Bull. Geol. Soc. 42, 13—22 (1970)

SCHIST BELT OF TIPASJÄRVI IN THE PARISH OF SOTKAMO, FINLAND

H. VARTIAINEN

Rautaruukki Co., Rovaniemi, Finland

ABSTRACT

The basement complex of eastern Finland near the schist belt of Tipasjärvi, the rocks of the schist area (arenites, argillites, amphibolites and ultrabasic rocks), the late kinematic granites and the dikes of the Tipasjärvi district are described. The tectonics of the schist belt is described and the position of the schist area in the evolution of the bedrock in eastern Finland is discussed. It is suggested that the schist belt of Tipasjärvi might be a part of the formations deposited on the basement but which are older than the Karelian (Sariolan, Jatulian, Kalevian) formations. Other schist areas of the same age are, perhaps, those of — and Ilomantsi.

Introduction of the schist belt consist of arenaceous sedi- mentary rocks. These are followed by the zone The auther carried out geological mapping in of metamorphosed basic and ultrabasic rocks of the Tipasjärvi district in the summer of 1962. magmatic origin. A wide mica schist bed com- The work was connected with the prospecting poses the upper part of the schist belt. Thin black operations of the Suomen Malmi Co. On the schist beds occur here and there in the schist area. basis of this field work the author wrote thesis South-east and north of the schist area younger, for his degree of M.A. at the University of Oulu late kinematic granites occur. Metadiabases and (Vartiainen, 1965) under the direction of Pro- aplites penetrate the schists. fessor Juhani Seitsaari. The tectonics of the schist area is also pre- The present paper deals with the schist area sented. The position of the schist area in the of Tipasjärvi, which has not previously been de- evolution of the bedrock in eastern Finland is scribed in detail in literature. Lake Tipasjärvi is discussed. situated in the parish of Sotkamo in eastern Fin- land, about 90 km ESE from the town of Ka- jaani (Fig. 1). The schist belt of Tipasjärvi is Basement and basal schist about 12 km long and 4 km wide (Fig. 2). South of the schist area is found the basement Basement. The basement of the Tipas- complex of eastern Finland, on which the sedi- järvi district belongs to the basement complex mentary rocks of the schist belt are deposited. in eastern Finland. This complex is fairly hetero- The southern and at the same time the lower part genous containing rocks from ultramafic to pot- 14 H. "Vartiainen

TABLE 1 Modal compositions of basement and late kinematic granites.

1 2 3 4 5

Plagioclase 36.0 47.2 36.5 49.3 48.0 46.8 35.6 36.0 26.1 35.1 Potash feldspar . . 1.6 7.9 23.8 16.7 14.5 Biotite 4.8 4.6 4.7 1.3 Muscovite — 3.4 3.5 2.3 0.1 Epidote 3.6 — — — Accessories 0.2 1.3 0.2 0.9 1.0 100. o lOO.o lOO.o lOO.o lOO.o 1. Basement, quartzdioritic, striped, gray 2. Basement, quartzdioritic, massive, reddish 3. Latekinematic granite, cataclastic 4. Latekinematic granite, massive, red 5. Latekinematic granite, massive, gray

occurs which is called here basal schist. It is a medium-grained and schistose rock grading into the basement and arenites. The basal schist prob- ably originated tectonically when the schist belt and the basement have sheared against each other.

Arenites

Meta-arkose. Only two outcrops of meta-arkose are found, both of which are situated about 100 m from the basement. Thus, unfortun- ately, the relation between the meta-arkose and the basement cannot be established. The matrix of the meta-arkose is macroscopically brownish gray. It consists of quartz, plagioclase, micas, chlorite, epidote and opacite. Whitish quartz and Fig. 1. Schist belts in eastern Finland. plagioclase pebbles is on an average 50 % of the volume of the rock. ash granites (Simonen, 1960, Eskola, 1963). The Mica-feldspar-quartz-schist. composition of the basement in Tipasjärvi is The meta-arkose grades gradually upwards to quartz dioritic (Table 1). Its strike conforms the chlorite-felspar-quartz-schist as first the with the southern edge of the schist belt. Micro- palgioclase and then also the quartz pebbles scopically the quartz dioritic granite gneiss is disappear. Thus, the clastic structure becomes cataclastic. granoblastic. The chlorite-feldspar-quartz-schist Basal schist. Between the SW boundary is a medium- or fine-grained and strongly of the schist belt and the basement a rock variety schistose rock. Schist belt of Tipasjärvi ... 15

