Rb-Sr mineral isochron ages of metamorphic rocks around Syowa Station and from the Yamato Mountains, East Antarctica

• Main Authors: Ken Shibata, Keizo Yanai, Kazuyuki Shiraishi
• Format: Report
• Language: English
• Published: Geological Survey of Japan/National Institute of Polar Research/National Institute of Polar Research 1985
• Subjects: East Antarctica; Queen Maud Land; Skarvsnes; Syowa Station; Yamato; Antarc*; Antarctica; Memoirs of National Institute of Polar Research; Polar Research
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=1791; http://id.nii.ac.jp/1291/00001791/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=1791&item_no=1&attribute_id=18&file_no=1

Rb-Sr mineral isochron ages were determined for three metamorphic rocks around Syowa Station and from the Yamato Mountains, eastern Queen Maud Land. The Rb-Sr isotopic data demonstrate that the complete Sr isotopic homogenization occurred among K-feldspar, plagioclase, biotite and whole-rock, and define isochron ages of 482.5±9.5,468.9±7.8 and 493.3±4.5 Ma for rocks from Syowa Station, Skarvsnes and the Yamato Mountains, respectively. These ages probably represent the time of cooling after the regional metamorphism or granite intrusion. K-Ar age determinations on three metamorphic rocks give biotite and hornblende ages of 469±14,480±15 and 483±15Ma, and 502±15Ma, respectively.