Determining the Age of Rocks
PURPOSE AND OBJECTIVES
5) To use radiometric dating and the principles of determining relative age to show how ages of rocks and fossils can be narrowed even if they cannot be dated radiometrically. Each team of 3 to 5 students should discuss together how to determine the relative age of each of the rock units in the block diagram ( Figure 1). In uranium–lead dating, the concordia diagram is used which also decreases the problem of nuclide loss. Finally, correlation between different isotopic dating methods may be required to confirm the age of a sample. For example, the age of the Amitsoq gneisses from western Greenland was determined to be ± 4 Nov The process of relative dating fossils uses which measure what do scientist use to date the exact age of fossils. What scientists use to Using various radiometric dating methods to measure the ages of rock samples. The process of relative Geology What Is Absolute Dating Of Fossils. The most important.
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Dating Rocks and Fossils Using Geologic Methods
If you already have an account, Sign in. Most scientists and many Christians believe that the radiometric dating methods prove that the earth is 4.
Recent research shows otherwise. The textbooks speak of the radiometric dating techniques, and the dates themselves, as Radiometric Hookup Methods Determine The Age Of Rock Formations By information. Far from being data, these dates are actually interpretations of see more data. As discussed before, the assumptions influence the interpretation of the data.
There are three main assumptions that must be made to accept radiometric dating methods. These must be accepted on faith in uniformitarian and naturalistic frameworks. Recent research by a team of creation scientists known as the RATE R link and the A ge of T he E arth group has demonstrated the unreliability of radiometric dating techniques.
Even the use of isochron dating, which is supposed to eliminate some initial condition assumptions, produces dates that are not reliable. Despite the fact that there are many scientific problems with radiometric dating, there is a more significant problem. A fear of God and reverence for His Word is the beginning of wisdom. Starting with the Bible and developing a model for dating events in earth history will lead us to the truth.
The Bible gives us a much more reliable history of the earth as it was recorded by God. When someone mentions scientific dating methods, the first thing to come to mind for most people is carbon dating.
However, there are many methods that can be used to determine the age of the earth or other objects. The textbooks focus on relative dating, based on the layering of the rocks, and radiometric dating. Relative ages are assigned to rocks based on the idea that rock layers lower in the strata were deposited before rock layers that are higher. There is also a difference in the timescale used to explain the layers. Determining the relative age of a rock layer is based on the assumption that you know the ages of the rocks surrounding here. Uniformitarian geologists use so-called absolute dating methods to determine the ages of the surrounding rocks.
FOSSILS: how fossils are dated - Date Hookup!
Certain types of rocks, especially those that form from magma igneouscontain radioactive isotopes of different elements.
It is possible to measure the ratio of the different radioactive parent isotopes and their daughter isotopes in a rock, but the ratios are not dates or ages. The dates must be inferred based on assumptions about the ratios. Carbon dating is another common technique, but it can only be used on carbon-containing things that were once alive.
The method of calculating radiometric dates is like using an hourglass. You can use the hourglass to tell time if you know several things: If any of these three conditions is not accurately known, the hourglass will give an inaccurate measure of time.
Using an hourglass to tell time is much like using radiometric dating to tell the age of rocks. There are key assumptions that we must accept in order for the Radiometric Hookup Methods Determine The Age Of Rock Formations By to be reliable. Radiometric dating is based on the fact that radioactive isotopes decay to form isotopes of different elements.
The starting isotope is called the parent and the end-product is called the daughter. The time it takes for one half of the parent atoms to decay to the daughter atoms is called the half-life. If certain things are known, it is possible to calculate the amount of time since the parent isotope began to decay. For example, if you began with 1 gram of carbon, after 5, years you read article be left with 0.
The rhenium-osmium method takes advantage of the fact that the osmium concentration in most rocks and minerals is very low, so a small amount of the parent rhenium can produce a significant change in the osmium isotope ratio. Each yearly varve layer consists of a mineral matter brought in by swollen streams in the spring. Essentially every method of measurement, whether a thermometer, a ruler, or a more complicated instrument, relies on calibration for accuracy.
The reason this age may not be a true age—even though it is commonly called an absolute age—is that it is based on several crucial assumptions. Most radiometric dating techniques must make three assumptions:. The major problem with the first assumption is that there is no way to prove that the decay rate was not different at some point in the past. It is true that radioisotope decay rates are stable today and are not largely affected by external conditions like change in temperature and pressure, but that does not mean that the rate has always been constant.
Recent research by a creation science group known as RATE R adioisotopes and the A ge of T he E arth has produced evidence of accelerated rates of decay at some point or points in the past. Creation scientists suggest that there are two possible times that God supernaturally intervened on a global scale—during Creation Week and the Flood. It is not unreasonable to assume that God used the energy of accelerated radioactive decay to initiate please click for source drive Radiometric Hookup Methods Determine The Age Of Rock Formations By major geologic changes in the earth that accompanied the Flood.