COARSE-GRAINED AMPHIBOL1 TE TAIC-CHLORITE-CARBONATE- GRANITE GNEIS (BASEMENT) A META-ARKOSE a ROCK

_- I ARENITES f,n E GRAINED HORNBLENDE-CHLORITE-SCHIST J IATEKINEMATIC GRANITES 1:13

AMYGDALAR . METADIABASE °°° I BRECCIA CONGLOMERATE S APLITE ~ I MICA SCHIST Q BANDED

^^ BLACK SCHIST PORPHYROBLAST1C

Fig. 2. Geological map of Tipasjärvi district

Mica-quartz-schist. There are two heterogenous rock. White layers, which are rich mica-quartz-schist beds on the southern side of in quartz, plagioclase and muscovite, intercalate the schist belt (Fig. 2). Originally these might with gray layers rich in biotite. The width of the have been of the same stratum that later tectonic layers ranges from some centimetres to tens of events broke up. The mica-quartz-schist is a metres. The contacts of the layers are either 16 H. "Vartiainen

TABLE 2 ational conglomerate but, on the other hand, Modal compositions of amphibolite varieties. breccia structures are also apparent. The breccia- conglomerate of Tipasjärvi has been descriped 1 2 3 4 previously (Vartiainen, 1966).

Hornblende .... 72.8 81.2 81.3 65.3 Quartz 7.6 13.5 8.0 15.2 Plagioclase 1.9 0.8 8.3 13.7 Argillites Carbonate 13.2 2.2 — — Chlorite 3.9 :— — — Biotite — — — 3.8 Mica-schist. The nothern part of the Apatite — 0.1 — 0.7 schist belt consists of a broad mica schist bed Ore 0.6 2.2 2.4 1.3 (Fig. 2). The contact with amphibolites is sharp lOO.o lOO.o lOO.o lOO.o but the border area against late kinematic granite 1. Coarse-grained amphibolite is covered by soil. The mica schist is composed 2. Fine-grained amphibolite of irregular lighter and darker layers. Their dif- 3. Amygdalar amphibolite 4. Amphibolite containing hornblende porphyroblasts ferences are due to the quantity of femic minerals and grain size; the more femic the minerals and the smaller the grain size, the darker is the layer sharp or diffuse. The primary sedimentary fea- in question. Strong metamorphism has destroyed tures have almost wholly disappeared. One out- the original sedimentary structures of the mica crop is found where graded beding is preserved schist. Because of the unstable character of the (Fig. 3). This shows bottom direction to the rock, the mineral composition varies. Chief min- basement. Sometimes blastoclastic structures are erals are biotite, quartz, muscovite and chlorite. also seen. The recrystallisation and the schistosity In places (light layers) the amount of the plagio- of the mica-quartz-schist is intensive. clase is also fairly high. Breccia-conglomerate. A few con- Black schist. The black schist is also glomeratic outcrops occur in the mica-quartz- described in this connection, since its material schist. These have clear features of interform- is not merely sapropelic but also argillaceous. It

Fig. 3. Graded bedding in the mica-quartzite-schist. Schist belt of Tipasjärvi ... 17 occurs in the schist area as thin beds (Fig. 2) and Other types are fine-grained. Their medium is composed of thin black and light layers grain size is 1.0—1.5 mm. Generally, they are (breadth 1.0—5.0 mm). The black layers are rich distinctly schistose and strongly recrystallised. in graphite. Quartz, plagioclase and chlorite are The fine-grained amphibolites show sharp con- the chief minerals of the light layers. tacts against the mica schist and they form layer- like intrusions into the mica-quartz-schist. Amphibolites Amygdalar features demonstrate the extrusive nature of the rocks. Amphibolites occur as a wide zone in the cen- The fine-grained amphibolite tral parts of the schist area (Fig. 2). The am- is a fairly homogenous rock without any distinct phibolites can be divided into five types: structural features. — coarse-grained amphibolite The amygdalar a m p h i b o 1 i t e con- — fine-grained amphibolite tains white amygdales filled with quartz and — amygdalar amphibolite plagioclase. — banded amphibolite The banded amphibolite consists — amphibolite containing hornblende por- of dark and light bands (breadth 5—30 cm). The phyroblasts mineral composition of the bands is almost con- The modal compositions of the different am- stant, but the grain size varies. In the dark bands phibolites are listed in Table 2. These reveal that the grain size of the femic minerals is greater all the amphibolites are fairly basic. Table 3 pre- than that of the light minerals. sents the optical properties of hornblende and The amphibolite containing the anorthite content of plagioclase in the various hornblende porphyroblasts has amphibolites. received its name from its peculiar porphyro- The coarse-grained amphibolite blastic structure. It is composed of hornblende occurs in the western part of the schist belt (Fig. porphyroblasts 0.5—1.5 cm in size, which have 2). It is a monotonous and wholly metamor- been oriented by schistosity. Between the por- phosed rock. All the primary features have dis- phyroblasts there is a fine-grained matrix con- appeared. The grain size of hornblende is on an taining about equal amounts of femic and salic average 0.5—2.0 cm. Other minerals form a fine- minerals. grained matrix between the hornblende grains.

