Swiss Journal of Geosciences

Table 3 Composition of phengite, paragonite and chlorite in TGU eclogite SW9

From: The Theodul Glacier Unit, a slab of pre-Alpine rocks in the Alpine meta-ophiolite of Zermatt-Saas, Western Alps

	Ph	Ph	Pg	Pg	Chl	Chl	Chl
	Ph	Ph	Pg	Pg	3	2	1
SiO₂	52.41	48.59	48.28	48.77	26.56	25.52	24.31
TiO₂	0.08	0.15	0.04	0.06	0.06	0.12	0.06
Al₂O₃	29.87	32.78	40.23	41.44	20.9	19.24	20.4
FeO	2.43	2.18	0.37	0.31	21.6	29.57	31.81
MnO	0.05	0.03	0.01	0.03	0.06	0.34	0.54
MgO	3.46	2.07	0.28	0.12	17.4	12.33	10.29
CaO	0.02	0.12	0.13	0.16
Na₂O	0.67	0.5	6.67	6.59
K₂O	9.8	9.34	1.11	0.46
Total	98.81	96.1	97.28	98.17	87.01	87.39	88.05
Si	3.353	3.231	3.019	3.007	2.764	2.774	2.663
Ti	0.004	0.008	0.002	0.003	0.005	0.01	0.005
Al	2.253	2.569	2.965	3.012	2.564	2.465	2.634
Fe²⁺	0.130	0.121	0.019	0.016	1.880	2.688	2.914
Mn	0.003	0.002	0.000	0.002	0.005	0.031	0.050
Mg	0.330	0.205	0.026	0.011	2.699	1.998	1.680
Ca	0.002	0.009	0.009	0.011
Na	0.083	0.064	0.808	0.788
K	0.800	0.792	0.089	0.036
X_Mg	0.72	0.63	0.57	0.41	0.589	0.426	0.365

Mica: Total includes traces of Cr. Traces of F and Cl are close to or below detection limit. XMg = Mg/(Mg + Fe)
Chlorite: Totals contain traces of Cr, Ca, Na and K. (1) chlorite in direct contact to garnet; (2) matrix chlorite intergrown with paragonite; (3) chlorite veins in garnet

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