Homo Erectus in North America.

[Forum Monk]

Not to open a C14 debate on this thread, I agree with you Beags, that the sample would be substantially "dead" as far as C14, although we all know, today's sophisticated instruments can measure very minute amounts. Funny though, when Creationists mention things like diamonds which are supposed to be C14 dead having measurable amounts, suddenly the scientists are claiming nothing is C14 dead, when before they are claimng a Clovis sample is under a "dead" layer of organic compounds. Guess it depends on one's perspective and what they're trying to prove.

[DougWeller]

Well, I hope everyone had a nice day. I'm just getting back in. As for the pre-Clovis debate, it's over for me.

At the Topper site this spring, I was shown all the proof I need by one of the Archaeologists working there. Down on the Pleistocene terrace is an excavated hole 15 ft. deep. There - plainly seen - is a dark mass of organic mattter - origin unknown. There is no C14 present in the matter.

Inches below that is a core of chert sticking out of the wall. It bears marks of human workmanship that leave no doubt in the minds of many experts who have examined it. It is dated at 50,300 years old.

I stared at it for some time. This core was , for me, the smoking gun that shot the Clovis First theory dead.

Your a few decades late then. It was over for me long, long ago.
Hm, dated 50,300 years old. What technique dates so precisely? I don't know of any.
No C14 at all surprises me also.

Long over for me as well Doug, it's just nice to stare at the smoking gun. That was my point. Al Goodyear and others determined the minimum date of the artifact based on the few inches of separation between it and the organic matter.

For you and R/S.
http://www.essortment.com/hobbies/scien ... m_sbvx.htm

Radioactive decay is measured in half-lives. The half-life of an isotope is the amount of time it takes for half of the substance to decay.


The half-life of carbon-14 is 5730 years. This means that half the carbon 14 in a sample will be gone in 5730 years, and in another 5730 years another half will be gone. In other words, ¾ of the Carbon 14 will be gone in about 11,460 years. Similarly, 7/8 will be gone after about 17,000 years. After 50,000 years, practically all the carbon 14 would have decayed. Thus, any ages greater than 50,000 years cannot be tested with Carbon–14 dating.

To say that all the C14 is gone is common terminology regarding the C14 dating process.

Thanks. That's fine, I thought that was what might have been meant. However, the 50,000 year figure is wrong -- were you told that or have you read it?

See http://www.nosams.whoi.edu/clients/data.html

You should know about this one:- Pedra Furada
[url]hhttp://www.abc.net.au/science/news/stories/s990775.htm[/url]

[Digit]

I underlined the appropriate part Doug but I'll explain. The article names the unversities that gave the dates, then the article continues by casting doubt on those dates, in other words, on the universities. Reason being, the dates don't fit that myth of concensus.
As regards doubting what I'm told, think WMD in Iraq. When a Prime Minister lies why should I believe his underlings?
Same with the Royal Society, when they hide inconvenient facts, why should I believe their other papers.
Same with that prophet of doom A. Gore, pontificates on 'green' issues then uses more power in his home than a third world country.
If these people want me accept what they tell they should first put their own house in order.
Even Einstein was so afraid of the 'establisment' that he falsified his figure on General Relativity otherwise he knew there was little chance of it being accepted by the mainstream.
I do not consider ANY of these matters as acceptable!
If we cannot have honesty from commentators can we please have silence!

[Beagle]

This is from the NOSAMS link you provided Doug.

A sample in which 14C is no longer detectable is said to be "radiocarbon dead." Fossil fuels provide a common example. They are derived from biomass that initially contained atmospheric levels of 14C. But the transformation of sedimentary organic debris into oil or woody plants into coal is so slow that even the youngest deposits are radiocarbon dead.

The abundance of 14C in an organic molecule thus provides information about the source of its carbon. If 14C is present at atmospheric levels, the molecule must derive from a recent plant product. The pathway from the plant to the molecule may have been indirect or lengthy, involving multiple physical, chemical, and biological processes. Levels of 14C are affected significantly only by the passage of time. If a molecule contains no detectable 14C it must derive from a petrochemical feedstock or from some other ancient source. Intermediate levels of 14C can represent either mixtures of modern and dead carbon or carbon that was fixed from the atmosphere less than 50,000 years ago.

Carbon 14 dates are currently being recalibrated for a variety of reasons. Still, for now, no scientist will,or should, date anything greater than 50Kya using this method.

Your second link did not come through.

[Forum Monk]

Another interesting (IMO) aspect to all of this is Firestone's extraterrestrial impact theory and its affect on C14 levels in North America. I recall someone posting some articles on this a few months ago, but I could not readily find the links. Seems, in any case, a recalibration may be required which further alters the C14 dates to some extent.

[Beagle]

G'morning Monk. Try the thread "Cycle of Cosmic Catastophe" started by Charlie. It should have some of that info.

And yes, because of that and other things, C14 dating is being recalibrated. Some things will turn out to be significantly older than we thought.

[Rokcet Scientist]

[...] For you and R/S.
http://www.essortment.com/hobbies/scien ... m_sbvx.htm

Radioactive decay is measured in half-lives. The half-life of an isotope is the amount of time it takes for half of the substance to decay.

The half-life of carbon-14 is 5730 years. This means that half the carbon 14 in a sample will be gone in 5730 years, and in another 5730 years another half will be gone. In other words, ¾ of the Carbon 14 will be gone in about 11,460 years. Similarly, 7/8 will be gone after about 17,000 years. After 50,000 years, practically all the carbon 14 would have decayed. Thus, any ages greater than 50,000 years cannot be tested with Carbon–14 dating.

