The strange rubbing boulders of the Atacama

Oct 11, 2011
These are huge boulders in Chile’s Atacama desert which appear to be rubbed very smooth about their midsections, leading University of Arizona geologist Jay Quade to wonder what could cause this in a place where water, Earth’s most common agent of erosion, is as almost nonexistent. Credit: Image courtesy of Jay Quade.

A geologist's sharp eyes and upset stomach has led to the discovery, and almost too-close encounter, with an otherworldly geological process operating in a remote corner of northern Chile's Atacama Desert.

The sour stomach belonged to University of Arizona geologist Jay Quade. It forced him and his colleagues Peter Reiners and Kendra Murray to stop their truck at a lifeless expanse of boulders which they had passed before without noticing anything unusual.

"I had just crawled underneath the truck to get out of the sun," Quade said. The others had hiked off to look around, as tend to do. That's when Quade noticed something very unusual about the half-ton to 8-ton boulders near the truck: they appeared to be rubbed very smooth about their midsections. What could cause this in a place where Earth's most common agent of erosion -- water -- is as almost nonexistent?

About the only thing that came to mind was earthquakes, said Quade. Over the approximately two million years that these rocks have been sitting on their sandy plain perhaps they were jostled by seismic waves. They caused them gradually grind against each other and smooth their sides. It made sense, but Quade never thought he'd be able to prove it.

Then, on another trip to the Atacama, Quade was standing on one of these boulders, pondering their histories when a 5.3 magnitude struck. The whole landscape started moving and the sound of the grinding of rocks was loud and clear.

"It was this tremendous sound, like the chattering of thousands of little hammers," Quade said. He'd probably have made a lot more observations about the minute-long event, except he was a bit preoccupied by the boulder he was standing on, which he had to ride like a surfboard."The one I was on rolled like a top and bounced off another boulder. I was afraid I would fall off and get crushed."

He managed to stay atop his boulder, of course, and became thoroughly convinced that the earlier hypothesis about the boulders was correct.

"I was just astonished when this earthquake came along and showed us how it worked," Quade said. Quade will explain the phenomenon on Tuesday, 11 Oct. at the annual meeting of the Geological Society of America in Minneapolis.

The whole story appears to be that the boulders tumbled down from the hills above -- probably dislodged by earthquakes. They accumulated on the sand flat, with no place else to go. Quade compares the situation to a train station where people are crowded together closely, rubbing shoulders as they waiting for a train. In this case the boulders have been stuck at the station for hundreds of millennia and the train never comes. So they just get more crowded and rub shoulders more over time.

Analyses of the boulder top surfaces suggest that they have been there one to two million years. That age, combined with the fact that seismic activity in the area generates a quake like that Quade witnessed on the average of once every four months, suggests that the average boulder has experienced 50,000 to 100,000 hours of bumping and grinding while waiting for that nonexistent train.

"It also answers a mystery that had been eating at me for years: How do the boulders get transported off the hills when there is so little rain," Quade said. "How do you erode a landscape that is rainless?"

Again the answer is seismic activity.

"It raises the question in my mind of other planets like Mars." If there is seismic activity, even from meteor impacts, might it also be creating similar landscapes? "I would predict that these kinds of crowds of boulders might be found on Mars as well, if people look for them."

Explore further: NASA balloons begin flying in Antarctica for 2014 campaign

More information: gsa.confex.com/gsa/2011AM/fina… /abstract_188948.htm

Provided by Geological Society of America

4.9 /5 (23 votes)

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User comments : 45

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CHollman82
3.5 / 5 (21) Oct 11, 2011
4 billion year old Earth plus 1
6000 year old Earth minus 1

Total so far is 2341256 to -2341252

Those crazy Christians :rofl:
knowitall599
3.2 / 5 (9) Oct 11, 2011
I haven't read the article yet, but I'm betting that the christians will say something irrational. For example, I bet they say god did it.
Husky
5 / 5 (5) Oct 11, 2011
i say the tremors are caused by the nonexistent train passing by
CHollman82
2.5 / 5 (13) Oct 11, 2011
Good theory!

Here is another, the Earth is 6000 years old and instead of one earthquake every 4 months for 2 million years that region has had one earthquake every ~14 seconds for 2.6 years!

