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For TAS diagram plot, one need to recalculate Major oxide data (NaO, K2O, SiO2).

Do one need to recalculate the ppms of Zr,Nb and Y and % of TiO2 for Zr/TiO2 vs Nb/Y diagram plotting for rock classification?

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  • $\begingroup$ By recalculate, you mean on an anhydrous basis? $\endgroup$ – Gimelist Sep 17 '19 at 12:24
  • $\begingroup$ Yes anhydrous basis. Say you have %5 LOI then you recalculate 95% to 100%. by increasing all oxides about %5 times. Then the sum is %100 again. $\endgroup$ – Muharrem Yavuz Sep 17 '19 at 16:16
  • $\begingroup$ Do you just mean renormalize so everything adds up to 100% after LOI? Just divide through by the sum of everything after LOI and everything should add back up to 100%. But it should not have a huge effect on the TAS diagram. $\endgroup$ – g.z. Sep 19 '19 at 22:34
  • $\begingroup$ g.z. i did normalisation for TAS. My question is different. I am asking if renormalizing is needed for other diagrams such as Zr/TiO2 - Nb/Y (winchester diagram) by normalising the values of TiO2,% and Zr, Nb, Y. ppm. $\endgroup$ – Muharrem Yavuz Sep 19 '19 at 23:05
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It is best to recalculate all major oxide (including TiO2), trace elements are not important. No need to recalculate them.

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If you are interested in the element ratios, you are looking at their relative abundance, not the absolute abundance. Therefore, as long as all the data you are comparing come from XRF, you do not need to normalise them for the ratio calculations in the plots.

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  • $\begingroup$ Parent magma gathers secondary volatiles by hydrothermal and weathering alteration during post volcanic processes. When we analyse the relative abundance of the elements with the addition of the secondary volatiles we will get low values on analyses results than the original value of the elements. So relative abundance of the elements in the XRF are renormalized. Element values increasing by renormalization. Say if we have 5% volatile and 60% SiO2 in the analyses result, then ask if i have 60%SiO2 in 95% total what would i have for %100. The normalized result will be 63,16. $\endgroup$ – Muharrem Yavuz Nov 28 '19 at 10:43

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