Books | Many common evolutionary dating methods are less reliable than they seem
by Timothy Clarey
Posted 1/20/21, 12:25 pm
Timothy Clarey, with a Ph.D. in geology and experience as a full professor of geology in Michigan, does not proceed from ignorance when he challenges skepticism about a worldwide flood and geological upheavals that could move mountains: “Contrary to uniformitarian thought, sedimentary rocks—and other geologic features—don’t require millions of years to form.” Clarey, who also spent eight years as a Chevron exploration geologist, states that “bacteria consume organic material even after it is buried,” so “Oil and gas cannot be millions of years old, otherwise the remains would have been devoured long ago.” Here, reprinted by permission from the Institute for Creation Research, is an excerpt from Clarey’s Carved in Stone, an honorable mention in WORLD’s 2020 Books of the Year list in the accessible science category. —Marvin Olasky
Principles of Absolute Time
Since the middle of the 20th century, secular scientists have claimed to be able to make determinations of absolute time using radioactive isotopes of certain elements. Commonly used radioactive elements are isotopes of uranium, thorium, rubidium, strontium, argon, and potassium. Most of the time, only igneous rocks are analyzed. Sedimentary rocks may contain the proper radioactive elements, but they are usually mixtures of rock types from various locations and therefore give mixed ages if analyzed. There are several methods for determining absolute ages of selected sedimentary rocks, but most are susceptible to much greater error and some can only be used on fairly recent sediments. Metamorphic events often “reset” the radioactive clocks, making age determinations trickier than with igneous rocks.
Absolute dates are based on the decay rate of unstable (radioactive) isotopes. Isotopes are elements that have the same proton number but different atomic masses (different number of neutrons). Decay rates are often directly measurable and are assumed to be constant with time (uniformitarianism again). We will see later that this does not hold true for all radioactive elements under all conditions. Decay rates are converted to a half-life, which is the time it takes for one-half of the radioactive element to decay to another element. The original radioactive element, or radioisotope, is called the parent isotope and the decay product is the daughter isotope.
Let’s illustrate radioactive decay with carbon-14. Although this method is rarely used in geology, it makes a good example because most people have heard of it. Carbon can come as three isotopes: carbon-12, the most common variety; carbon-13, the next-most common variety; and carbon-14, the rarest and only radioactive variety. All three carbon isotopes have six protons, which defines them as carbon. Carbon-12 has six neutrons, carbon-13 has seven neutrons, and carbon-14 has eight neutrons, making the latter unstable. Carbon-12 and carbon-13 remain the same forever. Carbon-14, by contrast, spontaneously decays into nitrogen-14 over time. Carbon-14 has a half-life of about 5,730 years, meaning that one-half of any quantity of carbon-14 will convert to nitrogen-14 in that time. By determining how much carbon-14 is left in an organic sample, compared to the modern amount of carbon-14 in living organisms, we can estimate the how long ago the organism died and hence its age. The longer ago an organism died, the smaller the amount of measurable carbon-14. If we have one-quarter of what we started with, we can assume two half-lives have passed and therefore determine that the sample is 11,460 years old (5,730 + 5,730).
The most modern instrumentation can only measure small amounts of carbon-14 equivalent to about 100,000 years before present. And this is why secular geologists rarely use this method for dating since they assume most fossils and rocks are millions or even billions of years old. And any carbon-14 from fossils in those rocks should have all decayed away. However, scientists are finding plenty of measurable carbon-14 in dinosaur bones. They are also finding original proteins, blood vessels, and cells.
RATE Project Carbon-14 Analyses
In the 2000s, the Radioisotopes and the Age of the Earth (RATE) research project, supported by ICR, sent numerous coal and diamond samples to be tested for carbon-14. Every one of the samples (10 coals, 12 diamonds) came back with measurable carbon-14, demonstrating these rocks and minerals are less than 100,000 years old. The coal samples were from every era of the Phanerozoic, Paleozoic, Mesozoic, and Cenozoic, dating back in presumed secular time to over 300 million years. Most diamonds are generally assumed to be Precambrian, or much older than the coal samples, and possibly a billion years old or more. Instead, the measurable carbon-14 in these samples places them closer to the biblical timeline. Secular claims of contamination are harder to justify in the diamonds since these minerals are the hardest natural substance and have a melting point of 4,000ºC.
