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Member (Idle past 1501 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
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Author | Topic: How Old is the Earth ? | |||||||||||||||||||||||||||
Minnemooseus Member Posts: 3945 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: Member Rating: 10.0 |
quote: See message 12 of this string, and especially go to the "Geologic Column" topic. Moose ------------------BS degree, geology, '83 Professor, geology, Whatsamatta U Old Earth evolution - Yes Godly creation - Maybe
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gene90 Member (Idle past 3845 days) Posts: 1610 Joined: |
[QUOTE][b]--Is there really anything else besides radiometric techniques that will give these ages?[/QUOTE]
[/b] You can use cosmic ray track counts in thin slices of lunar material and meteorites to estimate how long the specimen has been exposed to the space environment. But of course, these are exposure ages, not absolute ages.
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Kyle467 Inactive Member |
I am by no means an expert on radioactive dating. But I heard for many people (mainly creationists, of which I am one) that are flaws in this method.
I heard that radioactive dating relies on too many assumptions. One assumption was about the amount of carbon or other material that was originally present in the material dated. On the same note, the amount of the daughter material is also assumed. Examples of incorrect radioactive dates were given through the dating of materials whose dates were previously known. For example, a 200-year-old lava flow was dated to be around 3 billion years old. It sounded like a great argument, and I was wondering if anyone had heard anything about it. Has it been disproved, supported, etc? Please respond.
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joz Inactive Member |
quote: If he could do as he wished he could have made a non expanding universe and provided evidence of a young earth the fact that the evidence is for an old universe shows that either God is a practical joker with a pre teen sense of humour("You believed the evidence insttead of this book, LOL, ZAP....") or that the universe is old.... He`s omnicogniscient for... well his sake he could certainly figure out that it would be to confusing for us poor mortals if all the evidence pointed to an old universe....
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no2creation Inactive Member |
One small note. If God did actually create a mature world, a world 4.5billion years old. Then there would be no argument of a old/young earth.
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gene90 Member (Idle past 3845 days) Posts: 1610 Joined: |
[QUOTE][b]I heard that radioactive dating relies on too many assumptions. One assumption was about the amount of carbon or other material that was originally present in the material dated. On the same note, the amount of the daughter material is also assumed. Examples of incorrect radioactive dates were given through the dating of materials whose dates were previously known. For example, a 200-year-old lava flow was dated to be around 3 billion years old.[/QUOTE]
[/b] Can't use carbon dating on a lava flow. Carbon has to be fixed from the air by living things for that method to work, so you can only use carbon dating on something that was once alive and is still organic in composition.
[QUOTE]originally by no2creation[b]One small note. If God did actually create a mature world, a world 4.5billion years old. Then there would be no argument of a old/young earth.[/QUOTE] [/b] If God created an apparently mature world, then all of "Scientific Creationism" is invalidated, because then all evidence would necessarily indicate an old Earth. Hence, CvsE would be moot. [This message has been edited by gene90, 02-16-2002]
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TrueCreation Inactive Member |
"Can't use carbon dating on a lava flow. Carbon has to be fixed from the air by living things for that method to work, so you can only use carbon dating on something that was once alive and is still organic in composition."
--I think he may have been aware of that (probably not but, but hey theres always room to recover), I got the same thing by lud saying that they carbon dated moon rocks, but I know that he most likely knows what is wrong with that. "If God created an apparently mature world, then all of "Scientific Creationism" is invalidated, because then all evidence would necessarily indicate an old Earth. Hence, CvsE would be moot."--True, I think that its the factors that we look at that are evident of different things, currently I am only aware of radioisotopes that give you the ages of the 'earth' or the moon and celestial astroids, etc. Whether the world 'looks' old is a matter of opinion, whether the evidence says it looks old is a little more scientific. --What I find that is unfortunate is that there are no YEC Creationists here to join the debate, so there is a strong unbalancment there, but I am glad I can hold out in many areas the way I do. -----------------
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Minnemooseus Member Posts: 3945 From: Duluth, Minnesota, U.S. (West end of Lake Superior) Joined: Member Rating: 10.0 |
quote: We don't?! Where did they all go? Moose ------------------BS degree, geology, '83 Professor, geology, Whatsamatta U Old Earth evolution - Yes Godly creation - Maybe [This message has been edited by minnemooseus, 02-16-2002]
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TrueCreation Inactive Member |
"We don't?! Where did they all go?"
