SHRIMP U-Pb zircon geochronology of granites from Sansom Island, Prydz Bay, East Antarctica

• Main Authors: Yingchun, Cui, Xiaochun, Liu, Chenguang, Liu, Jianhui, Liu
• Format: Article in Journal/Newspaper
• Language: English
• Published: Polar Research Institute of China - PRIC 2018
• Subjects: Terrestrial; East Antarctica; Prydz Bay; The Landing; Sandefjord; Sansom Island; Landing Bluff; Sandefjord Bay; Advances in Polar Science; Antarc*; Antarctica; Polar Science
• Online Access: http://library.arcticportal.org/2659/; http://library.arcticportal.org/2659/1/A1802006.pdf

Sansom Island consists of two low nunataks in Sandefjord Bay, a marginal gulf of Prydz Bay, East Antarctica. These nunataks are composed of two kinds of undeformed biotite granites, and these granites have been dated by ion-microprobe U-Pb zircon geochronology. The zircons from these two samples yield SHRIMP zircon U-Pb concordant ages of 516±5 Ma and 495.8±4.2 Ma, respectively. The results indicate that these granites were emplaced in two pulses in the Cambrian, and further demonstrates the Pan-African event that has overprinted this area. The age of ca. 516 Ma suggests that the undeformed Sansom Island Granite had a different geological history from the Landing Bluff Granite, which contains deformed granite xenoliths dated at ca. 503 Ma, and probably indicates regional variations in the age and intensity of deformation.