Carbon-14 dating is different from all other radioisotope methods because it does not require determination of the amount of both the parent and daughter isotopes.
It merely measures the amount of carbon-14 that is left in a sample compared to the modern amount measured in living organisms. All living organisms on land gain a fairly equal ratio of carbon-14 to carbon-12 through breathing, eating, and/or photosynthesis. This method also assumes that a constant amount of carbon-14 is created in the upper atmosphere and therefore assumes cosmic radiation has always been constant. However, secular science knows that that is not entirely true. That is why they tried to calibrate carbon-14 dates with tree ring data, but tree ring data are rather ambiguous because more than a single ring can form in a calendar year.
Assumptions in All Radioisotope Methods
In principle, the general methodology works for all radioactive elements. It is based on a measurable scientific process and uses scientific reasoning. It can be very precise. But precision and accuracy are two different things. And testing two or three different radioisotopes can result in different dates for the same rocks, often with differences of over hundreds of millions of years. We will discuss more on this with some examples later. The assumptions in all of the methods do not warrant accuracy by any means. Secular science just gets the old ages it wants and claims they are factual. But nothing in science is factual if you cannot observe it, repeat it, or test it and produce the same results over and over again. You cannot go back in time to verify any of the radioisotope dating results.
In reality, the determination of absolute ages is very subjective and laden with unanswerable and unverifiable assumptions. Let’s run through four of these assumptions. First, secular scientists assume they can measure the decay rates of radioactive elements accurately. This may seem straightforward, but many radioactive isotopes used in geology have half-lives in the 100-million-year to billion-year range. These elements decay so slowly that measuring any decay is miniscule.
Second, they assume that the decay rates never change and have remained constant throughout all of geologic time. This is probably all they can assume, following strict uniformitarianism, but how do they really know the decay rate won’t change or hasn’t changed? The world has been around a long time, and we’ve only been measuring decay rates for about 100 years. Scientists at some of the world’s leading institutions (Brookhaven National Lab, the German PTB, Baylor College of Medicine, and Purdue University) have recently reported seasonal variations in the decay rate of several elements, including manganese-54, silicon-32, radium-226, and chlorine-36. They have noticed fluctuations of about 0.3% in decay rates with the seasons, possibly caused by changes in the distance to the sun throughout the year. What causes this variation is still a mystery, but it really calls into question the assumption that decay rates never change. Projecting back very small changes in the present creates great discrepancies in ages for ancient rocks.
A third assumption deals with the history of the rock or mineral sample that contains the radioisotope. Any metamorphic event, no matter how minor, can alter the apparent date of the sample. Many Precambrian-age rocks show evidence of several metamorphic events (likely caused by intense heat and pressure during the Flood).
The problem is with other metamorphic events we don’t see evidence for in the rocks today. These can cause the determined age to be in great error without knowing it.
Some elements, like the uranium-lead system, can partially compensate for such events, but many methods cannot be corrected. Isochrons may not be the solution either since they seem to be similar to mixing lines where end-member values have to be estimated.
The last assumption also deals with the history of the rock and the assumption of a closed system. To determine the age using most radioisotopes, the correct amounts of the parent and daughter isotopes in the rocks have to be determined accurately.
Groundwater is everywhere, and everything leaks. Water percolates through all natural materials over time—some materials faster than others. All rocks and minerals below the water table are in constant contact with moving water. Because water is the universal solvent, it will selectively dissolve nearly every natural substance, given enough time. The key word here is selectively. Water can obviously dissolve some minerals like halite (salt) easier than a mineral like quartz. There are differences in solubility in all substances. Uranium is very soluble in water. Many dinosaur bones from Colorado are enriched in radioactive uranium because the porous interior allowed concentration of the element via groundwater flow. Radioactive uranium isotopes ultimately decay into various isotopes of lead. If more uranium is selectively dissolved from the rocks compared to the lead, it will look like a lot of uranium has converted to the lead isotope. This will result in ages that are much older than they should be, even millions or billions of years older. Again, the problem is in determining the exact amount of the original parent and daughter isotopes at the start and also the amount of parent and daughter isotopes that have remained in place. Absolute ages are based on knowing the start and finish time on the radioisotope clock.
