Make the best samples for the kar dating method

For shorter timescales, it is unlikely that enough 40 Ar will have had time to accumulate in order to be accurately measurable.

K—Ar dating was instrumental in the development of the geomagnetic polarity time scale. One archeological application has been in bracketing the age of archeological deposits at Olduvai Gorge by dating lava flows above and below the deposits. In the K—Ar method was used by the Mars Curiosity rover to date a rock on the Martian surface, the first time a rock has been dated from its mineral ingredients while situated on another planet.

From Wikipedia, the free encyclopedia. National Nuclear Data Center. Retrieved 20 September Retrieved February 22, Retrieved from " https: Use dmy dates from May Views Read Edit View history. This page was last edited on 11 December , at By using this site, you agree to the Terms of Use and Privacy Policy. The Wikibook Historical Geology has a page on the topic of: Thus, discretion and interpretation of age dating is essential.

This technique allows the errors involved in K-Ar dating to be checked. Argon—argon dating has the advantage of not requiring determinations of potassium. Modern methods of analysis allow individual regions of crystals to be investigated. This method is important as it allows crystals forming and cooling during different events to be identified.

Radiometric dating

One problem with argon-argon dating has been a slight discrepancy with other methods of dating. Thus the Cretaceous—Paleogene extinction when the dinosaurs died out - previously dated at Similarly, the Permian-Triassic extinction is now dated at Most sedimentary rocks are thought to lose Argon because the crystal structure leaks Argon. A loss of Argon would cause the rock to date younger than it should according to evolutionary thought. This is probably the assumption that scientists make when they choose to present filtered data in a scientific paper. They see the young dates as those samples that have lost Argon.

It is an assumption that they probably view as having no alternatives, yet if this same issue was ever pursued, it might uncover other possibilities suggesting a short age time scenario. Another possibility is that the second assumption is being violated rather than the third. Some samples will not be fully reset, initially. Thus these rocks give a date which is older than what normally would happen if the rocks were fully reset. These older dating rocks give the kind of dates as expected by the scientific community.

On the other hand, those rocks that date younger, would not need to have had Argon leak from the crystal after the time when the reseting process occurs. Instead, the rock was probably more completely reset when it was molten.

This means that there was less Argon in the rocks to begin with, because the younger dating rocks were more fully set to zero in the reseting process. The second assumption sounds logical at first. Many text books say it is self-evident. The Age of the Earth.

1. Argon Geochronology Methods?
2. (K/Ar) Potassium Argon Dating Techniques I?
3. Argon–argon dating.
4. 40 days of dating show.

Stanford University Press, p. This is because Ar 40 is an inert gas that does not combine chemically with any other element and so escapes easily from rocks when they are heated. Thus, while a rock is molten the Ar 40 formed by the decay of K 40 escapes from the liquid. There are reasons and evidences for challenging the second assumption. The first assumption is often challenged by some creationists.

They think that the radioactivity could have speeded up during the flood producing dates with long ages.

But there is no known mechanism to explain or predict the increased rate of radioactivity. However there may be a new development in the field of nuclear reactions that could change this situation. People around the world are working on active "Cold Fusion" reactions. There is another group that has been conducting experiments for the express purpose of speeding up the transmutation process thus changing the half-life characteristics of radioactive materials.

Some of these reactions occur under admittedly extremely mild conditions, However, it is another question to suppose that these newly discovered processes can occur or did occur in natural conditions, in the history of our world. Dating mechanisms such as Carbon, work within the creationary paradigm without the need of having a change in half-lives. So since the time of the flood, there is no evidence that there has been any change in half-lives of radioactive materials. On the other hand, It is possible that the creation event could have caused changes in the half-lives of nuclides.

For more on Cold Fusion and the creation event click on Extinct Nuclides. The majority of the fossils are found in the phanerozoic from Cambrian up to the Pleistocene layers of the Geologic column. This includes the Paleozoic, Mesozoic, and Cenozoic layers. These are considered by most Creationists to have been laid down during the time of the flood. It is possible that the sedimentary layers in the upper Precambrian are also flood deposits See my Geology page.

So the volcanic rock and ash within these layers would have been been produced during the flood event. Only the rocks in the precambrian layers could have been affected by the creation event. Everything else would have been redeposited or re-melted in the global flood. When a scientist needs to measure the amount of Argon that is trapped in a rock, the first step in the process is to get the Argon out of the rock.

That is done by heating the rock in a vacuum. In a vacuum, virtually all the Argon comes out of the heated rock. What conditions could have been present when igneous and volcanic rock was formed? Were the rock layers laid down in a vacuum? Or might we suggest that molten rock was intruded at very high levels of pressure. Within the Creationary flood model, we also might expect layers to be made underwater.

Would all the Argon come out of the heated rock under these high pressure conditions? Since K-Ar dating is so widely used, we might expect that many experiments would have been done to see how well Argon is released under various heated conditions. We might also expect that hornblende and biotite, the most reliable types of rocks from an evolutionary perspective, would have been tested. But this kind of work has not been published.

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One has to wonder why these kinds of experiments were not originally done. It is always possible that these kinds of experiments were done, but the results never worked out, thus it was never published. I do not know. I do know that there have not been too many experiments to determine what really happens to the Argon in various conditions; But there are a few. Dr Giem see references below has been able to find only two published papers. Synthetic introduction of argon into mica at high pressures and temperatures. Isv Akad Nauk S. R Geol Ser ; 8: What they found was that the muscovite absorbed large quantities of Argon.

When these muscovite samples were then dated via normal K-Ar dating techniques, they were measured to have an age of up to 5 billion years since the clock was reset, or set to zero. In the experiment, the Argon that was absorbed into the rock looked just like the normal radiogenic Argon that comes from K 40! This is very interesting! From this experiment it sounds like the Argon can go either way. If Argon pressure outside the rock is high, then when the rock is heated up, Argon will flow into the rock rather than flowing out of the rock.

On the other hand, if the Argon has a place to go, as in a vacuum, then the Argon will escape out of the rock. So in both cases the Argon flows down the concentration gradient.