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Title: How to find age of rock 235U/207Pb, 238U/206Pb using ratios from Zircon sample of rock Post by: Victoria79 on Sep 18, 2019 half life of 235U 207Pb = 704 million years with a decay life of 9.8485x10-10
half life of 238U 206 Pb= 4.46 billion years with a decay constant of 1.55125x10-10 Ratio: 206Pb/238U 207Pb/235U zircon 1 : 0.732 32.25 What is the age of the rock. More zircon ratios continue below...I just need help working through one and I can probably do the rest. I've spent hours on this and it's just not making sense to me. Title: Re: How to find age of rock 235U/207Pb, 238U/206Pb using ratios from Zircon sample of rock Post by: bio_man on Sep 19, 2019 λ238 = 1.55125 ×10-10a-1 (t1∕2 = 4.468 gigayears or 1,000,000,000)
λ235 = 9.8485 ×10-10a-1 (t1∕2 = 703.8 million years) For this, you'll need to know the U-Pb system I found a tutorial here: https://www.ucl.ac.uk/~ucfbpve/geotopes/indexch5.html |