20 replies to this topic

[JayShel]

"Fossils are generally found in sedimentary rock—not igneous rock. Sedimentary rocks can be dated using radioactive carbon, but because carbon decays relatively quickly, this only works for rocks younger than about 50 thousand years.
So in order to date most older fossils, scientists look for layers of igneous rock or volcanic ash above and below the fossil. "

http://evolution.ber...micclocks.shtml


"To determine the ages of these specimens, scientists need an isotope with a very long half-life. Some of the isotopes used for this purpose are uranium-238, uranium-235 and potassium-40, each of which has a half-life of more than a million years.
Unfortunately, these elements don't exist in dinosaur fossils themselves. Each of them typically exists inigneous rock, or rock made from cooled magma. Fossils, however, form in sedimentary rock -- sediment quickly covers a dinosaur's body, and the sediment and the bones gradually turn into rock. But this sediment doesn't typically include the necessary isotopes in measurable amounts. Fossils can't form in the igneous rock that usually does contain the isotopes. The extreme temperatures of the magma would just destroy the bones.
So to determine the age of sedimentary rock layers, researchers first have to find neighboring layers of Earth that include igneous rock, such as volcanic ash. These layers are like bookends -- they give a beginning and an end to the period of time when the sedimentary rock formed. By using radiometric dating to determine the age of igneous brackets, researchers can accurately determine the age of the sedimentary layers between them."
http://science.howst...r-bone-age1.htm

Ok so essentially, they date fossils by igneous rock and volcanic ash nearby in corresponding layers. Not a problem. The problem is this:

"The radioactive potassium-argon dating method has been demonstrated to fail on 1949, 1954, and 1975 lava flows at Mt Ngauruhoe, New Zealand, in spite of the quality of the laboratory’s K–Ar analytical work. Argon gas, brought up from deep inside the earth within the molten rock, was already present in the lavas when they cooled. We know the true ages of the rocks because they were observed to form less than 50 years ago. Yet they yield ‘ages’ up to 3.5 million years which are thus false."
http://creation.com/...-dating-failure


The Uinkaret Plateau samples came from lava flows on the plateau at the top of the Grand Canyon. Some of these lava flows actually flow down into the canyon, so the eruption must have occurred after the canyon was formed. This lava is some of the youngest rock in the Grand Canyon. The radiometric ages for this formation go from 10,000 years (the 0.01 K-Ar date in the upper left section of the table) to 2.81 billion years (the Pb-Pb isochron date). Rubidium-strontium dates all agree that the rocks are about 1.3 billion years old, which would make them pre-Cambrian rocks, not modern Quaternary rocks (which they obviously are).
http://www.scienceag....org/v4i11f.htm

Native American artifacts found within Uinkaret Plateau lava flows (slides 20-23).
http://bara.arizona....magesonAZSt.pdf

So we have volcanic rocks being used to date fossils, measuring millions of years worth of age, when observation tells us that lava can show radiometric ages of millions of years when it is 50 years old. We also see artifacts that are determined to be 3000-1000 years old in lava that measures millions of years old.

This is a dating fail more awkward than forgetting to put on deodorant...

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"Fossils are generally found in sedimentary rock—not igneous rock. Sedimentary rocks can be dated using radioactive carbon, but because carbon decays relatively quickly, this only works for rocks younger than about 50 thousand years.
So in order to date most older fossils, scientists look for layers of igneous rock or volcanic ash above and below the fossil. "

http://evolution.ber...micclocks.shtml

Real Science Friday reported on rock solid data showing radiometric carbon found in dinosaur bones, and refuted the idea that the results could have been explained away by contamination or neutron capture:
http://kgov.com/dating-a-dinosaur
Yet another awkward dating fail... It takes awhile for refutations of old assumptions to be verified and passed around. Meanwhile, popular culture moguls stand by and take pot-shots at creationists out of ignorance.

Cheers.