That solves it, Christianity is safe once again!
CHollman82
1.8 / 5 (10) Oct 11, 2011
To prove that I didn't make those numbers up:

2,000,000 / 4,500,000,000 = 2.666 / 6000

1/4months = 3/year * 2,000,000 years = 6,000,000 total

1/14sec = 4.28/min = 257.14/hr = 6171.42/day = 2,252,571/yr * 2.666yrs = 6,005,354 total

6,005,354 ~= 6,000,000

Pretty close using back of the napkin math
Scottingham
not rated yet Oct 11, 2011
They really loved that train analogy.
Isaacsname
5 / 5 (1) Oct 11, 2011
Kind of like a geological Brazil nut effect.

Simonsez
2.6 / 5 (17) Oct 11, 2011
You Christian-haters and your troglodyte humor. You should realize by now that the "6000 year old earth/Creationism" crowd is a minority (albeit a vocal minority) among the religion and that they are even jeered by most forward-thinking Christians; that it is so well known is a product of its ridiculous assertion rather than any (falsely) perceived notion that it is common among Christians.

This article has absolutely zero to do with Christianity or in fact any other religion, yet you collectively take delight in injecting your hatred everywhere possible on PhysOrg. Yes, we get it, Creationism is a stupid idea that flies in the face of scientific fact. About as stupid as thinking that pointing this out repeatedly on a science forum makes you appear intellectual or witty.
CHollman82
4.2 / 5 (19) Oct 11, 2011
You should realize by now that the "6000 year old earth/Creationism" crowd is a minority (albeit a vocal minority) among the religion and that they are even jeered by most forward-thinking Christians; that it is so well known is a product of its ridiculous assertion rather than any (falsely) perceived notion that it is common among Christians.


No, sorry... get your facts straight.

As of 2008 a Gallup poll indicated that 36% of US adults agreed with the statement "human beings developed over millions of years from less advanced forms of life, but God guided this process.", 14% believed that "Human beings have developed over millions of years from less advanced forms of life, but God had no part in this process." and 44% of US adults agreed with the statement "God created human beings pretty much in their present form at one time within the last 10,000 years or so.

CHollman82
3.8 / 5 (20) Oct 11, 2011
Fundamentalism, creationism, etc are NOT minorities in the United States, they are the majority, and they are batshit insane and they are an EMBARRASSMENT to this country and to our species.
Jeddy_Mctedder
2 / 5 (8) Oct 11, 2011
what about wind erosion, how was this not even eliminated as a possibility in the article, not even mentioned!
tigger
5 / 5 (12) Oct 11, 2011
44% of US adults agreed with the statement "God created human beings pretty much in their present form at one time within the last 10,000 years or so."

I've read that many times before but it still makes me throw up a little when I read it.

chuck b
5 / 5 (5) Oct 11, 2011
what about wind erosion, how was this not even eliminated as a possibility in the article, not even mentioned!


Wind erosion would erode all the sides and top equally. The rocks had a clearly eroded mid-section, hence the reason wind erosion was ruled out.
Pete1983
4 / 5 (3) Oct 11, 2011
what about wind erosion, how was this not even eliminated as a possibility in the article, not even mentioned!


@Jeddy - Completely agree. If the rocks have been there for millions of years, one would think it is a possibility. Perhaps a geologist could say that it is impossible for whatever reasonss, however you'd think it would be mentioned.

@Simonsez - Yes bashing Christians (and all the other loopy religions out there), is incredibly easy and mostly pointless within these comments. However given that as a group these people are ruining the world for the rest of us (as well as allowing a lot of bronze age thinking to continue, not just the god idea), I think we can be forgiven for taking a few shots at Christians.

Also, as a Christian you are meant to forgive! Your master jebus tells you so!

Nearly all Christians/Jews/Islamists/etc are idiots, and wouldn't know truth if it fell on them.

Forgive me.
Code_Warrior
4 / 5 (8) Oct 11, 2011
Also, as a Christian you are meant to forgive! Your master jebus tells you so!

Nearly all Christians/Jews/Islamists/etc are idiots, and wouldn't know truth if it fell on them.

Forgive me.
You mock forgiveness as if it is a silly idea. It seems to me that the world could use more forgiveness.
Jayded
2 / 5 (4) Oct 12, 2011
ChuckB - That doesnt make sense, why would an earthquake provide more focused erosion than the wind? The guy mentioned his rock turning over so IMO it still is not an adequate description.
jsa09
4 / 5 (1) Oct 12, 2011
Rock vibration should at first glance cause more erosion to the edges.

Think of two cubes side by side being jostled. The only places they would knock together is at the edges and corners. In this article he states that the centers are more eroded than the edges.

