Geology Reference
In-Depth Information
Table 4.18 Modal composition of Holsteinberg Lamporites
Sample number
5647
5659
5622
5692
Olivine
2
1
11
9
Leucite
17
16
16
16
Phlogopite
31
55
48
32
Clinopyroxene
4
8
10
Richterite
15
12
6
16
K-Feldspar
13
8
13
Opaque
3
3
1
Serpentite
1
4
Carbonate
13
10
6
3
Apatite
1
3
1
1
Table 4.19 Chemical analysis of Holesteinberg Lamproites
Sample number
5622
5632
5643
5692
SiO
2
39.29
42.75
46.48
43.79
TiO
2
2.17
3.18
3.38
2.67
Al
2
O
3
4.90
8.47
7.66
7.04
Fe
2
O
3
1.35
1.74
3.14
1.35
FeO
6.25
5.01
4.09
5.73
MnO
0.10
0.09
0.07
0.09
CaO
4.73
7.38
5.54
5.21
Na
2
O
1.00
0.90
1.37
1.30
K
2
O
6.16
7.99
8.14
7.06
H
2
O
+
2.82
2.65
2.92
3.19
P
2
O
5
0.94
0.73
1.43
1.16
CO
2
5.14
4.96
3.05
2.94
Total
97.40
98.01
98.01
97.12
4.9.3 Kap Dalton (69
24
N, 24
10
W)
°
′
°
′
Woolley (1987) described the occurrence of malignites, monchiquites and leucite
nephelinite in association with Tertiary basalts near Kap Dalton (also see Wager
1935). The malignite comprising nearly 33 vol% of nephiline, aegirine augite,
orthoclase, abundant, analcime, tinguaite and altered nosean. Closely associated
with these rocks are leucite, nephilinites (nephiline + clinopyroxene + leucite
±
perov-
skite). Some leucite nephilinites contain about 75 vol% altered leucite.
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