Photographs and analytical data of zircons, pollen grains and plant macrofossils from the Late Miocene Mitoku Formation in Misasa Town, south-central Tottori Prefecture, western Japan

dataset

posted on 2025-04-24, 09:07 authored by Atsushi Yabe, Takeshi Saito, Michiyo Shimizu, Makiko Kobayashi, Tohru Danhara, Hideki Iwano, Takafumi Hirata

The location of analyzed samples are N35.409860°/E133.963038° (MSN-A); N35.4009932°/E133.963294° (MSN-C); N35.410759°/E133.963696° (MNS-P1); N35.410227°/E133.963430° (MSN-P2), respectively. For details of the samples, refer Yabe et al. (2025, Figs. 1, 2; https://doi.org/10.5575/geosoc.2025.0005)

Table S1. Instrumentation and operational settings used for the LA–ICP–MS U–Pb dating.

Table S2. Zircon U–Pb isotopic data for sample MSN-A and standards. * = Youngest zircon group. Disc.* = discordance = (1 – [²⁰⁶Pb/²³⁸U]/[²⁰⁷Pb/²³⁵U]) × 100. Concordance is based on whether the ²⁰⁶Pb/²³⁸U and ²⁰⁷Pb/²³⁵U ages are equivalent within 2σ analytical errors. Ages were calculated using the decay constants λ₂₃₈ = 1.55125 × 10^–10 yr^–1and λ₂₃₅ = 9.8485 × 10^–10 yr^–1(Jaffey et al., 1971). ²³⁵U was calculated from ²³⁸U based on ²³⁸U/²³⁵U = 137.88 (Jaffey et al., 1971). Rho was calculated from the ²⁰⁷Pb/²³⁵U–²⁰⁶Pb/²³⁸U error correlation. Rho = ([²⁰⁶Pb/²³⁸U]_error2σ/[²⁰⁶Pb/²³⁸U]_mean)/([²⁰⁷Pb/²³⁵U]_error2σ/[²⁰⁷Pb/²³⁵U_mean]).

Table S3. Zircon U–Pb isotopic data for sample MSN-C and standards. * = Youngest zircon group. Disc.* = discordance = (1 – [²⁰⁶Pb/²³⁸U]/[²⁰⁷Pb/²³⁵U]) × 100. Concordance is based on whether the ²⁰⁶Pb/²³⁸U and ²⁰⁷Pb/²³⁵U ages are equivalent within 2σ analytical errors. Ages were calculated using the decay constants λ₂₃₈ = 1.55125 × 10^–10 yr^–1 and λ₂₃₅ = 9.8485 × 10^–10 yr^–1 (Jaffey et al., 1971). ²³⁵U was calculated from ²³⁸U based on ²³⁸U/²³⁵U = 137.88 (Jaffey et al., 1971). Interference of ²⁰⁴Hg on ²⁰⁴Pb was corrected from the measurement of ²⁰²Hg during laser ablation and the natural ²⁰²Hg/²⁰⁴Hg ratio of 4.35. Rho was calculated from the ²⁰⁷Pb/²³⁵U–²⁰⁶Pb/²³⁸U error correlation. Rho = ([²⁰⁶Pb/²³⁸U]_error2σ/[²⁰⁶Pb/²³⁸U]_mean)/([²⁰⁷Pb/²³⁵U]_error2σ/[²⁰⁷Pb/²³⁵U_mean]).

Table S4. Pollen grains from the Misasa–Naru flora of the Mitoku Formation.

Table S5. Plant macrofossils of the Mitoku and Misasa–Naru flora from the Mitoku Formation. 0 = absent and 1 = present.

Fig. S1. Cathodoluminescence images of zircon crystals from sample MSN-A used for U–Pb dating. Analytical sites of the reported data are marked with an asterisk (*). Two or three spots were analyzed for some grains to avoid inclusions. For grain no. 1, an older xenocryst (core) age and a younger rim age were obtained. C = core and R2 = rim.

Fig. S2. Cathodoluminescence images of zircon crystals from sample MSN-C used for U–Pb dating. Analytical sites of the reported data are marked with an asterisk (*). Two sites were analyzed for one grain (no. 31) to avoid inclusions.

Fig. S3. Selected photographs of warm genera of pollen grains from the Mitoku Formation. (a) Cathaya, loc. P-8. (b) Keteleeria, loc. P-8. (c) Pseudolarix, loc. P-2. (d) Liquidambar, loc. P-2. (e) Quercus (evergreen), loc. P-2. (f) Reevesia, loc. P-2.

Fig. S4. Selected photographs of warm species of plant macrofossils from the Mitoku Formation. (a) Cinnamomum cf. camphora (L.) J. Presl, NSM PP-30064, loc. MSN-P2. (b) Liquidambar cf. miosinica Hu et Chaney, NSM PP-30062, loc. MSN-P1. (c) Liquidambar sp. (cupule), NSM PP-30061, loc. MSN-P1. (d–e) Keteleeria ezoana Tanai et Suzuki, NSM PP-30063a, loc. MSN-P1 and NSM PP-30063b, cuticle, loc. MSN-P1. (a–d) are photographs taken under oblique light; (e) photomicrographs taken using an epifluorescence microscope. Scale = 1 cm (a–d) and 0.1 mm (e). Abbreviations: SB = stomatal band and NC = normal cells.