TY - JOUR
T1 - A New LA-ICP-MS Method for Ti in Quartz
T2 - Implications and Application to High Pressure Rutile-Quartz Veins from the Czech Erzgebirge
AU - Cruz-Uribe, Alicia M.
AU - Mertz-Kraus, Regina
AU - Zack, Thomas
AU - Feineman, Maureen D.
AU - Woods, Glenn
AU - Jacob, Dorrit E.
N1 - Funding Information:
The authors thank N. Groschopf for EPMA analysis of the Heraeus glasses at the University of Mainz and D. Ruscitto for help with EPMA and LA-ICP-MS analyses of the Bishop Tuff quartz at RPI. The authors thank Heraeus Quarzglas GmbH & Co. for providing SiO2 glasses. Many thanks are due to J. Thomas and an anonymous reviewer for their helpful and constructive suggestions, which improved the manuscript greatly. This research was supported by National Science Foundation grant OISE-1036477 to M.F. and fellowships from the Ford and Sloan Foundations to A.C.
Publisher Copyright:
© 2016 The Authors. Geostandards and Geoanalytical Research © 2016 International Association of Geoanalysts
PY - 2017/3/1
Y1 - 2017/3/1
N2 - Experimental determination of the pressure and temperature controls on Ti solubility in quartz provides a calibration of the Ti-in-quartz (TitaniQ) geothermometer applicable to geological conditions up to ~ 20 kbar. We present a new method for determining 48Ti mass fractions in quartz by LA-ICP-MS at the 1 μg g−1 level, relevant to quartz in HP-LT terranes. We suggest that natural quartz such as the low-CL rims of the Bishop Tuff quartz (determined by EPMA; 41 ± 2 μg g−1 Ti, 2s) is more suitable than NIST reference glasses as a reference material for low Ti mass fractions because matrix effects are limited, Ca isobaric interferences are avoided, and polyatomic interferences at mass 48 are insignificant, thus allowing for the use of 48Ti as a normalising mass. Average titanium mass fraction from thirty-three analyses of low temperature quartz from the Czech Erzgebirge is 0.9 ± 0.2 μg g−1 (2s) using 48Ti as a normalising mass and Bishop Tuff quartz rims as a reference material. The 2s average analytical uncertainty for individual analyses of 48Ti is 8% for 50 μm spots and 7% for 100 μm spots, which offers much greater accuracy than the 21–41% uncertainty (2s) incurred from using 49Ti as an analyte.
AB - Experimental determination of the pressure and temperature controls on Ti solubility in quartz provides a calibration of the Ti-in-quartz (TitaniQ) geothermometer applicable to geological conditions up to ~ 20 kbar. We present a new method for determining 48Ti mass fractions in quartz by LA-ICP-MS at the 1 μg g−1 level, relevant to quartz in HP-LT terranes. We suggest that natural quartz such as the low-CL rims of the Bishop Tuff quartz (determined by EPMA; 41 ± 2 μg g−1 Ti, 2s) is more suitable than NIST reference glasses as a reference material for low Ti mass fractions because matrix effects are limited, Ca isobaric interferences are avoided, and polyatomic interferences at mass 48 are insignificant, thus allowing for the use of 48Ti as a normalising mass. Average titanium mass fraction from thirty-three analyses of low temperature quartz from the Czech Erzgebirge is 0.9 ± 0.2 μg g−1 (2s) using 48Ti as a normalising mass and Bishop Tuff quartz rims as a reference material. The 2s average analytical uncertainty for individual analyses of 48Ti is 8% for 50 μm spots and 7% for 100 μm spots, which offers much greater accuracy than the 21–41% uncertainty (2s) incurred from using 49Ti as an analyte.
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U2 - 10.1111/ggr.12132
DO - 10.1111/ggr.12132
M3 - Article
AN - SCOPUS:84981323590
VL - 41
SP - 29
EP - 40
JO - Geostandards and Geoanalytical Research
JF - Geostandards and Geoanalytical Research
SN - 1639-4488
IS - 1
ER -