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Author Topic:   How Old is the Earth ?
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 10 of 145 (4646)
02-15-2002 6:31 PM
Reply to: Message 9 by TrueCreation
02-15-2002 4:38 PM


Wasn't calculus a Roman Caesar?
May as well be......
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 9 by TrueCreation, posted 02-15-2002 4:38 PM TrueCreation has replied

Replies to this message:
 Message 11 by TrueCreation, posted 02-15-2002 6:39 PM mark24 has not replied

  
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 45 of 145 (4908)
02-18-2002 4:12 AM
Reply to: Message 33 by Kyle467
02-16-2002 7:21 PM


quote:
Originally posted by Kyle467:
I am by no means an expert on radioactive dating. But I heard for many people (mainly creationists, of which I am one) that are flaws in this method.
I heard that radioactive dating relies on too many assumptions. One assumption was about the amount of carbon or other material that was originally present in the material dated. On the same note, the amount of the daughter material is also assumed. Examples of incorrect radioactive dates were given through the dating of materials whose dates were previously known. For example, a 200-year-old lava flow was dated to be around 3 billion years old.
It sounded like a great argument, and I was wondering if anyone had heard anything about it. Has it been disproved, supported, etc? Please respond.

Submarine lavas are known to cool rapidly, forming a glassy edge & not allowing Argon to escape, giving a false result. This probably doesn’t account for the discrepancy. A small number of results come back wildly in error compared to the main body, a result of contamination, human error, etc.
http://www.ees.nmt.edu/Geol/labs/Argon_Lab/Data/Tables.html
If you look at the table at the top of this page you’ll see sample A has an age of 29 my. Whilst the others are all very close at about 62 my.
There may well be flaws in various methods, but they are now going to be small corrections. If you doubt that ages B to J are accurate, read the four examples of age correlation, why would this happen if radiometric dating was so inaccurate?
(Apologies to those who’ve seen this before)
Radiometric Dating
"The purpose of this paper is to describe briefly a few typical radiometric dating studies, out of hundreds of possible examples documented in the scientific literature, in which the ages are validated by other available information. I have selected four examples from recent literature, mostly studies involving my work and that of a few close colleagues because it was easy to do so. I could have selected many more examples but then this would have turned into a book rather than the intended short paper.
The Manson Meteorite Impact and the Pierre Shale
In the Cretaceous Period, a large meteorite struck the earth at a location near the present town of Manson, Iowa. The heat of the impact melted some of the feldspar crystals in the granitic rocks of the impact zone, thereby resetting their internal radiometric clocks. These melted crystals, and therefore the impact, have been dated by the 40Ar/39Ar method at 74.1 Ma (million years; Izett and others 1998), but that is not the whole story by a long shot. The impact also created shocked quartz crystals that were blasted into the air and subsequently fell to the west into the inland sea that occupied much of central North America at that time. Today this shocked quartz is found in South Dakota, Colorado, and Nebraska in a thin layer (the Crow Creek Member) within a thick rock formation known as the Pierre Shale. The Pierre Shale, which is divided into identifiable sedimentary beds called members, also contains abundant fossils of numerous species of ammonites, ancestors of the chambered nautilus. The fossils, when combined with geologic mapping, allow the various exposed sections of the Pierre Shale to be pieced together in their proper relative positions to form a complete composite section (Figure 1). The Pierre Shale also contains volcanic ash that was erupted from volcanoes and then fell into the sea, where it was preserved as thin beds. These ash beds, called bentonites, contain sanidine feldspar and biotite that has been dated using the 40Ar/39Ar technique. The results of the Manson Impact/Pierre Shale dating study (Izett and others 1998) are shown in Figure 1. There are three important things to note about these results. First, each age is based on numerous measurements; laboratory errors, had there been any, would be readily apparent. Second, ages were measured on two very different minerals, sanidine and biotite, from several of the ash beds. The largest difference between these mineral pairs, in the ash from the Gregory Member, is less than 1%. Third, the radiometric ages agree, within analytical error, with the relative positions of the dated ash beds as determined by the geologic mapping and the fossil assemblages; that is, the ages get older from top to bottom as they should. Finally, the inferred age of the shocked quartz, as determined from the age of the melted feldspar in the Manson impact structure (74.1 0.1 Ma), is in very good agreement with the ages of the ash beds above and below it. How could all of this be so if the 40Ar/39Ar dating technique did not work?
