The role of the antigorite + brucite to olivine reaction in subducted serpentinites (Zermatt, Switzerland)

Kempf, Elias D.; Hermann, Jörg; Reusser, Eric; Baumgartner, Lukas P.; Lanari, Pierre

doi:10.1186/s00015-020-00368-0

Swiss Journal of Geosciences

Table 4 Major and minor element composition of antigorite and chlorite

From: The role of the antigorite + brucite to olivine reaction in subducted serpentinites (Zermatt, Switzerland)

	Antigorite												Chlorite
Sample	FA						MF		AF2		Ol46		FA	Ol1	Ol46
wt%	p	p	p	p	p	r	p	r	p	r	p	r	p	p	p
SiO₂	41.89	42.04	41.65	41.92	42.14	43.78	43.01	44.05	42.30	43.62	42.32	43.60	34.35	34.52	33.89
TiO₂	0.02	0.01	0.02	0.02	b.d.	b.d.	0.02	0.01	b.d.	0.01	0.01	0.01	b.d.	b.d.	b.d.
Al₂O₃	2.53	2.59	2.56	2.33	2.77	1.30	2.18	0.78	2.15	1.39	2.58	1.30	11.55	12.59	11.49
Cr₂O₃	0.69	0.70	0.76	1.09	0.85	0.08	0.50	0.24	1.70	0.12	0.81	0.20	2.03	0.66	2.64
FeO	2.30	1.95	1.82	1.66	1.90	1.59	2.04	1.33	1.58	1.58	2.06	1.92	2.90	3.10	3.24
MnO	0.03	0.03	0.05	0.03	0.04	0.02	0.04	0.03	0.04	0.01	0.03	0.03	0.04	0.02	0.06
NiO	0.04	0.05	0.01	0.03	b.d.	0.08	0.16	0.06	0.08	0.09	0.03	0.02	0.10	0.07	0.10
MgO	39.53	40.53	40.69	39.94	40.04	40.66	40.33	41.78	39.89	40.58	39.98	40.30	35.92	35.51	35.45
CaO	b.d.	b.d.	0.02	b.d.	0.03	0.01	0.01	b.d.	0.02	0.01	b.d.	0.01	0.05	0.01	0.04
H₂O	12.02	12.15	12.10	12.04	12.14	12.18	12.22	12.28	12.12	12.16	12.14	12.14	12.65	12.65	12.59
Total	99.05	100.04	99.68	99.06	99.90	99.71	100.53	100.56	99.87	99.59	99.94	99.51	99.58	99.13	99.49
Si	32.395	32.168	31.997	32.362	32.261	33.413	32.716	33.347	32.430	33.339	32.400	33.392	3.257	3.272	3.229
Ti	0.011	0.003	0.012	0.012	–	–	0.010	0.007	–	0.008	0.006	0.004	–	–	–
Al	2.306	2.336	2.318	2.120	2.497	1.169	1.957	0.695	1.943	1.251	2.325	1.170	1.291	1.406	1.290
Cr	0.424	0.424	0.462	0.666	0.514	0.052	0.300	0.141	1.030	0.073	0.489	0.122	0.152	0.050	0.199
Fe⁺²	1.488	1.248	1.170	1.072	1.216	1.012	1.298	0.842	1.013	1.010	1.319	1.229	0.230	0.246	0.258
Mn	0.022	0.021	0.033	0.019	0.026	0.013	0.026	0.022	0.025	0.008	0.019	0.017	0.003	0.001	0.005
Ni	0.025	0.028	0.006	0.019	–	0.047	0.098	0.040	0.049	0.058	0.017	0.010	0.008	0.005	0.008
Mg	45.560	46.220	46.588	45.964	45.695	46.260	45.716	47.137	45.580	46.235	45.612	46.010	5.076	5.017	5.034
Ca	–	–	0.016	–	0.024	0.010	0.005	–	0.013	0.009	–	0.005	0.005	0.001	0.004
H	62.000	62.000	62.000	62.000	62.000	62.000	62.000	62.000	62.000	62.000	62.000	62.000	8.000	8.000	8.000
Mg#	96.7	97.3	97.5	97.6	97.4	97.7	97.0	98.1	97.7	97.7	97.1	97.3	95.5	95.2	94.9
Cat#	82.230	82.449	82.601	82.233	82.233	81.976	82.125	82.229	82.083	81.991	82.187	81.958	10.022	10.001	10.027
Al#	0.29	0.29	0.29	0.26	0.31	0.15	0.24	0.09	0.24	0.16	0.29	0.15
(Al + Cr)#	0.34	0.35	0.35	0.35	0.38	0.15	0.28	0.10	0.37	0.17	0.35	0.16

p peak metamorphic core, r retrograde, b.d. below detection limit
Antigorite normalized to 147 oxygens and 62 (OH), Chlorite to 18 oxygens and 8 (OH), total iron as FeO
Cat# = number of cations
Mg# = (Mg/(Mg + Fe + Ni + Mn))*100
Al# = Al/8, (Al + Cr)# = (Al + Cr)/8, according to Padrón-Navarta et al. (2013)

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