We could like c1 = (D1-D2)/P1 and c2 = D2/N2 as well as the formula D(p) = c1*P(p) + c2*N(p) looks like (if i failed to make any mistakes).

This represents the problem N1=N2

So this is a blending one to production an isochron offering an enthusiastic decades add up to a child so you can parent proportion out of (D1-D2)/P1, that is lower than the latest daughter to mother ratio away from rock A, which is D1/P1. And so the typical methods for augmenting and you will using up moms and dad and you can daughter substances continue to work in order to dictate the age of so it isochron. More child equipment form a mature years, and less child unit (prior to moms and dad) function a young many years. And i also think the brand new assumptions P2 = 0 and N1 = N2 and you will D1 > D2 was sensible, since the substance Letter, lead 204, is likely regarding almost constant amount in lot of magmas. It is also sensible to think that crustal matter out of continents was enriched both in parent and child tool according to the fresh water floor, comparable to the challenge D1 > D2, therefore we be aware that the ocean floors is extremely worst within the moms and dad issue (uranium in this situation).