--Oops! , I meant to say something along the lines of a collage major in a scientific field. Silly me ------------------
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zimzam Inactive Member |
You still really haven’t explained why this would be deceiving on Gods part. God created the heavens and the earth not only for His glory but also for a home for man. If God chose to create a mature earth to sustain life for man why is this deceiving? If he decided to create the universe as expanding or non-expanding that is His choosing and for reasons we may not understand. Perhaps an expanding universe is necessary is sustain our solar systems etc. There is also scripture to suggest that when man fell (sin) all of creation was also directly affected. Maybe the universe was created as non-expanding (perfect perpetual energy?) then when sin entered the world the universe immediately began to expand and lose energy. Could this of been the point of where the universe is now governed by mathematics and physics rather than God himself. I don’t know these to be facts but are interesting theories at least to me.
Rom 8:19-2119 The creation waits in eager expectation for the sons of God to be revealed. 20 For the creation was subjected to frustration, not by its own choice, but by the will of the one who subjected it, in hope 21 that the creation itself will be liberated from its bondage to decay and brought into the glorious freedom of the children of God.
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Mister Pamboli Member (Idle past 7599 days) Posts: 634 From: Washington, USA Joined: |
quote: The deception would not be in creating a mature world, but a world with the appearance of greater age than it had. Let's take an analogy. Select Help - About from your Internet Explorer menu (if that's what your using) or from some other software. You will find a copyright notice "1995-2002 Microsoft Corp." If this copyright notice said "1942-2002 Microsoft Corp" that would be a deception, because it is untrue. The deception in God's creation would not be in creating a fully developed earth, but in creating an earth with untrue evidence of a development which never happened.
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joz Inactive Member |
If God created a universe with an apparent age of billions of years then his creation decieves us into a false belief, as God is infinitely good he cannot decieve us (or he would not be infinitely good but instead a liar) therefore if an infinitely good God created the universe it would have ample evidence of the date of that creation.
Thus either: a)God is NOT infinitely good and decieves us.... Or: b)The universe has an age equivalent to its observed age..... You must remember that not only is the apparent age due to distant starlight, expanding universe, radiometric isotope decay, stellar generations etc but also the fossil record which if created to give an aged look to the universe would be an act of direct deception.....
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TrueCreation Inactive Member |
"The deception in God's creation would not be in creating a fully developed earth, but in creating an earth with untrue evidence of a development which never happened."
--What is the evidence that shows this and why is it evidence that could only be interpereted for such a vast age of the Earth? (added by edit) Oops, I just saw your post directly preceiding mine, though if there is anything else you would like to add to the list I could comment. ------------------ [This message has been edited by TrueCreation, 02-17-2002]
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LudvanB Inactive Member |
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mark24 Member (Idle past 5217 days) Posts: 3857 From: UK Joined: |
quote: Submarine lavas are known to cool rapidly, forming a glassy edge & not allowing Argon to escape, giving a false result. This probably doesn’t account for the discrepancy. A small number of results come back wildly in error compared to the main body, a result of contamination, human error, etc.
http://www.ees.nmt.edu/Geol/labs/Argon_Lab/Data/Tables.html If you look at the table at the top of this page you’ll see sample A has an age of 29 my. Whilst the others are all very close at about 62 my. There may well be flaws in various methods, but they are now going to be small corrections. If you doubt that ages B to J are accurate, read the four examples of age correlation, why would this happen if radiometric dating was so inaccurate? (Apologies to those who’ve seen this before)
Radiometric Dating "The purpose of this paper is to describe briefly a few typical radiometric dating studies, out of hundreds of possible examples documented in the scientific literature, in which the ages are validated by other available information. I have selected four examples from recent literature, mostly studies involving my work and that of a few close colleagues because it was easy to do so. I could have selected many more examples but then this would have turned into a book rather than the intended short paper. The Manson Meteorite Impact and the Pierre Shale In the Cretaceous Period, a large meteorite struck the earth at a location near the present town of Manson, Iowa. The heat of the impact melted some of the feldspar crystals in the granitic rocks of the impact zone, thereby resetting their internal radiometric clocks. These melted crystals, and therefore the impact, have been dated by the 40Ar/39Ar method at 74.1 Ma (million years; Izett and others 1998), but that is not the whole story by a long shot. The impact also created shocked quartz crystals that were blasted into the air and subsequently fell to the west into the inland sea that occupied much of central North America at that time. Today this shocked quartz is found in South Dakota, Colorado, and Nebraska in a thin layer (the Crow Creek Member) within a thick rock formation known as the Pierre Shale. The Pierre Shale, which is divided into identifiable sedimentary beds called members, also contains abundant fossils