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The Sliding Rocks of the Racetrack Playa Mystery

"One of the most interesting mysteries of Death Valley National Park is the sliding rocks at Racetrack Playa (a playa is a dry lake bed). These rocks can be found on the floor of the playa with long trails behind them. Somehow these rocks slide across the playa, cutting a furrow in the sediment as they move. "

The Question remains: "How do they move?"

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Picture of The Sliding Rocks of the Racetrack Playa Mystery
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bdboatr7 years ago
Could it be a combination of the theories, not necessarily a strong combination, but include the possibility of magnetic fields?
Sorry, but I haven't checked in for some time. The stones of the playa do not contain iron, and are not subject to magnetic fields. Ice sheets can't explain the splash patterns, and wind does not blow rocks uphill. The only realistic explanation is frost heave. The stones are sliding downhill.
Tarzan19627 years ago

The reason the rocks move is due to a common phenomenon known as frost heave. Ice lenses form beneath the surface creating slopes for the rocks to slide down. Any rainfall that occurs while ice lens formation is present is enough to set the rocks in motion. The frozen subsurface explains why stones leave a uniform depth of track no matter how much they weigh.

P.S.

Mud on ice is VERY slick.

Just out of curiosity, Mr. Berger, are you just posting your theory to every single site with reference to the Racetrack Playa?  And posting as though it were a "known fact" rather than your own personal guess?
I came up with this idea more than 20 years ago. Before I joined the debate, I decided to attack my own hypothesis trying to disprove it. I didn't want to look foolish if it was totally impossible, but I didn't succeed. Trying to get my hypothesis heard by anyone has become quite frustrating, so I started posting on blogs just to get my opinion heard. As for peer review, try getting anyone to even listen when you don't have a degree. I decided maybe it was best if I posted it as factual, and wait for people to start attacking it. When they wind up in my position of not being able to disprove it, maybe I'll make more headway. Please accept my invitation to be the first attacker, and good luck.

Mark B.
Greenville, OH
20 years ago?  You can certainly get good science published in peer-review without a degree.  I have examples which I can provide if necessary, but they are not pertinent to this issue.  If you have a good hypothesis, with good quantitative data to back it up, then you can definitely get it published.

What you are doing is not even close to the way science works.  Any crackpot (which you probably aren't) can come up with a hypothesis or three, then tell the community "now you have to disprove what I've said, or I must be right."  It is your responsibility to provide evidence supporting your hypothesis, and to outline observations or measurements which could be made, but have not, which would either support or refute your hypothesis.


Have you actually seen, or have any literature citations to support, permafrost in the Mojave desert?  Or even the kind of solid below-ground freezing necessary for frost heave?  Such data would go far to supporting your hypothesis as plausible.

I did not decide to join the debate until recently, and to be frank, I questioned myself as to how some nobody in small town Ohio could come up with a viable hypothesis when so many had been looking for so long. That is why I did a full scale attack against my own idea. I did not want to look the fool. As it stands now, I would love to have the opportunity to do a single core sample at the southern end of the playa. First to verify that a supply of water is available below the surface, and second to subject the soil to the Casagrande criterion. Passing both tests would mean it is not a matter of if it could happen, but only a matter of when it wil happen. That science is already recognized and understood. Unfortunately, I do not have the resources to do that. I would greatly appreciate any suggestions or advice you might have.

Thank you for your time,
Mark B.
(kelseyMH - apologies for butting in)

Ummm. It's not a good idea to assert as fact something which has absolutely no evidence backing it. I don't mean evidence that's questioned, or evidence that's been discarded, or evidence that's in controversy, or evidence that not everyone accepts - like you said, you don't have any evidence. At all.

So, setting aside the question of evidence for a moment, what do the arguments against your own hypothesis look like? What's it look like when you play devil's advocate?
When playing devil's advocate, I looked at wether frost heave could actually overcome the fact that the southern end of the playa is a few centimeters lower, because the minor amount of expansion caused by ice in soil simply could not generate the amount of upheaval necessary to bring about a sliding event. I researched frost heave, and discovered ice lens formation. I didn't think that the weather could get cold enough for frost heave, but a PBS show said it best, some times hell freezes over. The fact that the surrounding terrain features shield that area of the playa from the sun in the winter did not help my advocacy. In order for ice lens formation to occur, you need the right soil type, and a supply of water. A silt clay sediment mix is highly conducive to ice lens formation, and there are springs near that end of the playa. Every time I tried to argue against my own idea, I found more reason to believe it. I saw a picture of mud clumps that had slid across the surface, and you could still see faint traces of a fracture where they originated. Exactly the same way that frost heave tears up roads in Ohio. When I got to the point that not only can frost heave overcome the fact that the southern end of the playa is a few centimeters lower, it might actually be the reason it is lower because the surface layer of the playa is washing away as well, I gave up and started believing myself again.
It is still the case that you have a vague hypothesis, not an "answer", and it will remain a hypothesis until you (or somebody else) goes to the Playa to test it, or until a better hypothesis replaces it.

In this case, your "frost heave" idea is attractive, but you have not presented a mechanism whereby the frost will consistently "heave" on the SSW of the rocks (I can think of a mechanism that will produce a general tendency, but not a consistent pattern - can you?).

The available data supports the wind-blown hypothesis, not the frost-heave hypothesis, so the accepted hypothesis is "wind", not "frost".

This is nothing to do with popularity (science is not a democracy), but with evidence.

You have previously dismissed the wind hypothesis out of hand - would you care to present the evidence you possess that contradicts the wind hypothesis, or fits the available observations more accurately?


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