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RADIOACTIVE AGE ESTIMATION METHODS—Do they prove the earth is billions of years old?

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How old is planet Earth? There are enormous differences of opinion. The most common view is that Earth is approximately 4.5 billion years old.1 Others say it is older or younger. The lowest age defended on a scientific basis is in the 6 to 10 thousand year range. Evolutionism, of course, requires billions of years to support the plausibility of life's emergence and of subsequent Evolution from “amoeba” to man. Theoretically, Creationism remains workable within a wide range of age estimates.

Scientists have proposed numerous age estimation methods. Most systems promoted by Evolutionists involve radioactivity. Various radioactive elements are involved, including Carbon-14, Uranium-238, Thorium-232, and Potassium-40. By the way, it is important to understand that most rock strata “dates” were actually assigned long before the first use of radioactive age estimating methods in 1911.2

The Carbon-14 age estimating method is, at best, only useful for estimating the age of things that are thousands of years old, not millions or billions. And it does not work on rocks or thoroughly mineralized fossils; it is only useful for relatively well-preserved organic materials such as cloth, wood, and other non-fossilized materials. Other methods must be used to estimate the age of rocks and minerals. Two of the most widely-known systems are the potassium-argon method and the uranium-lead method.

A radioactive form of potassium is found in minute quantities in some rocks. It disintegrates at a measured rate into calcium and argon. Similarly, the radioactive element uranium decomposes into lead and some other elements.

How are these processes used to estimate the age of rocks? The principle is similar to that used with Carbon-14. The speed of the disintegration process is measured. A portion of the material is ground up and a measurement is made of the ratio of radioactive “parent” atoms to the decomposition products.

Age estimates which are obviously wrong or contradictory are sometimes produced.3 For example, new rock in the form of hardened lava flows produced estimated ages as great as 3 billion to 10.5 billion years, when they were actually less than 200 years old.4

A popular and supposedly foolproof method was used on two lava flows in the Grand Canyon that should be ideal for radioactive age estimation. The results were similarly bad. Young basalt rock at the Canyon's top produced an age estimate 270 million years older than ancient basalt rock at the Canyon's bottom. The problem seems to arise from basic wrong assumptions in the method (rubidium-strontium isochron). If such a sophisticated method is so flawed, geologist Dr. Steven Austin rightly wonders, "Has anyone successfully dated a Grand Canyon rock?"5

Assumptions and More Assumptions

Arriving at a “date” depends upon a chain of assumptions,6 each link in the chain being an assumption. The validity of the calculated date can be no stronger than the weakest link (weakest assumption) used in the calculation. What are some of the assumptions made by most Evolutionists in using these systems?

  • ASSUMPTION: Evolutionists generally assume the material being measured had no original “daughter” element(s) in it, or they assume the amount can be accurately estimated. For example, they may assume that all of the lead in a rock was produced by the decay of its uranium.

    PROBLEM: One can almost never know with absolute certainty how much radioactive or daughter substance was present at the start.

  • ASSUMPTION: Evolutionists have also tended to assume that the material being measured has been in a closed system. It has often been wrongly assumed that no outside factors altered the normal ratios in the material, adding or subtracting any of the elements involved.

    PROBLEM: The age estimate can be thrown off considerably, if the radioactive element or the daughter element is leached in or leached out of the sample. There are evidences that this could be a significant problem.7 Simple things such as groundwater movement can carry radioactive material or the daughter element into or out of rock. Rocks must be carefully tested to determine what outside factors might have changed their content.

  • ASSUMPTION: They assume that the rate of decomposition has always remained constant - absolutely constant.8

    PROBLEM: How can one be certain that decay rates have been constant over billions of years? Scientific measurements of decay rates have only been conducted since the time of the Curies in the early 1900s. Yet Evolutionists are boldly making huge extrapolations back over 4.5 billion years and more. There is some evidence that the rate of radioactive decay can change.9 If the decay rates have ever been higher in the past, then relatively young rocks would wrongly “date” as being old rocks.