If the boulders are tightly packed and already round then they would touch at the mid section and small vibration would rub that area away until they were more cubic in shape.

So to say that more erosion occurs around the mid section would depend on the original shape.

But the end result would be similar in shape.
dogma
5 / 5 (2) Oct 12, 2011
And why only the middle? I would think they'd be rounded into giant balls. Speaking of rocks doing strange things: Go to wiki and enter "sailing stones". That's a real head scratcher. Let us know what you think.
Isaacsname
5 / 5 (1) Oct 12, 2011
I read the wiki, the ice floe/wind drag on a saturated surface ideas make sense, especially if you've ever played with " slip " or done any " slipcasting ". The surface tension is different due to, my guess, a thin layer of water on top of the clay itself, only when sufficiently saturated, slicker than goose poo though. I think the rocks get pushed by the wind enough to break the suction of the surface tension of the clay itself, they hydroplane very small distances on the thin layer of water until they lose inertia and settle back into the clay surface, forcing out the thin film of wawa.

Then they wait for more wind.
scidog
4 / 5 (3) Oct 12, 2011
i would think the same thing,earth quakes,would explain the close fitting joints in the cyclopean stone walls in that part of the world.the joints are a perfect fit from years of rubbing and not expert stone mason work.
Vlasev
4.7 / 5 (3) Oct 12, 2011
i would think the same thing,earth quakes,would explain the close fitting joints in the cyclopean stone walls in that part of the world.the joints are a perfect fit from years of rubbing and not expert stone mason work.


Fitting them to stand on-top each other rather than rumble down is kinda "expert" stone mason work. Also you have to account for the frequency, intensity and duration of the earthquakes in the area for the time those walls stood upright. Note that Chilly sits besides subduction zone hence a lot of relatively strong earthquakes. And the time span for these bolders is huge
up to two million years.
DontBeBlind
1 / 5 (8) Oct 12, 2011
First page in the bible says the world is not 6k years old!!!
WTH can't people read???? The planet was already here when God did the 6day or (6kyear) creation event! You all talk smack to each other but no one is checking their facts.
1 point for God
-1 point for atheist.
210
3 / 5 (2) Oct 12, 2011
What happened here?
I read and reread the article.
No mention of anything religious or biblical..anywhere in the article that I could see or infer!
How did all this religious talk, and the evident hate, get in here?
I even saw nothing in the stories link...hummm.

word-
CHollman82
2.6 / 5 (5) Oct 12, 2011
The article is another piece of evidence to throw on the mountain of evidence against the ridiculous and childish beliefs of a large percentage of adults in America.
210
1 / 5 (1) Oct 12, 2011
The article is another piece of evidence to throw on the mountain of evidence against the ridiculous and childish beliefs of a large percentage of adults in America.

HEY! This is a science website: a place for discussion not BASHing faiths! Why, why, if you proceed in this fashion, every, single, story, on this website, will become a point of religious debate not a reasoned discussion of fact and intellectual probing. We don't have to resort to hate to make 'Our side' look better than 'Their Side' thats childish. And worse, look at all these posts. They did not start with a religious zealot throwing comment in here, it was started with a comment that ended with a vindictive characterization. Look, the more you bash a thing, the stronger it becomes! Now if someone hits you defend yourself, but this baiting is tiresome and will NOT convince most people to give up anything - not even fast food! The rocks...what do you think about THE ROCKS...seismics...c'mon?
word-to-ya-muthas
ForFreeMinds
1 / 5 (5) Oct 12, 2011
There is another place (also in Chile I think) where there are these moving rocks. There it's the rare rain storm which with the water, makes the ground very slippery and the rocks move with the wind. There might also be erosion on the rocks like this as well. Since they apparently topple the reported "midsection" might have been the bottom of the rock at one time.

