Everyone has heard about the great ages claimed by proponents of evolution, this is particularly true of Grand Canyon. The question is, do radioactive isotope dating methods provide convincing scientific evidence for billion-year old rocks?
Two lava-flow formations occur in the Grand Canyon: the Cardenas Basalt and the western Grand Canyon lava flows. In a recent study, these formations were both selected for radioactive isotope dating by the rubidium-strontium isochron technique.
The deeply buried Cardenas Basalt occurs among the oldest strata of the Grand Canyon. This basalt has been assigned to the Precambrian strata of the Unkar Group, which contains the lowest, and hence the oldest strata of the Grand Canyon. Some geologists that ascribe to the theory of evolution have suggested an "age" of more than one billion years.
As some of you know, the western Grand Canyon lava flows are among the youngest formations of the Grand Canyon. The youngest flows came from volcanoes on the Uinkaret Plateau north of the Colorado River, forming lava dams.
This is not my opinion, it is what C.E. Dutton, one of the first geologists wrote in his paper, 'The Tertiary History of the Grand Canyon District,' U.S, Geological Survey Monograph. He even said, "It looks as fresh as any coulee of Vesuvius ejected twenty or thirty years ago."
One K-Ar "model age" determination gave 1.2 + or - 0.2 million years for the lava dam, and geologists consider these lava flows to be Pleistocene in age, according to E.D. McKee, W.K. Hamblin, and P.E. Damon, in 'K-Ar Age of Lava Dam in the Grand Canyon,' Geological Society of American Bulletin, 2nd edition 1968.
IN recent geological studies, 28% of rubidium atoms are the isotope rubidium-87 (87 Rb). It decays to strontium-87 (87 Sr), which is a common, stable isotope of strontium. The radioactive decay of rubidium is slow, and would require 48.8 billion years for 1/2 the 87Rb of a rock to be converted to 87Sr, according to Gunter Faure's 'Principles of Isotope Geology, 2nd edition, 1986 (there may be a more current version available).
Evolutionary geologists have suggested the isotope ratios of 87Rb to 87Sr in rocks can be used to determine "ages" in hundreds of millions, even billions of years.
E.H. McKee & D.C. Noble working for the US Geological Survey, National; Science Foundation & the National Aeronautics & Space Administration made a plot of Rubidium-strontium for the Cardenas Basalt & western Grand Canyon flows (Pleistocene hawaiities of Uinkaret Plateau). The fact the data seem to describe a line on the plot of 87Sr versus 87Rb/86Sr is thought to testify to the validity of the method and the suitability of specimen, and thus the basalt was given an "age" interpretation by both geologists.
They reasoned the Cardenas Basalt issued from volcanoes, which originally had lavas with common ratio of strontium isotopes. The original ratio of 87Sr to 86Sr of Cardenas Basalt was believed to be 0.7065. According to the "age" interpretation, those samples of Cardenas Basalt with higher 87Rb have, over a very long period of time, acquired a large quantity of 87Sr radioactive decay, and it stays constant.
A simple calculations employed by these geologists indicates that 1.07 + or - 0.07 billion years would be required for the rock samples to acquire their various strontium isotope ratios by rubidium decay (Note: The "age" has been recalculated, using the new decay constant for rubidium-87). The age of 1.07 billion years is the "rubidium-strontium isochron age" of Cardenas Basalt, and is widely regarded by proponents of the theory of evolution as the best age obtained for Grand Canyon rocks.
Plots show the isotope ratios from hawaiite lava flows from the Uinkaret Plateau on the north rim of the Grand Canyon; four whole rock samples and one feldspar sample separated from one of the whole rock samples, which were submitted independently to three different laboratories for testing. The data on the plot show a linear trend on the 87Sr/86Sr versus 87Rb/86Sr; there is a distinct downward slope to the line, which was UNEXPECTED.
One would suppose these recent lava flows on the north rim of the Grand Canyon would be homogeneous with respect to strontium isotopes.
All the rocks should have had the <I>same strontium isotope ratios. Instead, the lava flows having HIGHER 87Rb also have HIGHER 87Sr!! The abundances vary in linear fashion.
An age relationship is suggested by the linear plot and the same equation used to date the Cardenas Basalt at 1.07 billion years gives an age of 1.34 + or - 0.04 billion years for these recent lava flows of the western Grand Canyon. That is even older than the Cardenas Basalt...ooops! There goes the evolutionary model, as it floats mindlessly down the mighty Colorado River.
This scientific observation showing recent lava flows from the north rim of Grand Canyon give ages even older than the deeply buried lava flows, and challenges the basic assumption upon which the isochron dating method is based. The discovery of an "old age" in the obviously "young" series of lava flows has encouraged further research.