The Ages of Meteorites
Meteorites, most of which are fragments of asteroids, are very interesting objects to study because they provide important evidence about the age, composition, and history of the early solar system. There are many types of meteorites. Some are from primitive asteroids whose material is little modified since they formed from the early solar nebula. Others are from larger asteroids that got hot enough to melt and send lava flows to the surface. A few are even from the Moon and Mars. The most primitive type of meteorites are called chondrites, because they contain little spheres of olivine crystals known as chondrules. Because of their importance, meteorites have been extensively dated radiometrically; the vast majority appear to be 4.4—4.6 Ga (billion years) old. Some meteorites, because of their mineralogy, can be dated by more than one radiometric dating technique, which provides scientists with a powerful check of the validity of the results. The results from three meteorites are shown in Table 1. Many more, plus a discussion of the different types of meteorites and their origins, can be found in Dalrymple (1991). There are 3 important things to know about the ages in Table 1. The first is that each meteorite was dated by more than one laboratory Allende by 2 laboratories, Guarena by 2 laboratories, and St Severin by four laboratories. This pretty much eliminates any significant laboratory biases or any major analytical mistakes. The second thing is that some of the results have been repeated using the same technique, which is another check against analytical errors. The third is that all three meteorites were dated by more than one method two methods each for Allende and Guarena, and four methods for St Severin. This is extremely powerful verification of the validity of both the theory and practice of radiometric dating. In the case of St Severin, for example, we have 4 different natural clocks (actually 5, for the Pb-Pb method involves 2 different radioactive uranium isotopes), each running at a different rate and each using elements that respond to chemical and physical conditions in much different ways. And yet, they all give the same result to within a few percent. Is this a remarkable coincidence? Scientists have concluded that it is not; it is instead a consequence of the fact that radiometric dating actually works and works quite well. Creationists who wants to dispute the conclusion that primitive meteorites, and therefore the solar system, are about 4.5 Ga old certainly have their work cut out for them!
The K-T Tektites
One of the most exciting and important scientific findings in decades was the 1980 discovery that a large asteroid, about 10 kilometers diameter, struck the earth at the end of the Cretaceous Period. The collision threw many tons of debris into the atmosphere and possibly led to the extinction of the dinosaurs and many other life forms. The fallout from this enormous impact, including shocked quartz and high concentrations of the element iridium, has been found in sedimentary rocks at more than 100 locations worldwide at the precise stratigraphic location of the Cretaceous-Tertiary (K-T) boundary (Alvarez and Asaro 1990; Alvarez 1998). We now know that the impact site is located on the Yucatan Peninsula. Measuring the age of this impact event independently of the stratigraphic evidence is an obvious test for radiometric methods, and a number of scientists in laboratories around the world set to work. In addition to shocked quartz grains and high concentrations of iridium, the K-T impact produced tektites, which are small glass spherules that form from rock that is instantaneously melted by a large impact. The K-T tektites were ejected into the atmosphere and deposited some distance away. Tektites are easily recognizable and form in no other way, so the discovery of a sedimentary bed (the Beloc Formation) in Haiti that contained tektites and that, from fossil evidence, coincided with the K-T boundary provided an obvious candidate for dating. Scientists from the US Geological Survey were the first to obtain radiometric ages for the tektites and laboratories in Berkeley, Stanford, Canada, and France soon followed suit. The results from all of the laboratories were remarkably consistent with the measured ages ranging only from 64.4 to 65.1 Ma (Table 2). Similar tektites were also found in Mexico, and the Berkeley lab found that they were the same age as the Haiti tektites. But the story doesn’t end there. The K-T boundary is recorded in numerous sedimentary beds around the world. The Z-coal, the Ferris coal, and the Nevis coal in Montana and Saskatchewan all occur immediately above the K-T boundary. Numerous thin beds of volcanic ash occur within these coals just centimeters above the K-T boundary, and some of these ash beds contain minerals that can be dated radiometrically. Ash beds from each of these coals have been dated by 40Ar/39Ar, K-Ar, Rb-Sr, and U-Pb methods in several laboratories in the US and Canada. Since both the ash beds and the tektites occur either at or very near the K-T boundary, as determined by diagnostic fossils, the tektites and the ash beds should be very nearly the same age, and they are (Table 2). There are several important things to note about these results. First, the