Today, scientists obtain the absolute dates of rocks using
radiometric methods. These radiometric methods use radioactive minerals
in rocks as geological clocks. The principle involved here is that the
atoms of some chemical elements have different forms, called isotopes.
These isotopes break down over time in a process scientists call
radioactive decay.
RADIOACTIVE DECAY
CALCULATING RADIOACTIVE DECAY
ASSUMPTIONS MADE BY SCIENTISTS
Assumption 1: Conditions at Time Zero
With regard to the volcanic lavas
that erupted, flowed, and cooled to form rocks in the unobserved past,
evolutionary geologists simply assume that none of the daughter argon-40
atoms was in the lava rocks.
For the other radioactive “clocks,” it is assumed that
by analyzing multiple samples of a rock body, or unit, today it is
possible to determine how much of the daughter isotopes (lead,
strontium, or neodymium) were present when the rock formed.
Yet lava flows that have occurred in the present have
been tested soon after they erupted, and they invariably contained much
more argon-40 than expected.
For example, when a sample of the lava in the Mt. St. Helens crater
(that had been observed to form and cool in 1986) (Figure 1) was
analyzed in 1996, it contained so much argon-40 that it had a calculated
“age” of 350,000 years!
Similarly, lava flows on the sides of Mt. Ngauruhoe, New Zealand, known to be less than 50 years old, yielded “ages” of up to 3.5 million years.
So
it is logical to conclude that if recent lava flows of known age yield
incorrect old potassium-argon ages due to the extra argon-40 that they
inherited from the erupting volcanoes, then ancient lava flows of
unknown ages could likewise have inherited extra argon-40 and yield
excessively old ages.
There are similar problems with the other radioactive “clocks.” For example, consider the dating of Grand Canyon’s basalts
(rocks formed by lava cooling at the earth’s surface). We find places
on the North Rim where volcanoes erupted after the Canyon was formed,
sending lavas cascading over the walls and down into the Canyon.
Obviously, these eruptions took place very recently,
after the Canyon’s layers were deposited. These basalts yield ages of
up to 1 million years based on the amounts of potassium and argon
isotopes in the rocks. But when we date the rocks using the rubidium and
strontium isotopes, we get an age of 1.143 billion years. This is the
same age that we get for the basalt layers deep below the walls of the
eastern Grand Canyon.
How could both lavas—one at the top and one at the
bottom of the Canyon—be the same age based on these parent and daughter
isotopes? One solution is that both the recent and early lava flows
inherited the same rubidium-strontium chemistry—not age—from the same
source, deep in the earth’s upper mantle. This source already had both
rubidium and strontium.
To make matters even worse for the claimed reliability
of these radiometric dating methods, these same basalts that flowed
from the top of the Canyon yield a samarium-neodymium age of about 916
million years,5 and a uranium-lead age of about 2.6 billion years!
The problems with contamination, as with inheritance, are already well-documented in the textbooks on radioactive dating of rocks. Unlike the hourglass, where its two bowls are sealed, the radioactive “clock” in rocks is open to contamination by gain or loss of parent or daughter isotopes because of waters flowing in the ground from rainfall and from the molten rocks beneath volcanoes. Similarly, as molten lava rises through a conduit from deep inside the earth to be erupted through a volcano, pieces of the conduit wallrocks and their isotopes can mix into the lava and contaminate it.
Because of such contamination, the less than 50-year-old lava flows at Mt. Ngauruhoe, New Zealand, yield a rubidium-strontium “age” of 133 million years, a samarium-neodymium “age” of 197 million years, and a uranium-lead “age” of 3.908 billion years!
Assumption 3: Constant Decay Rate
Physicists have carefully measured the radioactive decay rates of parent radioisotopes in laboratories over the last 100 or so years and have found them to be essentially constant (within the measurement error margins). Furthermore, they have not been able to significantly change these decay rates by heat, pressure, or electrical and magnetic fields. So geologists have assumed these radioactive decay rates have been constant for billions of years.
However, this is an enormous extrapolation of seven orders of magnitude back through immense spans of unobserved time without any concrete proof that such an extrapolation is credible. Nevertheless, geologists insist the radioactive decay rates have always been constant, because it makes these radioactive clocks “work”!
New evidence, however, has recently been discovered that can only be explained by the radioactive decay rates not having been constant in the past. For example, the radioactive decay of uranium in tiny crystals in a New Mexico granite yields a uranium-lead “age” of 1.5 billion years. Yet the same uranium decay also produced abundant helium, but only 6,000 years worth of that helium was found to have leaked out of the tiny crystals.
IF THESE CLOCKS ARE BASED ON FAULTY ASSUMPTIONS AND YIELD UNRELIABLE RESULTS, THEN SCIENTISTS SHOULD NOT TRUST OR PROMOTE THE CLAIMED RADIOACTIVE “AGES.” The assumptions on which the radioactive dating is based are not only unprovable but plagued with problems. As this article has illustrated, rocks may have inherited parent and daughter isotopes from their sources, or they may have been contaminated when they moved through other rocks to their current locations. Or inflowing water may have mixed isotopes into the rocks. In addition, the radioactive decay rates have not been constant.
So if these clocks are based on faulty assumptions and yield unreliable results, then scientists should not trust or promote the claimed radioactive “ages” of countless millions of years.
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