Ti in Quartz standards
Information on of Ti in Quartz standards for analysis.
A set of Ti in Quartz standards were synthesised at the Edinburgh Materials and Micro-Analysis Centre (EMMAC), University of Edinburgh. These standards followed the procedures of Biggar and O'Hara (1969) and Cairns (1983).
Ti occurs naturally in quartz as a trace element (Wark, 2006) and can be used to provide petrological information about the pressure and temperature (P-T) conditions of quartz crystallisation (Spears and Wark, 2009; Thomas et al., 2010). The result is that Ti can be used as a geothermometer and geobarometer as its solubility in quartz has a strong dependence on P-T. Therefore, it is important to have an accurate set of synthetic quartz standards with known trace Ti concentrations, which can be used to calibrate natural samples against when using a Secondary Ion Mass Spectrometry (SIMS) instrument.
Three silica glasses doped with Ti of different concentrations have been prepared, as well as a blank glass, as standard material for SIMS, electron microprobe and other micro-beam techniques. These were made by preparing gel starting mixtures from TEOS and 1000 Ti ca. AA solutions which were dried and then underwent fusion.
The set of four glasses contains:
- Blank glass containing 100% SiO2
- 100ppm Ti in 99.999% SiO2 glass
- 500ppm Ti in 99.995% SiO2 glass
- 1000ppm Ti in 99.99 SiO2 glass
The Ti is present in accurate trace concentrations that the silica was initially doped with and has been analysed independently by ICP OES, SIMS, as well as EMPA.
References
- Biggar, G.M. and O'HaraO'Hara, M.J. 1969. A Comparison of gel starting materials for phase equilibrium studies. Mineralogical magazine, 37, pp 198-205
- Cairnes, E. 1983. Preparation of rare earth glasses. Internal lab document.
- Thomas, J.B., Watson, E.B, Spear, F.S., Shemella, P.T., Nayak, S.K., and Lanzirotti, A. 2010. TitaniQ under pressure: the effects of pressure and temperature on the solubility of Ti in quartz. Contributions to Mineral Petrology. 160. pp 743-759.
- Spears, F.S. and Wark, D.A. 2009. Cathodoluminescence imaging and titanium thermometry in metamorphic quartz. Journal of Metamorphic Geology. 27. pp 187-205
- Wark, D.A. and Watson, E.B. 2006. TitaniQ: a titanium-in-quartz geothermometer. Contributions to Mineral Petrology. 152. pp 743-754