As with other isochron methods, the U-Pb isochron method has been questioned in the open literature, because often an excellent line of best fit between ratios obtained from a set of good cogenetic samples gives a resultant \u27isochron\u27 and yields a derived \u27age\u27 that has no distinct geological meaning. At Koongarra, Australia, U·Th·Pb Isotopic studias of uranium ore, host rocks and soils have produced an array of false \u27isochrons\u27 that yield \u27ages\u27 that are geologically meaningless. Even a claimed near·concordant U-Pb \u27age\u27 of 862Ma on one uraninite grain is identical to a false Pb-Pb isochron \u27age\u27, but neither can be connected to any geological event. Open system behaviour of the U-Th-Pb system is clearly the norm, as is the resultant mixing of radiogenic Pb with common or background Pb, even in soils in the surrounding region. Because no geologically meaningful results can be interpreted from the U-Th-Pb data at Koongarra (three uraninite grains even yield a 232Th/208Pb \u27age\u27 of OMa), serious questions must be asked about the validity of the fundamental/foundational basis of the U-Th-Pb \u27dating\u27 method. This makes the task of creationists building their model for the geological record much easier, since claims of U-Th-Pb radiometric \u27dating\u27 having \u27proven\u27 the claimed great antiquity of the earth, its strata and fossils can be safely side-stepped