Cretaceous and Tertiary periods were defined by geologists in the early 1800s. The boundary between these periods (the K-T boundary) is marked by an abrupt change in fossils found in sedimentary rocks worldwide. Its exact location in the stratigraphic column at any locality has nothing to do with radiometric dating it is located by careful study of the fossils and the rocks that contain them, and nothing more. Second, the radiometric age measurements, 187 of them, were made on 3 different minerals and on glass by 3 distinctly different dating methods (K-Ar and 40Ar/39Ar are technical variations that use the same parent-daughter decay scheme), each involving different elements with different half-lives. Furthermore, the dating was done in 6 different laboratories and the materials were collected from 5 different locations in the Western Hemisphere. And yet the results are the same within analytical error. If radiometric dating didn’t work then such beautifully consistent results would not be possible.
Dating of The Mt Vesuvius Eruption
In the early afternoon of August 24, 79 CE, Mt Vesuvius erupted violently, sending hot ash flows speeding down its flanks. These flows buried and destroyed Pompeii and other nearby Roman cities. We know the exact day of this eruption because Pliny the Younger carefully recorded the event. In 1997 a team of scientists from the Berkeley Geochronology Center and the University of Naples decided to see if the 40Ar/39Ar method of radiometric dating could accurately measure the age of this very young (by geological standards) volcanic material. They separated sanidine crystals from a sample of one of the ash flows. Incremental heating experiments on 12 samples of sanidine yielded 46 data points that resulted in an isochron age of 1925 94 years. The actual age of the flow in 1997 was 1918 years. Is this just a coincidence? No it is the result of extremely careful analyses using a technique that works. This is not the only dating study to be done on an historic lava flow. Two extensive studies done more than 25 years ago involved analyzing the isotopic composition of argon in such flows to determine if the source of the argon was atmospheric, as must be assumed in K-Ar dating (Dalrymple 1969, 26 flows; Krummenacher 1970, 19 flows). Both studies detected, in a few of the flows, deviations from atmospheric isotopic composition, most often in the form of excess 40Ar. The majority of flows, however, had no detectable excess 40Ar and thus gave correct ages as expected. Of the handful of flows that did contain excess 40Ar, only a few did so in significant amounts. The 122 BCE flow from Mt Etna, for example, gave an erroneous age of 0.25 0.08 Ma. Note, however, that even an error of 0.25 Ma would be insignificant in a 20 Ma flow with equivalent potassium content. Austin (1996) has documented excess 40Ar in the 1986 dacite flow from Mount St Helens, but the amounts are insufficient to produce significant errors in all but the youngest rocks. The 79 CE Mt Vesuvius flow, the dating of which is described above, also contained excess 40Ar. The 40Ar/39Ar isochron method used by the Berkeley scientists, however, does not require any assumptions about the composition of the argon trapped in the rock when it formed it may be atmospheric or any other composition for that matter. Thus any potential error due to excess 40Ar was eliminated by the use of this technique, which was not available when the studies by Dalrymple (1969) and Krummenacher (1970) were done. Thus the large majority of historic lava flows that have been studied either give correct ages, as expected, or have quantities of excess radiogenic 40Ar that would be insignificant in all but the youngest rocks. The 40Ar/39Ar technique, which is now used instead of K-Ar methods for most studies, has the capability of automatically detecting, and in many instances correcting for, the presence of excess 40Ar, should it be present.
Summary
In this short paper I have briefly described 4 examples of radiometric dating studies where there is both internal and independent evidence that the results have yielded valid ages for significant geologic events. It is these studies, and the many more like them documented in the scientific literature, that the creationists need to address before they can discredit radiometric dating. Their odds of success are near zero. Even if against all odds they should succeed, it still would not prove that the Earth is young. Only when young-earth creationists produce convincing quantitative, scientific evidence that the earth is young will they be worth listening to on this important scientific matter."
Creationists base their objections on the flawed results, extrapolating this to mean ALL radiometric dating is inaccurate. Each method faces its own challenges, but the sources of potential error are different, yet the various methods correlate to a remarkable degree.
Take the K-T Tektites. For the YEC position to be true, ALL four (40Ar/39Ar, K-Ar, Rb-Sr, and U-Pb) methods must be greater than 1,000,000% inaccurate. One MILLION per cent! How can they explain the vanishingly small chance they are ALL in error to this degree?
Mark
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 33 by Kyle467, posted 02-16-2002 7:21 PM Kyle467 has not replied