Just a thought.
AtomThick
1.7 / 5 (6) Oct 15, 2011
Rational people are skeptic about the Bible. I've read it some time ago and I remember a phrase that said "1 second for God is 10,000 years for humans." (this stuck to my mind because it seemed science fiction, I don't remember very clear what was the context). Curiosity made me compute how many years represent the God's 7 days and I got 6,048,000,000 years. 6 days add up to 5,184,000,000 years. I don't really know the exact age of the Earth but it seems we are still living in the 7th day. If this has some truth in it, it makes you wonder what will happen on the 8th day.
BradynStanaway
not rated yet Oct 15, 2011
Did anyone notice the overuse of "Quade"?
sherriffwoody
not rated yet Oct 15, 2011
I'd need more proof than this to believe this one. Some commenters theories sound more plausible than Quades.
ROBTHEGOB
2.3 / 5 (3) Oct 15, 2011
We'll never know for sure, but it is an interesting observation. We don't have time to wait a few million years to verify it, so we have to use educated guesses; that is what makes geology (and all science) interesting. Plus, the rocks just look cool.
Silan
2.3 / 5 (3) Oct 15, 2011
Hello Physorg,

I very much enjoy your website, but am increasingly turning away from it due to the creationalism trolling and petty religious arguing on almost every thread which discusses historical evidence or evolution.
A few users, who are only here to push their opposing, non scientific beliefs are ruining what could be a very good community.

Please find a way to prevent it.

Join me please: feedback@physorg.com
Ethelred
4 / 5 (4) Oct 15, 2011
1 second for God is 10,000 years for humans." (
It doesn't say that. You made it up.

It says DAY = THOUSAND.

2Pe 3:8 But, beloved, be not ignorant of this one thing, that one day [is] with the Lord as a thousand years, and a thousand years as one day.
So please check your math AND your Biblical quotes before doing the math.]

Days are considerably different from seconds AND it is unlikely that any of the writers of the Bible ever used seconds. Also thousand in many languages does not mean 1,000. It often means MANY.

Ethelred
scidog
3 / 5 (2) Oct 16, 2011
the religious trolls come here because no one will go to them and the posters with an interest in science are not going to let the site become a place for the trolls run free so we get the arguments.....time for a story--
back in 1965 in the second semester at a small college in Ohio we freshman were trying out our new brains,after all we had psych 101 and English lit 101 under our belts and we were on a roll.in the dorms common room,no TV and a dorm mothers back then we were going on about the "nature of reality" when this voice pipes up from behind a book in the corner-"thats all nonsense!for all you know the universe could be just a atom in the finger nail dirt of another creature!!".great line maybe he went on to write movie scripts..so anyway we did the WTF of the day and he stormed out and we got our new brains back in gear again.so since then whenever a troll type pops up,anywhere about anything i think about that put down.dirt under a finger nail and how shallow people can be
sherriffwoody
3 / 5 (2) Oct 16, 2011
I don't know, I sometimes see non religous folk trolling the forums first enticing the religous to bite. I think theres a bit both ways. But yeah, it is getting over the top and needs to be slammed.
Isaacsname
not rated yet Oct 16, 2011
Ok , I figured it out.

http://blog.trave...pod.html

This is what's been moving those boulders.

Seriously though, ...after some more reading, I think the main mechanism for the erosion is wind turbulence. Reason ? I went to look at pics of these boulders and many of them are rounded not just around the bases , but also the faces, which have nothing to rub against except the sand being blasted at them. Vortices often form on the lee side of isolated mountain masses. The magnitude, number, and strength of the vortices are highly dependent on the speed and direction of the airflow, and the orthogonality of the flow, etc. Not saying small tremors wouldn't contribute, but methinks the contribution would be small in comparison.

I bet if they did some large scale smoke testing for turbulence up there they'd see it.
AtomThick
1 / 5 (1) Oct 16, 2011
1 second for God is 10,000 years for humans." (
It doesn't say that. You made it up.

It says DAY = THOUSAND.

2Pe 3:8 But, beloved, be not ignorant of this one thing, that one day [is] with the Lord as a thousand years, and a thousand years as one day.
So please check your math AND your Biblical quotes before doing the math.]


My math is pretty good. And I'm not defending anything I just needed to get it out of my system. It seems however that you are indeed defending something...good luck with that
Ethelred
3 / 5 (2) Oct 16, 2011
Carefully executed math was based on bogus claims of what the Bible says so the results are wrong. So what you did was get NONSENSE out of your system.

Defending what? What the Bible actually says? It too has a lot of nonsense.

Have fun but don't expect rubbish based on misremembered statements that aren't in the Bible to make sense even to Fundamentalists.

Ethelred
Physmet
not rated yet Oct 16, 2011
Is this idea testable? Setup an earthquake simulator with a bunch of boulders. Have the simulator perform the earthquakes at varying intensities. 50,000 hours of simulations would take about six years, but of course there would be time in between simulations and they'd also want to analyze things as they went along. However, does this seem testable?
Azpod
not rated yet Oct 17, 2011
Wha...? What does this article have to do with Creationism? Yeah, 44% of Americans think God created the Earth in pretty much its present form 6,000 years ago (or thereabouts.) So what? A lot of people believe Elvis is alive too. Does that have anything to do with the article? No.

