COMMISSION GEOLOGIOUE - Arkisto.gsf.fi

94 Bulletin de la Commission geologique de Finlande N: 0 212.
Table 2. Analyses
I 11 IIa 111 III a III b
Si02 .............. 68.77 61.21 1.015 60.10 1.001 67.05
•••• 0 ••••••• •• Ti02 0.60 0.52 0.007 0.40 0.005 0.33
Al20 a . .. , ......... 14.02 17.78 0.174 19.86 0.195 13.06
Fe20 a ... . . .. .... . . 2.77 2.96 0.019 3.53 0.022 -
FeO .... ..... ..... 1.74 1.01 0.014 1.25 0.017 3.42
MnO .............. 0.05 0.05 0.001 - - -
MgO . . ... . ........ 0.93 0.13 0.003 0.90 0.022 1.47
CaO .............. 3.81 1.95 0.035 3.98 0.071 4.76
Na20 ...... .. ..... 3.56 5.23 0.084 7.74 0.128 8.57
K20 . .. .... ....... 3.10 7.74 0.082 1.90 0.020 1.37
P20 ......... .. .... 0.02 0.20 0.001 - - -
H20+ . . .......... 0.84 0.83 - 0.80 - -
H 2
O- ............ - - - - - -
Sp. Grav. ......... 1
100.21 1 99.61 1 100.71 1
An. I Unakite (.)helsinkite.») boulders from Alfsta, Sweden. Anal. Almström. Geol. Fören.
i Stockholm Förh. 47, p. 504.
An. I Mode Albite 31.03 (An.), microcline 18.35, epidote 17.24, chlorite 4.34, titanite 0.41,
ilmenite 0.68, apatite 0.03 %.
An. 11 Unakite, Ollikkaanvuori, NE Haapavesi. Anal. L. Lokka. Map Sheet C 4, Kajaani,
p. 122.
An. II Mode Albite 43, microcline 45, epidote 6, chlorite 1. 5, magnetite 3, titanite 1. 2, apatite O. 3%.
An. 111 Unakite of medium grain, Räsy, Oulainen. Anal. E. Mäkinen. Bull. Comm. geol.
Finlande 47 and 73.
An. III a Molecular proportions of IH.
An. III b Molecular percentages of Ur.
An. IIINorm. Albite 64.97, anorthite 13.07, orthoclase 13.07, nephelite 1.14, wollastonite 2.78,
olivine 1. 68, magnetite 2.78, ilmenite 0.76, hematite 1. 60.
An. 111 Mode Albite 67.07, microcline 11.12, epidote 15.43, chlorite 4.40, titanite 0.98, magnetite
1.62.
THE OCCURRENCE IN CENTRAL FINLAND OF GRANITE VEINS CUTTING
SOME OF THE HYPERSTHENE GRANITES AND UNAKITES
In his description of the hypersthene granites of the islands in Haukivesi,
Hackman (1931) states that in the islands of Anttosaaret, Paavalinsaari and
surrounding islands there occur granite veins of an aplitic character which
traverse the hypersthene granite. In describing the unakites of Pulkkila
and Rantsila Wilkman (1931) says that they are cut by granite veins.
This granite is fairly small-grained and has wh at closely resembles a
»panidiomorphic» structure (Rosenbusch). One of these granites has been
analysed and the analysis is published as No. IX in Table 1.
These granites piercing the hypersthene granites and pyroxene diorites are
thus the youngest intrusive igneous rocks of Central Finland. They occur
both as dykes and as small fields of igneous rock.