To say that all the C14 is gone is common terminology regarding the C14 dating process.

Cheers for clearing up you were actually referring to the C14 method's limitations rather than the absence of carbon.
So, doesn't carbon contain another isotope with a longer halflife?

[Digit]

The problem there Monk is that of calibration. Any form of calibration require an accurate standard for comparison. That is course the reason for needing re calibration and has always been the weak point in C14 dating.

[Digit]

None that I know of RS. Carbon is remarkably stable, which is fortunate as it is the building block of life.

[Beagle]

So, doesn't carbon contain another isotope with a longer halflife?

I'm no expert at isotopic dating R/S, but carbon also has C12. But I think it's a by product of C14 degradation and is considered unreliable.

Other methods include Thermoluminesence and OSL. There is Uranium and Argon testing methods. Those techniques were used at Topper on the core sample - giving a date of 50,300 yrs.

Since Charlie is not here, Cogs is probably more knowledgeable about Argon and Uranium.

Possibly either he or I will have a chance to talk to Charlie later today.

[Digit]

If you do talk to Charlie Beag, get him back!

[DougWeller]

This is from the NOSAMS link you provided Doug.

A sample in which 14C is no longer detectable is said to be "radiocarbon dead." Fossil fuels provide a common example. They are derived from biomass that initially contained atmospheric levels of 14C. But the transformation of sedimentary organic debris into oil or woody plants into coal is so slow that even the youngest deposits are radiocarbon dead.

The abundance of 14C in an organic molecule thus provides information about the source of its carbon. If 14C is present at atmospheric levels, the molecule must derive from a recent plant product. The pathway from the plant to the molecule may have been indirect or lengthy, involving multiple physical, chemical, and biological processes. Levels of 14C are affected significantly only by the passage of time. If a molecule contains no detectable 14C it must derive from a petrochemical feedstock or from some other ancient source. Intermediate levels of 14C can represent either mixtures of modern and dead carbon or carbon that was fixed from the atmosphere less than 50,000 years ago.

Carbon 14 dates are currently being recalibrated for a variety of reasons. Still, for now, no scientist will,or should, date anything greater than 50Kya using this method.

Your second link did not come through.

But Pedro Furada was dated earlier by C14 using something called ABOX.
the link again:
http://www.abc.net.au/science/news/stories/s990775.htm

I'm suspicious about it myself, but it says ""[ABOX] reliably removes contamination from charcoal and wood enabling credible radiocarbon dating to about 55,000 years before present," the report said."

What you don't get from anything but Dendrochronology is a date like 50300. Dates aren't that exact and come with confidence intervals. If it doesn't, be suspicious.
Doug

[Beagle]

Another interesting (IMO) aspect to all of this is Firestone's extraterrestrial impact theory and its affect on C14 levels in North America. I recall someone posting some articles on this a few months ago, but I could not readily find the links. Seems, in any case, a recalibration may be required which further alters the C14 dates to some extent.

Monk, I found this article in the "Cosmic Catastrophe" thread.

http://abob.libs.uga.edu/bobk/nuclear.pdf

It's very informative regarding C14 testing and, later on, how these dates need recalibration.

[Beagle]

This is from the NOSAMS link you provided Doug.

A sample in which 14C is no longer detectable is said to be "radiocarbon dead." Fossil fuels provide a common example. They are derived from biomass that initially contained atmospheric levels of 14C. But the transformation of sedimentary organic debris into oil or woody plants into coal is so slow that even the youngest deposits are radiocarbon dead.

The abundance of 14C in an organic molecule thus provides information about the source of its carbon. If 14C is present at atmospheric levels, the molecule must derive from a recent plant product. The pathway from the plant to the molecule may have been indirect or lengthy, involving multiple physical, chemical, and biological processes. Levels of 14C are affected significantly only by the passage of time. If a molecule contains no detectable 14C it must derive from a petrochemical feedstock or from some other ancient source. Intermediate levels of 14C can represent either mixtures of modern and dead carbon or carbon that was fixed from the atmosphere less than 50,000 years ago.

Carbon 14 dates are currently being recalibrated for a variety of reasons. Still, for now, no scientist will,or should, date anything greater than 50Kya using this method.

Your second link did not come through.

But Pedro Furada was dated earlier by C14 using something called ABOX.
the link again:
http://www.abc.net.au/science/news/stories/s990775.htm

I'm suspicious about it myself, but it says ""[ABOX] reliably removes contamination from charcoal and wood enabling credible radiocarbon dating to about 55,000 years before present," the report said."

What you don't get from anything but Dendrochronology is a date like 50300. Dates aren't that exact and come with confidence intervals. If it doesn't, be suspicious.
Doug

Thanks for that link Doug. I'll probably lift it and post it elsewhere. Now let me try and help with the 50,300K dating.

When I was at Topper for a week, the place was crawling with PhD's from many fields. They have been providing input to Al Goodyear, the Archaeologist in charge of the dig site. So we shouldn't be too quick to poo-poo the tentative dating.

Let me stress that this has not been published and we were all required to sign contracts preventing anyone from publishing on their own. I have spoke of the blade corps protruding from the rock wall, but I've posted no pictures of it or the organic material just above it.

After determining that the organic matter was AT LEAST 50,000 years old, the strata from it to the blade core was measured. From the examination of that small bit of strata it was determined that the blade core was AT LEAST 300 years older. Ergo - the dating. Perhaps it's helpful to know that the dating is tentative.

When Goodyear publishes, and that could be years from now, that date may be older. And probably will.

Hope that helps.

[DougWeller]

Ok, I think I see now.
Of course, the question, is it a core? (ducks and runs)