For the modal data, 1000 points have been counted in the thin sections on a 0.2x0.2 mm grid. The modal data are given in vol. %. Modal proportions of primary minerals are given excluding vein material and serpentinization of unknown origin. Total olivine includes serpentinization after olivine. Total orthopyroxene includes serpentinization after orthopyroxene. The geochemistry of the precursors (reconstructed contents) has been reconstructed by combining the modal proportions of the primary phases and their composition (averages of the microprobe analyses). Assumptions and procedures involved in calculation of the enrichment factors are discussed in the text of the referenced paper.