Dear Rajesh,
Since quartz is, to the best of my knowledge, not a temperature indicator, not even after granulite facies metamorphism, you need to loo for minerals contains in the sandstone that could be of help. It will be necessary to do a mineral separation, by crushing samples of the quartzite formation and then follow the mineral separation procedure of Wilfley table, possibly heavy liquid centrifuge if you have on a available, then further separate the fractions that you then have by magnetic and heavy fluid separations. The last step would be handpicking individual minerals. Zircons tend to be very resistive, a U-Pd dating of zircons will most probably give you the age of the zircons, this will be a mix of the age zones in the zircon (presuming the zircons are zoned). With a Shrimp ion-microprobe zones in zircon crystals can be dated separately, this is a good but expensive option. Hopefully you can find some muscovites or other minerals that can be dated by Rb-Sr fission teach or other methods, apatite is good for fission track analysis.
It pays to do a regional tectonic analysis, to provide the geological framework for your dating results but given your project I suppose you have done that already.
Success, Dirk Nieuwland
Dirk Nieuwland
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On Oct 19, 2012, at 6:30 AM, Rajesh Pandey <[log in to unmask]> wrote:
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> Respected Geoscientists
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> I am working in geochronology and my objective is to date deformed fabric from different tectonic units of Himalaya. At one of my study area I got a sandstone body which has metamorphosed due to thermal impulse
> but has not been converted to quartzite completely, matrix of quartzite (Sandstone) has been chloritized due to this thermal impulse.
> I want to work out the age of thermal impulse. For this, I need suggestion from eminent scientist to proceed.
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> Hopping Positively-
> Rajesh Pandey
> M. Tech.
> IIT Roorkee
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> Regards-
> Rajesh Pandey
> M. Tech.
> IIT Roorkee
>
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