It's awesome to see a theory which would seem almost implausible, except for an absence of any better theories, be confirmed in such a spectacular way. I just wish someone shot video of the event. If earthquakes are so frequent there, maybe someone could set up a video capture system hooked up to a seismograph. That's shut up any skeptics for sure!
CHollman82
2 / 5 (4) Oct 17, 2011
Wha...? What does this article have to do with Creationism? Yeah, 44% of Americans think God created the Earth in pretty much its present form 6,000 years ago (or thereabouts.) So what? A lot of people believe Elvis is alive too. Does that have anything to do with the article? No.


Yes, in that this is the 100,001th piece of evidence against their silly bullshit beliefs.

Oh, and the percentage of Americans that believe elvis is still alive, or any other silly myth, is measured by fractions of a percent. It is not comparable to the atrocity that is the widespread belief in a young Earth.
iamthegps
4 / 5 (1) Oct 18, 2011
I am a traditional Christian, and I have read Genesis. Not one place in Genesis does God say a single thing about the age of the earth. I believe He created this earth and all that is in it. I also believe the earth is 4.6 billion years old, and evolution is a real, natural process. I want to become a paleontologist when I graduate college, so I can study the animals that God created. I am not delusional, or ignorant, nor are my beliefs 'bullshit' or 'deluded'. I belive in God because I have felt Him in my heart and seen His works with my eyes. I want to study paleontology because I want to study what God has done on the earth. My faith and my science have never once clashed, and believe me I've given the matter serious consideration. We need to stop flaming one another over things that can be reconciled, and also, where in this article did anyone get the idea that this was to do with religion?! I certainly missed that line, if that's the case. We need to just calm down.
Ethelred
4 / 5 (4) Oct 18, 2011
I am a traditional Christian, and I have read Genesis. Not one place in Genesis does God say a single thing about the age of the earth.
You can just add up the times in the Bible to calculate the age of the Earth AND it was men that wrote it not a god.

I also believe the earth is 4.6 billion years old, and evolution is a real, natural process
The Bible has many things in it that strongly imply otherwise AND the dating in the Bible simply doesn't agree with you.

I want to become a paleontologist when I graduate college, so I can study the animals that God created
Very good. Perhaps learning will change what you think. It has done so for many.

I belive in God because I have felt Him in my heart
This can be done with electrodes. Really. Not so much a god as a feeling that people associate with what they think a god might be like

I want to study paleontology because I want to study what God has done on the earth
That is how many Agnostics became that way>>
Ethelred
3.7 / 5 (3) Oct 18, 2011
My faith and my science have never once clashed
Unusual but not unheard of.

We need to stop flaming one another over things that can be reconciled
They can be reconciled by people changing their minds. Tolerance is a different thing. I would appreciate less flaming myself but if someone starts it I don't back down.

where in this article did anyone get the idea that this was to do with religion?
I don't know EXCEPT that it clearly has an Old Earth and that upsets a number people that think the Earth is Young because the Bible tells them so. CHolman seems to have lost control over this.

We need to just calm down.
Well he does anyway. I am sure Kevin would have obliged him if he waited. It had only been a week since he last claimed something proved the world is young.

Kevin in action here
http://medicalxpr...ers.html

CHolman seems to be unable to contain himself after seeing too many of Kevin's posts.

Ethelred
TheGhostofOtto1923
2.6 / 5 (5) Oct 18, 2011
HEY! This is a science website: a place for discussion not BASHing faiths! Why, why, if you proceed in this fashion, every, single, story, on this website, will become a point of religious debate
Because Religionists routinely show up here and bash science. Their disinformation must be addressed and this is a pretty good place to do it.

Organized superstition threatens science and our future. It is well worth the effort to constantly keep reminding people of this, and Religionists posting their standard dogma presents a way of showing how false and dangerous it is. It is very revealing to see how the religious actually 'think' and what really motivates them.
forward-thinking Christians
Oxymoron
TheGhostofOtto1923
2.3 / 5 (3) Oct 18, 2011
where in this article did anyone get the idea that this was to do with religion?
Well you must admit that is pretty accessible evidence against a young earth. If god faked this then he is a pretty clever Deceiver.

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