Ultrabasic rocks TABLE 3 Optical properties of hornblende and anorthite content One great ultrabasic deposit and several small of plagioclase in the varieties of amphibolite. lenses occur in the schist area (Fig. 2). Two kinds

2Vx± 2° c A z 2—X colour An-% of ultrabasic rocks can be distinguised. These are in z-direc. of plag. named according to the chief minerals: 1 .... 76° 15° 0.022 green 33—46 % 2 74° 17° 0.022 green 30—40 % — talc-chlorite-carbonate-rock 3 .... 76° 17° 0.022 green 28—35 % — hornblende-chlorite-schist 4 .... 77° 18° 0.0 23 green 23—40 % 5 .... 73° 17° 0.021 green 20—33 % The talc-chlorite-carbonate- rock is massive and fine-grained. Its colour 1. Coarse-grained amphibolite 2. Fine-grained amphibolite varies according to the diverse amounts of the 3. Amygdalar amphibolite chief minerals. Light green types are rich in talc 4. Banded amphibolite and darker green varieties have more carbonate 5. Hornblende porphyroblastic amphibolite

3 5814—70 18 H. "Vartiainen and chlorite. The places rich in talc are soapstone- Dikes like. Talc and chlorite form in the typical talc- chlorite-carbonate-rock a small-meshed, net-like There are four metadiabase and two aplite structure in which carbonate is discerned as por- dikes in the schist belt of Tipasjärvi. Both dike phyroblastic grains. types brecciate the schists. The hornblende-chlorite-schist The metadiabases are aphanitic fine- is a medium green and fine-grained rock. It is grained and massive. Blastophitic structure is strongly schistose and partly foliated, breaking preserved only in one metadiabase dike. Quan- easily into thin flakes. As a whole the schist is titatively hornblende is the dominative mineral. macroscopically fairly homogenous. It is reaveled Other chief minerals are plagioclase and quartz. under the microscope that the hornblende-chlo- The aplites are massive, medium- and rite-schist contains thin shear planes covered by even-grained dikes. Albitic (An,) plagioclase is hornblende and chlorite and coarse-grained layer- the dominative mineral, although there is also a like units. In the shear planes the amounts of large amount of quartz. An unidentified brownish hornblende and chlorite are equal but in the mass occurs between the above minerals. coarse layers there is more hornblende than chlorite.

Tectonics of the schist belt Late kinematic granites All the rocks of the schist belt are schistose According to location, structure and mineral- except the talc-chlorite-carbonate-rock and the ogy there are two kinds of late kinematic granites dikes. The schistosity is parallel to the contours in the Tipasjärvi district. A massive granite is of the rocks. Thus, the common strike of the situated north of the schist belt and a cataclastic schistosity is NW-SE (Fig. 2). The dip is vari- granite type occurs to the south-east of the schist able, but its general direction is to the SW. The area (Fig. 2). folding type is isoclinal. The lineation largely coincides with the axes The massive granite is medium- of minor folds, whose strikes are usually to the grained and massive, grey or red in colour and south and plunges are 50°—70°. These and the with a granular texture. Its mineralogical com- deformation structures between the schist belt position is given in Table 1. and the basement (the basal schist) show that the The cataclastic granite is pressed schist belt has, in part at least, been pressed under as a thin wedge between the schist belt and the the basement. Thus the culmination is situated basement (Fig. 2). The contacts against the bor- north of the schist belt. dering rocks are covered by soil in the same way The Vuorisaari—Vuoriniemi—Kangaslampi as the contacts of the massive granite. However, area (Fig. 2) represents the most deformed sec- a few boulders of the cataclastic granite have been tion of the schist area. The strong deformation found which contain fragments from the schist is indicated by the tectonic breccia of the mica- belt. This indicates that the granite is younger quartz-schist, the fragmental structure of the than the schist belt. The cataclastic granite is red amygdalar amphibolite and the talc-chlorite- and medium-grained, with an oriented structure carbonate-rock as well as by the mylonisation of due to its very strong cataclase. The cataclase the fine-grained amphibolite and the faults of originated when the schist belt and the basement various sizes. Otherwise, the schist belt has no moved in relation to each other. peculiar tectonic structures. Schist belt of Tipasjärvi ... 19

