Topic: The Geologic Column (Read 2806 times)

Anthony Horvath · « **on:** October 04, 2005, 10:04:12 PM »

This thread comes by request. Its been awhile since I've dove into the geology questions, but I look forward to the opportunity to re-acquaint myself with the subject.

If no one knows what the geologic column is, they are seriously out of the loop. Here is a link, anyway: http://en.wikipedia.org/wiki/Geologic_time_scale

It is maintained that the primary means of deposit for the geologic column is through localized flooding. I think this defeats their own argument, because invoking flooding at all is to invoke catastrophism rather than uniformitarianism, and as I think a better explanation for the geologic column is a single catastrophy rather than a billion smaller ones, invoking any catastrophe at all opens the door for my view. Anyway, the geologic column is composed primarily of 'sedimentary rock.' That is, it is sediment that has become rock. And sediment is formed through water action. There are also igneous and metamorphic rock, of course, but it is all predominantly sedimentary rock.

My purpose in this thread is to raise questions that I think any one truly exhibiting skepticism would ask about the geologic column. I will be especially interested in the epistemology- why should we be confident of the explanation? Can it be tested? Repeated? Verified? Experimented on? Is it an inference? Etc.

Anthony Horvath · « **Reply #1 on:** October 04, 2005, 10:26:56 PM »

The traditional argument appeals to common sense. Whatever is on the bottom had to have been laid before that which comes after it. See:

Whether you think the deposits came fast or slow, this logic is more or less sound, although perhaps problematic in actual application.

However, we are talking about water, here. Flooding in particular. You either have river sedimentation, or lake flooding, or whatever. The point is, that it is not enough to simply say that the lower rocks are older, because water moves in a direction Its hard to imagine how we might conceptualize a sudden flood (they've almost all got to be sudden in order to trap the poor creatures that would certainly have fled to higher ground if it were static or slow) that didn't have any lateral movement.

So, we actually have TWO directions to look at when measuring time from a geologic POV:

There are four points labeled here: A, B, C, and D.

Surely we can agree that B is 'older' than A- at least, it was deposited first. And C likewise is older than D. However, if the water is moving in a particular direction, carrying sediment along and laying it down, surely we can't be so certain that C is older than A?

In fact, point 'C' may be several miles down the road, while point A has already been deposited, but the part of the layer that C comes to reside in may not yet have been deposited at all. A in this scenario is older than C, being deposited first, but geologists would assume that C is older than A.

It is a simple empirical fact that sediment moves, accumulates, stratifies, because the water moves in some particular direction.

Doesn't it therefore follow that the only 'age' comparison we can legitimately make would be when we have two points aligned vertically, while points elsewhere in the same column may or may not be older than these points? So, you could only 'absolutely' date A/B and C/D- unless you can determine the direction of the water and the consequential flow of the sediment, you cannot make any relative dating pronouncements comparing A/B to C/D.

Do geologists account for this reality? Not that I know of. It is a purely vertical game, with few exceptions of very limited size and scale (like varves, perhaps).

So, finding fossil X in fossil layer Z in one spot but finding fossil Y in layer Z on the other side of the planet does not assure us actually that they were laid down in the same era of events. Similarly, finding fossil A in layer Z in China but finding fossil B in higher layer W in North America does not assure us that fossil A is actually 'older' than fossil B. Such a determination would require horizontal scrutiny as well as vertical.

I don't know how this conclusion can be escaped, but it certainly calls into question the confidence we can ascribe to using the geologic column to provide any REAL knowledge about times and dates and sequences.

TheAtheistHeratic · « **Reply #2 on:** October 25, 2005, 02:49:24 PM »

Thats why there is Carbon dating.

Anthony Horvath · « **Reply #3 on:** October 25, 2005, 07:48:52 PM »

Carbon dating has a limited max range of usefulness. Only 10,000-50,000 years. Won't help here.

TheAtheistHeratic · « **Reply #4 on:** October 26, 2005, 02:43:12 PM »

Plutonium

Anthony Horvath · « **Reply #5 on:** October 26, 2005, 03:35:55 PM »

Plutonium is an artificially created radioactive element. It is not found naturally occurring, and therefore could not be expected to be useful in such contexts.

TheAtheistHeratic · « **Reply #6 on:** October 27, 2005, 02:34:40 PM »

How other types of natural ocurring radio-active elements?

Copernicus · « **Reply #7 on:** October 28, 2005, 10:42:07 AM »

Quote from: sntjohnny

The traditional argument appeals to common sense. Whatever is on the bottom had to have been laid before that which comes after it...

The characteristic fossils found in sedimentary layers can also be explained by the fact that the deposits were laid down in different eras. That is why dinosaur fossils are not found in the same layers as human fossils.

