Dating talkorigins


21-Jun-2019 13:28

In the case of the submarine pillow basalts, the results clearly indicated that these rocks are unsuitable for dating, and so they are not generally used for this purpose except in special circumstances and unless there is some independent way of verifying the results.Turner, however, made no such comment about excess argon in lunar rocks, and there are no data in his report on which such a conclusion could be based.Two studies independently discovered that the glassy margins of submarine pillow basalts, so named because lava extruded under water forms globular shapes resembling pillows, trap 40Ar dissolved in the melt before it can escape 36 This effect is most serious in the rims of the pillows and increases in severity with water depth.The excess 40Ar content approaches zero toward pillow interiors, which cool more slowly and allow the 40Ar to escape, and in water depths of less than about meters because of the lessening of hydrostatic pressure.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.The data are straightforward albeit technically complex measurements that fall on a straight line, indicating that the meteorite has obeyed the closed-system requirement.The decay constants used in the calculations were the same as those in use throughout the world in The age of 4.

For example, lavas taken from the ocean bottom off the island [sic] of Hawaii on a submarine extension of the east rift zone of Kilauea volcano gave an age of 22 million years, but the actual flow happened less than years ago.In the field, they look like large raisins in a pudding and even occur in beds piled one on top of the other, glued together by the lava.