"ice Age Death Trap" - Pbs Nova Show

[sward]

I saw a Nova (PBS) show last night entitled "Ice Age Death Trap". It was about a discovery of mammoths, mastadons, bison and other remains found in Snowmass, CO.

I believe this show was about the same area that 32fordboy was referring to in the "Bison Skull" thread. http://www.thefossil...ls/page__st__40

It was quite interesting. One theory they were proposing for the massive find was that a herd of mastadons was near the bank of a lake when an earthquake occurred. During the earthquake, the soil went through a process of "liquification", allowing the mastadons to sink. When the earthquake ended, the soil then quickly solidified again, trapping the herd where they stood.

One part of the show dicussed a partial mammoth or mastadon find (I don't remember which) that would be approximately 40,000 years old. It appears that it may have been weighed down with rocks to keep it submerged. One of the "experts" explained that he had found similar instances of parts of animals being submerged in water by weighing them down with rocks to better preserve the meat to eat later. However, these finds were much more recent. The "expert" explained this find seemed similar, but was contrary to the belief of man's existance in North America at that time period.

I'm sure the show will be aired again. I would recommend keeping an eye out for it.

Edited February 2, 2012 by sward

[Kehbe]

I saw the first half of it before I fell asleep! I did manage to hit the record button before nodding out so I will watch the rest of it tonight! It's a shame they are building a dam right over the top of that site

[sward]

Kehbe,

I agree with you completely!

One of the things I noticed was what seemed to be the lack of any "scientific recording", for lack of a better term. It seems they were just digging up bones and recovering them for the most part. However, they were operating under time constraints.

Edited February 2, 2012 by sward

[ashcraft]

I watched the show, very interesting. The part about the remains being 40,000 years old is puzzeling. The thing that I noted was that the bones could not be aged, for whatever reason, but the clay was. The problem with that situation is that the clay could have been reworked later and deposited with the bones. Also, no tools were found, and only one bone with possible cut marks was seen. The skull was also in the mix, which, to me, would have been unlikely to have been stored.

The liquifaction explanation seems a little far fetched also. Would be interesting to see all of the evidence that led them to that possibility.

Brent Ashcraft

[pleecan]

An excellent documentary!

[Indy]

Ice Age Death Trap

http://www.youtube.com/watch?v=nGy6mpkvtZ8

Edited February 2, 2012 by Indy

[AgrilusHunter]

Thanks sward for recomending this I really enjoyed it! Thanks to Indy as well for the link!

[Jesse]

Kehbe,

I agree with you completely!

One of the things I noticed was what seemed to be the lack of any "scientific recording", for lack of a better term. It seems they were just digging up bones and recovering them for the most part. However, they were operating under time constraints.

Do you know how boring "scientific recording" is? It makes for terrible TV!

And yes, they were digging the bones up as fast as possible, but that is the only way they can be preserved. The crew building the dam is contracted and on a time line. Every day they aren't building they are losing money. There is no law currently that says they have to allow research and excavations like this, it was a courtesy given to the museum to allow them to dig. I know a couple of the people who were at this dig, it was done with a great attention to detail given the time allowed.

Edited February 3, 2012 by Jesse

[Jesse]

The liquifaction explanation seems a little far fetched also. Would be interesting to see all of the evidence that led them to that possibility.

Brent Ashcraft

Here is a video showing the liquifaction process. This is a fairly common phenomenon in nature, the fossil record is full of all kinds of rapid death/burial/trap scenarios.

[jpc]

Thanks for posting this... so quickly, Indy. I don't have a TV, so I'll watch at least some of it. I was supposed to do a tour of the bones at the Denver Museum tomorrow morning, yes these very bones, but the meeting I was going to got canceled... big storm coming through Denver.

Ground sloth at high alltitude in Colorado... that is cool.

Edited February 3, 2012 by jpc

[jpc]

Do you know how boring "scientific recording" is? It makes for terrible TV! And yes, they were digging the bones up as fast as possible, but that is the only way they can be preserved. The crew building the dam is contracted and on a time line. Every day they aren't building they are losing money. There is no law currently that saws they have to allow research and excavations like this, it was a courtesy given to the museum to allow them to dig. I know a couple of the people who were at this dig, it was done with a great attention to detail given the time allowed.

Yes, this is a world class site, and we all owe a thank you to the dam outfit that worked with the DMNS to give them at least minimal time to get as many bones out as possible.

[Ramo]

That liquifaction video is cool. Reminds me of having my students mix corn-starch and a small amount of water in physical science class. It makes a similar substance. If you've never tried that experiment and like making a mess, you should try it.

