Tungsten-182 heterogeneity in modern ocean island basalts.

New tungsten isotope data for modern ocean island basalts (OIB) from Hawaii, Samoa, and Iceland reveal variable W/W, ranging from that of the ambient upper mantle to ratios as much as 18 parts per million lower. The tungsten isotopic data negatively correlate with He/He. These data indicate that each OIB system accesses domains within Earth that formed within the first 60 million years of solar system history.

High-precision analysis of W/W and W/W by negative thermal ionization mass spectrometry: Per-integration oxide corrections using measured O/O.

Here we describe a new analytical technique for the high-precision measurement of W/W and W/W using negative thermal ionization mass spectrometry (N-TIMS). We improve on the recently reported method of Trinquier et al. (2016), which described using Faraday cup collectors coupled with amplifiers utilizing 10 Ω resistors to continuously monitor the O/O of WO and make per-integration oxide corrections.