[JayShel]

Fossils, however, form in sedimentary rock -- sediment quickly covers a dinosaur's body, and the sediment and the bones gradually turn into rock.
http://science.howst...r-bone-age1.htm

Another common misconception:

http://creation.com/...-petrified-wood
http://creation.com/...aims-recognized

(Amber) Formation

Molecular polymerization, resulting from high pressures and temperatures produced by overlying sediment, transforms the resin first into copal. Sustained heat and pressure drives off terpenes and results in the formation of amber.^[14]

http://en.wikipedia....er#cite_note-13

Notice no mention of how long it takes (until later on in the article, which is an assumed formation age combined with dating surrounding rocks, see above). It takes heat, pressure, water and lots of resin, which would result from a large flood. I see no necessity for millions of years, much like fossilization.

[Reptoman]

Jay--this is not an area of my expertise when t comes to fossils, but having said this, I think these are excellent points there are other examples, again another reason why I gravitate towards YOung earth. I see no need for long periods of time. Even in the event of a gap between genesis scripture, I still don't regard long periods as necessary? Cheers!!! Thanks for providing the info!

Jay have you read anything about the carbon 14 test? IT seems that they have updated the process and it "may"be somewhat more reliable within the pale of 3,00 years. I read some ancient human tools and stuff actually being dated into very recent tines using the new method? Cheers!

[JayShel]

Jay--this is not an area of my expertise when t comes to fossils, but having said this, I think these are excellent points there are other examples, again another reason why I gravitate towards YOung earth. I see no need for long periods of time. Even in the event of a gap between genesis scripture, I still don't regard long periods as necessary? Cheers!!! Thanks for providing the info!

Jay have you read anything about the carbon 14 test? IT seems that they have updated the process and it "may"be somewhat more reliable within the pale of 3,00 years. I read some ancient human tools and stuff actually being dated into very recent tines using the new method? Cheers!

My pleasure. From what they said on Real Science Friday, they are now almost able to measure individual carbon atoms to determine the age, so the amount of radiometric carbon found is highly precise (even if the interpretation of such data may not be entirely accurate).

[Calypsis4]

Another common misconception:

http://creation.com/...-petrified-wood
http://creation.com/...aims-recognized



Notice no mention of how long it takes (until later on in the article, which is an assumed formation age combined with dating surrounding rocks, see above). It takes heat, pressure, water and lots of resin, which would result from a large flood. I see no necessity for millions of years, much like fossilization.

Thanks for the information, Jay.

[JayShel]

Thanks for the information, Jay.

It's my pleasure. Here is some more information of Amber formation:

How is amber formed?

Although the formation process is not fully understood, it is believed that amber is formed in three distinct stages over a period of 20 million years.

Stage 1 Resin
Resin is the semi-solid substance that is exuded through a trees' epithelial system in response to injury or disease.
Once pooled into a sufficient mass either outside of the tree or within the plants' internal fissures, the resin along with any subsequently trapped inclusions(bugs, insects or dust) begin to undergo polymerisation.
This process means that the semi-solid resin will begin to harden.

Stage 2: Copal
Copal is simply a form of resin that has matured to the point of hardening and despite a similar appearance to amber, has only undergone partial polymerisation. During this stage, the substance will continue to harden and the volatile oils (terpenes) that naturally occur in resin dissipate.
Large deposits of amber are usually found in areas through which oxygen cannot readily penetrate. Areas that are high in heavy sediments such as sand and clay are ideal.

Stage 3: Amber
The final stage is the change from copal to amber.

http://clearlyexplai...rals/amber.html

Therefore, amber is formed as a result of the fossilization of resin that that takes millions of years and involves a progressive oxidation and polymerization of the original organic compounds, oxygenated hydrocarbons. Although a specific time interval has not been established for this process, the majority of amber is found within Cretaceous and Tertiary sedimentary rocks(approximately 30-90 million years old).

[...]

