How do we date sedimentary rocks?

[Mr Strawberry]

I forgot. I am sure you know how. Or, you can push a button on the computer screen. Nowadays, one does not even need to do that.

Lol, someone's definitely not a happy hamster. Poor old juve. Still, he's only got himself to blame.

 

[PsychoSarah]

OK, the age is useless. But, it is still an age. Somebody will find an use of it. Because it is measured in an expensive laboratory.

Unless they are smart enough not to waste time measuring it to begin with

 

[Loudmouth]

I forgot. I am sure you know how. Or, you can push a button on the computer screen. Nowadays, one does not even need to do that.

A geology professor doesn't understand why U/Pb dating can not be used on a tree?

Either you need to refund your students' tuition fees, or you need to come clean about being a geology professor. The answer is that you can not date a tree with U/Pb dating because each tree will start life with a different U/Pb ratio. The clock does not have a zero time in trees like it does in minerals such as zircons. Even I, as a biologist with nothing more than a high school geology class, know this.

 

[Atheos canadensis]

What they tried to do is not my business.
You can pick up a rock in your backyard and date it 100 times. I don't care a bit on what you are trying to do.

I'm not sure what you mean by this. All I was saying is that three times you have attempted to support your points by citing papers that don't actually report what you say they do. It's just surprising is all.

 

[Atheos canadensis]

You might get a precise "age" from dating a tree bark. But you need to have a good reason to do all that. That is my message from the very beginning.

You would indeed get an age, but not a useful one. As Loudmouth explained, trees are not closed systems like a zircon crystal and so do not return meaningful dates.

 

[TLK Valentine]

You would indeed get an age, but not a useful one. As Loudmouth explained, trees are not closed systems like a zircon crystal and so do not return meaningful dates.

A geology professor would've known that, Juven.

 

[juvenissun]

You would indeed get an age, but not a useful one. As Loudmouth explained, trees are not closed systems like a zircon crystal and so do not return meaningful dates.

Any "age" is meaningful someway somehow. It all depends on the degree of understanding. That is why I say this is the art of geological science.

Just to change the flavor (I am quite bored on this thread and am about to quit), you give me an "age" and I will tell you what does it mean.

 

[PsychoSarah]

Any "age" is meaningful someway somehow. It all depends on the degree of understanding. That is why I say this is the art of geological science.

Just to change the flavor (I am quite bored on this thread and am about to quit), you give me an "age" and I will tell you what does it mean.

Fine, so a living tree contains 100 grams of carbon 14 at 5 years of age. How much will it contain when it dies 300 years later?

 

[Mr Strawberry]

Any "age" is meaningful someway somehow. It all depends on the degree of understanding. That is why I say this is the art of geological science.

Just to change the flavor (I am quite bored on this thread and am about to quit), you give me an "age" and I will tell you what does it mean.

Why would anyone be interested in your unqualified, ignorant opinion?

 

[juvenissun]

Fine, so a living tree contains 100 grams of carbon 14 at 5 years of age. How much will it contain when it dies 300 years later?

Would it depend on how big was the tree and what kind the tree was?

Did you learn this tricky question in school? Not bad.

 

[biggles53]

Any "age" is meaningful someway somehow. It all depends on the degree of understanding. That is why I say this is the art of geological science.

Just to change the flavor (I am quite bored on this thread and am about to quit), you give me an "age" and I will tell you what does it mean.

Yes, I can understand why you'd want to quit....you just got found out...!

 

[TLK Valentine]

Yes, I can understand why you'd want to quit....you just got found out...!

The Wizard of Oz, one of cinema's most famous frauds, kept his balloon handy, as he himself put it, "against the advent of a quick getaway." The moral being, a con artist should always have an escape plan ready.

 

[PsychoSarah]

Would it depend on how big was the tree and what kind the tree was?

Did you learn this tricky question in school? Not bad.

No, I just made it up. The point is that the question isn't answerable, even if you know what kind of tree it is, where it will grow, and how big it will get.

 

[juvenissun]

No, I just made it up. The point is that the question isn't answerable, even if you know what kind of tree it is, where it will grow, and how big it will get.

In fact, it is a good question for teaching purpose. Those unknowns could be assigned assumed values. It is answerable.

 

[PsychoSarah]

In fact, it is a good question for teaching purpose. Those unknowns could be assigned assumed values. It is answerable.

That many assumptions = problem isn't applicable to reality.

 

[juvenissun]

That many assumptions = problem isn't applicable to reality.

That is a sort of "modeling".

 

[lindart]

How do we date sedementary rocks?


Ask them if they want to " Rock n Roll"?

 

[PsychoSarah]

That is a sort of "modeling".

No, models are designed to help explain or observe stuff that is otherwise impossible to observe due to size constraints, etc. Models are not made for stuff that doesn't fit reality (not on purpose, anyways).

 

[juvenissun]

No, models are designed to help explain or observe stuff that is otherwise impossible to observe due to size constraints, etc. Models are not made for stuff that doesn't fit reality (not on purpose, anyways).

We do not know the reality.

 

[Seipai]

We do not know the reality.

We have a pretty good idea.