Early Palaeoproterozoic (2.5-2.4) Tornio - Narankavaara Layered Intrusion Belt and related Chrome and Platinum-Group Element mineralization, Northern Finland

110 Pages·7.965 MB·English

by  Alapieti T.T. (Ed.) , Karki A.J. (Ed.)

Geological Survey of Finland, Guide 51a
T. T. Alapieti and A. J. Kärki eds.
Geologian tutkimuskeskus Geological Survey of Finland
Opas 51a Guide 51a
FIELD TRIP GUIDEBOOK
EARLY PALAEOPROTEROZOIC (2.5-2.4)
TORNIO – NÄRÄNKÄVAARA LAYERED
INTRUSION BELT AND RELATED CHROME
AND PLATINUM-GROUP ELEMENT
MINERALIZATION, NORTHERN FINLAND
Edited by T.T. Alapieti and A.J. Kärki
PREPARED FOR
THE 10th PLATINUM SYMPOSIUM
IN OULU FINLAND 2005
GEOLOGIAN TUTKIMUSKESKUS
GEOLOGICAL SURVEY OF FINLAND
ESPOO 2005
Geological Survey of Finland, Guide 51a
Vammalan Kirjapaino Oy 2005
ISBN 951-690-929-9
ISSN 0781-643X
2
Geological Survey of Finland, Guide 51a
T. T. Alapieti and A. J. Kärki eds.
CONTENTS:
Chapter 1
Early Palaeoproterozoic (2.5-2.4 Ga) Tornio – Näränkävaara Layered Intrusion Belt and
Related Chrome and Platinum-group Element Mineralization, Northern Finland
Tuomo T. Alapieti Page 5
Chapter 2
The Kemi Intrusion and Associated Chromitite Deposit
Timo A. Huhtelin, Tuomo T. Alapieti Page 13
Chapter 3
The Sompujärvi, Ala-Penikka and Paasivaara PGE Reefs in the Penikat
Layered Intrusion, Northern Finland
Tapio Halkoaho, Tuomo Alapieti and Timo Huhtelin Page 33
Chapter 4
Portimo Layered Igneous Complex
Markku Iljina Page 77
Chapter 5
Koillismaa Layered Complex and Related Copper-nickel and PGE Mineralizations
Tuomo T. Alapieti Page 101
3

Geological Survey of Finland, Guide 51a
T. T. Alapieti and A. J. Kärki eds.
Chapter 1
EARLY PALAEOPROTEROZOIC (2.5-2.4 GA)
TORNIO – NÄRÄNKÄVAARALAYERED
INTRUSION BELTAND RELATED CHROME AND
PLATINUM-GROUP ELEMENT MINERALIZATION,
NORTHERN FINLAND
Tuomo T. Alapieti
Department of Geosciences, P.O. Box 3000, FIN-90014 University of Oulu, Finland
INTRODUCTION
Early Palaeoproterozoic layered intru- crust, in which komatiites, basalts and sili-
sions, 2.5-2.4 Ga in age, are widespread over ceous high-magnesium basalts represent the
a vast area of the northeastern Fennoscandian mafic members and rhyolites the felsic ones.
