Posted: Sun Jul 09, 2006 10:51 am
gone
"The heavens declare the glory of God; the skies proclaim the work of his hands." (Psalm 19:1)
https://discussions.godandscience.org/
Understanding the method allows one to identify situations in which the dating technique would yeild false results.Jbuza wrote:a couple snippets, sorry I have been unable to carry out any K - AR dating myself, so this comes from someone else.
"Processes of rock alteration may render a volcanic rock useless for potassium-argon dating . . 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."—VF. Evemden, et. al., " KJAA Dates and the Cenozoic Mammalian Chronology of North America, "in American Journal of Science, February 1964, p 154.
This is true however iron is not being tested in these cases. The tests are done on potassium silicate minerals which are insoluable in water and therefore are not subject to this process.Jbuza wrote:As much as 80 percent of the potassium in a small sample of an iron meteorite can be removed by distilled water in 4.5 hours."—*L.A. Rancitelli and D.E. Fisher, "Potassium-Argon Ages of Iron Meteorites," in Planetary Science Abstracts, 48th Annual Meeting of the American Geophysical Union (1967), p. 167.
No as you clearly show above in your quotes, there are cases in which the application of this method would be improper. This comes from an understanding of the technique. In your attempt to show that K-AR dating is unreliable, you have shown that scientists are very well aware of cases in which the technique should not be applied. Thus rendering the technique even more reliable.Jbuza wrote:ANd I would ask how do they know the rock has been rendered useless? Because it gives the wrong date?
The data comes first then the conclusion. The original data was taken from disparate sources, once collected it was plotted on a chart. The thing about this is Jbuza is that if it is the case that the data was tampered with, it should be quite simple for someone to make an expedition and get their own results.Jbuza wrote:Perhaps you have to throw away these useless rocks until you get the "real" date.
The data taken from realiable sources has been plotted nothing has been thrown out.Jbuza wrote:Same process the used to "age" the islands, I can see it now, Ooops that rock has been rendered useless, see it dosen't fall on our line.
You should read this study, it was a component in the lava known as xenoliths which produced the anamalous data. The enclosing lava itself did not date to the same age. In these cases AR-AR dating can be used to find the real date.Jbuza wrote: LOL HA HA HA. But if you have a sample that has had enough K leach out and enough argon migrate in you can get the rock of the proper "age".Submerged volcanic rocks, produced by lava flows off the coast of Hawaii near Hualalei in the years 1800-1801, were dated using potassium-argon. The lava forming those rocks is clearly known to be less than 200 years old, yet the potassium-argon dating of the rocks yielded great ages, ranging from 160 million to 2.96 billion years! (See *Science, October 11, 1968; *Journal of Geophysical Research, July 15, 1968).
I havn't made any conclusions yet, I am only trying to catalog a list of observations which you and I can agree with. Once that is done we can then examine the data.Jbuza wrote:I would point out this. When I talk about an evidence and then say could, that is far more scientific than stating the evidence, and than trying to promote ones own conclusions as fact.
There are degrees and details of the erosion which one can observe which you just seem to gloss over with your statement. For instance erosion which occurs now on Hawaii will lead to smaller exposed land mass. This is similar to what already has occurred on the older islands to the west.Jbuza wrote: The Seamounts, Darwins Points and Atolls show evidence of erosion as shown by the exposure of the different layers of volcanic rock.
Agreed, it is a huge problem on the new ISland as well.
The rock which forms during the various stages in island formation form under different conditions and therefore have different compositions. It is possible to analyze the composition of the various types of rocks and the relative locations in which they reside. From this analysis one can get another measurement of erosion.Jbuza wrote: On the islands which are currently active we can see these layers intact.
USGS
I don't know what you mean here. I think it is clear that all lava flows ever produced have been subject to weathering. Especially the newst ones that are actually exposed.
Correct no one is implying this.Jbuza wrote:There really is no evidence to show that the movement is uniform.
This is where you make the mistake. There is evidence for periods of higher activity, which means that the acticty is not a constant but fluctuates, you imply that the activity was much higher in the past, and the evidence does not show this.Jbuza wrote:There is evidence to suggest that volcanism, and geological activity were more dynamic in the past.
They would have at least have been near the ocean surface given their coral growths would you not agree?Jbuza wrote:IT is difficult to tell what amounts of erosion have taken place without knowing the size of the more western islands hefore the arosion.
During the lifespan of a volcano, different types of rocks are produced. We can see the various layers of rocks when an island erodes. From this we can estimate the amount of erosion which took place. In fact, going back to volcanic activity, it is from the types of rocks themselves which have lead to the conclusion that activity is not constant! Certain rocks only form in active conditions, and others in less active conditions.Jbuza wrote:Do you care to demonstrate how we know the amounts of erosion on the islands?
We can determine environmental variables by the composition of the rocks themselves. We can see that corals formed around the fringes of the islands and growing on top of each other. Do you have a problem with island subsidence and the formation of atols? Lets take a look at current subsidence rates.Jbuza wrote:This really isn't the realm of science without knowing the environmental variables present throughout the formation of the Islands.
Rates of subsidence would be important if there are coral growths present.Jbuza wrote:Sorry having trouble finding any real data to base any conclusions on. I have seen sinking rates as high as 40 cm a year, and as low as .3 cm a year. The amount of volcanic activity would effect the sinkage rates.
For these islands we can assume that conditions for coral growth are no longer or never were present. Therefore we can disregard these islands in terms of correlating coral growth and subsidence rates. Thats why we use data gathered at Kure and Midway.Jbuza wrote:Many of the seamounts don't show any coral growth especially the more northwest ones.
I don't think there should be any question the observation is simple. The column of coral at Kure reaches a depth of 325 meters. What do you propose the average subsidence rate at Kure had to be.Jbuza wrote:There is a lot of unsubstantiated narrative to much of this.
It's not a nebulous claim you are clouding the issue with unecessary observations. Given that it can be assumed that conditions for coral growth no longer or never did exist for these islands, these islands can be disregarded in the current discussion.Jbuza wrote:Nebulous claims like coral is found lower down the further west we move is misleading when we move far enough west we don't even see any coral at all.
Quite simple distance divided by time. You tell me how long I have and then we can calculate the average subsidence rate.Jbuza wrote:Sounds great I think I can work with this:
First I will say it doesn't "have" to be anything. I'm sure it has fluctuated quite a lot, and as you point out the sinking rate was higher when the Island was larger mass, it is quite possible that increased geothermal activity would increase the sinking rate as well due to increased elasticity of the crust. Increased volcanism would also increase rate of sinking, it would seem.The column of coral at Kure reaches a depth of 325 meters. What do you propose the average subsidence rate at Kure had to be.
I would presume that it would have fluctuated somewhere betwwen the upper and lower limits that I had posted before, but I'm not sure how to determine what the likely average rate of sinking since its formation would be.
You're forgeting the time it took for the island to reach atol stage. Before this coral reefs would occationally be destroyed by landslides or subsidence would occur too rapidly for long term accumulation. This as evidenced by examining the various islands and underwater formation along the island chain.Jbuza wrote:don't know when it formed, but I would suggest that it may have formed around the time of the flood. I think that would put it at like 4406 years.
As I said in my PM to you I think that put it somehwere around 7 CM a year.
But if it was formed 22 million years ago, than I guess that would make the rate on average 14 ten thousandths of a CM a year.
I'm not sure what this would tell us as it would appear that we would be picking arbitrary times based solely on our theretical perspectives.
One thing is clear requardless of our theoretical perspectives the Island sank at the rate it sunk at.