COMMISSION GEOLOGIOUE - Arkisto.gsf.fi

Suomen Geologinen Seura. N:o 35. Gcologiska Sällskapet i Finland. 95
of unakites.
IV
V VI VIa
VIb
VII
VIII
VIII a
60.10
0.68
18.60
2.32
2.43
0.07
1.09
1.45
5.15
6.67
0.13
1.13
-
100.16
An. IV
An. V
An. VI
An. VIa
An. VIb
An. VI Norm.
58.10 57.52 0.960
0.11 0.75 0.010
21.10 19.22 0.188
3.07 5.11 0.032
0.21 2.02 0.028
- - -
0.88 0.68 0.017
7.12 4.30 0.077
7.71 7.63 0.123
0.19 1.26 0.112
- - 0.95 1.06 -
- - -
99.54 I 99.45 I - I
64.84
0.68
12.71
-
6.22
-
1.15
5.21
8.31
0.88
-
- -
57.27
0.75
18.50
2.43
2.22
0.09
1.06
4.09
2.65
8.69
0.61
1.23
-
99.99 I
2.827
53.63
0.65
18.87
6.03
0.98
0.03
1.98
10.10
4.44
2.62
0.17
0.60
-
100.10 I
2.664
0.889
0.008
0.18 5
0.038
0.014
-
0.049
0.180
0.072
0.018
0.001
-
-
Unakite (»helsinkite,») fine-grained. Streaks in VII (with 0.19 % BaO and 0.16 CO 2
).
Anal. A. Bygden. Sveriges Geol. Unders. Sero C N:o 325.
Unakite (»helsinkite») Suursaari. Anal. A. Laitakari, Bull. Comm. geol. Finlande
N:o 51 (1918).
Unakite, felsitic. Räsy, Oulainen, Anal. E. Mäkinen, loc. cit., An. IU.
Molecular proportions of VI.
Molecular percentages of VI.
Albite 64.45, anorthite 14.73, orthoclase 6.67, diopside 3.67, wollastonite 0.8l.
hematite 2.24, magnetite 4.1 8, ilmenite 1.52 %.
An. VI Mode Albite 64.45, microcline 6.67, epidote 16.03, chlorite 4.24, magnetite 3.97.
An. VII Unakite (,)helsinkite,» rich in microcline, Aspetorp, Sweden (with 0.38 % BaO).
Anal. A. Bygden. Sveriges Geol. Unders., Sero C N:o 325.
An. VIII Unakite rich in epidote, Naistenkallio, Haapavesi. Anal. L. Lokka. Map sheet C 4,
Kajaani, p. 123.
An. VIII a Molecular proportions of VIII.
An. VIII Mode Albite (An 2
) 38.7, microcline 15.6, epidote 37. 7, chlorite 2.4, actinolite 2.6, titanite
1.6, magnetite 1.4 %.
THE SIGNIFICANCE OF THE OCCURRENCE OF HYPERSTHENE GRANITES
AND UNAKITES IN THE SAME PART OF THE COUNTRY AND THEIR MODE
OF ERUPTION
The many occurrences of hypersthene granites and unakites in Central
Finland are all situated in the same part of the country, with the hypersthene
granites and their more basic differentiation products, the hypersthene
granodiorites and various kinds of hypersthene diorites, mostly
occurring in the North Ostrobothnian parishes of Pattijoki, Paavola and
Kalajoki arid in the previously described zone to the southeast.
The unakites do not have quite so wide a spread as the hypersthene
granites. They occur not only in the northeastern half of the hypersthene
granite belt, but also outside this belt, directly southwest ofit, on the northwestern
extension ofthe belt formed by lines I and I! (Fig. 1) and southwest
of the intersection of lines I! and II! and, further, ab out 80 km SW of this