Read Evolution Impossible Online

Authors: Dr John Ashton

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Evolution Impossible (23 page)

BOOK: Evolution Impossible
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To reduce the errors from assumptions 1 to 3, a technique called isochron dating has been developed, whereby ratios of parent and daughter isotopes for different minerals from the same rock sample are calculated and plotted against each other. The age of the rock can then be calculated from the slope of the line. If a good straight-line fit is obtained, the result is considered reliable, and minimal losses of material are assumed. However, the isochron technique does not make the method bulletproof as we still have no way of knowing if other processes, such as the past mixing of younger and older rocks in the molten state, have affected the result. This is well illustrated by the number of cases where isochron dating of the same rock by different isotope methods gives wildly differing ages.

The isotope geology text by G. Faure cites a number of cases. One example is Pleistocene to recent lava dated as less than 1.6 million years old from its position in the rock layers, which has been dated as 773 million years old, using rubidium-strontium dating. Upper Miocene to Pliocene lava was dated at 5 to 9 million years old by potassium-argon dating and dated at 31–39 million years old by rubidium-strontium dating. In another case, lava dated stratigraphically as Pliocene to Holocene, that is, less than 5.3 million years old, gave rubidium-strontium–dated ages of 570 million years and 870 million years. Another Pliocene to Holocene rock was dated as being 1.5 billion years old by the rubidium-strontium method
and a Miocene to Holocene assigned rock (that is, less than 24 million years old) was dated as 1.2 billion years old by the rubidium-strontium method.
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A technical discussion of the assumptions associated with mixing line interpretation of results and other attempts to explain widely differing radioactive dating results on the same rocks is given by research geologist Dr. Andrew Snelling.
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More recently, that is, since 1997, multiple sample isochron dating studies using very careful methods of chemical analysis have yielded similar discordant results. For example, at Somerset Dam in Queensland, Australia, 15 rock samples from a conventionally dated Jurassic-Triassic intrusion (that is, supposedly 216 million years to 225 million years old) gave potassium-argon “model” ages ranging from 183 million years to 252 million years, with an isochron date of 174 million years, yet the error of the dating method was estimated to be only ± 9 million years. When dated by the rubidium-strontium isochron method, an age of 393 million years was obtained. When dated by the samarium-neodymium isochron method, an age of 259 million years was calculated. The lead-lead dating method gave an age of 1,425 million years ± 1,000 million years for the same rock intrusion.
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So how old would you say the intrusion was? 174 million years? 1,425 million years? Some date in between? Or some different date altogether?

Another example is the dating of the Cardenas Basalt in the eastern Grand Canyon in Arizona. The conventional age from previous radiometric dating was 1,103 ± 66 million years. Potassium-argon “model” ages, as dated from radioisotope analyses by the Geochron Laboratories, Cambridge, Massachusetts, ranged from 577 ± 12 million years to 1,013 ± 37 million years, with an isochron method age of 516 ± 30 million years. Ages calculated from radioisotope analyses by the isotope laboratory at the University of Colorado in Boulder, Colorado, gave rubidium-strontium–based isochron ages of 1,111 ± 81 million years for 19 samples and 892 ± 82 million years for 22 samples. Samarium-neodymium measurements from the same laboratory gave a calculated isochron age of 1,588 ± 170 million years, while lead-lead measurements gave an isochron age of 1,385 ± 950 million years.
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So how old is the basalt — 516 million years? 1.588 billion years? Or — you pick an age?

A similar spread of calculated ages was obtained from the very careful dating of 20 or so samples from the Brahma amphibolite rocks near the base of the Grand Canyon. The rubidium-strontium age was 1,240 ± 84 million years, the samarium-neodymium age was 1,655 ± 40 million years and the lead-lead age was 1,883 ± 53 million years.
6
In this case, we have over 600 million years’ difference in the ages calculated for the same rocks.

Another interesting case is the stark contrast between the age of zircon grains in the Jemez granodiorite of New Mexico, which date as 1.5 billion years old by the uranium-lead dating method, and date at only about 6 thousand years old by the uranium-helium diffusion method of dating.
7

There are also examples where rocks of historically known ages record very old dates when dated by radiometric dating. For example, historically recent (that is, only centuries old) lava flows in Hawaii were dated as being up to 3.34 billion years old.
8
Recent historically dated volcanic rocks from the Azores, Tristan da Cunha, and Vesuvius, although known to be only hundreds of years old, dated as ranging from 100 million years old to 10.5 billion years old using uranium-lead dating.
9
Geologists explain away these anomalous dates as representing much older mantle sources of the rock. However, they ignore the implications that this really makes radiometric dating meaningless.

A very careful radiometric dating study of lava flows from the 1949 and 1954 eruptions of the Mount Ngauruhoe volcano on the north island of New Zealand was undertaken in the late 1990s. Two or three rock samples weighing two to three kilograms each were collected from each of the following lava flows: February 11, 1949; June 4, 1954; June 30, 1954; and July 14, 1954, as well as two samples from the February 19, 1975, eruption avalanche deposits. Sub-samples were sent to the PRISE Laboratory in the Research School of Earth Sciences at the Australian National University in Canberra for rubidium-strontium, samarium-neodymium and lead-lead isotopic analyses. The rubidium-strontium isochron gave an apparent age of 133 ± 87 million years; the samarium-neodymium isochron gave an apparent age of 197 ± 160 million years; and the lead-lead isochron gave an apparent age of 3,908 ± 390 million years.
10

If rocks known to be less than 100 years old date as being hundreds of millions of years old and billions of years old, how can we really know the age of any rocks from radiometric dating results? Rocks dating as being hundreds of millions of years old could be any age if, in fact, they are simply reflecting some isotopic mixing of different rock from different parts of the mantle.

