Joined: July 2006
No references provided, so does anyone know where these data were found?
How Old Are the Cardenas Basalt Lavas?
[from “The Fallacies of Radioactive Dating of Rocks: Basalt Lava Flows in Grand Canyon” by Andrew A. Snelling, Ph.D., in the premier issue of ANSWERS magazine]
These radioactive dating methods have been used to calculate an absolute age of 1,103±66 million years for the Cardenas Basalt lavas. (The number after the ± symbol refers to the error margins in the “age” determination so that 1,103±66 million years means that the age is between 1,037 and 1,169 million years.) So it would seem! However, a closer examination of the results from all such studies reveals the fallacies of the radioactive dating methods.
The claimed age of 1,103±66 million years was obtained using the rubidium-strontium isochron method with 10 samples and has been regarded as the best radioactive dating result for any Grand Canyon rock unit. Nevertheless, potassium-argon model “ages” for each of 15 individual Cardenas Basalt samples range from 577±12 to 1,013±37 million years, while the potassium-argon isochron “age” obtained using 14 samples is only 516±30 million years. This is less than half the rubidium-strontium isochron “age” of 1,111±81 million years obtained using 19 samples. It is also less than the claimed Cambrian age of the Tapeats Sandstone that sits on top of, and well above the Cardenas Basalt lavas (Figure 4). Worse still, the samarium-neodymium isochron “age” obtained using 8 samples is 1,588±170 million years—more than three times the potassium-argon isochron “age” of 516±30 million years!
So what is the correct “age” of the Cardenas Basalt lavas?
• (a) 516±30 million years (the potassium-argon isochron age)
• (b) 1,111±81 million years (the rubidium-strontium isochron age)
• © 1,588±170 million years (the samarium-neodymium isochron age)
• (d) None of the above
How can we know for sure which is the correct age when there is no independent cross-check?