Evidence for the period of accelerated decay is found in zircon crystals. Zircon crystals in granite contain radioactive uranium, which decays into lead over time. As the uranium decays, helium is produced in the crystals. Helium escapes from the crystals at a known, measurable rate. If those rocks were over a billion years old, as evolutionists claim, the helium should have leaked out of the rock. The presence of lots of helium in the crystals is evidence in support of a young earth.
Fossils and rocks do not come with dates stamped on them. The dates must be interpreted based on the evidence. Biblical geologists start with the assumptions laid out in the Bible and conclude that the rocks must be less than 6, years old. Evolutionists reject the authority of the Bible and conclude that the rocks must be millions or billions of years old. Other important findings of the RATE project include detecting carbon in coal and diamonds. If these substances were really millions or billions of years old respectively, there should be no carbon left in them.
Carbon has a half-life of 5, years. With the most accurate mass spectrometers, the oldest calculated age of items containing carbon is about 80, years. Diamonds are assumed to be many billions of years old and should contain no detectable carbon as it would have all decayed to nitrogen long ago.
The same is true of coal which was supposedly deposited hundreds of millions of years ago, according to the evolutionary model.
The presence of carbon in these materials clearly supports the idea of a young earth as described by the Bible. The assumption that there has been no loss or gain of the isotopes in the rock assumption 2 does not take into account the impact of weathering by surface and ground waters and the diffusion of gases. It is impossible to know to what degree the parent and daughter products have been added to or removed from the rocks Radiometric Hookup Methods Determine The Age Of Rock Formations By the alleged millions or billions of years.
Also, samples taken a few feet apart can give ages that differ by many hundreds of millions of years. Many people do not realize that fossils themselves are usually not directly dated. Instead, layers that contain datable igneous rocks above or below a fossil-bearing layer are used to estimate the age of the fossil.
The age of the fossil can be estimated within the range of the layers above and below it. In some cases, the ages are correlated to other rock layers of supposedly known age or by using index fossils. These methods assume that the distribution of index fossils and the correlation of strata are well understood on a global scale. Another finding of the RATE team is very intriguing. The team visit web page samples of diabase, an igneous rock, and tested them using various radiometric dating techniques.
If the dating methods are all objective and reliable, then they should give similar dates. The rocks were tested as whole-rock samples using K-Ar dating and also separated into individual minerals. The whole-rock and separated mineral samples allow a method known as isochron dating to be done. This method is supposed to eliminate the assumption that the initial concentration of the daughter element is zero.
The facts from the rock layers do not speak for themselves—they must be interpreted. The assumptions used to interpret the data influence the conclusion. Starting with the Bible produces different conclusions than starting with evolutionary reasoning.
Despite removing this assumption, the RATE team has shown that this method is not reliable. Dating the Source Basalt, a layer near the bottom of Grand Canyon, and a volcanic layer from near the top of Grand Canyon produced an amazing result.
Based on the law of superposition, the lower layers in the canyon should be older than the upper layers unless there was an intrusion or other event that changed the order. Using isochron dating from a respected lab, the lower rocks were dated at 1.
It is true that radioisotope decay rates are stable today and are not largely affected by external conditions like change in temperature and pressure, but that does not mean that the rate has always been constant. Afterward, the amount of the radioactive isotope carbon in their remains decreases. These have been dated at up to about four billion years.
There is an obvious discordance disagreement in the data. Because these dates are based on methods with multiple assumptions, and are contrary to the Bible, we must reject that they are accurate.
There are many other methods that can be used to establish ages for parts of the earth and the solar system. These methods will be discussed in the following chapter. Regardless of what method we use, we must start with assumptions and interpret the facts accordingly. Understanding what those assumptions are is important. If we are not aware of the assumptions that are being used, we can easily be deceived. We should always start with the Bible, the ultimate source of truth.
Proponents of evolution suggest that radiometric dating has proven that the earth is between 4. But what is this age based on? A straightforward reading of the Bible shows that the earth was created in six days about 6, years ago. Radiometric dating uses ratios of isotopes in rocks to infer the age of the rock. Scientists use a mix of observational data and assumptions about the past to determine the radiometric age of a rock.
Comparing the amount of a parent isotope to the amount of its daughter isotope and knowing the rate of change from parent into daughter known as the half-lifethe age of the rock can be determined.
However, there are several assumptions that must be made in this process. An hourglass can be used as an analogy to explain the assumptions. An hourglass can be used to tell time only if more info know how much sand was in each chamber at the beginning, that there was no sand added or removed from either chamber, and that the sand falls at a constant rate.
If any of these factors is not known, the time given may not be accurate.