Extended Data Figure 2: Plot of μ¹⁸²W versus total HSE content relative to the present-day mantle, PM.

This is based on the assumption that before late accretion, the mantle was HSE-free and had a μ¹⁸²W of +10 to +30 p.p.m., assuming total contributions of late accretion to be between 0.3% and 0.8% of the mass of the mantle (see labels), as determined from HSE abundances in the Earth’s mantle⁴ and using W contents of 200 p.p.b. for chondrites¹⁴ and 13 p.p.b. for the current mantle³⁸. With the addition of chondritic materials, the total HSE abundances present in the mantle increase and the W isotopic composition decreases to present-day values. Evolution of the mantle composition by late accretion, or mixing between pre-late accretionary mantle and current accessible mantle, are represented by the grey field. Estimate for the HSE content of the lunar mantle (red circle) is taken from ref. 3; error bars, 2 s.d. of the data from the three rocks examined. Diamond symbol indicates the composition of the present-day mantle.