Detrital zircon U–Pb dates from the Sawando Complex of the Mino Terrane in the Takane area, Gifu Prefecture, Japan

Abstract

To increase the number of radiometric dates of Jurassic accretionary complexes in Japan, we conducted zircon U–Pb dating of a sandstone sample from the Sawando Complex in the eastern Mino Terrane using a multi-collector inductively coupled plasma mass spectrometer coupled with a multi-spot femtosecond laser ablation system (msfsLA-MC-ICP-MS). Thirty two concordant dates from 72 analyzed grains are divided into seven groups: 1920–1850 Ma (Paleoproterozoic), 1110 Ma (Mesoproterozoic), 492 Ma (Cambrian), 442 Ma (Silurian), 262–260 Ma (Permian), 250–218 Ma (Triassic), and 186–168 Ma (Jurassic). The youngest single grain date (YSG) is 168.0±6.9 Ma (±2σ). The YSG is within uncertainty of radiolarian ages reported in previous studies (late Callovian to middle Oxfordian).