Table 3.

Helium in whole-rock samples from the Mid-Cayman Rise and the Zambales ophiolite. All measurements were performed by crushing in vacuum.

					3He/4He
location	lithology	sample	crush 4He (cc STP/g)	crush 4He (nmol g−1)	(R/Ra)	2σ	CH4/3He
Cayman	gneissic metagabbro	ALV 620-3C	4.68 × 10−7	2.09 × 10−2	8.32	0.16	1.28 × 109
	olivine gabbro	ALV 620-5-1	2.26 × 10−9	1.01 × 10−4	7.02	0.24	2.56 × 1011
		ALV 624-5-1	7.70 × 10−9	3.44 × 10−4	7.25	0.17	2.67 × 1010
	troctolite	ALV 621-3-1	6.46 × 10−9	2.88 × 10−4	7.53	0.19	2.57 × 1010
		ALV 623-3-2	3.53 × 10−8	1.57 × 10−3	7.66	0.15	4.27 × 109
	peridotite	ALV 624-3-3	8.97 × 10−11	4.01 × 10−6	9.91	1.23	7.70 × 1010
		ALV 624-6-2	2.47 × 10−10	1.10 × 10−5	6.58	0.59	9.76 × 1010
Zambales	dunite	ZMCR-02	1.33 × 10−9	5.92 × 10−5	3.00	0.16	8.06 × 109
	peridotite	NSS-02	9.12 × 10−11	4.07 × 10−6	5.57	0.92	7.23 × 1011
		NSS-04	1.15 × 10−10	5.11 × 10−6	4.00	1.01	1.30 × 1012