Hi everyone
I had a problem that I tried use MAD to correct my sample using VizualAge UComPbine DRS, while my sample data yield a very low initial 207Pb/206Pb. I have tried to use excel to repeat correction processes followed by Chew 2014, getting a normal initial 207Pb/206Pb (near 0.85). Did I do something wrong in Iolite ? I really need your help.
Low initial Pb ratio in apatite dating using VizualAge UComPbine DRS
- Edited
I tried to use SRM 612 or none to correct 207Pb/206Pb in iolite, then I get a good initial 207Pb/206Pb. I used these parameters to correct my data.
Is it right ?
Hi Joe,
It turns out that this morning we discussed a similar problem here with my colleague. So if I understand you well if we want to use the reference material common Pb composition we should put the 207/206 reference to none. This is what I use to do, but what happen if you set the 207/206 reference to the RM name? Do you correct the common Pb twice? I ask that because my colleague saw an issue in one of his session on the secondary standard data. But he used to set the 207/206 reference to the RM before and never had issue before.
All the best
Nathan
Before V4.5.5 the 7/6 correction was done after the common Pb correction. So, if you had the 207/206 correction set to use the main reference material it effectively did nothing since the main reference material had already been corrected to have the 7/6 specified in the RM data. For version >= 4.5.5 the 7/6 correction is done before the common Pb correction. So, if you use the primary RM (that has variable common Pb, otherwise why use UcomPbine?) you will get a very strange 7/6 correction. If you were fine using the RM for 7/6 before, then you should now use none. Does that change explain what you were seeing?
All the best,
- Joe
