THE ACCURATE QUANTITIES OF ARGON (AQUA) PIPETTE SYSTEM: METROLOGICALLY CALIBRATED 40AR CONCENTRATIONS IN 40AR/39AR MINERAL STANDARDS
The approach taken herein applies modern technology and uncertainty propagation to the “first principles” method. We rely on the “Accurate Quantities of Argon” (or “AQuA” pipette system described by Morgan et al. (2011) and valve closing techniques described in Morgan and Davidheiser-Kroll (2015). The AQuA pipette emits metrologically calibrated quantities of high purity 40Ar to allow for high accuracy sensitivity calibration of mass spectrometers. Here we present preliminary metrologically calibrated 40Ar concentration values for biotite standards HDB1 and MD2 (GA1550). Age calculations for these standards are presented by combining 40Ar concentrations with existing 40K concentration data. These and similar data may be used as stand-alone values, and/or they may provide input data for future iterations of the optimization model of Renne et al. (2010, 2011).
References
Kuiper, K. F., et al., 2008, Science, v. 320, no. 5875, p. 500-504.
McDougall, I., and Wellman, P., 2011, Chemical Geology, v. 280, no. 1-2, p. 19-25.
Morgan, L. E., and Davidheiser-Kroll, B., 2015, Geochemistry, Geophysics, Geosystems, v. 16, p. 1923-1931.
Morgan, L. E., et al., 2011, Geochemistry, Geophysics, Geosystems, v. 12, no. 10.
Renne, P. R., et al., 2011, Geochimica et Cosmochimica Acta, v. doi: 10.1016/j.gca.2011.06.021.
Renne, P. R., et al., 2010, Geochimica et Cosmochimica Acta, v. 74, no. 18, p. 5349-5367.
Renne, P. R., et al., 1998, Chemical Geology, v. 145, no. 1-2, p. 117-152.