Campbell, IanGriffiths, Ross2015-12-130012-821Xhttp://hdl.handle.net/1885/77311The MgO content of the highest MgO plume-related komatiites and picrites remained constant at 32 ± 2.5% between 3.5 and 2.7 Ga, then fell to 21 ± 3% by ca. 2.0 Ga, a value similar to the present day value. Because there is a linear relationship between201410.1016/j.epsl.2013.11.0482015-12-11