Does radioactive dating produce exact results Wb kolkataxxxvideo
Clearly, basic crystal chemistry and physics dictates that zoned and other relatively large phenocrysts grew deep within the Earth and existed before the glass matrix that rapidly formed during the 1986 eruption. Similarly, Swenson also fails to comprehend the indisputable history that is associated with the plagioclase zoning and to properly recognize the important age differences between the coarsest phenocrysts and the volcanic glass. Again, the mineral textures, as well as the laws of chemistry and physics, dictate that the calcium-rich plagioclase cores grew at higher temperatures before the sodium-rich rims and that glasses only formed once the melt erupted at the surface. 'The 'heavy-magnetic concentrate' also had glassy particles (more abundant than in the 'heavy-nonmagnetic concentrate'). De Paolo, 1985, 'Radiometric Time Scale for the Upper Eocene and Oligocene Based on K/Ar and Rb/Sr Dating of Volcanic Biotites from the Pelagic Sequence of Gubbio, Italy', Geology, v. Austin simply assumes that the first explanation is correct and then he proceeds to use the 'presence' of 'excess argon' in his samples to question the reliability of all K-Ar dates on other rocks and minerals. The validity of either hypothesis #2 or #3 would provide additional evidence that Austin's application of the K-Ar method is flawed and that he has failed to prove that the K-Ar method is universally invalid. 49], the amounts of excess 40Ar and 36Ar found in the flows with anomalous 40Ar/36Ar ratios were too small to cause serious errors in potassium-argon dating of rocks a few million years old or older.'Phenocrysts of orthopyroxene, hornblende and plagioclase are interpreted to have occluded argon within their mineral structures deep in the magma chamber and to have retained this argon after emplacement and solidification of the dacite.
Although hypothesis #1 is plausible, until the argon isotope concentrations of the PURE glass are accurately measured for Austin's dacite (if this is even possible) we cannot properly evaluate this hypothesis.'The origin of the excess 40Ar is not entirely clear, but the discovery of excess 40Ar in Holocene quenched basalt glass [Dalrymple and Moore, 1968] indicates that radiogenic argon, released when older rocks are heated or melted, is dissolved in the melt and may be occluded by minerals as they crystallize.''Up to 2.6 x 10 to the -11 mole/gram of excess radiogenic 40Ar has been found in SUBMARINE basalts of Holocene age from Kilauea [Dalrymple and Moore, 1968; plus another reference], BUT IT'S OCCURRENCE THERE IS NOT SURPRISING IN VIEW OF THE HYDROSTATIC PRESSURE IN THE OCEAN DEPTHS and the rapidity with which SUBAQUEOUS flows are quenched.' [my emphasis]Although high-pressure ocean water may prevent argon gas from escaping from the rims of a lava flow on the ocean floor, the centers of modern submarine flows typically provide K-Ar dates of 'zero years' (Young, 1982, p. While YECs explain geology by invoking talking snakes, magical fruit, and a mythical 'Flood', Dalrymple (1969) discusses legitimate chemistry and fluid physics, which is hardly relying on flimsy 'rationalizations' or implausible excuses.'With the exception of the Hualalai flow [which contains noticeable ultramafic xenoliths, Dalrymple, 1969, p.
Considering the statements at the Geochron website and the lowest age limitations of the K-Ar method, why did Austin submit a recently erupted dacite to this laboratory and expect a reliable answer???
uninformed claim that ' Dr Austin carefully designed the research to counter all possible objections', Austin clearly demonstrated his inexperience in geochronology when he wasted a lot of money using the K-Ar method on the wrong type of samples.
This sample also had recognizable hornblende, evidently not completely isolated by magnetic separation.' 'The 'pyroxene concentrate' (DOME-IP) was dominated by orthopyroxene and much less clinopyroxene.
Because it was composed of finer particles (170-270 mesh), it contained far fewer mafic particles with attached glass fragments than DOME-IH.