Evolutionist William Stansfield, Ph.D., California Polytech State, has stated:

"It is obvious that radiometric techniques may not be the absolute dating methods that they are claimed to be. Age estimates on a given geological stratum by different radiometric methods are often quite different (sometimes by hundreds of millions of years). There is no absolutely reliable long-term radiological 'clock'."10

Evolutionist Frederick B. Jueneman candidly summarizes the situation:

"The age of our globe is presently thought to be some 4.5 billion years, based on radio-decay rates of uranium and thorium. Such 'confirmation' may be shortlived, as nature is not to be discovered quite so easily. There has been in recent years the horrible realization that radio-decay rates are not as constant as previously thought, nor are they immune to environmental influences. And this could mean that the atomic clocks are reset during some global disaster, and events which brought the Mesozoic to a close may not be 65 million years ago, but rather, within the age and memory of man."11

References and Endnotes


  • EVOLUTIONARY AGE OF THE EARTH. The current age estimate accepted by most Evolutionists for the Earth and our solar system is 4.54 billion years, plus or minus 0.02 billions years. What is this based on? This estimate was deduced from the ratios of different lead isotopes found in meteorites, Moon rocks, and Earth rocks. By other means, the oldest age estimate, to date, for an Earth rock is 3.96 billion years (Slave Province, Canada). The oldest age estimate for a meteorite is 4.6 billion years.

    "The best value for the age of the earth is based on the time required for the isotopic composition of lead in the oldest (2.6-3.5 b.y.) terrestrial ores, of which there are currently only four [235U to 207Pb to 238U to 206Pb], to evolve from the primordial composition, recorded in meteoritic troilite, to the composition at the time (measured independently) the ores separated from their parent rocks in earth's mantle. These calculations result in ages for the earth of 4.42 to 4.56 b.y. with a best value of 4.54 b.y."

    [List of methods used to arrive at old-age estimates]


    "The age of the universe has been estimated by astronomers from the velocity and distance of other galaxies as they recede from earth's perspective in the expanding universe. These estimates range from 7 to 20 b.y., depending on whether the expansion is considered to be constant or slowing due to gravitational attractions of galaxies to each other."

    [G. Brent Dalrymple, "So How Old Is the Earth, Anyway?," NCSE Reports, Volume 11, No. 4 (Winter 1991), pp. 17., also see: G. Brent Dalrymple, The Age of the Earth (Stanford: Stanford University Press, 1991).]


  • These pre-1911 “dates” were based on Evolutionary, uniformitarian presuppositions. Evolutionists have since attempted to lend increased credibility to these assumptions by use of radiometric dating (which, of course, is also based on uniformitarian presuppositions - as shall be shown).



  • The uranium-lead dating method has produced so many anomalous readings that it has fallen into disrepute, even among Evolutionists.

  • "It should be noted that dates (absolute dates) obtained by different methods [radioactive dating methods] commonly show some discrepancies… As the Committee on the Measurement of Geological Time said in 1950, 'These figures (i.e. dates) are, as railway timetables say, subject to change without notice.'" (p. 378)

    [D.G.A. Whitten and J.R.V. Brooks, The Penguin Dictionary of Geology (Middlesex, England: Penguin Books, 1972), 520 pp. (emphasis added).]

  • Robert H. Brown, "Graveyard Clocks: Do They Really Tell Time?", Signs of the Times (June 1982), pp. 8-9.

  • John Woodmorappe, “Radiometric Geochronology Reappraised,” Creation Research Society Quarterly, Vol. 16 (September 1979), pp. 102-129.

  • Randy L. Wysong, The Creation-Evolution Controversy (Midland, Michigan: Inquiry Press, 1976), pp. 154-156.


  • John G. Funkhouser, et al., "The Problems of Dating Volcanic Rocks by the Potassium-Argon Methods," Bulletin Volcanologique, Vol. 29 (1966), p. 709.

