SHRIMP U-Pb zircon geochronology of granites from Sansom Island, Prydz Bay, East Antarctica
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 yie...
Main Authors: | , , , |
---|---|
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Polar Research Institute of China - PRIC
2018
|
Subjects: | |
Online Access: | http://library.arcticportal.org/2659/ http://library.arcticportal.org/2659/1/A1802006.pdf |
Summary: | 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. |
---|