Major Element Abundances of Selected Lavas from the PHAT Volcanic Complex
Major Element
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
SiO2 48.05 48.43 47.92 48.21 49.16 49.2 49.71 50.1 50.37 50.56 50.74 50.85 50.92 51.24 53.42 40.01
51.50
51.29
0.04
TiO2 2.04 2.00 2.16 2.24 2.29 2.57 2.68 2.71 3.09 3.16 3.35 3.36 3.61 3.74 3.36 0.04
1.10
0.00
48.16
Al2O3 10.33 10.70 10.75 11.37 13.33 12.77 13.65 13.78 14.02 13.92 13.57 14.02 13.80 13.6 13.75 1.13
4.20
31.29
0.11
Fe2O3 1.34 1.15 1.08 1.50 1.31 1.50 1.19 1.89 1.88 1.78 1.36 1.90 1.85 1.87 1.96 0.30
1.50
0.08
9.65
FeO 10.19 10.08 10.65 10.18 9.71 10.05 9.72 9.46 10.07 10.18 10.63 10.44 10.71 11.19 10.45 12.33
6.00
0.00
39.82
MnO 0.17 0.17 0.18 0.18 0.16 0.17 0.17 0.17 0.17 0.18 0.18 0.18 0.19 0.18 0.18 0.17
0.20
0.00
0.43
MgO 17.39 16.29 15.43 13.94 10.41 10.00 8.24 7.34 6.75 6.33 6.16 5.68 5.46 5.12 3.92 44.77
16.20
0.00
1.17
CaO 8.14 8.67 9.33 9.74 10.93 10.75 11.59 11.46 10.39 10.24 9.94 9.71 9.45 9.03 7.75 1.23
19.00
13.62
0.07
Na2O 1.66 1.71 1.79 1.89 2.15 2.12 2.26 2.25 2.35 2.61 2.69 2.77 2.80 2.81 3.34 0.01
0.30
3.64
0.00
K2O 0.36 0.35 0.44 0.44 0.51 0.51 0.54 0.57 0.62 0.64 0.67 0.74 0.75 0.83 1.10 0.00
0.01
0.08
0.00
P2O5 0.19 0.18 0.23 0.22 0.16 0.25 0.25 0.27 0.32 0.33 0.37 0.38 0.40 0.41 0.59 0.00
0.01
0.00
0.00
Total 99.86 99.73 99.96 99.91 100.12 99.89 100.00 100.00 100.03 99.93 99.66 100.03 99.94 100.02 99.82 99.99 100.00
100.00
100.00
Mg# 75.3 74.2 72.1 70.9 65.6 63.9 60.2 58 54.4 52.6 50.8 49.2 47.6 44.9 40.1 86.6
73.00
5
F 34 35 38 38 43 44 47 48 51 52 53 53 54 56 56
22
27
0
97
M 59 57 55 53 46 44 40 37 34 32 31 29 28 26 21 78
72
0
3
A 7 7 8 9 12 12 13 14 15 16 17 18 18 18 24 0
1
100
0
D.I. 16.18 16.54 17.75 18.59 21.2 20.95 22.31 23.52 26.01 27.93 28.97 30.64 31.54 32.92 41.44
Normative Mineralogy
Q 0 0 0 0 0 0 0 1.11 2.46 2.1 2.25 2.83 3.42 4.24 6.68
Or 2.13 2.07 2.6 2.6 3.01 3.01 3.19 3.37 3.66 3.74 3.96 4.37 4.43 4.9 6.5
Ab 14.05 14.47 15.15 15.99 18.19 17.94 19.12 19.04 19.89 22.09 22.76 23.44 23.69 23.78 28.26
An 19.67 20.49 20 21.24 25.22 23.82 25.51 25.82 25.88 24.38 22.97 23.64 22.87 22.04 19.28
Cpx 15.6 17.14 19.95 20.65 22.66 22.61 24.74 23.87 19.3 19.92 19.69 18.17 17.66 16.63 12.77
Opx 21.12 21.12 14.87 15.99 14.45 18.66 16.92 18.28 19.51 18.32 18.84 17.48 17.41 17.67 15.74
Ol 21.04 18.57 21.2 16.51 9.98 6.21 3.13 0 0 0 0 0 0 0 0
Mt 1.94 1.67 1.57 2.17 1.9 2.17 1.73 2.74 2.73 2.58 1.97 2.75 2.68 2.71 2.84
Il 3.87 3.8 4.1 4.25 4.35 4.88 5.09 5.15 5.87 6 6.36 6.38 6.86 7.1 6.38
Ap 0.45 0.43 0.54 0.52 0.38 0.59 0.59 0.64 0.76 0.78 0.88 0.97 0.95 0.97 1.4

Footnotes
Mg# = the magnesium number (100 * Mg2+ / (Mg2+ + Fe2+)).
F, M, and A are the normalized values for plotting in the MgO-FeO-(Na2O+K2O) triangular variation diagram.
D.I. = the Thorton and Tuttle (1960) Differentiation Index.
Analysis number 16 is that of a typical olivine phenocryst found in PHAT basalts.
Analysis number 17 is that of a typical augite phenocryst found in PHAT basalts.
Analysis number 18 is that of a typical plagioclase phenocryst found in PHAT basalts.
Analysis number 19 is that of a typical ilmenite phenocryst found in PHAT basalts.