He, Ne and Ar systematics in single vesicles: Mantle isotopic ratios and origin of the air component in basaltic glasses

Noble gas constraints on the origin and evolution of Earth’s volatiles

“…4.6). The distinction might be explained by the different method of blank corrections (Raquin et al, 2008). Nevertheless, with the exception of one particularly radiogenic vesicle in Burnard's study (~64,000±8,000), both studies obtained 40 Ar/ 36 Ar of the order of ~40,000 in vesicles from the 2πD43 sample, compatible with the highest ratios measured in MORB, although higher (e.g., Staudacher et al, 1989).…”

“…This technique was successively applied to the gas-rich sample 2πD43 (Fig. 4.6) by Burnard et al (1997) and later on by us (Raquin et al, 2008). In Burnard's study, the analytical technique to "open" a vesicle was slightly different.…”

“…This method consists of the extraction of the gas in a single vesicle using a laser (Burnard et al, 1997;Burnard, 1999). Subsequent studies on single vesicles using laser ablation were reported by Raquin et al (2008) and Colin et al (2013). The traditional technique to extract gases from oceanic glassy samples had been either crushing or step heating of a large sample (~1 g) in order to get sufficient gas to make precise measurements.…”

Tracages isotopiques de l'origine et de l'évolution des magmas en milieu continental :

“…Ar of 27,000±4000 with an upper limit of 40,000 (Moreira et al, 1998;Raquin et al, 2008) and a radiogenic 4 He/ 40 Ar* = 2.5 (Graham, 2002). The crust has a 8 15 N> +7 %o (Javoy, 1997), a 40 Ar/…”

“…Ar of 35,000 ± 5000 by taking into account the observed variability in MORBs and popping rocks (Moreira et al, 1998;Raquin et al, 2008). The N isotopic composition of the lower mantle is less constrained.…”