Methods Of Dating Rock & Fossils

[RocksInMyHead]

Hey, brother. Be careful. There IS radiation in the rock.
"Don't put a pegmatite in your shirt pocket for long" is a joke. But it has some truth. Needless to say an U ore. (I gave my hot U-rich samples to physics department long time ago. It seems they don't mind but enjoy the clicking sound. But I do.)

There's no radiation in the rocks. There are isotopes that produce radiation, but radiation is a form of energy and isn't stored in the rocks. Either way, his use of the term "radiation" was incorrect - he was referring to daughter particles.

False.


"All forms of isochron dating assume that the source of the rock or rocks contained unknown amounts of both radiogenic and non-radiogenic isotopes of the daughter element, along with some amount of the parent nuclide."


Isochron dating - Wikipedia, the free encyclopedia

From your own link:

"The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions are needed about the initial amount of the daughter nuclide in the radioactive decay sequence. Indeed the initial amount of the daughter product can be determined using isochron dating. This technique can be applied if the daughter element has at least one stable isotope other than the daughter isotope into which the parent nuclide decays."

You really should read the whole article before citing it...

God was right. Really.

When did God ever comment on radioactive decay?

Good question. Half life is only useful when you know the clock was set to zero.

My understanding is that when molten lava cools into igneous rock, crystals are created that favor potassium-40 %100 (i.e. there is none of the daughter isotope argon-40 present). From that point forward we only need measure the argon relative to potassium to determine the age.

A pretty good explanation, though the K-Ar method is no longer used since there were too many uncertainties associated with it.

 

[juvenissun]

There's no radiation in the rocks. There are isotopes that produce radiation, but radiation is a form of energy and isn't stored in the rocks. Either way, his use of the term "radiation" was incorrect - he was referring to daughter particles.

OK, let see the description:

If a mineral embedded in a rock "is radiating" energy 24 hr/day, and a person is peeping into the rock at any time with a detector, would the person "detect" radiation in the rock? If he does, would it be right for him to say: "hey, there is radiation in the rock"?

Well, minor thing and almost not worthwhile to argue, unless you want to.

 

[Nabobalis]

OK, let see the description:

If a mineral embedded in a rock "is radiating" energy 24 hr/day, and a person is peeping into the rock at any time with a detector, would the person "detect" radiation in the rock? If he does, would it be right for him to say: "hey, there is radiation in the rock"?

Well, minor thing and almost not worthwhile to argue, unless you want to.

He would of said, the rock was emitting radiation.

 

[RickG]

A pretty good explanation, though the K-Ar method is no longer used since there were too many uncertainties associated with it.

Am I missing something there, because there are an awful lot of geochronology labs still using the K-Ar method.

 

[RocksInMyHead]

Am I missing something there, because there are an awful lot of geochronology labs still using the K-Ar method.

You sure? I could have sworn that it was completely replaced by Ar-Ar. I can't remember any recent papers I've read that used K-Ar data.

 

[Anovah]

If it's helpful, my information came from a source printed in 2009. I suppose a lot can happen in 3 years.

In either event, that's about the extent of my credentials. Well, besides "I read a book!" I've done some online reading but the explanation/analogy of zeroing clocks (or a stop watch) is the one that made the most sense to me so I'm hoping it will be equally helpful to others.

 

[RickG]

You sure? I could have sworn that it was completely replaced by Ar-Ar. I can't remember any recent papers I've read that used K-Ar data.

Quite sure. A quick Google for "Potassium/Argon dating labs" will give you a list of more than you would want to see. As for recent papers using the method, a quick search on a scientific search engine using the phrase "potassium argon dating" with a specified range of 2011 to present gave me 586 hits. Though I do agree the Ar-Ar method is much more reliable and in more common use today, but still, both are used in conjunction.

New techniques are being developed constantly, such as this one using GA1550 Biotite as a standard for K/Ar and 40Ar/39Ar.

McDougle et al. Calibration of GA1550 Biotite Standard for K/Ar and 40Ar/39Ar., Chemical Geology, Vol. 280, p. 19-25.

and another......

http://plclay.weebly.com/uploads/3/7/1/6/3716798/clay_et_al_2011.pdf

 

[RickG]

If it's helpful, my information came from a source printed in 2009. I suppose a lot can happen in 3 years.

In either event, that's about the extent of my credentials. Well, besides "I read a book!" I've done some online reading but the explanation/analogy of zeroing clocks (or a stop watch) is the one that made the most sense to me so I'm hoping it will be equally helpful to others.

It is quite an interesting subject, and it is amazing how many radiometric and non-radiometric methods are available today. And new techniques and methods are being developed all the time.