  • John G. Funkhouser and John J. Naughton, "Radiogenic Helium and Argon in Ultramafic Inclusions from Hawaii," Journal of Geophysical Research, Vol. 73, No. 14 (July 15, 1968), pp. 4601-4607 (especially p. 4606) (volcanic eruption of 1800 on Hualalai Island, Hawaii, produced rocks which falsely “dated” 160 million to 3 billion years).

  • C. Noble and John J. Naughton, "Deep-Ocean Basalts: Inert Gas Content and Uncertainties in Age Dating," Science, Vol. 162 (October 11, 1968), p. 265.

  • William Laughlin, "Excess Radiogenic Argon in Pegmatite Minerals," Journal of Geophysical Research, Vol. 74, No. 27 (December 15, 1969), p. 6684.

  • Sidney P. Clementson, "A Critical Examination of Radioactive Dating of Rocks," Creation Research Society Quarterly, Vol. 7, No. 3 (December 1970), pp. 137-141.


  • The two lava flows are the western Grand Canyon lava flows (basalt, 1.34 0.04 billion years) and the Precambrian Cardenas Basalt (1.07 0.07 billion years).

    [Steven A. Austin, "Excessively Old 'Ages' for Grand Canyon Lava Flows," Impact, No. 224 (Santee, California: Institute for Creation Research, February 1992), 4 pp.; "Grand Canyon Lava Flows: A Survey of Isotope Dating Methods," Impact, No. 178 (Santee, California: Institute for Creation Research, April 1988), 4 pp.]

Assumptions and Problems of Radioactive Methods


  • Radiochronologists must make certain basic assumptions about the rocks they “date”, assumptions about their total past environment, formation, and radioactive decay rates. However, Creationist Dr. Duane Gish claims:

    "Radiochronologists must resort to indirect methods which involve certain basic assumptions. Not only is there no way to verify the validity of these assumptions, but inherent in these assumptions are factors that assure that the ages so derived, whether accurate or not, will always range in the millions to billions of years (excluding the carbon-14 method, which is useful for dating samples only a few thousand years old)."

    [Duane T. Gish, Evolution: The Fossils Say No!, 3rd edition (Santee, California: Master Books, 1979), p. 63 (emphasis added).]

  • Also, see: John D. Morris, The Young Earth (Colorado Springs, Colorado: Master Books, 1994), pp. 52-62.

  • Physicist Donald DeYoung, Ph.D.:

    "The different methods of radiometric dating, when checked against each other, often are in approximate agreement. If the results are misinterpreted as to age, as proposed here, then a common unknown factor (a measurement or an assumption which is defective) may be perturbing all the age values to a longer apparent age than actual. Another explanation in some isolated cases of dating conclusions may be a 'tracking phenomenon.' By this is meant, a tendency of reported scientific measurements to cluster about an incorrect value. Researchers are often reluctant to report findings too far different from previous results in their published findings. This clustering effect shows up in reports of nuclear half-life determinations, and it may also rule the 4.5 billion year assumed history of the earth and moon."

    [John C. Whitcomb and Donald B. DeYoung, The Moon: Its Creation, Form and Significance (Winona Lake, Indiana: BMH Books, 1978), p. 102 (emphasis added).]

Leaching and contamination


  • U.S. Geological Survey:

    "…As much as 90 percent of the total radioactive elements of some granites could be removed by leaching the granulated rock with weak acid…as much as 40 percent of the uranium in most fresh-appearing igneous rocks is readily leachable."

    [M.R. Klepper and D.G. Wyant, Notes on the Geology of Uranium, U.S. Geological Survey Bulletin No. 1046-F (1957), p. 93 (emphasis added).]

  • John C. Whitcomb, Jr. and Henry M. Morris, The Genesis Flood (Philadelphia: Presbyterian and Reformed Publishing Company, 1961), pp. 335-340.

Decay Rate Changes


  • This most basic assumption is evidenced in the statement of Evolutionists Dott and Batten:

    "Neither heating nor cooling, changes in pressure, nor changes in chemical state can affect in any detectable way the average rate of spontaneous decay. Because the rate cannot be artificially changed in the laboratory, it is assumed that it always has been uniform for a given isotope."

