Skip to main content
U.S. flag

An official website of the United States government

Lu-Hf total-rock age for the Amîtsoq gneisses, West Greenland

January 1, 1981

Lu-Hf total-rock data for the Amîtsoq gneisses of West Greenland yield an age of 3.55±0.22Gy(2σ), based on the decay constant λ176Lu=1.96×10−11y−1, and an initial176Hf/177Hf ratio of 0.280482±33. The result is in good agreement with Rb-Sr total-rock and U-Pb zircon ages. In spite of severe metamorphism of the area at 2.9 Gy, zircons from two of the samples have remained on the total-rock line, and define points close to the initial Hf ratio. The initial176Hf/177Hf lies close to a chondritic Hf isotopic evolution curve from 4.55 Gy to present. This is consistent with the igneous precursors to the Amîtsoq gneisses having been derived from the mantle at or shortly before 3.6 Gy. Anomalous relationships between Hf concentration and the176Lu/177Hf ratio may suggest that trace element abundances in the Amîtsoq gneisses are partly controlled by processes related to metamorphism.

Publication Year 1981
Title Lu-Hf total-rock age for the Amîtsoq gneisses, West Greenland
DOI 10.1016/0012-821X(81)90093-5
Authors H.S. Pettingill, P. J. Patchett
Publication Type Article
Publication Subtype Journal Article
Series Title Earth and Planetary Science Letters
Index ID 70011972
Record Source USGS Publications Warehouse