Age, origin, and thermal evolution of the ultra-fresh ~ 1.9 Ga Winnipegosis Komatiites, Manitoba, Canada
文摘
Pristine Palaeoproterozoic komatiites are described, their cooling and crystallisation history is reconstructed Parental melts were nominally dry, with depleted compositions, and MgO contents ≈ 24 wt% Liquidus temperature of ~ 1501 °C requires anomalously hot mantle Formation from a mantle plume that was deflected by strong gradients in lithospheric thickness towards pre-existing rifts New U–Pb zircon age of 1870.3 ± 7.1 Ma for the Winnipegosis Komatiite Belt