Evaluation of fission-track and U-Pb double dating method for identical zircon grains:

Abstract

Using the double-dating approach, we have conducted fission-track (FT) and U-Pb age dating on the same zircon grain to evaluate the reliability of the resulting age data. The zircon grains (OD-) used for the investigation were collected from the Mihara Body of the Kawamoto Granodiorite, Shimane Prefecture, Japan. The zircon crystals yielded a FT age of Ma, with a spontaneous FT density of -cm . The U-Pb age data were obtained using inductively coupled plasma-mass spectrometry (ICP-MS) combined with a frequency quintupled Nd-YAG (λ = nm) laser ablation (LA) sample introduction system. The U-Pb age determinations on the zircon samples were performed after chemical leaching using % HF for hrs at room temperature, or after FT etching using a KOH-NaOH eutectic solution for hrs at °C. The resulting U-Pb age of Ma was concordant with the FT age data, suggesting that there was no significant loss of Pb during etching or chemical preparation, thus indicating the feasibility of FT and U-Pb double dating of single zircon grains. The results indicate that the zircon grains (OD-) from the Kawamoto Granodiorite (Mihara Body) can become a new working standard for precise U-Pb age determinations of young zircons.

U–Pb and fission‐track dating of Miocene hydrocarbon source rocks in the Akita Basin, Northeast Japan, and implications for the timing of paleoceanographic changes in the sea of Japan

“…Fission‐track and U–Pb double dating of identical zircon grains (Iwano et al, 2012) is a useful method to determine reliable ages of the eruption of volcaniclastic rocks because fission‐track method has lower closure temperature (ca. 250°C; Iwano et al, 2012), thus representing more reliable eruption ages. If fission‐track and U–Pb ages coincide well with each other, dated ages may reliably indicate the eruption ages of volcanic and volcaniclastic rocks (Iwano et al, 2012;Nakajima et al, 2019; Niwa et al, 2020).…”

Kinetics and pulses of zircon growth in migmatites beneath a volcanic arc: An example from the high‐T Ryoke Complex, southwest Japan

“…The zircons were mounted on PFA Teflon sheets and then polished with diamond paste, and the U–Pb ages were obtained using two systems of laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) at the Geochemical Research Center of the University of Tokyo, Tokyo, Japan, utilizing ArF excimer and femtosecond lasers. Several U–Pb dating standards were also prepared: 91500 (Wiedenbeck et al, 1995); GJ‐1 (Jackson et al, 2004); Plešovice (Sláma et al, 2008); and OD‐3 (Iwano et al, 2012; Iwano et al, 2013). The first three were mounted in epoxy, and OD‐3 was mounted in Teflon.…”

Rotated Transtensional Basins Formed During Back‐Arc Spreading in Japan: Simultaneous Rapid Tectonic Rotation and Basin Subsidence

“…We corrected for isotopic fractionation by normalizing to a 206 Pb/ 238 U ratio of 0.17917 for the Nancy 91500 standard zircon (Wiedenbeck et al, 1995). To check the accuracy of the results, we also analyzed the OD-3 (33 Ma;Iwano et al, 2012Iwano et al, , 2013 and Plešovice (337 Ma; Sláma et al, 2008) zircons as secondary standards. et al (2015).…”