One depositional environment for amber is marginal marine. Amber's specific gravity is slightly over 1 and it floats in saltwater; therefore amber becomes concentrated in estuarine or marine deposits, moved some distance from the original site (Langenheim, 1969, p. 1159). Trees and resin may be transported and deposited in quiet water sediments that formed the bottom of a lagoon or delta at the margin of a sea. Wood and resin are buried under the sediment and while the resin becomes amber, the wood becomes lignite. Wet sediments of clay and sand preserve the resin well because they are devoid of oxygen.

Therefore, given copious resin producing trees and appropriate burial conditions, amber is preserved in sedimentary clay, shale, and sandstones associated with layers of lignite, a woody brown coal. A generalized interpretation of the depositional conditions present in Kansas amber-bearing strata is that a transgressing or advancing Cretaceous sea in north-central Kansas led to deposition and preservation of fluvial, estuarine, and lagoon or bay deposits behind a barrier island system (Franks, 1980, p. 56).

http://academic.empo...susa/whatis.htm

and check out this forum for some interesting speculation:

Moontanman - Posted 18 May 2008 - 06:50 AM

I have been told, but I haven't personally seen, that large numbers of wooden barrels of pine tree sap were accidentally dumped into the Cape Fear River almost three hundred years ago. A couple of these barrels have been found and were just huge chunks of amber. If true this would seem to point to the possibility of a large amount of large amber chunks buried in the sediments of this river. Would such large chunks be possible and if they exist would they be valuable?

theblackalchemist - Posted 19 May 2008 - 06:44 AM
Of course!
Amber without air bubbles are more than their weight in GOLD!
also these amber chunks can be used to make many thngs
see the uses section of my article
Thanks
TBA
Moontanman - Posted 19 May 2008 - 06:52 AM
Is three hundred years long enough for amber to form?


theblackalchemist - Posted 19 May 2008 - 07:15 AM
as long as it is completely solidified its good


http://scienceforums...ic/14503-amber/

or here:
http://www.sciencefo...-to-make-amber/

[agnophilo123]

Took about ten seconds to google this:

"Potassium-argon dating will not work on sedimentary or metamorphic rocks, or on intrusive igneous rocks, and is even problematic to use on young volcanic rocks (because of the long half life of potassium-40), or on rocks with little potassium."

http://www.nature.np...a/age/index.cfm

Creationists once again using a screwdriver as a hammer and then claiming their own failure disproves the effectiveness of hammers.

[Calypsis4]

Took about ten seconds to google this:

"Potassium-argon dating will not work on sedimentary or metamorphic rocks, or on intrusive igneous rocks, and is even problematic to use on young volcanic rocks (because of the long half life of potassium-40), or on rocks with little potassium."

http://www.nature.np...a/age/index.cfm

Creationists once again using a screwdriver as a hammer and then claiming their own failure disproves the effectiveness of hammers.

Did you even bother to read carefully what Jay-shell posted above? The details make the difference.

There is nothing out of the ordinary about what he posted and this kind of information about the failure of modern dating methods to give us accurate time frames can be found in countless documented instances.

http://www.trueautho...radiometric.htm

http://www.answersin...ic-dating-prove

Your source said, " it wasn’t until the 1950s that absolute dating techniques were reliable and widely in use. Most absolute ages in geology are obtained through radiometric dating techniques..." but the truth is there is no such thing as 'absolute dating techniques'. This has been pretty well established by the fact no one knows what the content of the original samples was...nor can they; and also the discovery of accelerated decay rates.

You need to pull the blinders off and face the music.

I am an ex-evolutionist and I no longer believe the nonsense that the world is millions/billions of years old. The strongest evidence says otherwise.

[agnophilo123]

Did you even bother to read carefully what Jay-shell posted above? The details make the difference.

There is nothing out of the ordinary about what he posted and this kind of information about the failure of modern dating methods to give us accurate time frames can be found in countless documented instances.

http://www.trueautho...radiometric.htm

http://www.answersin...ic-dating-prove

You need to pull the blinders off and face the music.

I am an ex-evolutionist and I no longer believe the nonsense that the world is millions/billions of years old. The strongest evidence says otherwise.

