Laboratory name:
LTRACE, US Geological Survey, Denver, CO, USA
Sample type/mineral:
Zircon
Sample preparation:
Electro Pulse Disaggregator (EPD), water table, and heavy liquid mineral separation; hand pick; 25-mm epoxy resin mount; 1-mm polish to finish
Scanning Electron Microscope (SEM) Imaging:
Cathodoluminescence (CL) imaging: FEI Quanta FE-SEM (Denver Microbeam Lab, Denver, CO, USA)
Make, Model and type:
Applied Spectra Resolution S155 (unique ID: RAI-1098)
Ablation cell:
S155, ~9cm3 funnel volume
Laser wavelength (nm):
193 nm
Pulse width (ns):
5-8 ns
Fluence (J cm-2):
1.93 J cm-2
Repetition rate (Hz):
5 Hz
Ablation duration (s):
25 s
Spot diameter (μm) nominal/actual:
16 µm
Ablation rate in µm/shot:
0.06
Sampling mode / pattern:
Static spot ablation
Carrier gas:
0.4 l/min (He)
Note:
Make, Model and type
Agilent 8900 ICP-MS, single quad mode. N2 added to Ar gas at 4.0 mL/min
Sample introduction:
Laser Ablation: Ablation aerosol mixed with argon and sent into ICP-MS via squid mixing device
RF power (W):
1350 W
Make-up gas flows (l min-1):
1.15 (Argon)
Detection system:
Electron multiplier with pulse and analog mode of detection
Masses measured and dwell times (ms):
31P, 45Sc, 49Ti, 56Fe, 89Y, 91Zr, 93Nb, 139La, 140Ce, 141Pr, 146Nd, 147Sm, 153Eu, 157Gd, 163Dy, 165Ho, 166Er, 169Tm, 172Yb, 175Lu, 178Hf, 202Hg, 204Pb, 206Pb, 207Pb, 208Pb, 232Th, 235U, 238U with each isotope measured for 5 ms except for 204Pb and 207Pb 40 ms, 206Pb 30 ms, 208Pb, 232Th, 235U and 49Ti 10 ms, and 238U 20 ms
Total integration time per output data point (s):
0.289 s
IC Dead time (ns):
38
Calibration strategy:
Primary calibration using 91500 for U-Pb and Pb/Th data and NIST 610 for Pb isotopes and trace elements.
Reference material (zircon) information:
91500 (Wiedenbeck et al. 1995) Plešovice (Sláma et al. 2008)R33 (Black et al. 2004)QGNG (Black et al. 2004)GJ-1 (Jackson et al. 2004; Horstwood et al. 2016)
Data processing package used / Correction for LIEF:
LADR (Norris Scientific): https://norsci.com/?p=ladr
Interference corrections:
202Hg for 204Hg on 204Pb; assuming natural abundance in both cases
Correction(s) for elemental fractionation:
Polynomial down-hole Pb/U and Pb/Th correction
Uncertainty level & propagation:
2s, within-run
Quality control / Validation / Concordia Ages:
Plešovice, R33, QGNG, GJ-1, Mud Tank, FC-1, BHVO-2G, GSD-1g
References:
Black L.P. Kamo S.L. Allen C.M. Davis D.W. Aleinikoff J.N. Valley J.W. Mundil, R. Campbell I.H. Korsch R.J. Williams I.S. and Foudoulis C. (2004) Improved 206Pb/238U microprobe geochronology by the monitoring of a trace-element-related matrix effect; SHRIMP, ID–TIMS, ELA–ICP–MS and oxygen isotope documentation for a series of zircon standards. Chemical Geology, v. 205(1-2), p. 115-140. Horstwood M. S. A. Košler J. Gehrels G. Jackson S. E. McLean N. M. Paton C. Pearson N. J. Sircombe K. Sylvester P. Vermeesch P. Bowring J. F. Condon D. J. and Schoene B. (2016) Community‐derived standards for LA‐ICP‐MS U‐(Th‐) Pb geochronology–Uncertainty propagation, age interpretation and data reporting. Geostandards and Geoanalytical Research, v. 40, p. 311–332. Jackson S.E. Pearson J.J. Griffin W.L. and Belousova E.A. (2004) The application of laser ablation-inductively coupled plasma-mass spectrometry to in-situ U-Pb zircon geochronology. Chemical Geology. v. 211 p. 47-69.Slama J. Košler J. Condon D.J. Crowley J.L. Gerdes A. Hanchar J.M. Horstwood M.S.A. Morris G.A. Nasdala L. Norberg N. Schaltegger U. Schoene B. Tubrett M.N. and Whitehouse M.J. (2008) Plesovice zircon – A new natural reference material for U-Pb and Hf isotopic microanalysis. Chemical Geology. v. 249 p. 1-35.Wiedenbeck M. Alle P. Corfu F. Griffin W. Meier M. Oberli F. von Quadt A. Roddick J.C. Spiegel W. (1995) Three natural zircon standards for U-Th-Pb, Lu-Hf, trace element and REE analyses. Geostandards Newsletter. v. 19 p. 1-23.
Disclaimer:
Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