 

[RocksInMyHead]

Quite sure. A quick Google for "Potassium/Argon dating labs" will give you a list of more than you would want to see. As for recent papers using the method, a quick search on a scientific search engine using the phrase "potassium argon dating" with a specified range of 2011 to present gave me 586 hits. Though I do agree the Ar-Ar method is much more reliable and in more common use today, but still, both are used in conjunction.

New techniques are being developed constantly, such as this one using GA1550 Biotite as a standard for K/Ar and 40Ar/39Ar.

McDougle et al. Calibration of GA1550 Biotite Standard for K/Ar and 40Ar/39Ar., Chemical Geology, Vol. 280, p. 19-25.

and another......

http://plclay.weebly.com/uploads/3/7/1/6/3716798/clay_et_al_2011.pdf

Thanks! Huh...I guess my advisor just doesn't like K-Ar then. He's always going on about how terrible the dates he got from it were and how he's glad he doesn't have to work with anymore.

You learn something new every day.

 

[Tiberius]

False.


"All forms of isochron dating assume that the source of the rock or rocks contained unknown amounts of both radiogenic and non-radiogenic isotopes of the daughter element, along with some amount of the parent nuclide."


Isochron dating - Wikipedia, the free encyclopedia

"A radiogenic nuclide is a nuclide that is produced by a process of radioactive decay."

Radiogenic nuclide - Wikipedia, the free encyclopedia

So you see, this present state and decay are assumed. This is NOT known, and all dates are garbage until it is. God was right. Really.

Are you still on your "Things were different in the past, and even though I have no proof of this, you can't say that I'm wrong because you can't prove it" malarkey?

Dad, we've been over this...

If things really were different in the past, then the different techniques would give different results. This never happens, therefore radioactive decay MUST have always been the same.

 

[RickG]

Thanks! Huh...I guess my advisor just doesn't like K-Ar then. He's always going on about how terrible the dates he got from it were and how he's glad he doesn't have to work with anymore.

You learn something new every day.

It all depends upon the application. Some rocks lend themselves to it quite well, others don't.

 

[juvenissun]

He would of said, the rock was emitting radiation.

No no. "Emitting" is redundant. Radiation goes out only by emission.
So it would be either: the rock is radiating; or, the rock has radiation.

 

[Nabobalis]

No no. "Emitting" is redundant. Radiation goes out only by emission.
So it would be either: the rock is radiating; or, the rock has radiation.

People say the rock is emitting radiation, and the source was the radioactive isotopes inside the rock.

 

[juvenissun]

People say the rock is emitting radiation, and the source was the radioactive isotopes inside the rock.

I say "giving" radiation, "making radiation" or "radiating" is better.

 

[RickG]

I say "giving" radiation, "making radiation" or "radiating" is better.

I guess that makes you radioactive then. Your body contains 14C which is an unstable radionuclide. Do you glow in the dark?

 

[dad]

From your own link:

"The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions are needed about the initial amount of the daughter nuclide in the radioactive decay sequence. Indeed the initial amount of the daughter product can be determined using isochron dating. This technique can be applied if the daughter element has at least one stable isotope other than the daughter isotope into which the parent nuclide decays."

You really should read the whole article before citing it...

I did, you really should be careful about posting short sighted replies. For any decay...gaining or losing elements to have occured as we nnow know and measure it, we need out laws in place. Point...meet Rocksinmyhead.

When did God ever comment on radioactive decay?

You think eternity could involve that??

 

[dad]

Are you still on your "Things were different in the past, and even though I have no proof of this, you can't say that I'm wrong because you can't prove it" ...?

Yes. Except all proof man has supports the idea, and you cannot support any other same state business. Get over it. Done deal now.

Dad, we've been over this...

If things really were different in the past, then the different techniques would give different results. This never happens, therefore radioactive decay MUST have always been the same.

Take fossils, they would be the same. Take decay, the elements would be the same...just in another state. No old ages are possible. That is absolute now. Anyone claiming otherwise is uninformed, misled, and oh so wrong, and could never begin to support their silly, godless claims.

 

[juvenissun]

I guess that makes you radioactive then. Your body contains 14C which is an unstable radionuclide. Do you glow in the dark?

See me with a night vision goggle.

 

[Tiberius]

Night vision either amplifies low levels of available light, or uses an infra red light source.

It does not detect radioactivity.

 

[Anovah]

It is quite an interesting subject, and it is amazing how many radiometric and non-radiometric methods are available today. And new techniques and methods are being developed all the time.

Also, what's up with Georgia? Are there a lot of Universities there because I've been noticing you guys seem to have a lot of knowledgable biologists/scientists?