Bristen granite: a highly differentiated, fluorite-bearing A-type granite from the Aar massif, Central Alps, Switzerland

Bucher, Kurt; Seelig, Ulrike

doi:10.1007/s00015-017-0294-z

Swiss Journal of Geosciences

Table 2 Composition of sheet silicates, muscovite, biotite and chlorite

From: Bristen granite: a highly differentiated, fluorite-bearing A-type granite from the Aar massif, Central Alps, Switzerland

Mineral	Muscovite	Muscovite	Muscovite	Muscovite	Biotite	Biotite	Chlorite	Chlorite	Chlorite	Chlorite
Geol. unit	Brgr	Brgr	Brgr	cAgr	Brgr	cAgr	Brgr	Brgr	Brgr	cAgr
# Points	16	1	1	4	15	10	17	1	1	10
Assemblage			ps				Matrix	ps	Chl-Ab vein
SiO₂	47.95	46.30	43.92	47.85	34.25	35.79	22.71	22.81	22.45	25.38
TiO₂	0.16	0.28	0.31	0.01	1.03	1.57	0.06	0.15	0.07	0.06
Al₂O₃	28.96	28.46	27.07	29.79	17.45	16.2	19.42	18.93	20.11	18.73
FeO	7.45	8.38	8.81	4.25	31.48	24.36	43.43	41.45	42.36	32.11
MnO	0.11	0.18	0.26	0.04	0.55	0.54	1.36	2.03	2.15	1.04
MgO	0.58	0.58	0.57	1.90	0.99	7.59	1.03	1.4	1.31	10.37
CaO	0.02	0.02	1.56	bd	0.04	0.06	0.04	0.08	0.04	0.07
Na₂O	0.10	0.08	0.11	0.18	0.09	0.06	0.04	0.03	bd	0.03
K₂O	10.27	10.94	10.66	10.83	8.71	9.08	0.07	0.09	0.01	0.03
F	0.55	0.45	0.41	0.11	0.45	0.34	bd	bd	bd	bd
Total^d	94.74^a	94.26	92.29	94.16^b	93.82	94.48^c	88.16	86.33	88.51	87.82
Oxygen	22	22	22	22	22	22	28	28	28	28
Si	6.543	6.429	6.308	6.503	5.585	5.598	5.344	5.415	5.247	5.583
Al(IV)	1.457	1.571	1.692	1.497	2.415	2.402	2.656	2.585	2.753	2.417
sum T	8.000	8.000	8.000	8.000	8.000	8.000	8.000	8.000	8.000	8.000
Ti	0.016	0.029	0.033	0.001	0.126	0.185	0.011	0.027	0.012	0.010
Al(VI)	3.200	3.086	2.890	3.274	0.938	0.584	2.732	2.711	2.788	2.440
Fe(II)	0.850	0.973	1.058	0.483	4.292	3.186	8.547	8.227	8.279	5.907
Mn	0.013	0.021	0.032	0.005	0.076	0.072	0.271	0.408	0.426	0.194
Mg	0.118	0.120	0.122	0.385	0.241	1.770	0.361	0.495	0.456	3.400
Ca	0.003	0.003	0.240	–	0.007	0.010	0.010	0.020	0.010	0.016
sum M	4.200	4.232	4.375	4.148	5.680	5.807	11.932	11.888	11.971	11.967
Na	0.026	0.022	0.031	0.047	0.028	0.018	0.018	0.014	–	0.013
K	1.788	1.938	1.953	1.877	1.812	1.812	0.021	0.027	0.000	0.008
sum I	1.814	1.960	1.984	1.924	1.840	1.830	0.039	0.041	0.000	0.021
F	0.237	0.198	0.186	0.047	0.232	0.168	–	–	–	–
X_Fe	0.88	0.89	0.90	0.56	0.95	0.64	0.96	0.94	0.95	0.63

ps Ms + Chl pseudomorph after Bt, bd below detection limit
Total includes: ^a0.25 Rb₂O; ^b0.52 BaO; ^c0.11 BaO; ^d correction for O=F,Cl; traces of Cl in micas; Ms contains 15, 21, 25, 27 Cel

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