Secular geologists may try to work around these assumptions by using several different isotope methods, like uranium-lead and potassium-argon. If they get similar dates from the two or more methods, they feel more confident in their age determination. However, to my knowledge, nobody has really addressed the problem of selective dissolution by groundwater. How could someone? The earth is not a closed system. There is always movement in and out of the systems. How could someone possibly claim they know the entire history of the rock and its chemical interactions with groundwater? Groundwater is constantly flowing through the subsurface, dissolving radioactive and nonradioactive elements alike. It often leaves behind other minerals to replace the ones it dissolves, leaving no real way to trace the process.
This leads us back to our discussion at the beginning of this chapter. Do we really know the earth is 4.56 billion years old as taught by secular science, or is it 6,000 years old as many creationists believe? The Bible tells us that the earth is young. There is no true, verifiable science to counter this conclusion. In fact, the measurable carbon-14 in dinosaur fossils and the original proteins, like blood vessels and collagen, in dinosaur bones match best with the age of 6,000 years. Real science confirms the Bible.
Determining the Date of a Fossil
Fossils, because they are normally found in sedimentary rocks, cannot be dated directly using radioactive isotopes. Many people have gotten the wrong impression that paleontologists can magically stick a dinosaur bone into a machine and out comes the proper age. However, creation scientists have begun to directly date dinosaur bones using carbon-14 and have found measurable carbon-14 in samples claimed to be many tens of millions of years old.
How do secular scientists date fossils using absolute time if they cannot date the fossils themselves or the sedimentary rocks they are found in? Let’s assume secular scientists can make reasonable estimates of absolute time, even though we know this is not true. Secular geologists are then able to use these dates to determine an absolute age, or more appropriately, an age range for fossils by using bracketing and/or correlation.
Bracketing a fossil requires something like a volcanic ash bed or a lava flow above and below the layer containing the fossil. The absolute age of the ash or lava is determined with radioisotope dating and is assumed to be correct because they are believed to be from a single igneous event like an eruption of a nearby volcano. The fossil is then assigned an age between the two calculated igneous dates, thereby bracketing the age of the fossil. More often than not, however, there will not be an ash layer or lava flow near the fossils. Then, the geologist must correlate the rocks and fossils in the area of interest with rocks and fossils elsewhere that have ash layers and/or lava flows nearby. In this way, secular scientists can compare (or correlate) bracketed fossils with unbracketed fossils and assign absolute dates to the unbracketed fossils.
Once a fossil is dated this way, secularists assume the same dates for that same fossil found elsewhere. This is another assumption that seems to work in a regional context and in principle at least, but not necessarily globally. The basis for this assumption is the principle of faunal succession, which was established before the concept of absolute time. Nonetheless, as we saw above, all radioisotope dates are suspect due to the long list of assumptions that cannot be verified.
Testing the Accuracy of Absolute Dating Methods
A true scientific test of the validity of radioisotope dating techniques should yield the correct results and also repeatable results. Unfortunately, for these methods neither is the case. Other than the historically verifiable carbon-14 dates that are fairly accurate for the past few thousand years, none of the other radioisotope methods produce accurate or highly repeatable results. These tests invalidate the current methods that geologists use to determine absolute dates.
From Carved in Stone: Geological Evidence of the Worldwide Flood by Timothy Clarey. Copyright © 2020. Published by Institute of Creation Research. All rights reserved. Used with permission.
From 1984 to 1992, Dr. Clarey worked as an exploration geologist at Chevron USA, Inc., developing oil drilling prospects and analyzing assets and lease purchases. He was full professor and geosciences chair at Delta College in Michigan for 17 years before leaving in 2013 to join the science staff at the Institute for Creation Research.