Table 2. Representative microprobe analyses and calculated formula of plagioclase (single spots).

Table 2. Representative microprobe analyses and calculated formula of plagioclase (single spots).


Rock type:	Staurolite-bearing high-grade schist				Corundum-bearing schist		Gneiss		Granite
Sample:	161-976B-74X-1, 30-34 cm	74X-1, 30-34 cm	76R-1, 45-49 cm	74X-1, 30-34 cm	77R-2, 24-26 cm	77R-2, 24-26 cm	98R-1, 96-101 cm	98R-1, 96-101 cm	82R-1, 93-98 cm	82R-1, 93-98 cm
Textural position:	Plagioclase I core	Plagioclase I rim	Included garnet II	Included garnet I	Plagioclase I core	Plagioclase I rim	Core	Rim	Core	Rim
Analytic point:	C-50	C-52	B-124	C-35	F-12	F-21	80	81	43	37
SiO₂	50.35	53.17	55.51	49.07	45.66	50.19	57.16	57.01	58.96	60.41
Al₂O₃	31.19	29.71	28.72	32.58	34.43	31.59	25.83	26.11	24.88	24.78
TiO₂	0.01	0.00	0.01	0.01	0.00	0.00	0.00	0.02	0.00	0.01
Fe₂O₃	0.12	0.18	0.30	0.31	0.04	0.23	0.00	0.17	0.00	0.04
MnO	0.00	0.03	0.05	0.07	0.01	0.01	0.01	0.01	0.00	0.00
MgO	0.01	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
CaO	14.35	12.66	10.77	15.82	17.96	14.66	8.49	8.67	7.29	6.91
N₂O	3.05	4.32	5.38	2.62	1.03	3.11	6.80	6.65	7.30	7.68
K₂O	0.20	0.10	0.17	0.06	0.21	0.14	0.22	0.17	0.32	0.24
Total	99.28	100.18	100.89	100.55	99.35	99.94	98.51	98.82	98.75	100.08
Cations normalized to 32 oxygens (all Fe as Fe³⁺)
Si	9.234	9.616	9.919	8.936	8.463	9.161	10.402	10.349	10.658	10.757
Al	6.743	6.334	6.051	6.995	7.522	6.796	5.542	5.588	5.303	5.203
Ti	0.001	0.000	0.001	0.001	0.000	0.000	0.000	0.003	0.000	0.001
Fe³⁺	0.015	0.022	0.036	0.039	0.006	0.029	0.000	0.021	0.000	0.005
Mn	0.000	0.005	0.007	0.011	0.002	0.002	0.002	0.002	0.001	0.000
Mg	0.004	0.000	0.000	0.000	0.000	0.000	0.000	0.001	0.000	0.000
Ca	2.819	2.454	2.062	3.087	3.568	2.867	1.655	1.687	1.411	1.319
Na	1.086	1.516	1.865	0.926	0.372	1.101	2.399	2.340	2.557	2.651
K	0.046	0.023	0.038	0.014	0.049	0.034	0.050	0.039	0.073	0.055
Z	19.949	19.970	19.980	20.009	19.982	19.989	20.049	20.029	20.003	19.991
Ab	0.275	0.380	0.470	0.230	0.093	0.275	0.585	0.576	0.633	0.659
An	0.714	0.615	0.520	0.767	0.895	0.717	0.403	0.415	0.349	0.328
Or	0.012	0.006	0.010	0.003	0.012	0.008	0.012	0.010	0.018	0.014

Notes: End-member mole fractions are calculated as: [Na/(Ca + Na + K)]= Ab; [Ca/(Ca + Na + K)]= An; and [K/(Ca + Na + K)]= Or. Mineral abbreviations from Kretz (1983).