“On this fundamentally important question [the age of the Earth], the Natural History Museum and all other modern authorities are in complete agreement. The Earth is 4,600 million years old. What is more, different periods of the Earth’s history have been characterized by the formation of different kinds of rock containing the fossil remains of distinctive kinds of creature. These different periods have also been dated to give what is usually referred to as the Geological Column of the Earth’s history.
…By referring to the geological column anyone can tell the age of a rock or fossile that he or she finds. For instance, England’s white cliffs consist of chalk dating from the end of the Cretaceous period, which the column tells us, dates from 65 million years ago.
The dates attached to the geological column have been arived at and refined over the past century or so. The most recent evaluation, and the one quoted in Natural History Museum publications, is that of Van Eysinga published in 1975. This scheme…is closely similar to that used in most museums and universities since the early decades of century…
When I began to research this question a little more closely I uncovered a puzzle. Those experts I referred to and the authoritative textbooks I consulted all told me that modern dating has been accomplished by using radioactive methods and hence was an absolute dating method of a far higher order of accuracy than all previous methods–most of which relied on calculations involving one or more relative factors. These relative dating methods had relied on such factors as the increasing salinity of the oceans, or the Earth’s rate of cooling, and are now considered unreliable. Radioactive dating, though, is used to date the rocks and the fossils they contained directly and hence was welcomed as an absolute method.
The puzzle arrises because radioactive dating techniques can be applied only to volcanic rocks that contain some radioactive mineral-the primary rocks of the Earth’s crust. But the geological column consists of sedimentary rocks–rocks formed from sediments laid down on the beds of ancient seas and composed of particles of those primary rocks. So, of course, any age determination made using these particles will be the same as that of the primary rocks from which they were derived. In some common sedimentary rocks, such as chalk or limestone, there are not even particles of the primary rocks present and so radioactive dating cannot be used at all. Happily for English men and women, the white cliffs of Dover are not radioactive.
In The Age of the Earth published by the Institute of Geological Sciences, the position is succinctly explained by John Thackray:
The only sediments which can be dated directly are those in which a radioactive mineral is formed during diagenesis [laying down] of the sediment, such as the rather uncommon illite shales and glauconitic sandstones, other sediments give only the age of the parent rock from which the mineral grains that make them up are derrived.
How then did [scientists] arrive at the dates attached to the sediments of the geological column?
The Institute of Geological Sciences explains:
Where lavas or volcanic ashes are interbedded with a sediment of known stratigraphic age, then a date may be given to that stratigraphic division. Where an igneous rock intrudes one sedimentary unit and is blanketed by another, then the sediments may be dated from the igneous rock by inference. The rarity of such cases, together with analytical error inherent in age determination, mean that isotropic ages are unlikely to rival or replace fossils as the most important method of …correlation.
It turns out that what has been dated by radioactive decay methods is not the sedimentary rocks or fossils themselves but the isolated intrusion into them of igneous or primary rocks, usually as volcanic material. This has been a rare and purely fortuitous process and one that is unreliable–so rare and so unreliable that the Institute of Geological Sciences thinks it unlikely to replace or even rival fossils as a method of dating. Nor is this all, for the method depends in turn on a further chain of inference. For the geological column…is nowhere to be found in nature. It is an imaginary structure that has been synthesized from comparing a stratum of rock in one part of the world with a similar looking stratum in another part of the world.
… [W]hen Darwinists speak of absolute dating of the geological column and the fossils it contains by radioactive methods they are quite mistaken, there is nothing absolute about it. In fact the method ought to be referred to as “comparative dating,” because it dates the sedimentary rocks by inference alone thorugh their relationship to the rare samples of igneous or primary rocks that are being dated.
When I pursued this question a little further, I found that there is in reality another factor that has been used to arrive at the age of the geological column and the fossils it contains–conjecture. This process crept into geological dating at a very early stage when Charles Lyell, the nineteeth century’s most prominent geologist and Darwin’s mentor in geological matters, attempted to date the end of the Cretaceous period by reference to how long he thought it would have taken the shellfish (whose fossils are found in later beds) to have evolved into their modern descendants. Lyell estimated that the Cretaceous ended 80 million years ago–not too far from today’s accepted figure of 65 million, plus or minus 3 million.
According to Harold Levin of Washington University, “By comparing the amount of evolution exhibited by the marine molluscs in the various series of the Tertiary System with the amount that had occurd since the beginning of the Pleistocene Ice Age, Lyell estimated that 80 million years had elapsed since the beginning of the Cenozoic.”
Levin adds that, “He came astonishingly close to the mark.” In fact, it is not at all astonishing when you know that today’s accepted date has been derived not from an absolute, independent source but from conjectures including Lyell’s [emphasis added].
