³He/⁴He Ratio in Olivines from Linosa, Ustica, and Pantelleria Islands (Southern Italy)

Table 2

Measured He concentrations and isotope ratios in olivine crystals from basaltic-hawaiitic lava flows from Linosa, Pantelleria and Ustica volcanic islands.

Sample	Weight (g)	Number of strokes cumulative	R/Ra	^4He cumulative (10^−8 cm^3 STP/g)	R/Ra  cumulative
Linosa
Lin 15	0.50214	100	7.27	3.58	7.27
		200	7.82	3.96 ± 0.04	7.3 ± 0.2
Lin 20-1	0.51271	100	7.53	4.23	7.53
		200	7.36	5.06	7.50
		300	6.43	5.40	7.44
		400	7.52	5.61 ± 0.04	7.4 ± 0.2
Lin 20-2	0.49958	100	7.57	4.04	7.57
		200	7.55	4.91	7.56
		300	7.53	5.38	7.56
		400	7.54	5.62 ± 0.04	7.6 ± 0.2
Lin 27	0.50058	100	6.99	4.48	6.99
		200	7.26	4.77	7.00
		300	7.01	4.90 ± 0.04	7.0 ± 0.2
Pantelleria
Pant 8A	0.54177	100	7.65	0.249 ± 0.005	7.6 ± 0.3
Ustica
Ust 1	0.50126	100	7.68	11.49	7.68
		200	7.56	13.00	7.67
		300	7.80	13.96	7.68
		400	7.21	14.61	7.66
		500	8.14	15.05	7.67
		600	7.97	15.40	7.68
		700	8.24	15.7 ± 0.1	7.7 ± 0.2
Ust 2	0.50146	100	7.67	14.85	7.67
		200	7.43	17.34	7.63
		300	7.61	18.43	7.63
		400	6.96	19.31	7.60
		500	7.40	19.73	7.60
		600	7.60	20.18	7.60
		700	7.58	20.65	7.60
		800	7.54	20.9 ± 0.1	7.6 ± 0.2