    [R.H. Dott and R.L. Batten, Evolution of the Earth (New York: McGraw Hill, 1971), p. 99 (emphasis added).]

  • Geologist Andrew Snelling:

    "It is special pleading on the part of geochronologists and physicists to say that the radioactive decay rates have been carefully measured in laboratories for the past 80 or 90 years and that no significant variation of these rates has been measured. The 'bottom line' is really that 80 or 90 years of measurements are being extrapolated backwards in time to the origin of the earth, believed by evolutionists to be 4.5 billion years ago. That is an enormous extrapolation. In any other field of scientific research, if scientists or mathematicians were to extrapolate results over that many orders of magnitude, thereby assuming continuity of results over such enormous spans of unobserved time, they would be literally 'laughed out of court' by fellow scientists and mathematicians. Yet geochronologists are allowed to do this with impunity, primarily because it gives the desired millions and billions of years that evolutionists require, and because it makes these radioactive 'clocks' work!"

    [Andrew A. Snelling, "Radioactive Dating Method 'Under Fire'!, " Creation: Ex Nihilo, Vol. 14, No. 2 (Answers in Genesis, March-May 1992), p. 44 (emphasis added).]

Documentation of Decay Rate Changes

Researchers have also pointed out various reasons why small changes in decay rates in modern laboratory work would tend to be overlooked.


  • Theodore W. Rybka, "Consequences of Time Dependent Nuclear Decay Indices on Half Lives," Acts & Facts, ICR Impact Series, No. 106, (El Cajon, California: Institute for Creation Research, April 1982).

  • Geochimica et Cosmochimica Acta, Vol. 35 (1971), pp. 261-288, and Vol. 36 (1972), p. 1167. (Includes data indicating that different radioactive dating methods used on volcanic rock on Reunion Island in the Indian Ocean gave results varying from 100 thousand to 4.4 billion years. Results from different methods were contradictory.)

  • Donald B. DeYoung, “A Variable Constant,” Creation Research Society Quarterly, Vol. 16, No. 2 (September 1979), p. 142, and "The Precision of Nuclear Decay Rates", Creation Research Society Quarterly, Vol. 12, No. 2 (March 1976), pp. 38-41. (The latter lists half-life decay variation in 20 radioactive isotopes, including Carbon-14, and variations up to 5%).

  • K.P. Dostal, M. Nagel, and D. Pabst, "Variations in Nuclear Decay Rates," Zeitschrift fur Naturforschung, Vol. 32a (April 1977), pp. 345-361.

  • P.A. Catacosinos, "Do Decay Rates Vary?", Geotimes, Vol. 20, No. 4 (1975), p. 11.

  • J. Anderson and G. Spangler, "Radiometric Dating: Is the 'Decay Constant' Constant?", Pensee, Vol. 4 (Fall 1974), p. 34.

  • Harold L. Armstrong, "Decay Constant: Really Constant?", Creation Research Society Quarterly, Vol. 11, No. 1 (June 1974).

  • W.K. Hensley, W.A. Basset, and J.R. Huizenga, "Pressure Dependence on the Radioactive Decay Constant of Beryllium-7," Science, Vol. 181 (September 21, 1973). (Documents that the radioactive decay rate of Beryllium-7 varies with pressure).

  • J.L. Anderson, "Non-Poisson Distributions Observed During Counting of Certain Carbon-14 Labeled (Sub) Monolayers," Journal of Physical Chemistry, Vol. 76, No. 4 (1972). (Shows that the decay rate of Carbon-14 is influenced by the local atomic environment.)

  • G.T. Emery, "Perturbation of Nuclear Decay Rates," Annual Review of Nuclear Science, Vol. 22 (1972), pp. 165-202 (Shows that many radioactive elements, including Carbon-14 and Uranium-235, have had their decay rates altered in the laboratory.)

  • J.L. Anderson, Abstracts of Papers for the 161st National Meeting, Los Angeles (American Chemical Society, 1971).

