Re–Os isotopic composition of peridotitic sulphide inclusions in diamonds from Ellendale, Australia: Age constraints on Kimberley cratonic lithosphere

Mantle Sulfides and their Role in Re–Os and Pb Isotope Geochronology

“…20 Ma Ellendale lamproite pipes (Smit et al 2010 Os initial ratio suggests a Re depletion age of 2.96 Ga, indicating the presence of SCLM beneath Ellendale since at least the Mesoarchaean. This is supported by independent evidence for the presence of deep SCLM below the King Leopold Orogen and the Kimberley craton by seismic tomography (van der Hilst et al 1998;Kennett 2003;Fishwick et al 2005) and cool cratonic geotherms for the West Kimberley province (Griffin and Ryan 1995).…”

“…However, with increasing numbers of analyses, the distinction between these two groups of Siberian diamonds became less clear (Deines and Harris 1995;Bulanova et al 1996). Some studies (e.g., Smit et al 2010) have observed a pyroxenitic BMS paragenesis compositionally in between eclogitic and peridotitic, which perhaps may explain the less clear distinction for some BMS inclusions. Subsequent studies have found that a combination of Ni and Os abundances is a more robust discriminator ).…”

“…This technique produced the first successful date on a suite of diamonds from Koffiefontein, South Africa ). Since then this has been the preferred method for the dating of diamond formation (e.g., Pearson et al 1999a,b;Pearson and Shirey 1999;Richardson et al 2001Richardson et al , 2004Richardson et al , 2009Shirey et al 2001Shirey et al , 2002Aulbach et al 2004aAulbach et al ,b, 2009aAulbach et al ,b,c, 2011Westerlund et al 2004Westerlund et al , 2006Smit et al 2010).…”

“…Both bulk-rock and BMS Re-Os ages frequently show a correspondence between the crust and the underlying mantle, sampled as xenoliths, from which it is inferred to be derived (Pearson et al 1995a(Pearson et al ,b 2002Handler et al 1997;Carlson et al 1999;Chesley et al 1999;Menzies et al 1999;Hanghøj et al 2001;Irvine et al 2001Irvine et al 2003Lee et al 2001;Griffin et al 2002;Schmidt and Snow 2002;Carlson and Moore 2004;Marchesi et al 2010;González-Jiménez et al 2013. However, there are some examples where underlying mantle is apparently older than the overlying crust (Parkinson and Pearce 1998;Peslier et al 2000;Handler et al 2003;Smit et al 2010). …”

Deep Carbon

“…58 Figure 5.8 Lherzolitic diamond formation through time: ca. 2.1 to 1.8 Ga, diamonds from Premier (Kaapvaal craton) and 23rd Party Congress/Udachnaya (Siberian craton); 1.4 Ga, diamonds from Ellendale (Western Australia); 161 1.1 to 1.0 Ga, diamonds from 23rd Party Congress/Mir (Siberian craton) 162 and Venetia (Zimbabwe craton); 163 and 0.72 Ga, diamonds from Attawapiskat (Superior craton). 164 Numbers in parentheses give host kimberlite eruption ages (in giga-years) to illustrate the delay between lherzolitization and kimberlite magmatism.…”