Constraints on the U–Pb systematics of metamorphic rutile from in situ LA-ICP-MS analysis

In situ rutile U-Pb dating by laser ablation-MC-ICPMS

“…This rutile has been widely used in LA-ICPMS and SIMS labs for U-Pb isotope analyses (Kooijman et al, 2010;Li et al, 2011;Zack et al, 2011). A piece of R10 rutile fragment separated from a large single crystal was used in this study.…”

UPb LA-(MC)-ICP-MS dating of rutile: New reference materials and applications to sedimentary provenance

“…6a) are concordant within their analytical uncertainty, and for all the individual grains the weighted average of the 207 Overall, these results show that: (1) Sugluk-4 is a rutile characterized by nearly concordant ID-TIMS and concordant (within uncertainty) LA U-Pb analyses, with long-term reproducibility on the order of 2-4 %, ~ 1% more than natural zircon materials routinely used for U-Pb dating; (2) the intra-and inter-grain scatter in the isotopic ratios of Sugluk-4 are interpreted to reflect real geological rather than analytical phenomena and are most likely caused by cooling-related diffusion compatible with the slow cooling of many natural rutiles from granulite terrains; (3) PCA-S207 is characterized by a larger variability than Sugluk-4, usually within 4% for individual grains; (4) R10 has a large degree of intergrain heterogeneity with respect to common Pb and each portion needs to be characterised for homogeneity if a common Pb correction is not to be applied to the data; (5) we recognise some real variation between and within grains likely pertaining to cooling history of many rutiles as recognised by others (e.g. Flowers et al 2006;Kooijman et al 2010). …”

“…within relatively large grains (up to 280 m in size) from granulite facies Archean metapelitic rocks showing systematic core-to-rim decrease of several tens of millions of years (640 to 510°C) and increase in age-gradient, lead Kooijman et al (2010) to interpret the intragrain UPb variations as cooling ages recording points in time where the system effectively closed for…”

“…Growing interest is also being paid to U-Pb chronology of detrital rutile as a provenance indicator (Allen and Campbell, 2007;Birch et al, 2007;Rösel et al, 2011;Meinhold et al, 2011;Okay et al, 2011). While U-Pb chronology of rutile by ID-TIMS is a well established technique and allows high precision ratios to be measured (e.g., Ludwig and Cooper, 1984;Schärer et al, 1986;Corfu and Andrews, 1986;Mezger et al, 1989;Davis, 1997;Cox et al, 2002;Treloar et al, 2003;Schmitz and Bowring, 2003), rutile can also be dated by microprobe (secondary ion mass spectrometry -SIMS, LA-ICP-MS) techniques (Sircombe, 1995;Clark et al, 2000;Vry and Baker, 2006;Harrison et al, 2007;Storey et al, 2007;Kooijman et al, 2010;Meinhold et al, 2011;Schmitt and Zack, 2012;Taylor et al, 2012).…”

“…Alternatively, making use of the observation that rutiles contain very low Th (hence negligible radiogenic 208 Pb from 232 Th decay), the measured isotopic ratios can be corrected for common Pb by measuring 208 Pb and assuming it is virtually entirely common Pb (Clark et al, 2000;Allen and Campbell, 2007;Kooijman et al, 2010;. Currently, strategies are not available for handling reference material data with variable common-Pb to determine normalisation factors for LA U-Pb dating.…”