The tectonics of the schist area of Tipasjärvi The late kinematic granites, the metadiabases corresponds to the tectonic pattern of Lover and the aplites are the youngest rocks in the Ti- Proterozoic formations as presented by Russian pasjärvi district. They intruded after folding. geologists. According to Kratz (1960), the early The schist area of Tipasjärvi is regionally a Karelian folding gathered Lower Proterozoic small unit (Fig. 1) which, nevertheless, does not formations to a great extent into steep, tightly prevent discussion of its position in the evolu- stressed, isoclinal folds which in most cases are tion of the bedrock in eastern Finland. The mat- inclined to diapires, domes or local culminat- ter has previously been under consideration in ions. Thus the schist belt of Tipasjärvi is inclined literature: according to Wilkman (1921) the Ti- to its nothern culmination. The early Karelian pasjärvi belt belongs to the Kalevian formations; folding according to the interpretation of the on the map of Mikkola (1961) it is a Jatulian or Russians obviously gave the schist belt of Tipas- Kalevian formation; Väyrynen (1954) regards it, järvi so firm a structure that later orogenies have as well as the schist belt of Kuhmo—Suomus- not been able to affect. salmi and Ilomantsi, as pre-Karelian, which the discordance separates from the Karelian form- The geological development of the Tipasjärvi ations, but whose basement is unknown; accord- district and the position of the schist area in the evolution of the bedrock in eastern ing to Matisto (1958) the Kuhmo—Suomussalmi Finland belt, to which the schist area of Tipasjärvi indi- rectly belongs, is a Karelian formation with basal The structures of the arenites show that they conglomerates, and finally Eskola (1963) places were consolidated from the material transported the schist belt of Tipasjärvi on a level with the for a short distance from the granite gneiss. Otravaara and Hevoskumpu (Tuupovaara) areas, Based on the general stratigraphic principles one which are pre-Karelian and enclosed by granite can state that the arenites and the argillites were gneiss. deposited in the same basin. But one cannot say if the argillaceous material was deposited straight The fact is that the granite gneiss does not on the arenites or if there was an unconformity penetrate the schist belt of Tipasjärvi. The de- between them, for the basic magmatism has de- formation has destroyed the actual contact of the stroyed the connection of these sedimentary for- schist area with the granite gneiss (the basal mations. schist). The observations from the arenites how- ever indicate that they deposited on the granite The coarse-grained amphibolite which has gneiss. But the rocks of the Tipasjärvi belt, as been thoroughly metamorphosed and lost all those of Kuhmo—Suomussalmi belt, are of dif- its primary structural features, obviously repre- ferent type from the Jatulian and Kalevian rocks. sents a deeper and previously crystallised basic Also their litological association is different. In rock. Later a partly extrusive magmatism fol- Tipasjärvi, the typical Sariolan facies does not lowed. The products of this have been converted occur, the marine-Jatulian is absent, the arenites into the fine-grained amphibolites. The talc- of Tipasjärvi and the quartzites as well as the chlorite-carbonate-rock and the hornblende- quartz-feldspar-schist of the Kuhmo—Suomus- chlorite-schist have originated from ultrabasic salmi belt have no resemblance with the - rocks. an quartzites and the Karelian serizite-quartzites. As a whole the high grade of the metamor- phism of the schist belt (amphibolite fasies), the The strong recrystallisation and the vanishing vanishing of the primary structural features and of the structural features, the strong schistosity the steep, isoclinal folds have demanded inten- of the rocks and the stressed pattern of folding sive folding. do not characterise the Karelian formations. 20 H. "Vartiainen

