Here I want to concentrate on another source of error, namely, processes that take place within magma chambers. To me it has been a real eye opener to see all the processes that are taking place and their potential influence on radiometric dating. Radiometric dating is largely done on rock that has formed from solidified lava. Lava properly called magma before it erupts fills large underground chambers called magma chambers. Most people are not aware of the many processes that take place in lava before it erupts and as it solidifies, processes that can have a tremendous influence on daughter to parent ratios. Such processes can cause the daughter product to be enriched relative to the parent, which would make the rock look older, or cause the parent to be enriched relative to the daughter, which would make the rock look younger. This calls the whole radiometric dating scheme into serious question.
Dating Rocks and Fossils Using Geologic Methods
The same was long true of the cosmos. The ancient Greeks Eratosthenes and Aristarchus measured the size of the Earth and Moon, but could not begin to understand how old they were. With space telescopes, we can now even measure the distances to stars thousands of light-years away using parallax, the same geometric technique proposed by Aristarchus, but no new technology can overcome the fundamental mismatch between the human lifespan and the timescales of the Earth, stars, and universe itself.
Despite this, we now know the ages of the Earth and the universe to much better than 1 percent, and are beginning to date individual stars. Our ability to measure ages, to place ourselves in time as well as in space, stands as one of the greatest achievements of the last one hundred years.
RATE (Radioactivity and the Age of The Earth). Analysis and Evaluation of Radiometric Dating. RATE – cover of popular book, spacer gif. What is RATE.
H ow old is planet Earth? There are enormous differences of opinion. The most common view is that Earth is approximately 4. The lowest age defended on a scientific basis is in the 6 to 10 thousand year range. Theoretically, Creationism remains workable within a wide range of age estimates. Scientists have proposed numerous age estimation methods.
Most systems promoted by Evolutionists involve radioactivity. Various radioactive elements are involved, including Carbon, Uranium, Thorium, and Potassium The Carbon age estimating method is, at best, only useful for estimating the age of things that are thousands of years old, not millions or billions. And it does not work on rocks or thoroughly mineralized fossils; it is only useful for relatively well-preserved organic materials such as cloth, wood, and other non-fossilized materials.
Other methods must be used to estimate the age of rocks and minerals. Two of the most widely-known systems are the potassium-argon method and the uranium-lead method. A radioactive form of potassium is found in minute quantities in some rocks.
Age of Earth
When paleontologist Mary Schweitzer found soft tissue in a Tyrannosaurus rex fossil , her discovery raised an obvious question — how the tissue could have survived so long? The bone was 68 million years old, and conventional wisdom about fossilization is that all soft tissue, from blood to brains , decomposes. Only hard parts, like bones and teeth, can become fossils.
But for some people, the discovery raised a different question.
In , shortly after the discovery of radioactivity , the American chemist Bertram Boltwood suggested that lead is one of the disintegration products of uranium, in which case the older a uranium-bearing mineral the greater should be its proportional part of lead. Analyzing specimens whose relative geologic ages were known, Boltwood found that the ratio of lead to uranium did indeed increase with age.
After estimating the rate of this radioactive change, he calculated that the absolute ages of his specimens ranged from million to 2. Though his figures were too high by about 20 percent, their order of magnitude was enough to dispose of the short scale of geologic time proposed by Lord Kelvin. Versions of the modern mass spectrometer were invented in the early s and s, and during World War II the device was improved substantially to help in the development of the atomic bomb.
Soon after the war, Harold C. Urey and G. Wasserburg applied the mass spectrometer to the study of geochronology. This device separates the different isotopes of the same element and can measure the variations in these isotopic abundances to within one part in 10, By determining the amount of the parent and daughter isotopes present in a sample and by knowing their rate of radioactive decay each radioisotope has its own decay constant , the isotopic age of the sample can be calculated.
For dating minerals and rocks, investigators commonly use the following couplets of parent and daughter isotopes: thorium—lead, uranium—lead, samarium—neodymium, rubidium—strontium, potassium—argon, and argon—argon The SHRIMP Sensitive High Resolution Ion Microprobe enables the accurate determination of the uranium-lead age of the mineral zircon, and this has revolutionized the understanding of the isotopic age of formation of zircon-bearing igneous granitic rocks.
Another technological development is the ICP-MS Inductively Coupled Plasma Mass Spectrometer , which is able to provide the isotopic age of the minerals zircon, titanite, rutile, and monazite. These minerals are common to many igneous and metamorphic rocks.
