Earth, Planets and Space

Table 2 Average major composition of olivine (Ol), orthopyroxene (Opx), clinopyroxene (Cpx), and plagioclase (Pl) in the studied winonaites (wt%)

From: The layered structure model for winonaite parent asteroid implicated by textural and mineralogical diversity

	NWA 725				NWA 6448
	Ol	Opx	Cpx	Pl	Ol	Opx	Cpx	Pl
SiO₂	41.6 ± 0.69	58.6 ± 0.84	55.5 ± 0.84	64.6 ± 1.80	41.9 ± 0.93	57.7 ± 0.65	54.4 ± 0.87	64.2 ± 1.10
TiO₂	b.d.	0.16 ± 0.04	0.58 ± 0.08	0.06 ± 0.05	b.d.	0.22 ± 0.10	0.65 ± 0.08	0.05 ± 0.06
Al₂O₃	b.d.	0.21 ± 0.08	0.69 ± 0.11	22.1 ± 0.56	b.d.	0.23 ± 0.09	0.74 ± 0.11	21.8 ± 0.79
Cr₂O₃	b.d.	0.20 ± 0.05	1.02 ± 0.15	0.10 ± 0.56	b.d.	0.31 ± 0.18	1.03 ± 0.20	b.d.
FeO	6.44 ± 0.87	5.35 ± 0.36	2.11 ± 0.39	0.49 ± 0.40	4.62 ± 0.41	4.27 ± 0.27	2.08 ± 0.82	0.28 ± 0.35
MnO	0.48 ± 0.10	0.58 ± 0.07	b.d.	b.d.	0.30 ± 0.09	0.47 ± 0.22	b.d.	b.d.
MgO	51.2 ± 0.61	34.4 ± 0.90	17.4 ± 0.63	0.03 ± 0.10	52.9 ± 1.46	34.7 ± 1.21	17.4 ± 1.03	b.d.
CaO	0.03 ± 0.03	0.78 ± 0.25	22.4 ± 0.46	2.51 ± 0.22	0.02 ± 0.05	0.67 ± 0.25	21.7 ± 1.29	2.97 ± 0.18
Na₂O	b.d.	0.02 ± 0.03	0.71 ± 0.06	9.23 ± 0.55	b.d.	0.03 ± 0.04	0.69 ± 0.07	9.02 ± 0.60
K₂O	b.d.	b.d.	b.d.	0.87 ± 0.32	0.03 ± 0.08	0.03 ± 0.08	b.d.	0.61 ± 0.22
Total	99.85	100.30	100.4	100.0	99.80	98.68	98.7	99.00
Fo/En	93.4	90.6	50.1		95.3	92.3	51.0
Fa/Fs	6.6	7.9	3.4		4.7	6.4	3.4
An				12.4				14.9
Ab				82.5				81.5
No.	14	10	14	10	8	7	12	14

	GRV 022890				GRV 021663^a
	Ol	Opx	Cpx	Pl	Ol	Opx	Cpx	Pl
SiO₂	42.9 ± 0.37	56.7 ± 8.56	55.2 ± 0.97	64.5 ± 0.70	41.72	57.59	56.85	63.4
TiO₂	b.d.	0.16 ± 0.11	0.69 ± 0.09	0.05 ± 0.04	0.03	b.d.	0.77	0.06
Al₂O₃	b.d.	0.23 ± 0.14	0.74 ± 0.08	22.6 ± 0.53	0.01	0.41	0.93	22
Cr₂O₃	b.d.	0.21 ± 0.09	0.61 ± 0.13	b.d.	0.47	0.9	1.5	b.d.
FeO	2.72 ± 0.15	2.83 ± 0.22	1.17 ± 0.35	0.25 ± 0.14	5.18	3.15	1.48	0.47
MnO	0.40 ± 0.05	0.49 ± 0.10	b.d.	b.d.	0.47	0.47	0.31	b.d.
MgO	54.3 ± 0.57	37.8 ± 9.72	18.3 ± 0.53	b.d.	50.74	34.37	18.12	0.05
CaO	0.02 ± 0.01	0.72 ± 0.45	22.5 ± 0.56	3.39 ± 0.12	0.03	1.59	20.69	4.26
Na₂O	b.d.	0.02 ± 0.03	0.57 ± 0.05	8.86 ± 0.30	b.d.	b.d.	0.61	8.19
K₂O	b.d.	b.d.	b.d.	0.68 ± 0.10	b.d.	b.d.	b.d.	0.67
Total	100.4	99.19	99.8	100.4	98.65	98.49	101.3	99.09
Fo/En	97.3	94.6	52.1		5.4	92.3	53.6
Fa/Fs	2.7	4.0	1.9			4.7	2.4
An				16.8				21.5
Ab				79.2				74.6
No.	17	14	17	22	10	10	8	3

