Origin of cratonic lithospheric mantle roots: A geochemical study of peridotites from the North Atlantic Craton, West Greenland

Origins of subcalcic garnets and their relation to diamond forming fluids—Case studies from Ekati (NWT-Canada) and Murowa (Zimbabwe)

“…Hence major elements are not useful for estimating melting regimes and are mostly fairly insensitive to melting depth. The depth of melting of peridotite is more reliably constrained from mildly incompatible trace elements such as HREE (Kelemen et al, 1998;Canil, 2004;Simon et al, 2007;Wittig et al, 2008). The low HREE abundances and the fractionation of Lu from Yb in all cratonic peridotites so far measured is most consistent with melting at low pressure (<3 GPa), ruling out the high pressure option.…”

“…Griffin et al (1999) and Griffin et al (2008) propose deep melting (5-7 GPa) on the basis of Al-Cr and Mg-Fe systematics. However, Wittig et al (2008) point out that such major ele- ment systematics are highly sensitive to the pervasive metasomatism experienced by cratonic peridotites. In particular, the most depleted residues will be the most sensitive to modal mineral addition.…”

The age and history of the lithospheric mantle of the Siberian craton: Re–Os and PGE study of peridotite xenoliths from the Obnazhennaya kimberlite

“…(b) Literature data on mantle xenoliths from Udachnaya: Re-Os T RD for whole-rock peridotites, "megacrystalline dunites" (Pearson et al, 1995a) and eclogites (Pearson et al, 1995b) and Lu-Hf T RD and isochron ages of clinopyroxene from spinel peridotites ; (c) Re-Os isochron ages for sulfide inclusions in diamonds from Siberian kimberlites including Udachnaya (Wiggers de Vries et al, 2013); (d) U/Pb ages of detrital zircons and model Sm-Nd ages (T DM ) for crustal basement rocks from the Siberian craton (Rosen, 2002;Rosen et al, 2005). (e) Age distribution plots (T RD ) for peridotite xenoliths from South Africa and North America: the Kaapvaal craton (continuous black line) (Carlson et al, 2004;Carlson et al, 1999;Irvine et al, 2001;Simon et al, 2007), the Slave craton (dashed line) (Aulbach et al, 2004;Irvine et al, 2003;Westerlund et al, 2006) and the North Atlantic craton (grey line) (Bernstein et al, 2006;Hanghøj et al, 2001;Wittig et al, 2008). The Re-Os model ages are calculated with chondritic mantle values after Walker et al (2002) as presented by Pearson and Wittig (2008).…”

Comparison of mantle lithosphere beneath early Triassic kimberlite fields in Siberian craton reconstructed from deep-seated xenocrysts

“…The highly depleted mantle in the lower part is common for some parts of Kuoyka and other northern kimberlitic fields belonging to the Khapchan terrane. It seems that exhausting of the deeper horizons of the SCLM is not a characteristic feature of the marginal part of cratons, but is typical for the shield areas such as Aldan, northern part of Zimbabwe craton (Smith et al, 2009) and Greenland (Wittig et al, 2008).…”