David H. Bailey does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment. In one respect, science and religion have been largely reconciled since the 19th century, when geologists such as Charles Lyell recognised the evidence for a very old Earth.
Within a few decades, most mainstream religious denominations accepted this view as well. But, much to the consternation of scientists, young-Earth creationism , which holds Earth is only about 6, years old, continues to be promoted in some quarters, and remains very popular with the public, especially in the United States.
This page has been archived and is no longer updated. Despite seeming like a relatively stable place, the Earth’s surface has changed dramatically over the past 4. Mountains have been built and eroded, continents and oceans have moved great distances, and the Earth has fluctuated from being extremely cold and almost completely covered with ice to being very warm and ice-free. These changes typically occur so slowly that they are barely detectable over the span of a human life, yet even at this instant, the Earth’s surface is moving and changing.
As these changes have occurred, organisms have evolved, and remnants of some have been preserved as fossils. A fossil can be studied to determine what kind of organism it represents, how the organism lived, and how it was preserved. However, by itself a fossil has little meaning unless it is placed within some context.
The age of the fossil must be determined so it can be compared to other fossil species from the same time period. Understanding the ages of related fossil species helps scientists piece together the evolutionary history of a group of organisms. For example, based on the primate fossil record, scientists know that living primates evolved from fossil primates and that this evolutionary history took tens of millions of years.
By comparing fossils of different primate species, scientists can examine how features changed and how primates evolved through time. However, the age of each fossil primate needs to be determined so that fossils of the same age found in different parts of the world and fossils of different ages can be compared. There are three general approaches that allow scientists to date geological materials and answer the question: “How old is this fossil?
Relative dating puts geologic events in chronological order without requiring that a specific numerical age be assigned to each event.
RADIOACTIVE AGE ESTIMATION METHODS—Do they prove the Earth is billions of years old?
Planet Earth doesn’t have a birth certificate to record its formation, which means scientists spent hundreds of years struggling to determine the age of the planet. So, just how old is Earth? By dating the rocks in Earth’s ever-changing crust, as well as the rocks in Earth’s neighbors, such as the moon and visiting meteorites, scientists have calculated that Earth is 4. Related: How Big is Earth? Scientists have made several attempts to date the planet over the past years.
They’ve attempted to predict the age based on changing sea levels, the time it took for Earth or the sun to cool to present temperatures, and the salinity of the ocean.
This belief in long ages for the earth and the existence of life is derived largely from radiometric dating. These long time periods are computed by measuring the.
This value is derived from several different lines of evidence. Unfortunately, the age cannot be computed directly from material that is solely from the Earth. There is evidence that energy from the Earth’s accumulation caused the surface to be molten. Further, the processes of erosion and crustal recycling have apparently destroyed all of the earliest surface.
The oldest rocks which have been found so far on the Earth date to about 3. Some of these rocks are sedimentary, and include minerals which are themselves as old as 4. Rocks of this age are relatively rare, however rocks that are at least 3. While these values do not compute an age for the Earth, they do establish a lower limit the Earth must be at least as old as any formation on it.
This lower limit is at least concordant with the independently derived figure of 4. This involves measurement of three isotopes of lead Pb, Pb, and either Pb or Pb If the solar system formed from a common pool of matter, which was uniformly distributed in terms of Pb isotope ratios, then the initial plots for all objects from that pool of matter would fall on a single point. Over time, the amounts of Pb and Pb will change in some samples, as these isotopes are decay end-products of uranium decay U decays to Pb, and U decays to Pb
Clocks in the Rocks
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. These assumptions include: 1 the initial amount of the daughter isotope is known, 2 neither parent or daughter product has migrated into, or out of, the closed rock system, and 3 decay has occurred at a constant rate over time.
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.
Dating the Earth, the Sun, and the Stars. Might stellar rotation explain the variance of ages seen in star clusters? By Timothy David Brandt · Published .
You’ve got two decay products, lead and helium, and they’re giving two different ages for the zircon. For this reason, ICR research has long focused on the science behind these dating techniques. These observations give us confidence that radiometric dating is not trustworthy. Research has even identified precisely where radioisotope dating went wrong. See the articles below for more information on the pitfalls of these dating methods. Radioactive isotopes are commonly portrayed as providing rock-solid evidence that the earth is billions of years old.
Since such isotopes are thought to decay at consistent rates over time, the assumption is that simple measurements can lead to reliable ages.