	NWA 4024				SAH 02029
	Ol	Opx	Cpx	Pl	Ol	Opx	Cpx	Pl
SiO₂	41.1 ± 1.13	58.3 ± 1.01	54.6 ± 1.57	67.5 ± 3.48	42.1 ± 0.36	58.3 ± 0.74	54.8 ± 0.86	55.2 ± 0.85
TiO₂	b.d.	0.34 ± 0.27	0.60 ± 0.15	0.04 ± 0.07	b.d.	0.20 ± 0.08	0.48 ± 0.10	0.03 ± 0.04
Al₂O₃	b.d.	0.13 ± 0.17	0.62 ± 0.11	20.5 ± 2.94	0.03 ± 0.04	0.64 ± 0.09	1.25 ± 0.13	27.8 ± 0.45
Cr₂O₃	b.d.	0.07 ± 0.12	0.59 ± 0.32	b.d.	0.30 ± 0.03	0.48 ± 0.08	0.39 ± 0.10	b.d.
FeO	4.33 ± 0.16	4.58 ± 0.71	1.76 ± 0.26	0.55 ± 1.29	2.78 ± 0.16	1.82 ± 0.15	1.15 ± 0.82	0.23 ± 0.25
MnO	0.18 ± 0.06	0.18 ± 0.07	b.d.	0.06 ± 0.19	0.29 ± 0.05	0.31 ± 0.03	b.d.	b.d.
MgO	53.9 ± 1.23	35.3 ± 1.66	18.2 ± 0.46	b.d.	54.0 ± 0.75	35.7 ± 0.48	19.9 ± 0.32	0.20 ± 0.04
CaO	0.02 ± 0.02	0.85 ± 0.30	22.5 ± 0.62	1.05 ± 1.91	0.23 ± 0.05	2.21 ± 0.07	20.9 ± 0.38	10.3 ± 0.33
Na₂O	b.d.	0.02 ± 0.03	0.61 ± 0.12	10.25 ± 1.4	0.02 ± 0.02	0.05 ± 0.06	0.30 ± 0.05	5.24 ± 0.18
K₂O	b.d.	b.d.	b.d.	0.85 ± 0.66	b.d.	b.d.	b.d.	0.02 ± 0.03
Total	99.61	99.85	99.5	100.8	99.75	99.67	99.20	99.10
Fo/En	95.7	91.7	51.4		97.2	93.2	56.0
Fa/Fs	4.3	6.7	2.8		2.8	2.7	1.8
An				5.1				52.0
Ab				90.0				47.8
No.	7	9	6	8	7	7	14	11

Fo = atomic 100 × Mg/[Fe + Mg], En = atomic 100 × Mg/[Mg + Fe + Ca], Fa = atomic 100 × Fe/[Fe + Mg], Fs = atomic 100 × Fe/[Mg + Fe + Ca], An = atomic 100 × Ca/[Ca + Na + K], Ab = atomic 100 × Na/[Ca + Na + K]
Error for the analyzed elements are 2-sigma standard deviation (2 SD)
b.d. = below detection limit
No. = number of analyses
^aData were taken from Li et al. (2011)

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