"Table 9. Whole-rock chemical composition (weight percent) of substrate rocks on six seamounts.  
[Chemical composition determined by X-ray fluorescence (XRF); LOI, Loss on ignition at 900ūC; --, no data]"									
	Rodriguez		San Marcos		Adam				
	"D3-5B
"	"D4-4
"	D5-1D	D6-19	D7-1	D8-1B	D9-1A	D9-9D	D9-33A
	Breccia	Vesicular basalt	Basalt	Vesicular basalt	Mudstone	Vesicular basalt	Altered tuff	Altered hyaloclastite	Dolostone
SiO2	41.9	46.1	46.4	46.7	50.6	49.8	46.3	45.4	7.79
Al2O3	13.9	17.8	17.2	17.3	11.3	15.9	12.4	13.6	2.00
Fe2O3	6.31	3.76	5.89	5.37	6.85	3.35	9.25	8.43	3.13
FeO	4.14	4.48	4.53	4.44	.11	4.76	.11	--	.72
TiO2	2.12	2.67	2.80	2.82	.59	1.69	1.60	1.33	.10
Na2O	3.04	3.29	3.68	3.92	3.79	3.03	2.81	2.61	.46
MgO	7.26	5.74	4.42	4.00	3.87	6.44	4.28	4.12	16.7
K2O	1.47	1.52	1.73	1.76	2.07	.41	1.77	1.66	.29
CaO	5.77	8.07	8.63	9.65	2.46	12.7	.82	1.82	27.4
P2O5	.31	1.10	.86	.94	.44	.24	.11	.11	.27
MnO	.49	.13	.17	.26	.52	.14	.23	3.37	.62
LOI	12.3	4.83	3.27	2.37	15.3	1.55	19.5	17.0	40.6
Total	99.0	99.5	99.6	99.5	97.9	100.0	99.2	96.8	100.1
									
H2O+	2.79	.72	1.68	1.93	1.45	.47	5.14	5.16	1.52
H2O-	8.59	3.84	1.81	.79	8.69	.70	12.6	10.6	.75
CO2	.14	.06	.02	<.01	.60	.57	.05	.08	--
									
	Adam	Hoss		Little Joe		Ben			
	D9-34B	D10-4B	D11-1	D14-2A	D14-3A	D17-7	D17-8	D17-25	D17-29
	Dolostone	Mn-cemented breccia	Calcareous porcellanite	Dolomitic mudstone	Phosphorite (breccia)	Hyalo-clastite	Phosphorite (breccia)	Basalt	Basalt
SiO2	9.84	41.6	69.8	68.4	2.92	46.8	8.95	50.3	46.6
Al2O3	2.66	11.4	4.26	8.93	.58	12.3	1.68	15.2	18.9
Fe2O3	2.70	9.10	.98	2.86	.31	10.4	1.58	3.36	7.59
FeO	.44	--	1.09	1.19	.21	--	.57	5.43	3.52
TiO2	.13	1.26	.25	.51	<.02	1.25	.04	1.41	1.03
Na2O	.53	2.56	1.30	1.68	1.44	2.86	1.50	2.74	2.52
MgO	16.5	4.92	1.08	2.58	1.00	4.17	1.25	6.77	3.02
K2O	.43	1.44	.84	1.63	.13	2.63	.60	0.11	.25
CaO	26.0	4.11	7.29	3.07	48.3	1.85	4.6	13.7	14.1
P2O5	.36	.15	.26	.91	30.2	.06	26.6	0.13	.41
MnO	.14	6.93	<.02	.07	<.02	1.19	<0.02	0.16	.11
LOI	40.1	12.5	11.8	7.51	10.6	16.2	11.1	.90	2.16
Total	99.8	93.5	99.0	99.3	95.7	99.2	96.5	100.2	100.2
									
H2O+	1.90	4.83	3.38	2.52	3.22	6.16	2.49	.32	1.44
H2O-	.71	6.69	3.02	2.41	1.86	9.87	3.00	.34	.85
CO2	38.9	.06	8.75	3.17	7.26	.05	7.59	.23	.16