The ICR's Grand Canyon Dating Project does not strike a telling blow against the reliability of isochron dating.
The conditions which caused the "false isochron" in this case are fairly well-understood, and easy to avoid by proper sample selection.
Besides, this line of argument does not address the fact that the result is a known and expected behavior of isochrons.It can be a virus, bacterium, protist, fungus, plant or an animal.The earth is home to various organisms and these organisms can be classified taxonomically.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.
Search for realtive dating:
The canyon must be younger than the rock layers that it cuts into.