  
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 62 of 145 (4993)
02-18-2002 6:59 PM
Reply to: Message 60 by TrueCreation
02-18-2002 6:54 PM


quote:
Originally posted by TrueCreation:
"Now, I am going to ask you again, do you have some substantive information on radiometric dating?"
--Not currently, I am not arguing with radioisotopic methods right now.

That's exactly what you were doing.
So, to repeat the original question, what positive evidence do you have of a 6,000 year old earth?
Mark
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 60 by TrueCreation, posted 02-18-2002 6:54 PM TrueCreation has replied

Replies to this message:
 Message 64 by TrueCreation, posted 02-18-2002 7:05 PM mark24 has replied

  
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 66 of 145 (4999)
02-18-2002 7:09 PM
Reply to: Message 64 by TrueCreation
02-18-2002 7:05 PM


quote:
Originally posted by TrueCreation:
"That's exactly what you were doing.
So, to repeat the original question, what positive evidence do you have of a 6,000 year old earth?"
--lbhandli accused me as being ignorant from me haveing 'limited knowledge' on the issue. The question that I asked that he accounted ignorance on my part, is, are there any other dating techniques not associated with radiometric dating that gives you 4.5 billion years as your date for the age of the earth.

And the question being asked of you is if there is any positive evidence of a 6,000 year old earth? Rather than knocking a well supported, highly corroborated method.
Mark
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 64 by TrueCreation, posted 02-18-2002 7:05 PM TrueCreation has not replied

  
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 69 of 145 (5008)
02-18-2002 7:38 PM
Reply to: Message 67 by TrueCreation
02-18-2002 7:14 PM


quote:
Originally posted by TrueCreation:
--My question was are there any sort of dating techniques that will also give you an age of the earth's 'existance', not that it is more than 6000 years old. Different questions.

But the question, once again, asked of you, is....... is there positive evidence of a 6,000 year old earth, in the same way that there is evidence (highly corroborated) of a much older earth?
Mark
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 67 by TrueCreation, posted 02-18-2002 7:14 PM TrueCreation has not replied

  
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 82 of 145 (5062)
02-19-2002 5:42 AM
Reply to: Message 79 by zimzam
02-19-2002 5:07 AM


quote:
Originally posted by zimzam:

Do you consider God, creation, and supernatural events as a possibility?
If you dont why?
If you do what evidences are you willing to accept?

I do consider the supernatural as a possibility.
When comparing the natural mechanistic framework to the supernatural mechanistic framework (ugly terms, but I can think of nothing better) you get this :
List of natural mechanisms:
Electron behaviour & interaction, radioactive decay, combustion, evaporation, sublimation, inertia, nuclear fission, nuclear fusion, meiosis, mitosis The list goes on & on.
List of known supernatural mechanisms:
Nothing, absolutely zilch.
So, although the second list is empty, there MAY be entries that can be made. But, until there are, there is no REASON to infer the supernatural over the natural. By definition, to do so is unreasonable. Which begs the question, by what mental process do you (or anyone) infer the supernatural over the natural, & claim it to be reasonable? By simply saying well, science can’t explain this or that, you are falling into the God-of-the-gaps. We are talking about the rationality of inferring the natural or supernatural. The conclusion is that there is no REASON to infer the supernatural. NONE.
So, what would a supernatural event be? For our purposes, anything that can be shown to contravene well known natural laws, & to be guided by an intelligence outside our universe.
e.g The bible states the sun stops in the sky, meaning the earth stops turning, despite the property of mass, inertia, & it’s resulting angular momentum. This event also occurs for a purpose, hence the guiding intelligence.
Mark
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 79 by zimzam, posted 02-19-2002 5:07 AM zimzam has replied

Replies to this message:
 Message 89 by zimzam, posted 02-20-2002 3:20 AM mark24 has replied

  
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 87 of 145 (5071)
02-19-2002 10:36 AM
Reply to: Message 79 by zimzam
02-19-2002 5:07 AM


quote:
Originally posted by zimzam:
1. In part I joined this discussion to educate myself about these so called proofs regarding the earth being more than or less than 6-10,000 years old. What I do know is only what I have read and what others have taught me. Up to this point it seems there have always been 2 sides to everything. An evolutionist claims that evidence X proves his side while a creationist can take the same evidence X and say it proves creation. I just got done reading 25 posts between TC and the rest of you arguing geological proofs without anyone giving a single one. I will admit that is frustrating.

