We can only speculate on where Kofahl and Segraves obtained their numbers. The approximate age ofyears was the mean of the results from four samples from the Island of Hawaii, which is much younger than Kauai.The Kilauea Submarine Pillow Basalts Many of the rocks seem to have inherited Ar40 from the magma from which the rocks were derived.Initial 40Ar There is far too much Ar40 in the earth for more than a small fraction of it to have been formed by radioactive decay of K This is true even if the earth were really 4.In the atmosphere of the earth, Ar40 constitutes This is around times the amount that would be generated by radioactive decay over the hypothetical 4.Initial 87Sr There is really no valid way of determining what the initial amounts of Sr87 in rocks were.As discussed above in the section on Rb-Sr dating the simplest form of Rb-Sr dating i.
They come from deep within the mantle and were carried upward to the surface by the lava.
The purpose of these two studies was to determine, in a controlled experiment with samples of known age, the suitability of submarine pillow basalts for dating, because it was suspected that such samples might be unreliable.
Such studies are not unusual because each different type of mineral and rock has to be tested carefully before it can be used for any radiometric dating technique.
Excess argon produced apparent ages ranging from million to 2.
The flow is unusual because it carries very abundant inclusions of rocks foreign to the lava.Since geochronologists assume that errors due to presence of initial Ar40 are small, their results are highly questionable.