On the basis of the evidence given above one This Lower Proterozoicum is divided accord- hardly can consider the Tipasjärvi sequence: ing to Kratz (1969) into lower and upper section. The lower section grades gradually into the — mica-schist Archean or lies discordantly on it. To the lower — amphibolites and ultrabasic rocks section belong basic volcanites, leptites, different — arenites, phyllites, mica-, talc-, chlorite-, etc. schists, mag- as a part of the basement or as a Jatulian or netite-quartzites and different amphibolites. To Kalevian formation. It seems possible that the the upper section belong basic extrusive rocks, schist belt of Tipasjärvi have deposited on the quartzites, arkoses and mica-, etc. schists. The granite gneiss but is older than the Karelian rocks of Tipasjärvi resemble in the first place the formations. rocks of the lower section. Thus, the biotite- The Russians have continuously explored the and quartz-sericite-schists, the different amph- Kola and Karelia. These are the key districts in ibolites and the metamorphic ultrabasic rocks questions concerning the Precambrian strati- of the Pohmos-Prosozero series (Kratz, 1958), graphy (Timofejev, 1934, Robonen, 1958, Kratz, the quartzite-schists and phyllites of the 1958, Haritonov, 1962, Bogdanov et al., 1962, Himola—Kosozero lake series (Robonen, 1958), Simon, 1965, Semihatov, 1966). The students of the slates and the volcanic amphibolites of these districts are not quite unanimous about the the Himola—Parantova series (Simonen, 1957) stratigraphy of the Precambrium (Negrutsa, are fairly similar to the corresponding rocks of 1967). The opinions of the Finns and the Rus- Tipasjärvi. It was mentioned above that basic sians also differ from each other in respect of the volcanites and iron ores are typical of the lower stratigraphy of the eastern part of the Baltic section of the Lower Proterozoicum. These do Shield. These differences can be briefly set forth not occur in Tipasjärvi but Papunen (1960) has as follows: descriped them from the Siivikkovaara area in the Kuhmo—Suomussalmi schist belt. The geo- logical development and the tectonic structure Finns Russians (Kratz, 1960) of the Tipasjärvi schist belt presented above, are also analogical to those of the Lower Protero- Jotnian Upper Proterozoicum zoicum. According to Kratz (1960), the intensive c/3 geosynclinal sedimentation of the Lower Pro- Kalevian ^ Q terozoicum began with the deposition of the Jatulian j H Middle Proterozoicum sedimentary and volcanic beds whilst spilite- Sariolan ^ g keratophyres and quartz-banded iron ores origi- 3 * nated. Terrigenic flysch material ended the sedi- * O Lower Proterozoicum PH mentation. During the pre-Karelian folding ul- trabasic, basic and intermediate magmas intruded BASEMENT, the granite gneiss complex and after the folding the intrusions of microcline- granites, which are partly microcline-orthoclase- Pre-Karelian schists granites, took place. The similarity in geological development, The most noteable difference between the tectonic structure and lithological nature Finnish and Russian terminology is that the between the schist belt of Tipasjärvi and the Russians have a section of the Karelian form- Lower Proterozoic formations of the Russians ations which is still older than the Sariolan and seems to indicate that the schist belt of Tipas- which they call Lower Proterozoicum. järvi could be placed on a level with the Schist belt of Tipasjärvi ... 21

Lower Proterozoicum, above all with its mantsi (Fig. 1), the rocks of which are quite lower section. similar to those of Tipasjärvi (Väyrynen, 1954). The schist belt of Tipasjärvi is probably a According to Väyrynen (1954) and Eskola (1963) depression preserved as a relict from a longer the schists of Ilomantsi are pre-Karelian. Thus, zone, which was in line with the Kuhmo—Suo- one may present the stratigraphic scale of the mussalmi belt (Fig. 1). According to Kratz (1960), schist areas in eastern Finland as follows: the Lower Proterozoic fold structures directed the outlines of the Middle Proterozoic (Sariolan, nicrmcc T^i- I The schist belt of North-Karelia, KAREI.1DES latuhan !-T, . , Jatulian, Kalevian) geosynclines. This is also the ibariola . . n I Kainuu and Kuusamo case in the Kainuu district. The schist areas of The schist belt of Tipasjärvi, Tipasjärvi and Kuhmo—Suomussalmi are paral- Kuhmo—Suomussalmi and Ilomantsi lel the basins of the Kainuu and Kuusamo belts DISCORDANCE (Fig- !)• THE GRANITE GNEISS COMPLEX On the basis of all that has been descriped above, it seems probable that formations might The schist areas of Tipasjärvi, Kuhmo—Suo- occur in eastern Finland which are deposited on mussalmi and Ilomantsi principally include the the granite gneiss complex but which are older phases of the orogenic cycle: the sedimentation than the Sariolan, Jatulian and Kalevian form- on the granite gneiss, the folding and the mag- ations. These older formations may be placed on matism connected with it and finally the intru- the level of the Lower Proterozoicum. The schist sions of the late kinematic granites. These fea- area of Tipasjärvi and Kuhmo—Suomussalmi tures may indicate that the schist belts in question may be of this age as also the schist belt of Ilo- could represent an independent orogeny.