Um, for logical, mechanical reasons potassium-argon dating often doesn't work accurately with recent volcanic rocks. The above article uses that dating method with those rocks.

If there was a counter-argument in your above very patronizing comment I fail to find it.

[Calypsis4]

Um, for logical, mechanical reasons potassium-argon dating often doesn't work accurately with recent volcanic rocks. The above article uses that dating method with those rocks.

If there was a counter-argument in your above very patronizing comment I fail to find it.

I can see you didn't bother looking up my sources. Again, an example of an evolutionist who doesn't pay close attention to details.

The truth is that every single dating method has been thoroughly examined and found wanting in establishing long ages for the earth. So before you get back with me you be sure and take a look at those details. I gave you two sources and I can give you many more.

[agnophilo123]

I can see you didn't bother looking up my sources. Again, an example of an evolutionist who doesn't pay close attention to details.

The truth is that every single dating method has been thoroughly examined and found wanting in establishing long ages for the earth. So before you get back with me you be sure and take a look at those details. I gave you two sources and I can give you many more.

You're just ignoring what I said. That particular form of dating does not work well in recent volcanic rocks for logical reasons. So creationists go out of their way to date recent volcanic rocks and claim the method of dating doesn't work at all in any circumstance. Ie using a screwdriver as a hammer to disprove the effectiveness of hammers/screwdrivers.

[Calypsis4]

You're just ignoring what I said. That particular form of dating does not work well in recent volcanic rocks for logical reasons. So creationists go out of their way to date recent volcanic rocks and claim the method of dating doesn't work at all in any circumstance. Ie using a screwdriver as a hammer to disprove the effectiveness of hammers/screwdrivers.

You are the one ignoring things and everyone posting here can see that.

[eclectic1993]

Hi,
Just read about the potassium-argon method posted by agnophilo123. Here's an excerpt.

Prior to crystallization of the volcanic rock, argon-40 just bubbles out of the magma. Solidification starts the clock, because the crystal structure traps any argon-40 produced by radioactive decay. Dating the time of crystallization of a volcanic rock requires analysis for the amounts of potassium and argon-40 in the rock, and calculation of the age using the known half life of potassium-40

My question is somewhat basic. I understand that to use this method one must determine the amount of potassium-40 and the amount of argon-40 in a sample. A calculated ratio, along with the decay rate, can provide an estimation of time.

Does it matter what sample size is chosen in dating? Could you grab a 1 kg of a rock and perform an analysis? Do you chip away using a 'screwdriver' and 'hammer' (j/k) and grab a sample 1 g in size to analyze? Is is possible to grab two samples (1 g each) and to produce different ratios? Or is the ratio fairly uniform throughout the sample?

Thanks,
Chuck

[gilbo12345]

Um, for logical, mechanical reasons potassium-argon dating often doesn't work accurately with recent volcanic rocks. The above article uses that dating method with those rocks.

If there was a counter-argument in your above very patronizing comment I fail to find it.

Why doesn't it work with recent rock? IF the method works it should work for recent rocks, wouldn't that be the test of verification to see if the method works at all?

If you claim it only works on things of which we do not know the actual age then how can the method be tested for its reliability? Its the same as if I said that when I and everyone else in the same room as me close our eyes, (and there are no cameras looking) I turn invisible... There is no way to test or confirm it since all avenues to do so are unavailable...

Yet considering its failure with recent rocks then one should be skeptical that the method works at all... (well one should, doesn't mean they will be)

[TerryL]

The K-Ar method is only useful for dating minerals >100 ka to about 4 Ga. Due to the long half-life of 40K it takes a while (a long while) for 40Ar to accumulate to levels that can be measured accurately; hence, the >100 ka 'upper' limit. It is a detection issue.

Cheers,

Terry.

[gilbo12345]

The K-Ar method is only useful for dating minerals >100 ka to about 4 Ga. Due to the long half-life of 40K it takes a while (a long while) for 40Ar to accumulate to levels that can be measured accurately; hence, the >100 ka 'upper' limit. It is a detection issue.

