Progress in Earth and Planetary Science

Table 3 Average compositions of plagioclase, K,Ba-feldspar and silica in the silicic clast

From: Formation of ferroan dacite by lunar silicic volcanism recorded in a meteorite from the Moon

	Plagioclase		K,Ba-feldspar		Silica
n	13		6		11
wt%	mean	s.d.	mean	s.d.	mean	s.d.
SiO₂	47.29	1.13	62.81	1.86	99.61	0.78
TiO₂	<0.05		0.18	0.12	0.16	0.03
Al₂O₃	31.91	1.14	19.57	0.60	0.55	0.18
Cr₂O₃	<0.04		<0.04		<0.04
FeO	1.15	0.29	0.14	0.05	0.11	0.08
MnO	<0.04		<0.04		<0.04
MgO	<0.02		<0.02		<0.02
CaO	18.14	0.79	0.31	0.12	0.05	0.03
Na₂O	1.26	0.25	0.42	0.04	0.09	0.04
K₂O	0.33	0.14	14.61	1.00	0.28	0.14
P₂O₅	<0.03		<0.03		<0.03
BaO	0.09	0.05	3.45	2.30	0.03	0.02
Total	100.17		101.49		100.88
atoms per oxy at.	8		8		2
Si	2.187	0.051	2.919	0.050	0.992	0.002
Ti	b.d.		0.007	0.004	0.001	0.000
Al	1.740	0.058	1.073	0.046	0.006	0.002
Cr	b.d.		b.d.		b.d.
Fe	0.045	0.011	0.005	0.002	0.001	0.001
Mn	b.d.		b.d.		b.d.
Mg	b.d		b.d.		b.d.
Ca	0.899	0.038	0.016	0.006	0.001	0.000
Na	0.113	0.023	0.038	0.004	0.002	0.001
K	0.020	0.008	0.866	0.049	0.003	0.002
P	b.d		b.d.		b.d.
Ba	0.002	0.001	0.063	0.043	0.000	0.000
total	5.006		4.987		1.006
Ab	10.9		3.9
An	87.0		1.6
Or	1.9		88.1
Cn	0.2		6.4

Note: Our values in “s.d.” column are the standard deviations (1σ) of the individual mineral compositions and reflect the compositional variation of each mineral in the silicic clast. The number of analyses is indicated by “n”, “b.d.” means below the detection limit. The BaO content was determined in 11 of the 13 analyses of plagioclase feldspar

Back to article page