REFERENCES

BOGDANOV, J., VOINOV, A., SUHANOV, V., & HAROTO- MATISTO, A. (1958) Suomen geologinen yleiskartta, Leht: NOV, L. (1962) Karclisen muodostuksen rakenteelli- D 5. Suomussalmi. Kivilajikartan selitys. sesta suhteesta Kemin alueella Itä-Karjalassa. — MIKKOLA, T. (1961) Sediment groups, particularly flysch, Doklady Akademii Nauk SSSR, 3. The translation of the Precambrian in Finland. Bull. Comm. géol. collection of Geological Survey of Finland, 21. Finlande, 196. NEGRUTSA, T. F. (1967) Karelidien geologinen rakenne ESKOLA, P. (1963) The Precambrian of Finland. — The Geologic Systems: The Precambrian, edited by K. Lehtinskin synkliinin lounaissiivellä. — Vestnik Rankama, London. leningradskova Universiteta, 18. Finnish translation as manuscript by V. Makkonen, Rautaruukki Co. HARITONOV, L. J. (1962) Balttilaisen kilven geologisen PAPUNEN, H. (1960) Havaintoja Siivikkovaaran alueen rakenteen pääpiirteet. — Moskova—Leningrad. The kallioperästä Kuhmon pitäjän Vieksin kylässä. — translation collection of Geological Survey of Fin- Manuscript at the Institute of Geology, University of land, 10. Helsinki.

KRATZ, K. O. (1958) Karjalan proterozoicum in jaotte- ROBONEN, V. I. (1958) Karjalassa olevan ent. Tunkueen lusta ja terminologiasta. — Izvestija Kareljskogo i (Tungude) piirin ala-proterozoicumin stratigrafiaa Koljskogo filialov Akademii Nauk SSSR, 3. The koskevia uusia tietoja. — Trudy Kareljskogo filiala translation collection of Geological Surveys of Fin- Akademii Nauk SSSR, 11. The translation collection land, 5. of Geological Survey of Finland, 3. — (1960) Balttilaisen kilven itäosan prekvartäärisen geo- SEMIIIATOV, M. A. (1966) Prekambriumin stratigraafisen logian pääpiirteet. — Trudy Laboratorii Geologii kaavion probleemasta. — Izv. An. SSSR, 4. Finnish Dokembrija, 9. The translation collection of Geo- traslation as manuscript by V. Makkonen, Rauta- logical Surveys of Finland. ruukki Co. 22 H. "Vartiainen

SIMON, A. (1957) Kuollan karelidien stratigrafiasta. — VARTIAINEN, H. (1965) Tipasjärven alueen kallioperä. — Doklady Akademii Nauk SSSR, 165. The translation Manuscript at the Institute of Geology, University of collection of Geological Survey of Finland, 42. Oulu. SIMONEN, A. (1957) Itä-Karjalan ja Kuolan kallioperästä. — (1966) Tipasjärven breksia/konglomeraatti Sotkamon Geologi, 10. pitäjän kaakkoisosassa. — Geologi, 3—4. — (1960) Pre-Quaternary rocks in Finland. — Bull. WILKMAN, W. W. (1921) Suomen geologinen yleiskartta, Comm. géol. Finlande ,191. Lehti D 4. . Vuorilajikartan selitys. Geologi- TIMOFEJEV, W. W. (1934) Die Geologie Kareliens. nen komissio. »Arbeiten der Ersten Allsowjetischen Forschungs- VÄYRYNEN, H. (1954) Suomen kallioperä. Helsinki. konferenz für wissenschaftliche geologische Prospek- tion». Leningrad. The translation collection of Geo- logical Survey of Finland, 33. Manuscript received, April 15, 1969