Radiocarbon dating - Wikipedia
Radiometric dating methods estimate the age of rocks using calculations For some evidence for a young sun, see sendangsono.info If these conditions are not satisfied, the error can be arbitrarily large. .. It is also being claimed that the standard deviations are not too large. scrupulous inter- and intramethod calibration in absolute time is required. However uncertainty in comparisons between dating methods and between targets typical of those used to illustrate precision and accuracy. Below them are . uncertainties may be displayed in the same error bar. In the two. Radiometric dating involves dating rocks or other objects by sample will decay can be calculated to varying degrees of accuracy. A proper radiometric date should read years before present (with being present) ± range/2 at x standard deviations (Xσ)', .. Saloon bar · To do list · What is going on?.
As far as I know, no study has been done to determine how different methods correlate on the geologic column excluding precambrian rock. The reason for my request is that a correlation is not implied by the fact that there are only 10 percent anomalies, or whatever. I showed that the fact that the great majority of dates come from one method K-Ar and the fact that many igneous bodies have very wide biostratigraphic limits, where many dates are acceptable, makes the percentage of anomalies irrelevant to the question I am asking.
And since this agreement is the strongest argument for the reliability of radiometric dating, such an assumption of agreement appears to be without support so far. The question of whether different methods correlate on the geologic column is not an easy one to answer for additional reasons. Since the bulk of K-Ar dates are generally accepted as correct, one may say that certain minerals are reliable if they tend to give similar dates, and unreliable otherwise.
We can also say that certain formations tend to give reliable dates and others do not, depending on whether the dates agree with K-Ar dates. Thus we can get an apparent correlation of different methods without much of a real correlation in nature.
It's also possible for other matter to be incorporated into lava as it rises, without being thoroughly melted, and this matter may inherit all of its old correlated radiometric dates. Coffin mentions that fission tracks can survive transport through lava, for example. It may also be that lava is produced by melting the bottom of continents and successively different layers are melted with time, or there could be a tendency for lighter isotopes to come to the top of magma chambers, making the lava there appear older.
But anyway, I think it is important really to know what patterns appear in the data to try to understand if there is a correlation and what could be causing it.
Not knowing if anomalies are always published makes this harder. It is often mentioned that different methods agree on the K-T boundary, dated at about 65 million years ago. This is when the dinosaurs are assumed to have become extinct. This agreement of different methods is taken as evidence for a correlation between methods on the geologic column.
One study found some correlated dates from bentonite that are used to estimate the date of the K-T boundary. I looked up some information on bentonite. It is composed of little glass beads that come from volcanic ash.
This is formed when lava is sticky and bubbles of gas in it explode.
How Old Is the Mount St. Helens Lava Dome?
So these small particles of lava cool very fast. The rapid cooling might mean that any enclosed argon is retained, but if not, the fact that this cooling occurs near the volcano, with a lot of argon coming out, should guarantee that these beads would have excess argon. As the gas bubble explodes, its enclosed argon will be rushing outward along with these tiny bubbles as they cool.
This will cause them to retain argon and appear too old. In addition, the rapid cooling and the process of formation means that these beads would have Rb, Sr, U, and Pb concentrations the same as the lava they came from, since there is no chance for crystals to form with such rapid cooling.
So to assume that the K-Ar dates, Rb-Sr dates, and U-Pb dates all reflect the age of the lava, one would have to assume that this lava had no Sr, no Pb, and that all the argon escaped when the beads formed. Since the magma generally has old radiometric ages, I don't see how we could have magma without Pb or Sr. So to me it seems to be certain that these ages must be in error. Furthermore, the question arises whether bentonite always gives correlated ages, and whether these ages always agree with the accepted ages for their geologic period.
I believe that bentonite occurs in a number of formations of different geologic periods, so this could be checked.Types of error-bars for mean: SD SE CI
If bentonite does not always give correlate and correct ages, this calls into question its use for dating the K-T boundary. Back to top Note that if there are small pockets in crystals where both parent and daughter product can accumulate from the lava, then one can inherit correlated ages from the lava into minerals. Thus even the existence of correlations is not conclusive evidence that a date is correct.
Back to top If a date does not agree with the expected age of its geologic period, and no plausible explanation can be found, then the date is called anomalous. But if we really understand what is going on, then we should be able to detect discrepant dates as they are being measured, and not just due to their divergence from other dates. Geologists often say that the percentage of anomalies is low.
