Table 3.

The chemical composition of major oxides (wt%), loss of ignition, and alteration indices of the studied bulk samples.

Sample no.	AZ01	AZ02	AZ03	AZ04	AZ05	AZ06	AZ07	AZ08	AZ09	AZ10
SiO2	55.42	53.87	54.05	56.07	53.28	54.73	55.11	54.58	54.26	54.64
Al2O3	26.84	27.45	28.43	29.01	27.46	28.35	27.05	27.26	28.18	28.76
TiO2	1.32	0.52	1.68	1.71	1.82	1.84	1.77	0.96	0.71	1.73
Fe2O3 TT	2.02	2.89	1.86	1.45	2.36	1.77	2.37	2.83	3.51	2.55
MgO	0.28	0.34	0.32	0.36	0.37	0.31	0.34	0.32	0.33	0.38
CaO	0.08	0.11	0.09	0.11	0.05	0.07	0.12	0.13	0.06	0.08
K2O	0.15	0.12	0.11	0.21	0.19	0.17	0.15	0.18	0.17	0.19
Na2O	0.24	0.22	0.19	0.23	0.18	0.17	0.23	0.17	0.22	0.21
P2O5	0.04	0.05	0.03	0.03	0.04	0.04	0.03	0.06	0.05	0.04
LOI	13.25	14.50	12.71	10.35	13.73	12.42	12.47	13.64	12.22	11.36
Total	99.64	99.62	99.47	99.53	99.48	99.87	99.64	99.86	99.71	99.94
SiO2/Al2O3	2.06	1.96	1.90	1.93	1.94	1.93	2.04	2.00	1.93	1.90
Flux	2.77	2.68	2.87	3.36	3.15	2.49	3.21	2.63	3.29	3.41
CIA	98.28	98.39	98.65	98.07	98.49	98.57	98.19	98.27	98.43	98.36
ICV	0.15	0.15	0.16	0.18	0.18	0.15	0.18	0.16	0.18	0.18
CEC	10.00	11.00	11.00	11.00	10.00	11.00	10.00	9.00	10.00	10.00

TT total iron as Fe₂O₃, LOI loss on ignition, CIA chemical index of alteration, ICV index of composition variability, CEC cation exchange capacity.