Another factor that is assumed is that decay rates have been constant. Some years ago it was suggested that changes in physical pressure can change the rate of decay.
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Also from Einstein’s general theory of relativity, changes in gravity affect the rate of nuclear decay. For example, atomic clocks work on radioactive decay rates. An atomic clock at the National Bureau of Standards in the high altitude mountains of Boulder, Colorado, runs about 5 microseconds faster per year. This is because of the lower gravity at that high altitude, compared to the same atomic clock near sea level at the Royal Observatory in Greenwich, England.

We do not know how gravitational and other forces may have affected the rate of decay in the past. However, we do have geological evidence of accelerated radioactive decay in the past, which also would give the appearance of much greater age to rocks dated by these methods. It includes research scientists’ reports on accumulation and diffusion rates from radioactive decay observed in Precambrian granitic rocks at Fenton Hill in New Mexico. These suggest that hugely accelerated rates of radioactive decay occurred in the recent past, that is, only thousands of years ago.
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Other studies of the comparison of uranium-238 radiohalos and polonium radiohalos in granites and metamorphic rocks have suggested that these particular types of rock signatures must have formed relatively recently as a result of accelerated nuclear decay.
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These findings seriously challenge the validity of the assumption, as used in radiometric dating calculations, that decay rates have been constant for billions of years. It also implies that real ages are going to be very much younger than radiometric dating ages based on long half-life isotopes.
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There are other methodological assumptions that are applied to radiometric dating. These include some scientists’ suggestions that if the radiometric age is not consistent with stratigraphic data, the radiometric date is not reliable.
15
When this criteria is applied, it amounts to a circular reasoning bias, thus raising questions concerning the number of radiometric dates that have not been published because they did not concur with the standard geologic column age, or those perhaps re-dated to fit with widely supported evolutionary theories. For example, a volcanic deposit in Kenya called the KBS Tuff, which was rich in fossils, was originally dated at around 212–230 million years old. However, because this date did not match the fossil record dating, the deposit was re-dated by the same researchers using different samples and a new age of 2.61 million years was obtained.
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However, famous anthropologist Dr. Richard Leakey found a modern-looking human-like skull below the KBS Tuff in a layer that had been dated around 2.9 million years.
17
Primitive tools had also been found in the KBS layer, and there was a lot of interest in determining the date of the KBS Tuff. Fossil horizons similar to those found below the KBS strata studied at the Omo River in Ethiopia had been dated at a much younger 2 million years. A subsequent study by researchers at the University of California, Berkeley, redated the KBS Tuff at a correspondingly younger 1.6 million years.
18

Over the next five years, further dating studies were carried out and the tuff was again re-dated by Australian university researchers. They reported ages of 1.87 million years and 1.89 million years, which were consistent with the estimated age for the mammal fossils on the basis of the evolutionary time scale.
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Dr. J.L. Kulp, professor of geochemistry at Columbia University, who helped collate revised dates for the geological column, proposed that for practical purposes the half-life of the radioisotope system chosen must be the same order of magnitude as the time span to be measured. He suggested that for ancient rocks, isotopes with half-lives of hundreds of millions of years should be chosen.
20
Assuming the age of the rock initially probably influences the result somewhat and again may introduce a bias. For example, following this principle, coal and diamonds, which are essentially carbon in different forms, would never be analyzed by carbon-14 dating. This is because they generally are assumed to be hundreds of millions of years old and out of the range of carbon-14 with its half-life of only 5,730 years.

Life on earth is based on compounds made from carbon-12. Plants in particular have a high carbon content and, when fossilized, can form coal. Plants get their carbon from carbon dioxide gas that forms a small percentage of the earth’s atmosphere. Atomic particles called neutrons, which result from cosmic rays’ interactions in the upper atmosphere, sometimes knock out a proton from the common nitrogen-14 atoms, transmuting a small number of them into radioactive carbon-14 atoms. Only about one carbon atom in a trillion carbon atoms is radioactive. These atoms subsequently emit a beta particle (electron), decaying back into nitrogen-14 atoms over time.

While plants and animals are alive they have essentially the same ratio of carbon-14 to carbon-12 as found in the atmosphere. (There is also a small percentage, approximately 1 percent, of carbon-13 atoms that are stable like carbon-12.) However, when plants or animals die and are buried, they cease to exchange carbon-14 with the atmosphere, and the level of carbon-14 slowly decreases as per the earlier decay formula. Consequently, after around 5,730 years, only about half as much carbon-14 would be expected. It follows that if a sample analyses tests as only having half as much carbon-14, it would be said to have an age of around 5,700 years. However, this assumes that the carbon-14 content of the atmosphere remains constant over time, and we have already seen that this is dependent on whether or not the flux of cosmic rays reaching the earth has been constant in the past. Cosmic rays are made up of high-energy protons that are positively charged, hence their impact on the atmosphere is affected by the earth’s magnetic field. Cosmic ray intensities from the solar system and outer space may have varied considerably in the past, and the earth’s magnetic field has also varied significantly in the past. For example, the earth’s magnetic dipole moment has decreased 6.5 percent since the year 1900.
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If cosmic ray activity was lower at times in the past, measurements made at the present time would give much greater ages than their real age.

The accurate measurement of the ratio of carbon-14 to carbon-12 was also problematic up until the early 1980s when accelerator mass spectrometer (AMS) methods became available.

In the late 1990s, Australian research geologist Dr. Andrew Snelling had a number of fossilized wood samples from strata conventionally dated as being from 40 million to 250 million years old, according to the geologic column. However, the carbon-14 dating ages, as determined by a commercial dating laboratory using AMS technology, gave ages ranging from 20,700 ± 1,200 years and 44,700 ± 950 years.
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