U_Pb_Geochronology

Because it is a young rock we use the 206pb238u ages

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Unformatted text preview: .2 G 348.4 0.8 Fraction 206Pb/238U age +/- %2σ Max Age Min Age A 347.8 1.2 349 346.6 G 348.4 0.8 349.2 347.6 Midpoint of maximum age spread is = (349.2+346.6)/2 = 347.9 Ma Errors are = ±1.3 Ma Hence, the age is 347.9 ±1.3 Ma Wednesday, 15 August, 12 Example: Augen Granite, Yukon data-point error ellipses are 2σ 0.0578 360 0.0574 206Pb/238U 0.0570 356 0.0566 0.0562 352 0.0558 0.0554 348 0.0550 0.405 0.415 0.425 207 0.435 0.445 Pb/235 From Ruks et al. (2006) Wednesday, 15 August, 12 Example: Augen Granite, Yukon 207Pb/235U age 206Pb/238U age 207Pb/206Pb Z1A 353.3±0.7 358.4±1.2 392±6 Z1B 350.2±0.7 352.0±0.9 364±4 Z2A 360.0±0.7 370.4±0.8 436±3 Z3A 348.9±0.7 350.4±0.8 360±2 Wednesday, 15 August, 12 age Example: Augen Granite, Yukon 207Pb/235U age 206Pb/238U age 207Pb/206Pb Z1A 353.3±0.7 358.4±1.2 392±6 Z1B 350.2±0.7 352.0±0.9 364±4 Z2A 360.0±0.7 370.4±0.8 436±3 Z3A 348.9±0.7 350.4±0.8 360±2 What do we do in this case? Wednesday, 15 August, 12 age Example: Augen Granite, Yukon data-point error ellipses are 2...
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This document was uploaded on 03/06/2014 for the course ES 4502 at Memorial University.

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