Shield (also known as the Baltic Shield) in These intrusions are now located within the
Finland, Russia and Sweden (Fig. 1); an area basement itself and/or at the contact between
amounting to about 600 × 900 km2 (Alapieti the basement and the unconformable overly-
and Lahtinen 2002). Many of these intrusions ing Proterozoic supracrustal sequence of fel-
are known to have anomalous zones enriched sic or mafic volcanics, subvolcanic sills, or in
in platinum-group elements (PGE). In ad- places polymictic conglomerates, which all
dition, a younger group of intrusions, about are younger than the intrusions. In addition,
2.05 Ga in age, are also encountered in the Palaeoproterozoic acid intrusive rocks, which
same area, one of which, the Keivitsa (or Kev- are not spatially associated with layered in-
itsa) Intrusion, is known to contain a large, trusions, although commonly occurring in
low-grade Cu-Ni-PGE-Au deposit (Mutanen, their vicinity, are widespread in northeastern
1997). Fennoscandia. These acid intrusions include
The bedrock of the northeastern part the Kynsijärvi quartz alkali-feldspar syenite
of the Fennoscandian Shield is mainly com- (2440 Ma) in the Koillismaa area (Landén
posed of late Archaean tonalitic gneisses and Mänttäri, 2002), alkaline granite-syenite
(2.8-2.6 Ga) and late Archaean and early Pa- complexes (~2455 Ma) on the Kola Peninsula
laeoproterozoic greenstone belts. The Pro- (Balashov, 1996), the Nuorunen granite (2450
terozoic layered intrusions are usually em- Ma) in Russian Karelia (Buiko et al., 1995),
placed through the Archaean basement and and a granite porphyry dyke (2435 Ma) east
the lowermost Proterozoic supracrustal rocks. of the Kuhmo Greenstone Belt (Luukkonen,
They were preceded by bimodal volcanism 1988).
soon after cratonization of the late Archaean The Palaeoproterozoic intrusions in Fin-
1 T. Alapieti’s text in this guide book is partly based on the paper: Alapieti and Lahtinen: “Platinum-group element mineralization in layered
intrusions of northern Finland and the Kola Peninsula, Russia”. Full paper originally published in CIM Special Volume 54 (2002) ‘The Geol-
ogy, Geochemistry, Mineralogy and Mineral Beneficiation of Platinum-Group Elements.’Quoted with permission from the Canadian Institute
of Mining, Metallurgy and Petroleum.
5
Geological Survey of Finland, Guide 51a
land began to interest prospecting organisa- sity of Oulu in cooperation. These investiga-
tions in the 1950s, leading in the first instance tions led almost immediately to the discovery
to the discovery of the large chromitite deposit of three PGE-mineralised zones in the Penikat
in the Kemi Intrusion found by the Geologi- Intrusion, which were found to be continuous
cal Survey of Finland in 1959 (Alapieti et al., for almost the entire 23 km length of the intru-
1989a), which is still currently being mined. sion, and also to the discovery of the RK Reef
Soon after this discovery, Outokumpu Oy also and PGE-bearing offset deposits in the Por-
began chrome exploration in the areas of the timo Complex. Thus all the currently known
Penikat and certain other intrusions. The re- PGE deposits in the Penikat and Portimo ar-
sults did not prove encouraging, however, and eas were discovered and had been studied in
efforts were terminated quite soon. Thereafter, a preliminary manner before the end of the
the main exploration effort in the 1960’s and 1980’s. Arctic Platinum Partnership (APP), a
1970’s was focused on the Ni-Cu ores, and company established in 2000 by Outokumpu
as a result, large, low-grade PGE-bearing sul- Mining Oy and Gold Fields Limited and later
phide occurrences were found within the mar- on Gold Fields Arctic Platinum Oy (GAAP)
ginal series of the Koillismaa Complex (Ala- have continued these exploration activities
pieti and Piirainen, 1984, Lahtinen, 1985), as and examined the possibility of producing
well as many types of PGE-bearing massive palladium and platinum by mining in the Pe-
and disseminated base-metal sulphide depos- nikat and Portimo areas.
