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.
Issue is that sometimes the geologic periods of rocks are revised to agree with the ages computed.
The point is that there is now no reason to believe that radiometric dating is valid on the geologic column.
Ages derived from fossils, which occur only in sedimentary rocks, absolute ages are obtained from minerals that grow as liquid rock bodies cool at or below the surface.
Just as the use of the fossil record has allowed a precise definition of geologic processes in approximately the past 600 million years, absolute ages allow correlations back to earths oldest known rocks formed more than 4 billion years ago.
In addition, because sediment deposition is not continuous and much rock material has been removed by erosion, the fossil record from many localities has to be integrated before a complete picture of the evolution of life on earth can be assembled.
The construction of this time scale was based on about 380 radioisotope ages that were selected because of their agreement with the presumed fossil and geological sequences found in the rocks.
Scientists who use radiometric dating typically use every means at their disposal to check, recheck, and verify their results, and the more important the results the more they are apt to be checked and rechecked by others.
Tied to the earth's rotational energy lack the precision of isotopic dating methods, and they are only applicable to a small number of formations which have excellent preservation of fairly small details.
Radiometric dating of sedimentary rocks
My experience is that whenever i look into an evidence for evolution or (now) the reliability of radiometric dating on the geologic column, it blows up on me, too.
With the k-ar dating techniques developed after world war ii, this time scale was refined to the standard geologic time scale adopted in 1964.
But there are quite a number of rather outstanding anomalies in radiometric dating that creationists have collected.
In most instances, these efforts are flawed because the authors have misunderstood or misrepresented the data they attempt to analyze (for example, woodmorappe 1979; morris hm 1985; morris jd 1994).
There are other dating techniques such as isochrons and discordia which avoid the need to estimate initial daughter product concentrations.
In the lead-uranium systems both uranium and lead can migrate easily in some rocks, and lead volatilizes and escapes as a vapor at relatively low temperatures.
Furthermore, it is possible that the craters were chosen as those for which the dating methods agreed.
Rocks that are being dated, contamination with atmospheric argon is a persistent problem that is mentioned a number of times.
For example, it would be about one in 100 million for rocks in the vicinity of 57 million years old.
Radiometric dating of sedimentary rocks is unreliable because
Similar situation is reported in the december 1997 issue of creation ex nihilo in which lava with a k-ar age of about 45 million years overlays wood that was carbon dated by 3 laboratories using ams dating to about 35,000 years.
Accept radiometric dating methods as proof that the earth is millions of years old, in contrast to the biblical timeline.
However, it does not seem likely that sedimentary rocks would be this hot very often, except near lava or magma flows.
Geology, determining a chronology or calendar of events in the history of Earth, using to a large degree the evidence of organic evolution in the sedimentary rocks accumulated.
It also needs to be determined whether the daughter products for methods other than uranium-lead dating also yield isochrons among the different meteorites.
Plaisted wants to give his readers the impression that argon can readily move in and out of minerals and, therefore, the gas is too volatile for radiometric dating.
The geochronologist considers the ca40 of little practical use in radiometric dating since common calcium is such an abundant element and the radiogenic ca40 has the same atomic mass as common calcium.
Historically, the decay constants used for the various radiometric dating systems have been adjusted to obtain agreement between the results obtained.
It seems to be a common pattern that when dating methods are revised, we are told how inaccurate the old methods were, but are not told how inaccurate the current methods are.
, as for c14 dating in general, it seems clear that many, many results are much too young according to the standard view, and that explaining away one or two of them does not appreciably diminish the problem.
For example, if 80 percent of the measurements were done using k-ar dating, and the other 20 percent gave random results, we still might be able to say that most of the measurements on a given strata agree with one another reasonably well.
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.
This is taken as a confirmation of radiometric dating, since the earth's rotation should be gradually slowing down due to the effect of the moon and tides.
This is significant because it is known that neutrinos do interact with the nucleii of atoms, and it is also believed that much of the energy of supernovae is carried away by neutrinos.
Such situations occur mainly where old rocks have been locally heated, which released argon-40 into pore spaces at the same time that new minerals grew.
The rocks in the lower slab undergo changes in their mineral content in response to heat and pressure and will probably become exposed at the surface again some time later.
Also see mussett and mccormack (1978) on using a three dimensional plot to distinguish initial and excess argon in k/ar dating.
Scientists and many Christians believe that the radiometric dating methods prove that the earth is 4.
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.
247) mentions a study showing that volcanic rocks contain excess atmospheric argon, some of which cannot be removed by baking in a vacuum.
Radiometric dating and certain other approaches are used to provide absolute chronologies in terms of years before the present.
Of known recent age give dates of millions, and even billions,Of years supports the claim that radiometric dating cannot provide.
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.
Other creationists have focused on instances in which radiometric dating seems to yield incorrect results.
's apply this to potassium argon dating, where x is k40, y is ar40, and z is probably ar36.
How could all of this be so if the40ar/39ar dating technique did not work?
The timing of cycles involving the expulsion of fluids from deep within the crust can be ascertained by dating new minerals formed at high pressures in exposed deep crustal sections.
All its argon will either remain inside and give an old age to the flow, or will travel through surrounding rock, where it can be absorbed by other rocks.
Response to the disagreements between different dating methods, henke states:To really understand what's going on you have to sample the recent works of many different authors.
In 1997 five specimens were taken from this dome at five different locations and subjected to conventional potassium-argon dating.
Potassium is present in most geological materials, making potassium-argon dating highly useful if it really works.
The article i referred to is the following:"direct dating of cretaceous-jurassic fossils (and other evidences for human-dinosaur coexistence)" (1992 twin cities creation conference).
If the radiometric dating problem has been solved in this manner, then why do we need isochrons, which are claimed to be more accurate?
Without absolute ages, investigators could only determine which fossil organisms lived at the same time and the relative order of their appearance in the correlated sedimentary rock record.
"the latter [sedimentary layers of cambrian or later age] are worldwide phenomena and many of the formations cover areas of hundreds or thousands of square miles.
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.
In uranium-lead (u-pb) dating of zircon, the zircon is found to exclude initial lead almost completely.
.It must also be concluded, therefore, that because nuclear decay has been shown to have occurred at grossly accelerated rates when molten rocks were forming, crystallizing and cooling, the radiometric methods cannot possibly date these rocks accurately based on the false assumption of constant decay through earth history at todays slow rates.
But how can we know that this claim is true, without knowing the history of rocks and knowing whether they have in fact experienced later heating or leaching?
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.
Some so-called creation scientists have attempted to show that radiometric dating does not work on theoretical grounds (for example, arndts and overn 1981; gill 1996) but such attempts invariably have fatal flaws (see dalrymple 1984; york and dalrymple 2000).
Where are the data and age calculations that result in a consistent set of ages for all rocks on earth, as well as those from the moon and the meteorites, no greater than 10 000 years?
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.
Those of us who have developed and used dating techniques to solve scientific problems are well aware that the systems are not perfect; we ourselves have provided numerous examples of instances in which the techniques fail.
If you were to measure ar40 concentration as function of depth, you would no doubt find more of it near the surface than at deeper points because it migrates more easily from deep in the earth than it does from the earth into the atmosphere.