forastero
Posts: 458 Joined: Oct. 2011
|
Quote (JonF @ Nov. 13 2011,13:49) | Quote (forastero @ Nov. 13 2011,12:32) | Quote (JonF @ Nov. 13 2011,08:35) | Quote (forastero @ Nov. 12 2011,19:04) | Quote (noncarborundum @ Nov. 12 2011,17:32) | Quote (JonF @ Nov. 12 2011,06:58) | You mean mot, not mute. | Or possibly "moot".
Quote (forastero @ Nov. 12 2011,14:34) | Quote | You said more than one radioisotope. Remember?
"Isochron dating is taking several measurements from several surrounding samples with several radioisotopes. "
And you're still wrong. ?One radioisotope, one daughter isotope, one stable isotope of the daughter isotope. Not "more than one type of daughter isotope". Daughter isotopes are produced only by radioactive decay. |
Your own site that you keep telling me to read says: “Isochron dating requires a fourth measurement to be taken, which is the amount of a different isotope of the same element as the daughter product of radioactive decay. (For brevity's sake, hereafter I will refer to the parent isotope as P, the daughter isotope as D, and the non-radiogenic isotope of the same element as the daughter, as Di). In addition, it requires that these measurements be taken from several different objects which all formed at the same time from a common pool of materials. (Rocks which include several different minerals are excellent for this.)” http://www.talkorigins.org/faqs.......ng.html | The reading comprehension is not strong in this one, is it? Either that, or the ability to look up "radioisotope" in any convenient dictionary and understand the result. |
Thats three radioisotopes in that quote. A parent isotope can decay to different daughter or even granddaughter isotopes
To make it easy on you look at these isochron parent to daughter isotope dating techniques. I-Xe, K-Ar, Rb-Sr, Sm-Nd Ar-Ar, La-Ba, Pb-Pb, Lu-Hf, Ne-Ne, Re-Os, U-Pb-He, U-U. |
Nope. One radioisotope, one daughter isotope, one stable isotope of the daughter element. Some radioisotopes (including 40K) decay to more than one daughter, but that's irrelevant. |
“The most direct means for calculating the Earth's age is a Pb/Pb isochron age, derived from samples of the Earth and meteorites. This involves measurement of three isotopes of lead (Pb-206, Pb-207, and either Pb-208 or Pb-204). A plot is constructed of Pb-206/Pb-204 versus Pb-207/Pb-204.” http://www.talkorigins.org/faqs.......th.html
http://books.google.com/books?i....f=false |
Hee hee hee! You dug up one of the unusual isochron methods!
In the quote from the isochron page at T.O., which is what we are discussing, there is one radioisotope, one daughter isotope, and one stable isotope of the daughter isotope element. You were wrong.
But Pb-Pb isochrons involve many radioisotopes and daughter isotopes and one stable isotope of the daughter isotope, I hear you whine!
I'm way ahead of you. As usual. Back on page 27 I responded to you:
Quote (JonF @ Nov. 10 2011,14:28) | Quote (forastero @ Nov. 10 2011,13:38) | Btw 2, you also seem to be projecting your own inabilities to put arguments in your own words? Isochron dating is taking several measurements from several surrounding samples with several radioisotopes. It doesnt mean though those surrounding rocks were not all drenched and for millennia by the same radioisotopic contamination. |
You still don't have the faintest idea of how isochron dating works. When you figure it out, from the links I gave, maybe we can have a discussion.
(In almost all the isochron methods, only one radioisotope is used. And you haven't a clue from whence samples come). |
Note that you said "Isochron dating is taking several measurements from several surrounding samples with several radioisotopes". Not "A few isochron methods involve taking several measurements from several surrounding samples with several radioisotopes".
You were wrong. In general, isochron dating involves one radioisotope, one daughter isotope, and one stable isotope of the daughter element. The T.O. page on isochrons, which the subject of this side discussion, that's the kind of isochrons that are covered.
But I carefully wrote "In almost all the isochron methods, only one radioisotope is used". Note "...almost all the isochron methods...". I know about Pb-Pb isochrons, which are not at all typical of isochron methods. I was correct. Again.
Wotta maroon! |
The following popular isochron parent to daughter elements involve a parent radioisotope decaying to a daughter radioisotope that in turn almost always decays either beta, alpha, Isomeric,electron capture, or fission radioactivity
K-Ar, Rb-Sr, Sm-Nd Ar-Ar, La-Ba, Pb-Pb, Lu-Hf, Ne-Ne, Re-Os, U-Pb-He, U-U.
|