  • SOME FEEL THIS PRECLUDES THE POSSIBILITY OF ACCURATE RADIOMETRIC DATING: See: A.F. Kovarik, "Calculating the Age of Minerals from Radioactivity Data and Principles," Bulletin #80 of the National Research Council (June 1931), p. 107.

  • A unique study in regard to evidence of changing radioactive decay rates is being made by Robert Gentry (formerly associated with Oak Ridge National Laboratories, Atomic Energy Commission). Dr. Gentry believes the measurements of ancient radiohalos provide possible evidence of past rate variation. These halos are permanently etched into certain crystallized minerals and were caused by the energy released by the disintegration of the radioactive atom at their center. Dr. Gentry measured and compared the radiohalos in various rocks and discovered what appear to be significant variations in the measured ring diameters. This may indicate that radioactive decay rates have changed. However, measurement uncertainty in the tiny radiohalo diameters may preclude any definitive statement on this matter.

    John D. Morris, The Young Earth (Colorado Springs, Colorado: Master Books, 1994), pp. 62-64

    Robert H. Brown, "Radiohalo Evidence Regarding Change in Natural Process Rates," Creation Research Society Quarterly, Vol. 27, No. 3 (December 1990), pp. 100-102

    Robert V. Gentry, "Critique of 'Radiohalo Evidence Regarding Change in Natural Process Rates'," Creation Research Society Quarterly, Vol. 27, No. 3 (December 1990), pp. 103-105

    Robert H. Brown, Harold G. Coffin, L. James Gibson, Ariel A. Roth, and Clyde L. Webster, “Examining Radiohalos,” Origins, Vol. 15, No. 1 (Loma Linda, California: Geoscience Research Institute, Loma Linda University, 1988), pp. 32-38 (Creationists suggest problems with some aspects of Gentry's interpretations)

    Dennis Crews, "Mystery in the Rocks," The Inside Report (October/November 1987), pp. 3-6, (January 1988), pp. 3-6, (March/April 1988), pp. 3-10 (Provides an interesting account of Gentry's research - described in layman's language)

    Robert V. Gentry, Creation's Tiny Mystery, 2nd edition (Knoxville, Tennessee, 37912-0067: Earth Science Associates, 1988), 347 pp.

    Paul D. Ackerman, It's a Young World After All (Grand Rapids, Michigan: Baker Book House, 1986), pp. 101-110 (easy layman-type explanation)

    Jim Melnick, "The Case of the Polonium Radiohalos," Origins Research, Vol. 5, No. 1 (1982), pp. 4-5.

General Problems with Radioactive Dating Methods

  • John D. Morris, The Young Earth (Colorado Springs, Colorado: Master Books, 1994).

  • Henry M. Morris and John D. Morris, Science, Scripture, and the Young Earth (El Cajon, California: Institute for Creation Research, 1989), pp. 39-52.

  • Russel Arndts and William Overn, Isochron Dating and the Mixing Model (Minneapolis: Bible-Science Association, 1983), 36 pp.

  • Randal L.N. Mandock, Scale Time Versus Geologic Time in Radioisotope Age Determination, Master of Science Thesis (Santee, California: Institute for Creation Research Graduate School, August 1982), 160 pp.

  • Henry M. Morris, editor, Scientific Creationism, General Edition (Santee, California: Master Books, 1974), pp. 131-149.

  • Sidney P. Clementson, "A Critical Examination of Radioactive Dating of Rocks," Creation Research Society Quarterly, Vol. 7 (December 1970), pp. 137-141.

  • Melvin A. Cook, Prehistory and Earth Models (London: Max Parrish and Co., 1966), pp. 23-72 (includes suggestion that most of the “radiogenic” lead in Earth's crust could have been produced by capture of free neutrons in the vicinity).


  • William D. Stansfield, The Science of Evolution (New York: Macmillan Publishing Co., 1977), p. 84.

  • William D. Stansfield: Evolutionist / Ph.D. / Biology Department, California Polytechnic State University.


  • Frederic B. Jueneman, “Secular Catastrophism,” Industrial Research and Development, Vol. 24 (June 1982), p. 21.

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