of numerous species of ammonites, ancestors of the chambered nautilus. The fossils, when combined with geologic mapping, allow the various exposed sections of the Pierre Shale to be pieced together in their proper relative positions to form a complete composite section (Figure 1). The Pierre Shale also contains volcanic ash that was erupted from volcanoes and then fell into the sea, where it was preserved as thin beds. These ash beds, called bentonites, contain sanidine feldspar and biotite that has been dated using the 40Ar/39Ar technique. The results of the Manson Impact/Pierre Shale dating study (Izett and others 1998) are shown in Figure 1. There are three important things to note about these results. First, each age is based on numerous measurements; laboratory errors, had there been any, would be readily apparent. Second, ages were measured on two very different minerals, sanidine and biotite, from several of the ash beds. The largest difference between these mineral pairs, in the ash from the Gregory Member, is less than 1%. Third, the radiometric ages agree, within analytical error, with the relative positions of the dated ash beds as determined by the geologic mapping and the fossil assemblages; that is, the ages get older from top to bottom as they should. Finally, the inferred age of the shocked quartz, as determined from the age of the melted feldspar in the Manson impact structure (74.1 0.1 Ma), is in very good agreement with the ages of the ash beds above and below it. How could all of this be so if the 40Ar/39Ar dating technique did not work? The Ages of Meteorites Meteorites, most of which are fragments of asteroids, are very interesting objects to study because they provide important evidence about the age, composition, and history of the early solar system. There are many types of meteorites. Some are from primitive asteroids whose material is little modified since they formed from the early solar nebula. Others are from larger asteroids that got hot enough to melt and send lava flows to the surface. A few are even from the Moon and Mars. The most primitive type of meteorites are called chondrites, because they contain little spheres of olivine crystals known as chondrules. Because of their importance, meteorites have been extensively dated radiometrically; the vast majority appear to be 4.4—4.6 Ga (billion years) old. Some meteorites, because of their mineralogy, can be dated by more than one radiometric dating technique, which provides scientists with a powerful check of the validity of the results. The results from three meteorites are shown in Table 1. Many more, plus a discussion of the different types of meteorites and their origins, can be found in Dalrymple (1991). There are 3 important things to know about the ages in Table 1. The first is that each meteorite was dated by more than one laboratory Allende by 2 laboratories, Guarena by 2 laboratories, and St Severin by four laboratories. This pretty much eliminates any significant laboratory biases or any major analytical mistakes. The second thing is that some of the results have been repeated using the same technique, which is another check against analytical errors. The third is that all three meteorites were dated by more than one method two methods each for Allende and Guarena, and four methods for St Severin. This is extremely powerful verification of the validity of both the theory and practice of radiometric dating. In the case of St Severin, for example, we have 4 different natural clocks (actually 5, for the Pb-Pb method involves 2 different radioactive uranium isotopes), each running at a different rate and each using elements that respond to chemical and physical conditions in much different ways. And yet, they all give the same result to within a few percent. Is this a remarkable coincidence? Scientists have concluded that it is not; it is instead a consequence of the fact that radiometric dating actually works and works quite well. Creationists who wants to dispute the conclusion that primitive meteorites, and therefore the solar system, are about 4.5 Ga old certainly have their work cut out for them! The K-T Tektites One of the most exciting and important scientific findings in decades was the 1980 discovery that a large asteroid, about 10 kilometers diameter, struck the earth at the end of the Cretaceous Period. The collision threw many tons of debris into the atmosphere and possibly led to the extinction of the dinosaurs and many other life forms. The fallout from this enormous impact, including shocked quartz and high concentrations of the element iridium, has been found in sedimentary rocks at more than 100 locations worldwide at the precise stratigraphic location of the Cretaceous-Tertiary (K-T) boundary (Alvarez and Asaro 1990; Alvarez 1998). We now know that the impact site is located on the Yucatan Peninsula. Measuring the age of this impact event independently of the stratigraphic evidence is an obvious test for radiometric methods, and a number of scientists in laboratories around the world set to work. In addition to shocked quartz grains and high concentrations of iridium, the K-T impact produced tektites, which are small glass spherules that form from rock that is instantaneously melted by a large impact. The K-T tektites were ejected into the atmosphere and deposited some distance away. Tektites are easily recognizable and form in no other way, so the discovery of a sedimentary bed (the Beloc Formation) in Haiti that contained tektites and that, from fossil evidence, coincided with the K-T boundary provided an obvious candidate for dating. Scientists from the US Geological Survey were the first to obtain radiometric ages for the tektites and laboratories in Berkeley, Stanford, Canada, and France soon followed suit. The results from all of the laboratories were remarkably consistent with the measured ages ranging only from 64.4 to 65.1 Ma (Table 2). Similar tektites were also found in Mexico, and the Berkeley lab found that they were the same age as the Haiti tektites. But the story doesn’t end there. The