Radiometric Dating: How Rocks Can Look Older Than They Are

Researchers find that the most common dating method can produce “spuriously old” dates.

A team from Europe took a closer look at how uranium-lead ages are determined, and found problems. One of the assumptions going into dating zircons (zirconium silicate crystals encasing uranium that decays to lead) is that the clock is “reset” when the parent rock under goes the high heat and pressure of metamorphism. This team found that nanosphere inclusions of extraneous metallic lead (Pb) can confuse the dating technique, making the rock look older than it is. Writing in PNAS, they say:

Zircon (ZrSiO₄) is the most commonly used geochronometer, preserving age and geochemical information through a wide range of geological processes. However, zircon U–Pb geochronology can be affected by redistribution of radiogenic Pb, which is incompatible in the crystal structure. This phenomenon is particularly common in zircon that has experienced ultra-high temperature metamorphism, where ion imaging has revealed submicrometer domains that are sufficiently heterogeneously distributed to severely perturb ages, in some cases yielding apparent Hadean (>4 Ga) ages from younger zircons.

The paper provides what they feel are safeguards to prevent erroneous dates. It appears, however, that this finding overthrows common assumptions used in the dating technique.

The reliability of the oldest zircon ages, which include some reversely discordant analyses (i.e., with U–Pb ages older than ²⁰⁷Pb/²⁰⁶Pb ages), has been questioned based on evidence from ion imaging for disturbance of the U–Pb system. This is important because ²⁰⁷Pb/²⁰⁶Pb ages are generally considered to be more robust than U–Pb ages for older zircons. However, if radiogenic Pb has been decoupled from its parent U and not locally incorporated into the crystal lattice during an ancient geological event, when radiogenic ²⁰⁷Pb/²⁰⁶Pb values are significantly higher than at present, reverse discordance and spuriously old ²⁰⁷Pb/²⁰⁶Pb age estimates may result.

In other words, the more lead in the crystal (“decoupled from its parent U”), the more a scientist might infer that it is billions of years old, when some of that lead got mixed in when a younger rock underwent metamorphism.

In the ICR publication Acts & Facts, Dr. Vernon R. Cupps has been publishing a detailed analysis of how results can be corrupted in radiometric dating. He has shown numerous ways that deceptively old dates can be produced, depending on the assumptions used. The mathematical techniques are sound, but like with computer programs, wrong assumptions can make for garbage-in, garbage-out conclusions. Those interested may wish to study this new PNAS paper to see how often this problem occurs in practice.

Feel free to think what you wish, and to inhabit a world of your imagination in which everything that exists somehow spontaneously arose from time + chance + matter. I would suggest that this is the height of irrationality.

There is a reason why poll after poll shows that after a generation of indoctrination in public schools and throughout our culture, viz, that “macro-evolution is true: discussion over,” only a distinct minority of respondents believe that natural processes are sufficient to account for the universe and all there is in it. It is self-evident that some wondrously great Intelligence stands behind the astounding level of design evident throughout creation.

The insistence that, like everything else, God must have a cause betrays a false premise: that God is a contingent being like His creation. You first accept your presupposition as true, then smugly conclude that people of faith are hopelessly in error because they do not accept your conclusion. That is known as circular reasoning. You have rejected the eternality of God in favor of the eternal, unchangeable nature of Father Time.

Similarly, atheist Richard Dawkins argues that an even more sophisticated Being must exist to have created the God who created this universe, and so on ad nauseam throughout eternity. But this argument only stands when one fundamentally redefines the nature of God and then attacks their self-defined caricature.

The Judeo-Christian worldview holds that unlike His creation, God does not exist within, nor is He bound by, the space-time continuum. He stands eternally apart from His creation and all the space-time limitations inherent within the physical universe.

You describe yourself as “agnostic”: I suspect that you use that appellation rather than “atheist” because you realize the untenability of confidently asserting that God does not exist. If true, you would be well advised to be open to the reality of God without first insisting that “God” conforms to your preconceptions.

Long ago the agnostic Herbert Spence dismissed belief in God: “Man has never been known to fly into the heavens to discover God.” Unfortunately, he did not consider the other possibility, that the personal-infinite God has reached down from Heaven to reveal Himself to humankind. That, I would suggest, is precisely what happened, and furthermore that His wonderful acts are recorded in the Bible.

You might try what many others have done, with life-transforming results: set aside your preconceptions and offer the simple, heartfelt prayer: “God, if you exist, please reveal yourself to me.” Why not give it a try?

I quoted you when you said everything needed a cause. I took you at your word; I promise, I’ll never do that again.

Your supposition that sufficiently complex things require a designer, to paraphrase, means that the Designer, itself a very complex entity, must also require a meta-designer. The logic is inescapable and yet, you call foul when I point out this obvious conclusion.

There is nothing in conflict in accepting both a Big Bang and a Creator but it’s, thankfully, not my job to bring you to this also obvious conclusion. And no, I’m not interested in reading more cut-and-paste apologetics.

RE: If something is really 100 million years old, instead of 200 million years old, it still invalidates the Creation timeline.

You are half right. It’s true that cutting 100 million years in half wouldn’t fit a Biblical time frame.

The problem for me lies in your last sentence: “If something is really 100 million years old.…”

How would someone ever know that, without trusting in an indirect dating method? No human ever experienced a million years, let alone a hundred million. Over and over, we have seen “unknown unknowns” arise that cast doubt on widely-trusted radiometric dating methods.

This article reported a recent case, where scientists were misled by assuming they knew how much daughter material was present when the clock started. What other unknown unknowns and unknowable unknowns are there?

I would suggest we not put false confidence in things they cannot know about initial conditions and processes.

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