What information is obtained from radioactive dating
The "type" of rock is not sufficient to establish the samples being cogenetic.Since the stratigraphic evidence indicates that the flows did not all occur at the same time, the case could only be made by other isotopic analysis such as taking internal isochrons of the individual flows.If it is not the flows' age, that is not a "problem" with isochron dating, and it is not relevant to the large number of Rb/Sr isochrons which were computed from mineral separations of a single object.At the GSA meeting, Austin discussed the inheritance of a mantle age.An angular unconformity is the result of tilting and eroding of the lower layers before the upper ones are deposited.These tilted and eroded layers are Precambrian in age (blue in Figure 1, above).
I would recommend that future prospective critics attempt to deal directly and explicitly with the three items in the "criticisms" section above.
Carbon is most commonly obtained from coal deposits, although it usually must be processed into a form suitable for commercial use.
History and Uses: Carbon, the sixth most abundant element in the universe, has been known since ancient times.
There are a number of lava flows on the plateau that the canyon is cut into (yellow in Figure 1, above).
These lava flows are Cenozoic in age, and some of them spill into the canyon.
He didn't pretend that the age of the flows was the expected result, and he didn't make the false claim that his result was sufficient to call all isochron dating into question.