Quote

Surely we can agree that B is 'older' than A- at least, it was deposited first. And C likewise is older than D. However, if the water is moving in a particular direction, carrying sediment along and laying it down, surely we can't be so certain that C is older than A?

No, but we can still be sure that C is older than B. It takes a long time for sedimentary rock to form, but the formation of sediment is not uniform in the short term. It is also well to bear in mind that the flooding was not uniform. There never was a global flood, and sediment formed in different places under different conditions. Scientists use the fossil record to help date such layers, since we know that characteristically different species lived in different geological eras. One can also look at the composition of the sediment, fossils, and radiometric data.

It was the 18th century geologist, James Hutton, who first proved that the Earth was far older than the scripture-based calculations of Bishop Ussher suggested. As our friend sntjohnny reveals, there are still a few reasonably intelligent people who reject or quibble with scientific findings in an effort to cling to the discredited scriptural hypothesis.

Anthony Horvath · « **Reply #8 on:** October 28, 2005, 11:02:44 AM »

"The characteristic fossils found in sedimentary layers can also be explained by the fact that the deposits were laid down in different eras."

There is nothing in this statement that is different than what I said about sedimentary rock.

"No, but we can still be sure that C is older than B."

Not necessarily, which is the whole point of my argument here.

"It takes a long time for sedimentary rock to form,"

Under the right conditions, it can form very quickly.

"but the formation of sediment is not uniform in the short term. It is also well to bear in mind that the flooding was not uniform."

You are only supporting my argument.

Broken · « **Reply #9 on:** October 31, 2005, 12:32:58 PM »

Quote from: sntjohnny

Plutonium is an artificially created radioactive element. It is not found naturally occurring, and therefore could not be expected to be useful in such contexts.

Plutonium does occur naturally, but it has a short half life compared to uranium: 24,000 years for Pu-239 vs 713 million years for U-235 and 4.5 billion years for U-238.

The long half life of U-235 and U-238 make these elements suitable for dating very old rocks, such as those which crystalized when the Earth was formed.

Plutonium is produced naturally in uranium ore when neutrons from U-235 decay collide with U-238 to produce Pu-239. The relatively short half life of Pu-239 prevents any significant quantities of Pu-239 from accumulating.

According to the theory of Stellar Nucleosynthesis, elements heavier than Hydrogen and Helium are created in stars through nuclear fusion. Elements heavier than Iron, including Uranium and Plutonium, are mostly produced in stars that explode in a Super-Nova, since these elements do not yield energy in nuclear fusion reactions.

Anthony Horvath · « **Reply #10 on:** October 31, 2005, 02:12:43 PM »

I stand corrected.

http://en.wikipedia.org/wiki/Plutonium

"While almost all plutonium is manufactured synthetically, extremely tiny trace amounts are found naturally in uranium ores."

TheAtheistHeratic · « **Reply #11 on:** December 13, 2005, 04:55:30 PM »

pete · « **Reply #12 on:** January 25, 2006, 09:47:49 AM »

sntjohnny, you never answered the questions about dating methods. I would like to hear how you explain why scientist say the earth 4.5 billion years old, yet YEC's claim 6,000-10,000. I doubt that geologists have overlooked the argument you present here. I am sure you are not the first to make it, either.

Anthony Horvath · « **Reply #13 on:** January 25, 2006, 10:14:02 AM »

"sntjohnny, you never answered the questions about dating methods."

I don't see how its relevant to this particular thread. Usually, the first step is to say something like, "Hi, would you like to go out on a date?" That's pretty straightforward and unromantic, but I suggest it anyway.

"I would like to hear how you explain why scientist say the earth 4.5 billion years old,"

Why is it my job to explain the 'scientist's' position?

"yet YEC's claim 6,000-10,000."

I have already explained to you that YECs have an entirely different interpretation of all of the data. There are a number of reasons for the young earth claim. If you would like, we can go into this in depth if you like, though I suggest a new thread about radiometric dating and/or the YEC position.

"I doubt that geologists have overlooked the argument you present here."

Oh? I have my geology text book right here. I don't know if they've overlooked it or not. I can't find any mention of it. I guess you'll have to do some thinking for yourself- does what I say make sense to you? Do you think geologists should account for it? If they don't, what does that say? If geologists dismiss it, but it makes sense to you, are you willing to be your own man and make up your own mind, or are you going to simply take whatever position people with the label 'scientist' tells you to?

"I am sure you are not the first to make it, either."

I'm not. On the other hand, this thread has been around for awhile now, and you can see that no one has yet tried to challenge it. You're welcome to be the first.

pete · « **Reply #14 on:** January 25, 2006, 10:40:23 AM »

AH did by stating there are other methods for determining the age of rocks.

pete · « **Reply #15 on:** January 25, 2006, 10:41:50 AM »

Quote

"sntjohnny, you never answered the questions about dating methods."

