U pb age dating
Because no geologically meaningful results can be interpreted from the U-Th-Pb data at Koongarra (three uraninite grains even yield a Pb age of 0Ma), serious questions must be asked about the validity of the fundamental/foundational basis of the U-Th-Pb dating method.
Similar anomalous or false isochrons are commonly obtained from U-Th-Pb data, which is hardly surprising given the common open system behavior of the U-Th-Pb system.
Amber from northern Myanmar has been commercially exploited for millennia, and it also preserves the most diverse palaeobiota among the worlds' seven major deposits of Cretaceous amber.
Recent estimated ages vary from Albian to Cenomanian, based on palynology, an ammonoid, and Mesozoic insect taxa preserved within the amber.
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 isochron and yields a derived age that has no distinct geological meaning.
At Koongarra, Australia, U-Th-Pb isotopic studies of uranium ore, host rocks and soils have produced an array of false isochrons that yield ages that are geologically meaningless.