Cheers,

Terry.

Thanks for the info, I am a Biologist so this is out of my league.. However I would be skeptical about the veracity of the data from this method if it cannot be independantly confirmed, much radioisotope dating is based on inescapable assumptions which would place doubt on it.

[TerryL]

Thanks for the info, I am a Biologist so this is out of my league.. However I would be skeptical about the veracity of the data from this method if it cannot be independantly confirmed, much radioisotope dating is based on inescapable assumptions which would place doubt on it.

NP. I am certain that there are examples of K-Ar ages being corroborated by other geochronological methods, for example fission track and perhaps luminescence. I may be able to provide examples if you wish.

What are these inescapable assumptions?

Cheers,

Terry.

[gilbo12345]

NP. I am certain that there are examples of K-Ar ages being corroborated by other geochronological methods, for example fission track and perhaps luminescence. I may be able to provide examples if you wish.

What are these inescapable assumptions?

Cheers,

Terry.

Thanks.

The assumption that x, y, z have been doing the same thing in history as it is doing today.

[aelyn]

Hi, Just read about the potassium-argon method posted by agnophilo123. Here's an excerpt. My question is somewhat basic. I understand that to use this method one must determine the amount of potassium-40 and the amount of argon-40 in a sample. A calculated ratio, along with the decay rate, can provide an estimation of time. Does it matter what sample size is chosen in dating? Could you grab a 1 kg of a rock and perform an analysis? Do you chip away using a 'screwdriver' and 'hammer' (j/k) and grab a sample 1 g in size to analyze? Is is possible to grab two samples (1 g each) and to produce different ratios? Or is the ratio fairly uniform throughout the sample? Thanks, Chuck

I can't give the exact answer to that specific question but scientists are well-aware of issues of sampling, and they have many techniques to get as accurate results of sampling as they can, and to figure out how accurate the sample is. For example they might test several samples from whatever they're trying to date to check whether the ratio is indeed uniform, and to get a more accurate measurement if it is (by taking the average for all the samples).
There is also the fact that different kinds of rocks or other objects will have different distributions of minerals and different formation histories, so a ratio that would be uniform for one type of rock might be all over the place with another type. You figure out which is which by testing different types of rocks and knowing things about how rocks form. In those cases you'll use a given technique only in cases where it is applicable, i.e. where the ratios are uniform and so forth. It's why you won't use Kr/Ar dating in recent volcanic rocks, because that method is known not to work in that case for both experimental and theoretical reasons. From what I've read it seems to be that with such young rocks there is too little radiogenic Argon-40 to distinguish it from the atmospheric Argon-40. This problem isn't an issue when the amount of radiogenic Argon-40 is large enough to make the atmospheric levels negligible.

As to how we know it's accurate at longer timescales, aside from the theoretical bases : there are many, many different dating methods, and they overlap with each other; when you find a new dating method you test it (and calibrate it) on the ranges where it overlaps with other dating methods, and that way you get the error bars on that particular method.

If you're interested the Wikipedia page on radiocarbon dating has a good summary of the cases where C14 dating is useful, those where it isn't, and its level of accuracy in various circumstances. All dating methods have such domains of application and margins of error.

[Bonedigger]

... It's why you won't use Kr/Ar dating in recent volcanic rocks, because that method is known not to work in that case for both experimental and theoretical reasons. From what I've read it seems to be that with such young rocks there is too little radiogenic Argon-40 to distinguish it from the atmospheric Argon-40. This problem isn't an issue when the amount of radiogenic Argon-40 is large enough to make the atmospheric levels negligible...

Not my area of expertise, but a question immediately comes to mind. How would you distinguish radiogenic Argon-40 from atmospheric Argon-40? I'm talking physically or chemically, not from a post de facto assumption that because of some other method also used the sample must be old enough for the Argon-40 to have been produced in place, therefore it must be radiogenic in origin.