its within the Portimo Complex (Alapieti et The Geological Survey of Finland com-
al., 1989b). However, these discoveries have menced explorations on mafic intrusions in
not led to any mining activity to date. In ad- Finnish Lapland in 1969. After a brief inter-
dition, Rautaruukki Oy became interested in ruption, the work continued in 1973 leading
the vanadium-bearing magnetite gabbros of to the discovery of chromitite layers in the
the Koillismaa Layered Series, and vanadium Koitelainen and Akanvaara Intrusions, the up-
mining commenced at Mustavaara in 1976. permost ones of these being PGE-bearing, and
Stimulated by PGE discoveries in the of the low-grade Cu-Ni-PGE-Au deposit in the
Stillwater Complex, Outokumpu Oy started a Keivitsa Intrusion (Mutanen, 1997). Explora-
new exploration programme in 1981 aimed at tion in the central part of the Kola Peninsula
discovering PGE deposits (Alapieti and La- has a long history, but the focus on PGE inten-
htinen, 1986). Lapin Malmi, established in sified in the 1990’s. Erratic zones enriched in
1982 as a joint venture between Outokumpu PGE were discovered within the marginal and
Oy and Rautaruukki Oy then continued PGE layered series of the Monchegorsk and Fedo-
exploration. At the same time, ore geological rova Tundra - Pana Tundra Intrusions leading
investigations related to this Lapin Malmi’s to the current feasibility study (Dedeev et al.,
exploration program also began at the Univer- 2002; Mitrofanovet al., 1998).
EARLY PALAEOPROTEROZOICLAYEREDINTRUSIONS IN THE FEN-
NOSCANDIAN SHIELD
Approximately two dozen early Palaeo- with the Tornio Intrusion, the western part of
proterozoic layered intrusions and intrusion which is known in Sweden as the Kukkola
fragments are found scattered in a zone across Intrusion, the Kemi and Penikat Intrusions
the Fennoscandian Shield between latitudes and the scattered remnants of the Portimo and
65.5oand 69.5o, i.e. on both sides of the Arctic Koillismaa Complexes. Another belt trends
Circle, in Sweden, Finland and Russia (Fig. 1). in a southeasterly direction through Finnish
The southernmost group of intrusions forms a Lapland into Russia, and includes the Tsohk-
discontinuous belt from west to east named koaivi, Koitelainen and Akanvaara Intrusions
the Tornio-Näränkävaara Belt, beginning in Lapland and the Oulanka Complex (also
6
Geological Survey of Finland, Guide 51a
T. T. Alapieti and A. J. Kärki eds.
RUSSIA
Barents Sea
SWEDEN
FINLAND
NORWAY
s
e
d
ni
o
d Mt.
e
al Generalskaya
C MURMANSK
NORWAY
RUSSIA
Tsohkkoaivi ... Monchegorsk ........................................................... ............... PanaTundra
SWEDEN Koitelainen .. Imandra FTeduonrdorvaa
KKooiitteellaaiinneenn
Keivitsa
Akanvaara
FINLAND Arctic Circle
N
Oulanka White Sea
Kukkola Portimo
Tornio ..
Penikat
Kemi Koillismaa
Caledonides
.........
Paleozoicalkalinerocks
OULU
Jothniansedimentaryrocks
a
ni Proterozoicgranitoids
h
ot Proterozoicsupracrustalrocks
B
of Layeredintrusions(2.4-2.5Ga)
ulf
G Archaeanrocks
Burakovo
Lake
0 50 100km Onega
Fig 1. Generalized geological map of the northeastern part of the Fennoscandian Shield showing the locations of
the most important Palaeoproterozoic layered intrusions. Modified from Alapieti et al. (1990).
7
Geological Survey of Finland, Guide 51a
transliterated Olanga) on the Russian side of Tundra Complex are 2491±1.5 Ma (Mitro-
the border. In addition, Fennoscandia’s larg- fanov and Bayanova, 1999) and 2501±1.4 Ma
est layered intrusion, the Burakovo (or Bura- (Amelin et al., 1995), and the , (2487±51)
Nd
kovsky) Intrusion in Russian Karelia, may be value is -2.1±0.5 (Balashov et al., 1996). The
regarded as a continuation of this belt. The lay- emplacement of the above Palaeoproterozoic
ered intrusions on the Kola Peninsula include intrusions marks a large plume event in the
Mt. Generalskaya (or Luostari, according to geological history of the northeastern Fen-
its former Finnish name), Karikjavr in the noscandian Shield, suggesting that the plume
northwestern part of the Kola Peninsula, the remained active for about 100 Ma, from 2505
Monchegorsk and Monche Tundra Intrusions, Ma to 2396 Ma (Mitrofanov and Bayanova,
the Imandra Lopolith, and the Fedorova Tun- 1999). The long-term plume event could be in
dra, Lastyavr and Pana Tundra (also known as a complex relationship with the initial break-
Pansky Tundra) Intrusions in the central part down of the Late Archaen supercontinent.
