Archaean age and Proterozoic metamorphic overprinting of the crystalline basement at Victoria Fjord, North Greenland

Abstract

Zircon U-Pb and Rb-Sr whole-rock isotope data show that the crystalline rocks at the head of Victoria Fjord, North Greenland, have Archaean ages (c. 3000 Ma), but that strong disturbance of the isotope systems has taken place later. K-Ar analyses on hornblende show that the area underwent a phase of high-grade metamorphism during the Proterozoic, probably around 1850 Ma.