I don't see how its relevant to this particular thread. Usually, the first step is to say something like, "Hi, would you like to go out on a date?" That's pretty straightforward and unromantic, but I suggest it anyway.

You know what I meant. Now, quit 'dancing' around the subject.

Anthony Horvath · « **Reply #16 on:** January 25, 2006, 10:49:48 AM »

You liked that, didja?

Its an 'old' joke. Baddabing baddaboom.

Oh, I didn't realize you counted what AH said. He invoked Carbon dating and Plutonium dating. Both of which were addressed to show that neither of the two are adequate. No doubt other dating methods could be mentioned, but they haven't yet.

However, these are not going to be relevant to this thread's stated intent, which was to talk about whether or not the geologic column should only be interpreted vertically, and whether or not in fact it should be interpreted horizontally. Copernicus issued some challenges, but they only supported what I was saying. I don't see anything from anyone yet citing any statements by geologists about this.

The clearest example I can think of where geologists take into account horizontal dating is varves. Google varves. I am unaware of such an accounting in regards to the overall geologic column.

So that this thread will stay on topic, let me suggest that you consider whether or not your radiometric dating questions really relate to a horizontal reading of the geologic column. If you think it does, I suppose post it here (with some explanation, because I'm not yet convinced it does). Or, just start a new thread.

pete · « **Reply #17 on:** January 25, 2006, 11:03:08 AM »

I agree that that you cannot use the column alone for determinig the age of a particular layer, but used in conjunction with the radiometric dating mehtods stated above you can say that fossil 'x' from layer 'z' in North America is the same age as fossil 'x' from layer 'z' in China. Their depth under ground may be different, though.

Anthony Horvath · « **Reply #18 on:** January 25, 2006, 11:25:37 AM »

"I agree that that you cannot use the column alone for determinig the age of a particular layer,"

It might be helpful to point out that geologists use the terms 'absolute' and 'relative' in these contexts. I suppose we may need to use these terms soon.

How they find the age of a particular layer might interest you.

"but used in conjunction with the radiometric dating mehtods stated above you can say that fossil 'x' from layer 'z' in North America is the same age as fossil 'x' from layer 'z' in China. Their depth under ground may be different, though."

Let us suppose that given certain assumptions, in theory this analysis of yours is correct. Since we don't have a specific example we are working with, we'll have to acknowledge we are speaking generally. With that in mind, Fossil x in North America (henceforth x(NA) ) is currently determined to be the same age x(CH) by their location in the same strata z. Thus, x(NA) and x(CH) are the 'same age' because of their mutual relationship to z.

This would be relative dating, and does not require radiometric dating methods, as you suppose.

However, in order to get an absolute date, you would need an independent dating mechanism for one or both of them. Thus, let's say you get an estimate of 2 million years old (2mya) for x(NA). GIVEN that it is fair to believe that strata z was all deposited at the same time, if you had the age for x(NA), you would infer then, anything in strata z, in this case, x(CH), would also be the same age.

But this is an important assumption we have just made. How can we justify that all parts of z were really deposited at the same time? Furthermore, they are thousands of miles away. That is an immense horizontal difference. How is it that the same kind of sediment was laid in locations thousands of miles apart from each other? How did there come to be an abundance of only that kind of sediment? Where was all the dirt of different sorts while this sediment, and this sediment alone, was deposited in various areas across the globe?

Can we really be sure that what we are calling 'z' in NA is really 'z' in CH? GIVEN that z was deposited more or less at the same time, z, even by old earth theories, would have been deposited over millions and millions of years. There could be hundreds of thousands, if not millions of years, separating the existence of x(NA) and z(NA) even within the same strata.

I would be more comfortable applying the radiometric age attained in our x(NA) sample for other fossils found in the same strata in the vicinity of x(NA), provided we can get a measure of the horizontal flow of the water to ensure that the strata really was deposited together. Obviously, we have the Pacific Ocean breaking up strata z, so its safe to say we will not be able to show this conformity. It would have to be inferred.

I have just listed a long string of 'givens' and 'inferreds.' But that's modern geology for ya.

pete · « **Reply #19 on:** January 25, 2006, 11:42:21 AM »

I agree with you 100%. I think you would understand me better if I said fossil x(NA) was found at a depth of 100ft. ( I am not that familiar with geology other than at a public high school, so I am just using arbitrary numbers.) Fossil x(CH) was found at 200ft. The composition of the sediment they were found in was similar. One could assume they were the same age. In order to verify this you could use radiometric dating. You would have to test both fossils, of course. I can't imagine that a scientist would just assume that 2 fossils found at similar depths on opposite sides of the world are the same age.

Author Topic: The Geologic Column (Read 2806 times)