Bulk chemistry (a,b,c) and relation between Mg/(Mg + Fe) (atomic percent) and modal compositions of olivine (d). They are in abyssal and continental cratonic peridotites. Data for abyssal peridotites are after Michael and Bonatti (1985), Dick (1989), Dick and Natland (1996), Arai and Matsukage (1996), and Matsukage et al. (2005). Data for the Kaapvaal and Siberian cratons are after Nixon and Boyd (1973), Cox et al. (1973), Carswell et al. (1979), Boyd et al. (1993), Boyd et al. (1997), Gibson et al. (2008), Katayama et al. (2009), Goncharov et al. (2012), and Doucet et al. (2013). CI chondrite, geochemical fractionation trend, and cosmochemical fractionation trend are referred from Jagoutz et al. (1979).