Rb sr isochron dating
An explanation of the method and its rationale are given.
Mixing lines, an alternative explanation for apparent isochron lines are explained.
To see how we actually use this information to date rocks, consider the following: Usually, we know the amount, N, of an isotope present today, and the amount of a daughter element produced by decay, D*.
By definition, D* = N-1) (2) Now we can calculate the age if we know the number of daughter atoms produced by decay, D* and the number of parent atoms now present, N.
Prior to 1905 the best and most accepted age of the Earth was that proposed by Lord Kelvin based on the amount of time necessary for the Earth to cool to its present temperature from a completely liquid state.
Although we now recognize lots of problems with that calculation, the age of 25 my was accepted by most physicists, but considered too short by most geologists. Recognition that radioactive decay of atoms occurs in the Earth was important in two respects: Principles of Radiometric Dating Radioactive decay is described in terms of the probability that a constituent particle of the nucleus of an atom will escape through the potential (Energy) barrier which bonds them to the nucleus.
Thus, if we start out with 1 gram of the parent isotope, after the passage of 1 half-life there will be 0.5 gram of the parent isotope left.
Unfortunately, there is no way to deal with the subject without at least mentioning mathematics.A model for flattening of "isochron" lines utilizing fractional separation and partial mixing is developed, and its application to the problem of reducing the slope of "isochron" lines without significant time is outlined.It is concluded that there is at present a potentially viable explanation for isochron "ages" that does not require significant amounts of time that may be superior to the standard long-age explanation, and that short-age creationists need not uncritically accept the standard long-age interpretation of radiometric dates.An event like metamorphism could heat the crystal to the point where Pb will become mobile.Another possible scenario involves U leakage, again possibly as a result of a metamorphic event.