One of the most fundamental principles of archaeology is the Law of Superposition. The law states that strata that are younger will be deposited on top of strata that are older, given normal conditions of deposition. This law is the guiding principle of stratigraphy, or the study of geological or soil layers. Stratigraphy is still the single best method that archaeologists have for determining the relative ages of archaeological materials. James Hutton and William Smith advanced the concept of geologic time and strengthened the belief in an ancient world. Hutton, a Scottish geologist, first proposed formally the fundamental principle used to classify rocks according to their relative ages. He concluded, after studying rocks at many outcrops, that each layer represented a specific interval of geologic time. Further, he proposed that wherever uncontorted layers were exposed, the bottom layer was deposited first and was, therefore, the oldest layer exposed; each succeeding layer, up to the topmost one, was progressively younger. The Major Divisions of Geologic Time are shown here, arranged in chronological order with the oldest division at the bottom, the youngest at the top. Stratigraphy is the study of strata, or layers.
Radiometric dating is a means of determining the “age” of a mineral specimen by determining the relative amounts present of certain radioactive elements. By “age” we mean the elapsed time from when the mineral specimen was formed. Radioactive elements “decay” that is, change into other elements by “half lives. The formula for the fraction remaining is one-half raised to the power given by the number of years divided by the half-life in other words raised to a power equal to the number of half-lives.
Testing Assumptions of Isochron Dating major portion of earth history, whose parent isotopes (40K, 87Rb, Sm, U, U, and Th) should have been altered by signiﬁcant amounts of decay to produce signiﬁcant quantities of daughter isotopes (40Ar, 87Sr, Nd, Pb, Pb, and Pb respectively).We sought to date rocks.
Now such a closed system does not really exists, but open system affects can’t be determined easily, so it is hoped that they about balance out. These methods all have the same basic assumptions. No gain or loss of parent or daughter isotope. Known amounts of daughter isotope at start. Realizing the difficulty of dealing with assumptions 2 and 3 above Isochron Dating was developed in an attempt to solve this problem.
According to theory the sample starts out with daughter isotopes ratio with other isotopes of the same element at a constant value, but with the parent isotope is arbitrary. As a result is forms a strait horizontal line on a graph. As parent decays to daughter, the ratios change and the straight line remains but becomes angled. The slope of the line equals the number of half-lives of the parent isotope has passed sense solidification.
Given this when one looks at an Isochron plot how can one really tell where the true Isochron line should be. Sufficient contamination can produce any Isochron pattern regardless of the true Isochron.
What did the Authors of the Bible Intend? It is also quite clear that these authors were actually trying to convey a literal historical narrative — not an allegory. They actually believed that what they wrote was literal history. Take, for example, the comments of well-known Oxford Hebrew scholar James Barr:
Isochron Dating. Paul Giem. However, in many other methods of radiometric dating the assumption that the daughter isotope is driven off is clearly invalid. For example, 87 Sr (strontium), the daughter product of 87 Rb, is not volatile, and is chemically incorporated into minerals when a melt  cools.
There are lots of ways to guesstimate ages, and geologists knew the earth was old a long time ago and I might add that they were mostly Christian creationist geologists. But they didn’t know how old. Radiometric dating actually allows the measurement of absolute ages, and so it is deadly to the argument that the earth cannot be more than 10, years old.
Radiometric methods measure the time elapsed since the particular radiometric clock was reset. Radiocarbon dating, which is probably best known in the general public, works only on things that were once alive and are now dead. It measures the time elapsed since death, but is limited in scale to no more than about 50, years ago. Generally applied to igneous rocks those of volcanic origin , they measure the time since the molten rock solidified.
If that happens to be longer than 10, years, then the idea of a young-Earth is called into question. If that happens to be billions of years, then the young-Earth is in big trouble. As of January, , The oldest rocks found on earth are 4. This is reported in the paper Priscoan 4. Williams; Contributions to Mineralogy and Petrology 1: The previous record was 3.
The putative age of the Earth, about 4, , , years is based on the radiometrically measured age of meteorites, and is also about , , years older than the oldest rocks.
Young Earth or Old Earth
How old is the earth? First published in Refuting Evolution , Chapter 8 Evolutionists fallaciously think that billions of years of time makes particles-to-people evolution possible. So Teaching about Evolution and the Nature of Science presents what it claims is evidence for vast time spans. This is graphically illustrated in a chart on pages 36—
Some assumptions have been made in the discussion of generic dating, for the sake of keeping the computation simple. Such assumptions will not always be accurate in the real world. These include: The amount of daughter isotope at the time of formation of the sample is zero (or known independently.
In this issue we will look at the isochron technique and at new research on Helium diffusion that gives an exciting confirmation of the Biblical age of the Earth. There are three key assumptions of radioactive dating techniques that have been called into question by young earth creationists. The First of these is that there is a constant decay rate of the radioactive elements.
Creationists now have done their own experimental research that calls this assumption into question. The research on Helium diffusion in zircon crystals that follows is one line of evidence to that effect. Other major assumptions of radiometric dating are that the sample has been a closed system while the decay occurred and that the initial concentrations of the radioisotopes is known. In real rocks and minerals, the closed system assumption would mean that there was no non-radioactive process that changed the amounts of the radioactive elements while the radioactive decay was taking place.