The kind of surmise used to supplement the relative dates yielded by radioactive dating includes assumptions about the rates at which sediments are laid down on the bottoms of lakes, seashores, and ocean floors; estimates of the rates at which forests are turned into coal deposits; and estimates of the rates at which certain very long-lived families of creatures might have evolved. But although these conjectures are embodied in the modern view of the age of geological deposits, they are rarely if ever disclosed in geological or biological textbooks, and they are rarely exposed to debate.
Curiously, too, no geologist seems to have checked out the geological column dates with an electronic calculator on a common-sense basis. …[T]here is a remarkable consistency between assigned age and thickness of deposit. For instance the Cretaceous period is said to have lasted 65 million years and is 15,000 meters thick–an average annual rate of deposition of 0.2 millimeters. Now look at the Silurian period: this, too, yields an average rate of deposition of about 0.2 milimeters per year–as does the Ordovician, the Devonian, the Carboniferous, and the rest. It is only when we come to relatively modern times in the Cenozoic era that the rates of deposition very much, and here they appear to speed up slightly.
This is a very remarkable finding. One naturally expects Uniformitarian geology to favor uniformity, but this is too much of a good thing. Throughout widely changing climactic conditions, advancing and retreating oceans, droughts, and Ice Ages, the rate of sedimentation appears to remain amazing constant regardless–through the thousands of millions of years that are said to have elapsed. …[I]t is worth pausing in passing to note that such a slow rate would be quite incapable of burying and fossilizing entire forests, dinosaurs, or even a medium-sized tadpole.
…
Darwin and his supporters realized at an early stage that their theory demanded vast reaches of geological time to support the supposed microscopic changes in form from one generation to antoher. Equally, evolutionists stood in need of a geological basis for this great antiquity–a mechanism that worked slowly and gradually rather than one that worked suddenly and all at once [catastrophism]. They rejected catastrophism and instead found the mechanism they sought in an idea taking shape among the new generation of secular geologists who asserted that sedimentary rocks (that is, fossil-bearing rocks) were formed slowly by the same processes that can be seen on the ocean bottom today: the deposition of silt and sand that becomes cemented and compacted over millions of years to form successive strata of rock.
Under the reassuring-sounding label of uniformitarianism these ideas were actively promoted by secular geologists like James Hutton and later Charles Lyell…Â The uniformitarian doctrine is summed up in the famouse phrase “the present is the key to the past”–a concept eagery accepted by Darwinists as ready-made for their theory and one expounded on at length in Lyell’s Principles of Geology, the primary geological work of the century, published between 1824 and 1833.
The important point to note here is that it was the imperative need for great antiquity that deposed catastrophism, rather than any new scientific discoveries or observations; it was a new way of looking at things, not a new piece of knowledge. But, superficially, that change in view seemed to be a shift away from naive belief in biblical tales of creation and flood, and toward a newly established scientific viewpoint….
Darwinists needed time, and lots of it: unformitarians had the geological theory that demonstrated great antiquty. Geologists needed a firm foundation for the relative dating and correlation of the many sediments piled on on another in the past–the many strate of the geological column: Darwinists were able to supply the key to the stratigraphical succession of the rocks by comparative anatomy of the fossils contained in those strata, interpreted along evolutionist lines. Thus an unusual academic interdependence sprang up between the two sciences that continues to this day. A geologist wiwshing to date a rock stratum would ask an evolutionist’s opinion on the fossils it contained. An evolutionist having difficulty dating a fossil species would turn to the geologist for help. Fossils were used to date rocks: rocks were used to date fossils [emphasis added].
A modern example of paleantologists using fossils to date rocks in a circular way is provided by one of the most famous of all North American dinosaur discovery sites: the rocks at Como Bluffs, Wyoming. …
Of the site, Robert Bakker says:
…We don’t have radioactive beds that can give us a nice hard number [on the age of the deposit]. But by comparing the fossils we get at the bottom of the section and at the top, it’s about 10 million years. So all of this history is played out roughly over about 2 million dinosaur generations, 10 million chronological years.
Ironically, not only is there no radioactive basis for the dating of Como Bluffs, there is, as Robert Bakker says [elsewhere], not even a complete history of a single dinosaur family at the stie. Yet we are given the confident assertion concerning the number of dinousaur generations and the number of years to which this sequence is equivalent, with no solid physical basis. No other scientific discipline would be permitted even to consider such procedures, but when paleontologists date rocks by means of fossils, they do so with the authority of Charles Darwin himself.
Milton, Richard (1992, 1997). Shattering the Myths of Darwinism, Rochester, Vermont: Park Street Press (pp. 19-23; 27-29)
By the way, I might add that when it comes to the age of the Earth, I agree with him. I do not believe the Bible requires only a few thousand years for the age of the Earth; on the other hand, there are some problems with some of the dating methods regarding rocks. (Note: measurements in astronomy seem more accurate; but that would only give us the age of the universe as a whole and not the Earth in particular.)
