers at Emory U and TIT found over a million alternatives to the ribose sugar-phosphate backbones of RNA and DNA.
https://www.extremetech.com/extreme/301888-researchers-find-more-than-1-million-alternatives-to-dna
Alternatives to the five nucleobases, A, C, G and T or U, presumably exist as well.
Beyond which totally different chemical architectures might work.
Stromatolites would be remarkable, since on Earth they’re typically built by cyanobacteria. It took hundreds of millions of years for cyanobacteria to evolve here. Oxygenic photosynthesis arose on Earth only once. Chloroplasts in plants evolved from the endosymbiosis of cyanobacteria in eukaryoyes, similar to how mitochondria developed.
Truly fascinating imagery, especially for an old stratigrapher/sedimentologist like yours truly. Who wooda thought we’d reach this stage of knowledge about Mars?
The name “Jezero” resonates as I am of Slavic origin: it means “Lake” (or reservoir)
They can see the evidence of flooding on a dry planet but refuse to see the evidence of a global flood on a planet mostly covered by water.
They see it alright. It’s just one of those things that can’t be discussed in polite company.
There is no such evidence to be seen. Nor was it even possible 4500 years ago, or at any time since continents have existed. There have been a few intervals however in which water ice did indeed cover most if not all the world’s land. But the frozen water came from the oceans.
Where do you suppose the 3.5 times as much water as now in the oceans went after this physically impossible global flood, covering even Mt. Everest?
Hmm – could that be because there IS evidence of water on Mars and ZERO evidence of a global flood on Earth? I think that might be it.
Please state what evidence you imagine exists for the fact-free fantasy of a global flood 4500 years ago. Thanks!
Also, how did kangaroos, wombats, lemurs, flightless parrots, kiwis and dodos get to Noah?
¨Now they just need to drive Perseverance over there, pick up a suite of rock samples and drill a few cores and see if it quacks like a delta.¨
Surely no ducks (fossils) there?
Still, it is a real puzzle. The plot thickens!
If there are any fossils that’s a good place to look, although it might be like looking for a needle in a haystack; a very big haystack and a needle that you’re not sure was ever there in the first place!
And you don’t even know what a Martian needle is supposed to look like… 😉
A Martian needle ?
Probably looks like a stromatolite. Got them dated to 3.5 billion years in the Pilbara, Western Australia.
https://newsroom.unsw.edu.au/news/science-tech/earliest-signs-life-scientists-find-microbial-remains-ancient-rocks
That was 2019, with NASA and ESA both checking the pyrites there.
Within is a link from 2017 :
https://newsroom.unsw.edu.au/news/science-tech/oldest-evidence-life-land-found-348-billion-year-old-australian-rocks
“This may have implications for an origin of life in freshwater hot springs on land, rather than the more widely discussed idea that life developed in the ocean and adapted to land later.”
What is a poor Perseverance robot to do – life just so unpredictable?
According to Bill Clinton, they look like this:


David: Thank you for a very informative geology lesson. You missed your calling – you should be the head of a major university geology department. Of course if you were you’d have to kowtow to the climate change zealots to get funding. No room for free thinking in academia these days. Anyway I always enjoy your posts and always learn something from them. Well done.
I’d also need a couple of more degrees in geology… 🙂
I’ve seen little evidence of any correlation between degrees and true knowledge and understanding. The best teachers I have had didn’t have Ph.Ds but did have a lot of real world experience. Too bad our educational system is dominated by credentialists.
Degrees are academic union cards.
Awesome picture of an ancient braided, fantail river delta with a fat meteoroid crater in the middle! Other worldly, and rightly so…
Thanks for the education on riverine delta deposition, David.
Another interesting statement by a UK politician:
‘You can’t just say “we’re following the science’’– you have to dig down and ask why scientists are saying what they’re saying. That challenge should have happened earlier’.
– Jeremy Hunt, chair of the health select committee, speaks to Sky News
He was not, unfortunately, referring to climate change but to COVID.
Science really has nothing to do with either one, except as a hammer to drive a social/political agenda through. There is nothing scientific in the declaration that human activities will change the earths atmosphere into something like that of Venus. Just as there is nothing scientific in mandating this So called vaccine for only a portion of a country’s population.
portion of the Worlds population.
Off topic.
One of the images has a feature named Neretva Vallis

Neretva is a river not too far from Jezero (Lake) both in Bosnia (ex-Yugoslavia) where a WWII battle took place between partisan guerrilla and German army, immortalised by a film with Yul Brynner and Orson Welles among others lesser known.
Be careful,
https://balkaninsight.com/2020/10/15/bosnia-presidency-fails-to-agree-on-recognition-of-kosovo/
Biden’s Admin will likely sanction Mars, or even send Nuland there to hand out cookies!
Nuland will only go if the result has already been fixed first!
Don’t forget Franco Nero!
Kim Stanley Robinson wrote a long 3 book Trilogy of Mars worth reading as it is well regarded science fiction literature.
Red Mars (Nebula winner for best science Novel of the year, BSFA winner)
Green Mars (Hugo winner, Locus award, Ignotus winner)
Blue Mars (Hugo winner, Locus award)
2312 (Nebula winner) A story about mankind spread out in the Solar System
I have read the first two and have the books still.
Read the first three books years ago. Good reads!
“Named Lake Jezero”
Word ‘Jezero’ (pronounced Yezero) it actually means Lake in number of Slavic languages, Village Jezero is located in Bosnia
https://www.jpl.nasa.gov/news/nasa-mars-mission-connects-with-bosnian-town
Maybe next time search the whole planet for an ancient hot springs deposit–just one, any will do.
Recent estimates are that a large asteriod impact will create a hot-springs environment similar to a Yellowstone Park environment, on Earth-like planets.
There are a lot of asteriod impacts on Mars, so there were probably a lot of ancient Yellowstone Park type environments on Mars, down through time.
Does this imply the existence of a hydrologic cycle on Mars at one time?
It implies that there was some type of fluid material, that moved for long enough to create that topography.
JPL tried that informal naming of features routine years ago, with the Spirit rover. It was so informal that no one knew who had named what feature what, until they finally had a big “come to Jesus” meeting to sort it all out. To their dismay, they discovered that there were so many features named “Starbucks” that no one could figure out where the rover was, had been, or was going.
Okay, I made that last part up.
In fact, I made the first part up, too. But it should have been true, dammit.
Were you the 13th Apostle at that meeting?
Mea culpa. In fact, you may have seen me defamed in the wildly inaccurate film “Apostle 13.”
I so want them to find a subterranean cave system.
Finally Griff has proof that windmills are reliable and economic!