But there are quite a number of rather outstanding anomalies in radiometric dating that creationists have collected. These anomalies are reported in the scientific literature.
For example, one isochron yielded a date of 10 billion years. A Rb-Sr isochron yielded a date of 34 billion years. K-Ar dates of 7 to 15 billion years have been recorded. It's also not uncommon for two methods to agree and for the date to be discarded anyway. Samples with flat plateaus which should mean no added argon can give wrong dates.
Samples giving no evidence of being disturbed can give wrong dates. Samples that give evidence of being disturbed can give correct dates. The number of dates that disagree with the expected ages is not insignificant.
I don't know what the exact percentage is. Many dates give values near the accepted ones. But even these often differ from one another by 10 or 20 percent. And quite a few other dates are often much, much farther off. Whatever is making some of these dates inaccurate could be making all of them inaccurate. It's interesting to note that in a few cases, old radiometric dates are above young ones. The fact that different methods often give different dates is noted by geologists. Here are some quotes from http: Age estimates on a given geological stratum by different radiometric methods are often quite different sometimes by hundreds of millions of years.
There is not absolutely reliable long-term radiological "clock". The uncertainties inherent in radiometric dating are disturbing to geologists and evolutionists One example is the rocks from the Kaupelehu Flow, Hualalai Volcano in Hawaii which was known to have erupted in These rocks were dated by a variety of different methods.
- Radiometric dating
- How Old Is the Mount St. Helens Lava Dome?
Of 12 dates reported the youngest was million years and the oldest was 2. The dates average 1. Geologists explain the Kaupelehu date by the lava being cooled rapidly in deep ocean water and not being able to get rid of its enclosed argon.
Instead, the uncertainty grows as more and more data is accumulated In addition, Woodmorappe gives over sets of dates "that are in gross conflict with one another and with expected values for their indicated paleontological positions. This does not include dates from minerals that are thought to yield bad dates, or from igneous bodies with wide biostrategraphic ranges, where many dates are acceptable. He states that the number of dates within range are less than the number of anomalies, except for the Cenozoic and Cretaceous.
When one adds in the fact that many anomalies are unreported, which he gives evidence for, the true distribution is anyone's guess. There have been criticisms of John Woodmorappe's study, but no one has given any figures from the literature for the true percentage of anomalies, with a definition of an anomaly, or the degree of correlation between methods.
Steven Schimmrich's review of this study often concerns itself with John W's presentation of geologists explanation for anomalies, and not with the percentage of anomalies; the later is my main concern. Here are a couple of more quotes about anomalies: The carbon age of the buried trees is only years, but some of the overlying volcanic material has a ,year potassium-argon age.
Still another evidence for problems with radiometric dating was given in a recent talk I attended by a man who had been an evolutionist and taken a course in radiometric dating. The teacher gave 14 assumptions of radiometric dating and said something like "If creationists got a hold of these, they could cut radiometric dating to pieces.
Many sedimentary uranium ores are not. On another point, if we can detect minerals that were not molten with the lava, as has been claimed, then this is one more reason why there should be no anomalies, and radiometric dating should be a completely solved problem.
But that does not appear to be the case, at least especially on the geologic column. I'm not claiming that anomalous results are being hidden, just that the agreement of a mass of results, none of which has much claim to reliability, does not necessarily mean much.
Picking out a few cases where radiometric dates appear to be well-behaved reminds me of evolutionary biologists focusing on a few cases where there may be transitional sequences. It does not answer the overall question. And as I said above, I'm also interested to know how much of the fossil-bearing geologic column can be dated by isochrons, and how the dates so obtained compare to others.
Concerning K-Ar anomalies, here is a quote from Woodmorappe's paper cited above, p. Gerling et al called attention to some chlorites yielding K-Ar dates of 7 to 15 b. It had been noted that some minerals which yield such dates as beryl, cordierite, etc.
They also pointed out that for the anomalies to be accounted for by excess argon, unreasonably high partial pressures of Ar during crystallization would have to be required. They concluded by suggesting some unknown nuclear process which no longer operates to have generated the Ar. Here is another quote from Woodmorappe about isochrons, since some people think that mixing scenarios or other age-altering scenarios are unlikely: If this condition does not hold, invalid ages and intercepts are obtained.