This assumption is seldom completely valid. Scientists try to account for these other processes. There is a tenancy for there to be unaccounted for processes that either take away the parent isotopes or add to the daughter isotopes, making the radiometric age figure turn out too large. The initial concentration assumption has to do with knowing the starting conditions of the mineral that the decay took place in. If the age calculation incorrectly assumes there was none of the radioactive daughter element present when the rock formed, this will throw off the age result.
Daughter elements present when the mineral formed can make the sample seem older than it really is, if it is not accounted for properly in the calculation. The Isochron Technique The isochron dating technique was devised as a way to avoid errors caused by the assumptions above not being true.
He bases his case for the truth of the Bible on two assertions: Veith remarks p that we should be impressed by the fact that the Bible has had tremendous influence and that many have suffered death rather than deny their faith in it. Why should that impress us, since the same can be said of the Koran and many other writings held sacred by many different civilizations?
Veith comments p that the Bible “has stood the test of time. As a literal record, in other words, the Bible is losing ground.
For this purpose, isochron dating was developed, a process “that solves both of these problems (accurate date, assumptions) at once” (Stasson ). A natural clock must meet four requirements. 1) The process must be irreversible.
Assuming that the half life of a radioactive isotope is in fact constant and therefore is a constant , we are still faced with a problem. So is there no way to determine the age of rocks from radioactive isotopes present in the rocks? There are multiple possible methods for determining the age of rocks. The method I will focus on is the rubidium-strontium isochron method. There are two naturally occuring isotopes of rubidium. Strontium and Strontium are two stable isotopes of strontium.
If a group of rocks are co-genetic, meaning they are formed at the same time and place and are derived from the same parent material, they will have the same ratio of when they are formed 2. Assuming that the rocks are closed systems, the amount of at the time of in the rocks should be the same today as when the rocks were formed, since is not produced by radioactive decay.
The amount of in each rock at the time of formation should be different from the amount of in each rock today, since can form from the decay of.
Comments on “The Radiometric Dating Game
If we walk into a room and observe an hourglass with sand at the top and sand at the bottom, we could calculate how long the hourglass has been running. By estimating how fast the sand is falling and measuring the amount of sand at the bottom, we could calculate how much time has elapsed since the hourglass was turned over. All our calculations could be correct observational science , but the result could be wrong.
This is because we failed to take into account some critical assumptions.
The isochron method. Many radioactive dating methods are based on minute additions of daughter products to a rock or mineral in which a considerable amount of daughter-type isotopes already exists.
Isochron Dating as a Current Scientific Clock By Calvin Krogman Radioactive decay has become one of the most useful methods for determining the age of formation of rocks. However, in the very principal of radiometric dating there are several vital assumptions that have to be made in order for the age to be considered valid.
But what if one or some combination of these assumptions is incorrect? Then the computed age based on the accumulation of daughter products will be incorrect Stasson In order to use the valuable information provided by radiometric dating, a new method had to be created that would determine an accurate date and validate the assumptions of radiometric dating.
For this purpose, isochron dating was developed, a process “that solves both of these problems accurate date, assumptions at once” Stasson A natural clock must meet four requirements. Isotope dating satisfies this requirement, as daughter products do not decay back to the original parent element. It has been established through extensive experimentation that radioactive decay occurs at a constant rate.
In this case, the initial condition is the amount of daughter isotope in the rock when it was formed. This amount is often unknown and is one of the downfalls of conventional radiometric dating. However, isochron dating bypasses this assumption, as explained below.
Rubidium—strontium method The radioactive decay of rubidium 87Rb to strontium 87Sr was the first widely used dating system that utilized the isochron method. Because rubidium is concentrated in crustal rocks, the continents have a much higher abundance of the daughter isotope strontium compared with the stable isotopes. A ratio for average continental crust of about 0. This difference may appear small, but, considering that modern instruments can make the determination to a few parts in 70, , it is quite significant.
Dissolved strontium in the oceans today has a value of 0. Thus, if well-dated, unaltered fossil shells containing strontium from ancient seawater are analyzed, changes in this ratio with time can be observed and applied in reverse to estimate the time when fossils of unknown age were deposited.
The assumptions of conventional whole-rock and mineral isochron radioisotope dating were tested using a suite of radioisotopes from two Precambrian rocks. Amphibolite from the Beartooth Mountains of Wyoming shows evidence of thorough metamorphism by isochemical processes from andesite by an early Precambrian magma-intrusion event.
These graphs supposedly tell how old the rock is. The isochron method is considered by some to be the most accurate rock dating method when it confirms evolutionary prejudice. They just accept the results on face value. Minerals, Elements, and Isotopes Rocks are made up of minerals. Minerals are specific chemical combinations of atoms. For example, table salt is a mineral called sodium chloride.
At the time that Darwin’s On the Origin of Species was published, the earth was “scientifically” determined to be million years old. By , it was found to be 1. In , science firmly established that the earth was 3.
Radioactive Dating Method ‘Under Fire’ but because we know of observations contrary to these assumptions. The isochron dating method. Apart from the initial conditions, the major problem facing geochronologists is that geological systems are invariably open to external influences. However, it is this isochron dating method that has.
Does Genesis Really Matter? Jake Hebert of the Institute for Creation Research. I could write a rather lengthy article in response, but I will try to keep things brief. I will start my review by quoting Dr. If radiometric dating works—and I believe it reveals accurate dates most of the time—Christians should not be intimidated. Geologists have known for a long time that the isotope geochemistry of Earth is complex, and that radiometric dating does not always return what is considered to be a geologically-valid result, but there is no reason for old-Earth Christians to be intimidated by discrepant dates.