Supplemental data for Warren et al. (2009): Plagioclase Major Element Compositions																											
																											
Error is the 2 sigma standard deviation among averaged analyses.																											
M indicates the peridotite matrix of a veined sample and V indicates a pyroxenite vein.																											
"For sample RC27-9-6-2, matrix and vein averages are from Lee (1997)."																											
																											
Sample	Grain	Pts	SiO2	2 sig	Al2O3	2 sig	FeO	2 sig	MgO	2 sig	CaO	2 sig	Na2O	2 sig	K2O	2 sig	Total	An	Ab	Comments							
Van7-96-09V	Plag 1	5	49.75	0.25	31.91	0.22	0.11	0.02	0.01	0.01	14.29	0.19	3.11	0.12	0.00	0.00	99.18	71.7	28.3	Pyroxenite vein							
Van7-96-09V	Plag 2	6	46.15	0.53	34.77	0.48	0.13	0.01	0.00	0.01	17.27	0.20	1.46	0.15	0.01	0.00	99.79	86.7	13.2	Pyroxenite vein							
Van7-96-16V	Plag 1	6	47.07	0.17	34.41	0.19	0.12	0.03	0.01	0.01	17.14	0.03	1.66	0.12	0.01	0.01	100.41	85.1	14.9	Pyroxenite vein							
Van7-96-16V	Plag 3	6	45.72	0.28	35.35	0.13	0.16	0.04	0.01	0.00	18.28	0.17	1.00	0.09	0.01	0.01	100.53	91.0	9.0	Pyroxenite vein							
Van7-96-19M	Plag 1	5	51.23	0.29	30.37	0.35	0.12	0.05	0.37	0.40	12.87	0.36	4.24	0.15	0.00	0.01	99.20	62.6	37.3	Peridotite matrix near vein							
Van7-96-19V	Plag 3	5	51.86	0.37	30.27	0.26	0.11	0.02	0.00	0.00	12.53	0.24	4.57	0.14	0.01	0.00	99.34	60.2	39.7	Pyroxenite vein							
Van7-96-21V	Plag 1	5	50.16	2.06	32.21	1.19	0.09	0.03	0.01	0.01	14.17	1.41	3.23	0.86	0.00	0.00	99.86	70.8	29.2	Pyroxenite vein							
Van7-96-21V	Plag 2	5	51.94	1.72	31.00	0.70	0.09	0.02	0.02	0.01	12.90	1.07	4.00	0.70	0.00	0.00	99.94	64.1	35.9	Pyroxenite vein							
Van7-96-21V	Plag 3	5	52.50	2.15	31.00	1.09	0.13	0.05	0.02	0.01	12.64	1.47	4.08	0.71	0.00	0.00	100.37	63.1	36.9	Pyroxenite vein							
RC27-9-6-2M	Average	2	54.15	0.00	29.79	0.01	0.14	0.23	0.03	0.26	11.87	0.01	5.03	0.02	0.09	0.15	101.10	56.3	43.2	Peridotite matrix near vein
RC27-9-6-2V	Average	6	49.80	0.80	32.60	0.33	0.12	0.03	0.05	0.07	15.24	0.63	3.00	0.38	0.00	0.00	100.81	73.7	26.3	Clinpyroxenite vein