Ramo

[ashcraft]

Here is a video showing the liquifaction process. This is a fairly common phenomenon in nature, the fossil record is full of all kinds of rapid death/burial/trap scenarios.

I live on top of the New Madrid fault. I am well aware of liquification and sand blows. I imagine there is a reason why they chose liquifaction out of all the possible scenarios that could cause a mass death scene. I am just curious as to what those reasons are. I would think that carbon dioxide burping, from my extremly limited knowledge, would be more likely. Do you happen to know why their reasoning led them in that direction?

Brent Ashcraft

[Jesse]

I just know what I was told, I have no insights into the upcoming publications or ongoing research.

The liquification is still happening at the same spot today so it is not to much of a leap to think that could have caused the trapping scenario seen at the sight. Are you thinking that CO2 burping caused some kind of localized suffocation kill sight? The area the lake is in is not the kind of environment that these types of things typically occur in. The animals at the sight are accumulated over a long period of time, similar to other mire trap sights.

Here is an article published on some of the evidence for the liquification scenario.

http://www.denverpost.com/breakingnews/ci_19314710

[2ynpigo]

I thought it was a great show. Amazing preservation of many of the bones.

Also what a great place to collect -- Snowmass, Colorado!!!

[AgrilusHunter]

I recomend watching this here as I found it better quality ... though still not the best, I'll be glad to see it on television some time.

http://www.pbs.org/wgbh/nova/earth/ice-age-death-trap.html

[ashcraft]

I just know what I was told, I have no insights into the upcoming publications or ongoing research.

The liquification is still happening at the same spot today so it is not to much of a leap to think that could have caused the trapping scenario seen at the sight. Are you thinking that CO2 burping caused some kind of localized suffocation kill sight? The area the lake is in is not the kind of environment that these types of things typically occur in. The animals at the sight are accumulated over a long period of time, similar to other mire trap sights.

Here is an article published on some of the evidence for the liquification scenario.

http://www.denverpos...ews/ci_19314710

Thanks, I think this quote from the Aspen paper says it al

l“The bones were beautifully preserved, but they weren't attached to each other,” Johnson said. “Pretty elaborate theory … it's one of the few ways we have to explain the pattern we see.”

Are there other kill sites that have been attributed to liquifaction? When the New Madrid eqathquakes of 1811-12 struck, S.E. Mo was under flood conditions. There are a series of a sand hills that rise some 20-30 feet above that flood plain, that held large number of bison at that time. There is no record of bison being found mired by liquifaction, in an area that was prime for it.

Burping could occur under this scenario. Large buildup of organic material that is slowly decaying in the bottom of the pond, CO2 is trapped in the ooze. Earthquake strikes, and much like shaking a soda bottle, CO2 erupts, filling the basin and causing suffocation. Don't know if the pond was large enough-paintings depict it as being very small.

Will be an interesting story to follow.

Brent Ashcraft

[bdevey]

Thanks, I think this quote from the Aspen paper says it al

l“The bones were beautifully preserved, but they weren't attached to each other,” Johnson said. “Pretty elaborate theory … it's one of the few ways we have to explain the pattern we see.”

Are there other kill sites that have been attributed to liquifaction? When the New Madrid eqathquakes of 1811-12 struck, S.E. Mo was under flood conditions. There are a series of a sand hills that rise some 20-30 feet above that flood plain, that held large number of bison at that time. There is no record of bison being found mired by liquifaction, in an area that was prime for it.

Burping could occur under this scenario. Large buildup of organic material that is slowly decaying in the bottom of the pond, CO2 is trapped in the ooze. Earthquake strikes, and much like shaking a soda bottle, CO2 erupts, filling the basin and causing suffocation. Don't know if the pond was large enough-paintings depict it as being very small.

Will be an interesting story to follow.

Brent Ashcraft

Interesting thought Brent. Another co2 scenario is called "Lake overturn" or a Limnic eruption, It can be caused by a simple landslide, that forces the co2 compessed water from the bottom of a lake to the surface, releasing the co2. It happend a couple times in the 80's killing hundreds of people and livestock in Africa.

I kinda think its random deaths, near a favorite watering hole, with a burying mechanism. "Elephant grave yard"

Bob

[Jesse]

@ashcraft, You are right, CO2 burping could have caused that, I have no clue what lies under the silty lake sediments, could be a large mass of decomposing plant matter...

They like the liquification hypothesis because the conditions are similar there today and they can observe it at the sight. If I have learned anything since working at the museum here and with other researchers, no one is going to stick their neck out on any hypothesis unless there is a lot of evidence in support of it. With that said, liquification is the easiest to swallow scenario since it is happening there as we speak and will be all but impossible to disprove.