Table 1.

EMP glass analysis.

Pumice sample	37	37	T4	T4	T4	T4	T4	T4	T4	T3	T3	T3	T3
SiO2	60.94	61.58	60.41	57.27	62.12	61.56	56.53	61.18	60.26	61.16	60.92	60.96	62.60
TiO2	0.62	0.61	0.61	0.57	0.63	0.61	0.51	0.61	0.60	0.40	0.40	0.38	0.31
Al2O3	17.24	17.63	17.46	16.78	17.86	17.45	16.10	17.63	17.12	18.48	18.53	18.38	18.98
MgO	0.29	0.29	0.38	0.31	0.32	0.32	0.41	0.33	0.33	0.60	0.57	0.57	0.53
CaO	0.96	0.95	0.93	0.86	0.93	0.95	0.92	1.00	0.90	2.50	2.50	2.41	2.57
MnO	0.34	0.30	0.37	0.31	0.40	0.42	0.31	0.38	0.36	0.15	0.15	0.15	0.19
FeO	2.74	2.81	2.74	2.61	2.86	3.02	2.66	2.87	2.72	3.23	3.20	3.01	3.13
Na2O	7.93	7.82	7.71	7.46	7.84	7.76	6.68	7.95	7.90	3.29	3.16	2.60	2.40
K2O	5.99	5.92	5.97	5.91	6.29	6.11	5.48	6.22	5.96	8.86	8.55	8.54	8.24
P2O5	0.03	0.07	0.03	0.07	0.00	0.05	0.05	0.03	0.00	0.06	0.15	0.12	0.09
SO3	0.11	0.03	0.05	0.09	0.00	0.04	0.04	0.02	0.03	0.12	0.11	0.12	0.14
F	0.31	0.45	0.44	0.24	0.49	0.54	0.31	0.19	0.56	0.08	0.18	0.27	0.07
Cl	0.73	0.71	0.79	0.68	0.75	0.76	0.83	0.78	0.71	0.48	0.46	0.41	0.43
Total	98.24	99.16	97.91	93.15	100.49	99.59	90.83	99.18	97.44	99.39	98.88	97.94	99.66
SiO2*	60.94	61.58	62.53	62.15	62.59	62.66	63.06	62.30	62.67	61.16	60.92	60.96	62.60
K2O + Na2O*	14.34	14.02	14.16	14.51	14.24	14.12	13.56	14.43	14.41	12.31	11.93	11.47	10.74
*Recalculated at 100 on dry basis
K2O/Na2O	0.76	0.76	0.77	0.79	0.80	0.79	0.82	0.78	0.75	2.69	2.71	3.28	3.44