Open AccessIsotopic evidence for a Precambrian metamorphic event within the Charcot Land window, East Greenland Caledonian fold belt
Author(s) -
Bent Hansen,
R. Steiger,
A.K Higgins
Publication year - 1981
Publication title -
bulletin of the geological society of denmark
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.674
H-Index - 28
eISSN - 2245-7070
pISSN - 0011-6297
DOI - 10.37570/bgsd-1980-29-10
Subject(s) - geology , metamorphism , precambrian , overprinting , geochemistry , fold (higher order function) , metamorphic rock , window (computing) , intrusion , basement , gondwana , tectonics , paleontology , archaeology , mechanical engineering , computer science , engineering , history , operating system
Rb-Sr, U-Pb and K-Ar analyses on rocks and minerals from a tectonic window below a Caledonian thrust sheet in the westernmost part of the Scoresby Sund region (70°-72°N) give evidence for a Precambrian age of formation. The Charco't Land supracrustal sequence rests on a basement that is probably of Archaean development and older than at least 2100 m.y. The major regional metamorphism of the supracrustal rocks is probably not much older than the intrusion of two post-kinematic bodies, i.e. about 1840 m.y. Low-grade metamorphism in a tillite and low-grade retrogressive overprinting of the supracrustal rocks are related to Caledonian orogenesis.