dating help

lol and i don't mean help getting a datecould someone explain (in simple terms using your own words) the different types of dating, and how they are calculated - just so i know how they work before i make an argument and make myself look stupid.thanks

anyone? theres so many topics that have people mention dating surely someone who used them must be able to inform me in simplistic terms on the different types and how they work out their calculations?

Most dating methods are based upon the principle of radioactive decay. A radioactive naturally occurring element decays into daughter element(s) at a fixed rate, and so by measuring the relative amounts of parent and daughter element you can calculate how long it has been decaying.One of the common problems with radiometric dating is that it is possible that the sample already contained some daughter element when the sample first formed, and this will throw off the measurement. This is a common problem with the uranium/lead method, though it is often possible to make realistic estimates of the amount of orginal daughter material. This is much less so with the other methods. Common radiometric dating methods are:

• Uranium/Lead (U/Pb)
• Potassium/Argon (K/Ar)
• Rubidium/Strontium (Rb/Sr)
• Argon/Argon (Ar/Ar)
• Samarium/Neodynium (Sm/Nd)
• Lutetium/Hafnium (Lu/Hf)
• Rhenium/Osmium (Re/Os)
• Uranium/Thorium/Lead (U/Th/Pb)
• Lead/Lead (Pb/Pb)

There's also a non-radiometric technique known as thermoluminescence.--Percy

There are several major classes of dating methods.1) Radiodecay dating -- Carbon-14, potassium-argon, and quite a few more are radiodecay dating method. Basically, certain radioactive elements (chemicals) decay into other elements at a constant rate. Thus, if you know the ratios of the elements when the sample formed, you can measure the current ratio and get a date-- within a margin of error. The trick is in knowing the starting ratios. For example, C14 exists in the atmosphere and accumulates in lining organisms, but not non-living material. When the organism dies, the accumulation stops and the clock starts.2) Tree ring dating -- Pretty self explainitory. Trees grow a new ring each year-- Some trees and environments are more reliable than others. So, by counting the rings you can travel back through time.3) Varve dating -- similar to tree ring dating but with a particular form a sedimentary deposition. Emuseum – Minnesota State University, Mankato4) Ice core dating -- similar to varve and tree ring dating but with ice cores5) Relative dating -- something buried in the ground is probably older than something buried above it. Fairly reasonable, eh?There are more... Page Not Found | Minnesota State University, Mankato 403 Forbidden The Radiometric Dating GameNo webpage found at provided URL: http://www.origins.tv/darwin/datingmethods.htm------------------
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thanks alot for the information-but could you clear this up for me-
"Thus, if you know the ratios of the elements when the sample formed, you can measure the current ratio and get a date-- within a margin of error. The trick is in knowing the starting ratios. For example, C14 exists in the atmosphere and accumulates in lining organisms, but not non-living material. When the organism dies, the accumulation stops and the clock starts."does that mean that when testing anything - you have to know the original ratio of elements in it? do you mean ratio of the product/substance you have at that time, or the ratio of when that thing first came to be?!sorry if i've confused you with my question.thanks

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does that mean that when testing anything - you have to know the original ratio of elements in it? do you mean ratio of the product/substance you have at that time, or the ratio of when that thing first came to be?

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Well, yes to both question. You can measure the current ratios. You have to estimate the originals. That is why specific elements are used and why specific conditions have to have occurred for the dating to be accurate. That is also why many samples are dated and if possible several different methods are used.For example: ------------------
No webpage found at provided URL: www.hells-handmaiden.com

Well, it's a concern; it's not much of a problem. We can use a system like K-Ar in which the probability of initial daughter is low, although we don't do that much anymore. Or we can measure a rock like zircon, in which physics guarantees essentially no initial daughter. Or we can use an isochron method which is unaffected by initial daughter. Er, the vast majority of U-Pb analyses are performed on zircons, for several reasons ... one of which is the fact that zircon stronglyrejects lead at solidification so, to a very good approximation, the daughter product is zero. Of course, geochronologists nowadays are looking for such precise ages that a first approximation isn't good enough, and a correction factor based on measured non-radiogenic lead is applied.

In some methods you have to know the original ratios of the appropriate elements. In such cases, we only use systems in which we can estimate the original ratios with a high probability of success. For example, K-Ar dating in which the daughter product (argon) is a gas that is unlikely to be trapped in lava (although this does happen, and K-Ar isn't as popular as it used to be). There's also U-Pb concordia-discordia dating of zircons, in which the physics of zircon solidification ensures that there will be essentially no lead in the crystal at solidification.In other methods you do not need to know the initial ratios; the application of the method is not dependent on knowing the initial ratios. There's a good explanation of the simplest of such methods at Isochron Dating.