An integrated petrological, geochemical and Re–Os isotope study of peridotite xenoliths from the Argyle lamproite, Western Australia and implications for cratonic diamond occurrences

The seismic mid-lithosphere discontinuity

“…Amphibole percentage refers to the amount of amphibole within the xenoliths except where noted. Numbers in parentheses refer to references as follows: (1) Ferguson and Sheraton (1979); (7) Wass and Rogers (1980); (8) Griffin et al (1984); (9) Griffin and O'Reilly (1986); (10) Powell et al (2004); (11) Handler et al (2005); (12) Edwards et al (1992); (13) Downes et al (2007); (14) Luguet et al (2009);(15) Tappe et al (2008); (16) Meyer et al (1994); (17) Vicker (1997); (18) Best (1974a); (19) Wilshire et al (1980); (20) Griffin et al (1999); (21) Kopylova and Russell (2000); (22) Kopylova et al (1999); (23) Kopylova and Caro (2004); (24) Carbno and Canil (2002); (25) Pearson et al (1995); (26) Boyd et al (1997); (27) Ionov et al (2006); (28) Hawkesworth et al (1990); (29) Konzett et al (2000); (30) Waters and Erlank (1988); (31) c From an assessment of >600 thin sections (Hawkesworth et al, 1990).…”

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

“…The peridotitic sulphide inclusions from Ellendale have Re/Os ratios significantly higher (with lower Os concentration) than the extensive harzburgitic sulphide inclusion suite at Panda (Westerlund et al, 2006) and show strong similarity to those of lherzolitic xenoliths from both Udachnaya (Pearson et al, 1995a,b) and Argyle (Graham et al, 1999;Luguet et al, 2009) (Fig. 3), as well as the (hypothetical) primitive upper mantle (PUM) composition determined by Meisel et al (2001).…”

“…The upper limit on the initial 187 Os/ 188 Os ratio gives a Re depletion age of 2.96 Ga, indicating the presence of SCLM beneath Ellendale since at least the Mesoarchaean, with the lherzolitic diamond-forming event much younger and unrelated to the craton keel stabilisation. Luguet et al (2009) recently reported Neoto Mesoarchaean T RD ages for lherzolite xenoliths from Argyle, which indicates that ancient lithospheric mantle extends beneath the entire Kimberley region. This is also supported by low initial Nd isotope ratios (e Nd $ À3 at the isochron age of 1.58 ± 0.06 Ga) of silicate inclusions in diamonds and lherzolite xenoliths from Argyle (Richardson, 1986;Graham et al, 1999).…”

“…Complementing the seismic evidence, cool cratonic geotherms have been established for the West Kimberley (Griffin and Ryan, 1995), East Kimberley and North Kimberley provinces (Griffin and Ryan, 1995;Wyatt et al, 1999). Xenolith studies from the Kimberley area (including Argyle as well the Seppelt kimberlite intruded into the northern Kimberley craton) have shown that the SCLM is largely lherzolitic in composition (with minor harzburgite component) and was stabilised in the Archaean (Jaques et al, , 1989Lucas et al, 1989;Ramsay et al, 1994;Smith et al, 1994;Griffin and Ryan, 1995;Graham et al, 1999;Wyatt et al, 1999;Downes et al, 2007;Luguet et al, 2009).…”

“…Eclogite xenoliths-Udachnaya (Pearson et al, 1995a,b). Lherzolite xenoliths-Udachnaya (Pearson et al, 1995a,b); Argyle (Graham et al, 1999;Luguet et al, 2009). Harzburgite xenoliths-Panda (Westerlund et al, 2006).…”