See if you can answer my question in message 45 (at the bottom), if you doubt the accuracy of radiometric dating methods.
Mark
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 79 by zimzam, posted 02-19-2002 5:07 AM zimzam has replied

Replies to this message:
 Message 88 by Pete, posted 02-19-2002 7:16 PM mark24 has not replied
 Message 93 by zimzam, posted 02-20-2002 4:16 AM mark24 has replied

  
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 94 of 145 (5133)
02-20-2002 4:23 AM
Reply to: Message 89 by zimzam
02-20-2002 3:20 AM


quote:
Originally posted by zimzam:
I do think it is somewhat interesting that we can look at the same thing and come up with the exact opposite conclusions. I look at the universe, earth, animals, and man and see amazing designs that can not be explained without an intelligence behind them. If we went to the moon and dug up a simple machine like a bicycle all of mankind would immediately come to the conclusion that intelligent life created it and then left it there. Why do you and others look at everything beautiful and wonderous in the universe and immediately refute any intelligent design?
How do you rationalise inferring the supernatural whwen it has NEVER been observed. In fact only natural mechanisms have been observed. It's your logic I'm questioning.
"When comparing the natural mechanistic framework to the supernatural mechanistic framework (ugly terms, but I can think of nothing better) you get this :
List of natural mechanisms:
Electron behaviour & interaction, radioactive decay, combustion, evaporation, sublimation, inertia, nuclear fission, nuclear fusion, meiosis, mitosis The list goes on & on.
List of known supernatural mechanisms:
Nothing, absolutely zilch.
So, although the second list is empty, there MAY be entries that can be made. But, until there are, there is no REASON to infer the supernatural over the natural. By definition, to do so is unreasonable. Which begs the question, by what mental process do you (or anyone) infer the supernatural over the natural, & claim it to be reasonable? By simply saying well, science can’t explain this or that, you are falling into the God-of-the-gaps. We are talking about the rationality of inferring the natural or supernatural. The conclusion is that there is no REASON to infer the supernatural. NONE."
Please address this.
Mark
------------------
Occam's razor is not for shaving with.

This message is a reply to:
 Message 89 by zimzam, posted 02-20-2002 3:20 AM zimzam has replied

Replies to this message:
 Message 105 by zimzam, posted 02-20-2002 4:26 PM mark24 has replied

  
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 95 of 145 (5134)
02-20-2002 4:46 AM
Reply to: Message 93 by zimzam
02-20-2002 4:16 AM


quote:
Originally posted by zimzam:
Give me some time to research this and I will at least come up with some questions for you involving radiometric whatever

If you're just going to ask me how do I explain x, or y anomoly, then you're not answering the question. Also, by pointing out why why U-Pb, or K-Ar methods are innacurate, you're still not answering the question. Despite these two common creationist tactics, in the K-T tectite example, four methods corroborate each other to such a degree that they must be innacurate to the order of a million per cent, if the YEC position is true. Now, the reasons creationists say these methods are innacurate is to point to potential amomolies that could cause errant dates, plus a small batch of samples that produce bad dates. However, the four methods (excepting K-Ar, & Ar-Ar) have different potential anomolies, so you're also saying that these possible errors all produce EXACTLY the same error in the final calculated date? That's just this example, there are three others in the post that offer similar corroberations, some with non-radiometric methods.
So please address the issues in message 45, I've been given the runaround before, ie, instead of having my questions answered, having different questions posed in place of an answer.
Mark
------------------
Occam's razor is not for shaving with.
[This message has been edited by mark24, 02-20-2002]

This message is a reply to:
 Message 93 by zimzam, posted 02-20-2002 4:16 AM zimzam has replied

Replies to this message:
 Message 104 by zimzam, posted 02-20-2002 4:19 PM mark24 has not replied

  
mark24
Member (Idle past 5194 days)
Posts: 3857
From: UK
Joined: 12-01-2001


Message 108 of 145 (5200)
02-20-2002 9:44 PM
Reply to: Message 105 by zimzam
02-20-2002 4:26 PM


quote:
Originally posted by zimzam:
Science can only explain how it works but nothing can explain how it got there in the first place. If not intelligent design then what? No one can answer that therefore a supernatural created beginning is not an illogical thought. The more natural mechanisms you list the more I see extremely complex design that has to be the result of some intelligent design. The universe and everything in it screams "DESIGN!"
Rubbish.
Unknown natural mechanisms CAN explain how it got there. Natural mechanisms exist. Supernatural mechanisms don't.
Rationalise it.
Who designed the designer?
Mark
------------------
Occam's razor is not for shaving with.
[This message has been edited by mark24, 02-20-2002]

This message is a reply to:
 Message 105 by zimzam, posted 02-20-2002 4:26 PM zimzam has not replied

  
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