Tremolite–calcite veins in the footwall of the Simplon Fault, Antigorio Valley, Lepontine Alps (Italy)

Meggiolaro, Vito; Sapigni, Michele; Fioretti, Anna Maria

doi:10.1007/s00015-011-0074-0

Swiss Journal of Geosciences

Table 1 Representative chemical composition of tremolite from Alagua, Rio Antolina and Simbo; the crystallochemical formula is based on 23 atoms of oxygen

From: Tremolite–calcite veins in the footwall of the Simplon Fault, Antigorio Valley, Lepontine Alps (Italy)

	Tremolite												Phlogopite
	Alagua						Antolina					Simbo	Alagua	Antolina
Analysis	1-Tr1	2-Tr1	3a-Tr1	3a-Tr2	14-Tr1	14-Tr2	5-Tr1	8-Tr1	10-Tr1	10-Tr2	10-Tr3	2-Tr1	14-Ph	10-Ph
SiO₂	58.82	58.58	57.99	58.16	58.24	58.77	59.28	57.77	58.7	58.62	58.12	59.18	41.43	43.48
TiO₂	0.02	0.00	0.01	0.18	0.02	0.02	0.00	0.01	0.02	0.03	0.03	0.02	0.35	0.16
Al₂O₃	0.36	0.53	0.68	1.03	0.95	0.41	0.46	0.24	0.54	0.89	0.59	0.98	13.56	11.9
FeO	3.66	2.46	4.98	2.04	5.88	4.62	1.74	5.2	0.67	1.32	4.52	0.85	8.01	4.38
MnO	0.11	0.22	0.16	0.17	0.25	0.30	0.25	0.38	0.17	0.18	0.40	0.11	0.08	0.07
MgO	21.86	22.68	21.06	23.17	20.67	21.67	23.42	20.9	24.04	23.43	21.32	23.3	21.46	25.00
CaO	13.48	13.45	12.92	13.25	12.89	13.46	13.82	12.86	13.47	13.42	13.06	13.69	0.22	0.20
Na₂O	0.09	0.14	0.17	0.21	0.15	0.11	0.24	0.12	0.18	0.25	0.11	0.07	0.05	0.26
K₂O	0.03	0.06	0.05	0.09	0.06	0.04	0.10	0.05	0.17	0.10	0.05	0.11	9.10	9.00
F	nd	nd	0.09	0.37	0.35	0.30	nd	nd	0.73	0.83	0.32	nd	0.82	2.28
Total	98.43	98.11	98.11	98.67	99.46	99.7	99.29	97.54	98.69	99.07	98.52	98.31	95.06	96.71
Si	8.019	7.985	7.978	7.884	7.943	7.984	7.971	7.998	7.958	7.943	7.976	7.980	5.938	6.015
Al^iv	0.000	0.015	0.022	0.116	0.057	0.016	0.029	0.002	0.042	0.057	0.024	0.020	2.062	1.940
Al^vi	0.058	0.070	0.088	0.049	0.096	0.050	0.044	0.038	0.044	0.086	0.071	0.137	0.228	0.000
Ti	0.002	0.000	0.001	0.018	0.002	0.002	0.000	0.001	0.002	0.003	0.003	0.002	0.037	0.017
Fe³⁺	0.000	0.000	0.069	0.111	0.14	0.008	0.000	0.104	0.003	0.00	0.069	0.000	0.000	0.000
Fe²⁺	0.417	0.280	0.504	0.120	0.531	0.517	0.195	0.499	0.073	0.150	0.450	0.095	0.960	0.506
Mn	0.013	0.025	0.019	0.020	0.029	0.035	0.028	0.045	0.019	0.020	0.047	0.012	0.009	0.008
Mg	4.443	4.608	4.319	4.682	4.203	4.389	4.695	4.314	4.859	4.734	4.360	4.684	4.584	5.155
Ca	1.969	1.965	1.904	1.924	1.884	1.959	1.991	1.908	1.957	1.949	1.920	1.979	0.033	0.029
Na	0.024	0.037	0.045	0.055	0.040	0.029	0.062	0.031	0.048	0.064	0.031	0.017	0.014	0.070
K	0.005	0.010	0.009	0.016	0.010	0.007	0.017	0.01	0.029	0.018	0.009	0.019	1.664	1.588
F	nd	nd	0.039	0.159	0.151	0.129	nd	nd	0.313	0.354	0.139	nd	0.373	0.995
Mg#	0.91	0.94	0.90	0.97	0.89	0.89	0.96	0.90	0.99	0.97	0.91	0.98	0.83	0.91

Average chemical composition of phlogopite from Alagua (mean of two analyses) and Rio Antolina (mean of eight analyses); the crystallochemical formula is based on 22 atoms of oxygen. The standard deviation of the mean values is below 0.5 for major elements, and below 0.2 for minor elements. The database of analyses is available on line as electronic supplementary material (Online Resource 1 & 2)
nd not analysed
Mg# Mg/(Mg+Fe²⁺)

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