Models yield isochron ages that are too high, too low, or in the future, sometimes by orders of magnitude. The fact that the only "valid" K-Ar isochrons are those for which the concentration of non-radiogenic argon Ar36 is constant, seems very unusual. This suggests that what is occuring is some kind of a mixing phenomenon, and not an isochron reflecting a true age.
The following quote is from http: We have analyzed several devitrified glasses of known age, and all have yielded ages that are too young. Some gave virtually zero ages, although the geologic evidence suggested that devitrification took place shortly after the formation of a deposit. Back to top One of the main arguments in favor of radiometric dating is that so many dates agree with each other, that is, with the date expected for their geologic period.
But it's not evident how much support this gives to radiometric dating. If a rock dates too old, one can say that the clock did not get reset. If it dates too young, one can invoke a later heating event.
Neither date would necessarily be seen as anomalous. If lava intrudes upon geologic period X, then any date for the lava of X or later will not be seen as anomalous.
And even if the date is one or two geologic periods earlier, it may well be close enough to be accepted as non-spurious. If one does not know the geologic period of a rock by other means, then of course one is likely to date it to find out, and then of course the date agrees with the geologic period and this will not be seen as anomalous. So it is difficult to know what would be a reasonable test for whether radiometric dating is reliable or not. The percentage of published dates that are considered as anomalous has little bearing on the question.
Back to top The issue about igneous bodies may need additional clarification. If a lava flow lies above geologic period A and below B, then allowable ages are anything at least as large as A and no larger than B. This is called the biostratigraphic limit of the flow.
Now, according to Woodmorappe's citations, many lava flows have no such limits at all, and most of them have large limits. For example, a flow lying on precambrian rock with nothing on top would have no limits on its dates. And such flows often have a large internal scatter of dates, but these dates are not considered as anomalies because of the unrestricted biostratigraphic limit.
Other flows with wide biostratigraphic limits have weak restrictions on allowable dates.
This is one reason why just reporting the percentage of anomalies has little meaning. Thus these ages, though they generally have a considerable scatter, are not considered as anomalies. He cites another reference that most igneous bodies have wide biostrategraphic limits. Thus just by chance, many dates will be considered within the acceptable ranges. Again, the percentage of anomalies means nothing for the reliability of radiometric dating. Now, igneous bodies can be of two types, extrusive and intrusive.
Extrusive bodies are lava that is deposited on the surface. These cool quickly and have small crystals and form basalt. Intrusive bodies are deposited in the spaces between other rocks.
So, hopefully you now know a bit more about what those strange block diagrams mean. These are basically just data points along mixing lines between 2 or more different things. I am going to make a creamy chocolate coconut dessert. Both of these ingredients contain cream. If I know what the proportion of chocolate to cream is in the ganache, and the proportion of coconut to cream in the coconut pudding, then I can calculate how much chocolate, coconut and cream there is in different mixtures of ganache and coconut pudding.
If I calculate some ratios of the ingredients, and then plot them up on some graphs, we can see that the composition of the ganache — coconut pudding mixtures all lie on a straight line between the compositions of the 2 main ingredients.
That means, as you move to the right of the graph, you either have more chocolate, or less cream or both.
Radiometric dating - RationalWiki
That also means that, if you move to the left of the graph, you have less chocolate or more cream or both. We can see from the diagram that this ratio is 1; if you look at the table, you can see that the composition of coconut pudding is If we draw a line through them and extrapolate it to both axes, we can calculate the compositions of our original ingredients.
Here are a couple of schematic isotope correlation diagrams that I sketched. They are both the same kind of diagram, but illustrating different types of samples. This is frequently because the selected technique is used outside of its appropriate range, for example on very recent lavas.
Smoking Gun Evidence of an Ancient Earth: GPS Data Confirms Radiometric Dating
In attempting to date Mt. Helens, creationists attempted discredit the discipline through dishonest practices. Ultimately these "creation scientists" were forced to admit that even for methods they accepted as sound, the age of the Earth would be vastly greater than the 6, they set out to prove. Is radioactive decay constant?
An enormous amount of research shows that in the lab decay rates are constant over time and wherever you are. Faced with this, creationists say that you can't extrapolate from this to deduce they are correct over billions of years. A few experiments have found small variations in decay rates, at least for some forms of decay and some isotopes.
While it may require further investigation to see if this is a real phenomenon, even the biggest positive results do not offer anything like a variation that would allow the truth of young earth creationism.