An improved method for TIMS high precision neodymium isotope analysis of very small aliquots (1–10 ng)

Pulsed dehydration and garnet growth during subduction revealed by zoned garnet geochronology and thermodynamic modeling, Sifnos, Greece

“…All samples (cleansed garnet separates, fine garnet powders, and rock matrices) were treated with a mixed 147 Sm-150 Nd spike prior to loading through a three-stage column chromatography procedure following Harvey and Baxter (2009). Three-column blanks with in-house, distilled 2-methyl lactic acid, run alongside all of the samples, ranged from 1-2 pg of Sm and 4-6 pg of Nd, leading to high sample-to-blank ratios, appropriate for high precision analysis at such low sample sizes.…”

Metrology and Traceability of U-Pb Isotope Dilution Geochronology (EARTHTIME Tracer Calibration Part I)

“…The issue of variable oxygen isotopic composition within the thermal ionisation source environment where isotopic fractionation could occur has been encountered in other high-precision isotopic determinations where the isotopes were measured as oxide. Notable studies include Wasserburg et al (1981) and Harvey and Baxter (2009) with TIMS NdO + measurements and associated with negative-ion TIMS Os analyses (Luguet et al, 2008). These studies documented intra-laboratory variation in R 18 , as well as within-run variation.…”

Sm–Nd dating of hydrothermal carbonate formation: An example from the Breitenau magnesite deposit (Styria, Austria)

“…Nd extracted from each of these leachates ranged from 2 to 7 ng. Due to their small size, the Nd was loaded with 2 μL of H 3 PO 4 and Ta 2 O 5 activator slurry onto a single Re filament and collected in static mode with amplifier rotation as NdO + (Harvey and Baxter, 2009). Procedural blanks during the timespan of these analyses were b23 pg; the effect of blank corrections was evaluated and is insignificant for this study.…”

“…This sequential extraction resulted in five carbonate fractions from a single sample. Each leachate was dried down and brought up in 2 N nitric acid, treated with a mixed 147 Sm-150 Nd spike and passed through a three stage column procedure: an anion exchange column to remove Fe, a TRU-spec column to isolate the REEs, and a hydroxyisobutyric acid column to isolate Nd and Sm (Harvey and Baxter, 2009). …”