K-T boundary is recorded in numerous sedimentary beds around the world. The Z-coal, the Ferris coal, and the Nevis coal in Montana and Saskatchewan all occur immediately above the K-T boundary. Numerous thin beds of volcanic ash occur within these coals just centimeters above the K-T boundary, and some of these ash beds contain minerals that can be dated radiometrically. Ash beds from each of these coals have been dated by 40Ar/39Ar, K-Ar, Rb-Sr, and U-Pb methods in several laboratories in the US and Canada. Since both the ash beds and the tektites occur either at or very near the K-T boundary, as determined by diagnostic fossils, the tektites and the ash beds should be very nearly the same age, and they are (Table 2). There are several important things to note about these results. First, the Cretaceous and Tertiary periods were defined by geologists in the early 1800s. The boundary between these periods (the K-T boundary) is marked by an abrupt change in fossils found in sedimentary rocks worldwide. Its exact location in the stratigraphic column at any locality has nothing to do with radiometric dating it is located by careful study of the fossils and the rocks that contain them, and nothing more. Second, the radiometric age measurements, 187 of them, were made on 3 different minerals and on glass by 3 distinctly different dating methods (K-Ar and 40Ar/39Ar are technical variations that use the same parent-daughter decay scheme), each involving different elements with different half-lives. Furthermore, the dating was done in 6 different laboratories and the materials were collected from 5 different locations in the Western Hemisphere. And yet the results are the same within analytical error. If radiometric dating didn’t work then such beautifully consistent results would not be possible. Dating of The Mt Vesuvius Eruption In the early afternoon of August 24, 79 CE, Mt Vesuvius erupted violently, sending hot ash flows speeding down its flanks. These flows buried and destroyed Pompeii and other nearby Roman cities. We know the exact day of this eruption because Pliny the Younger carefully recorded the event. In 1997 a team of scientists from the Berkeley Geochronology Center and the University of Naples decided to see if the 40Ar/39Ar method of radiometric dating could accurately measure the age of this very young (by geological standards) volcanic material. They separated sanidine crystals from a sample of one of the ash flows. Incremental heating experiments on 12 samples of sanidine yielded 46 data points that resulted in an isochron age of 1925 94 years. The actual age of the flow in 1997 was 1918 years. Is this just a coincidence? No it is the result of extremely careful analyses using a technique that works. This is not the only dating study to be done on an historic lava flow. Two extensive studies done more than 25 years ago involved analyzing the isotopic composition of argon in such flows to determine if the source of the argon was atmospheric, as must be assumed in K-Ar dating (Dalrymple 1969, 26 flows; Krummenacher 1970, 19 flows). Both studies detected, in a few of the flows, deviations from atmospheric isotopic composition, most often in the form of excess 40Ar. The majority of flows, however, had no detectable excess 40Ar and thus gave correct ages as expected. Of the handful of flows that did contain excess 40Ar, only a few did so in significant amounts. The 122 BCE flow from Mt Etna, for example, gave an erroneous age of 0.25 0.08 Ma. Note, however, that even an error of 0.25 Ma would be insignificant in a 20 Ma flow with equivalent potassium content. Austin (1996) has documented excess 40Ar in the 1986 dacite flow from Mount St Helens, but the amounts are insufficient to produce significant errors in all but the youngest rocks. The 79 CE Mt Vesuvius flow, the dating of which is described above, also contained excess 40Ar. The 40Ar/39Ar isochron method used by the Berkeley scientists, however, does not require any assumptions about the composition of the argon trapped in the rock when it formed it may be atmospheric or any other composition for that matter. Thus any potential error due to excess 40Ar was eliminated by the use of this technique, which was not available when the studies by Dalrymple (1969) and Krummenacher (1970) were done. Thus the large majority of historic lava flows that have been studied either give correct ages, as expected, or have quantities of excess radiogenic 40Ar that would be insignificant in all but the youngest rocks. The 40Ar/39Ar technique, which is now used instead of K-Ar methods for most studies, has the capability of automatically detecting, and in many instances correcting for, the presence of excess 40Ar, should it be present. Summary In this short paper I have briefly described 4 examples of radiometric dating studies where there is both internal and independent evidence that the results have yielded valid ages for significant geologic events. It is these studies, and the many more like them documented in the scientific literature, that the creationists need to address before they can discredit radiometric dating. Their odds of success are near zero. Even if against all odds they should succeed, it still would not prove that the Earth is young. Only when young-earth creationists produce convincing quantitative, scientific evidence that the earth is young will they be worth listening to on this important scientific matter." Creationists base their objections on the flawed results, extrapolating this to mean ALL radiometric dating is inaccurate. Each method faces its own challenges, but the sources of potential error are different, yet the various methods correlate to a remarkable degree. Take the K-T Tektites. For the YEC position to be true, ALL four (40Ar/39Ar, K-Ar, Rb-Sr, and U-Pb) methods must be greater than 1,000,000% inaccurate. One MILLION per cent! How can they explain the vanishingly small chance they are ALL in error to this degree? Mark ------------------Occam's razor is not for shaving with.
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