I know that in order to obtain reliable temperatures using the Zr-in-rutile thermometer the system needs to be buffered by zircon and quartz in equilibrium with rutile. However, I have samples of Ti-Fe ores with abundant Zr-rich rutile but with no coexisting zircon or quartz. I wonder if is still possible to obtain temperatures despite the absence of these minerals. Thanks for the help.
I recommend to read the paper entitled Crystallization thermometry for zircon and rutile. I think will find a valueble information help you to acheive your questiin that you request
You are unlikely to get reliable temperatures in such a system. In the absence of zircon, the zircon-rutile partitioning behavior that is the basis for the thermometer is invalid. Do you have baddelyite?
Hi James, thanks for your answer. Yes, indeed there is baddeleyite in the sample.
Hi Alejandro,
I'm afraid not as you need to have an abundance of both quartz and zircon in order to obtain any sort of meaningful P-T information using the Zr-in-rutile geothermometer. You need to be able to clearly demonstrate that rutile grew in co-existence with both of these phases. A lack of zircon means that there is little free Zr in the system for rutile to uptake during prograde metamorphism resulting in low Zr concentrations in rutile (and thus corresponding to lower temperatures), while a lack of quartz as a buffering phase can result in the overestimation of Zr-in-rutile temperatures. I would recommend reading papers by Zack et al., 2004, Watson et al., 2006 and Tomkins et al., 2007 which go into more detail.
I also don't think you can use baddeleyite can be used in place of zircon in terms of applying the Zr-in-rutile geothermometer. Zircon can coexist with baddeleyite in silica-undersaturated systems however this is relatively uncommon in crustal rocks (Watson et al., 2006). If you are looking to obtain reliable P-T information it might be better to have a look at other phases present within your sample.
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