of the Kola Peninsula (Fig. 1). In addition, it The Fennoscandian Palaeoproterozoic
should be mentioned the 2058±4 Ma Keivitsa layered intrusions have undergone a com-
Intrusion in Central Finnish Lapland (Huhma plex history of post-emplacement disruptions
et al., 1996, Mutanen, 1997, Mutanen and associated with the deposition of Jatulian
Huhma, 2001), since it hosts the aforemen- (2200-2100 Ma) and Kalevian (2000-1900
tioned remarkable low-grade Cu-Ni-PGE-Au Ma) sedimentary formations and with defor-
deposit. Roughly contemporaneous with the mation and metamorphic events associated
Keivitsa intrusion is the gabbro-anorthosite with the Svecofennian Orogeny (1900-1800
complex of Otanmäki (2060 Ma, Talvitie and Ma). In the first stage after consolidation,
Paarma, 1980) some 300 km south of Keivit- when the layering was mostly quite flat, many
sa and about 100 km southeast of Oulu. This of the intrusions became affected by brittle
complex was known for its vanadium-titani- vertical faults, which commonly broke up
um-iron ores, which were mined until 1986. the intrusions into several blocks and moved
Numerous age determinations have them on different levels. Land uplift and
been carried out on the Fennscandian Pal- erosion, which even exposed the overlying
aeoproterozoic layered intrusions using the granophyres and the uppermost cumulates to
U-Pb method for zircon and baddeleyite and weathering in some cases, followed this fault-
the Pb-Pb whole rock and Sm-Nd methods. ing phase, and thus these also have frequently
These have provided a fairly coherent set of been obliterated. The younger sedimentary
ages, the mean being about 2440 Ma. The and volcanic rocks, the lowermost members
age determinations have yielded a U-Pb age of which were generally represented by pol-
of 2440 Ma (Kouvo, 1977, Alapieti and La- ymictic conglomerates, were then deposited
htinen, 1986) and a Sm-Nd age of 2410±64 on this erosional surface, so that they nowa-
Ma (Huhma et al., 1990) for the Penikat In- days form the discordant hanging walls of the
trusion. The initial , (2440) for this intru- many intrusions. The main tilting phase took
Nd
sion was determined to be -1.6 ±0.6 (Huhma place considerably later, the blocks reaching
et al.,1990). The Portimo Complex proved to their final orientation during the Svecokare-
be too seriously altered for U-Pb dating, and lian Orogeny. This tilting has meant that rep-
no acceptable determination is available. The resentative stratigraphic sections for the intru-
, (T) values show a relatively wide range, sions are in many cases exposed at the present
Nd
between -0.3±0.6 and -3.9 ±0.5 (Iljina, 1994). ground surface.
The Koillismaa Complex has provided a set The tectonic events affected the intru-
of U-Pb ages with an average of 2436±5 Ma sions in the eastern parts to a lesser degree,
(Alapieti, 1982), while the Koitelainen and whereas those in the western parts were gen-
Akanvaara Intrusions have yielded U-Pb ages erally more heavily metamorphosed. Simi-
of 2439±3 Ma and 2436±6 Ma, respectively larly the primary magmatic minerals were
(Mutanen and Huhma, 2002). The U-Pb ages altered in variable ways in the west, while in
for the gabbronorite of the Fedorova - Pana the easternmost intrusions they generally re-
8
Geological Survey of Finland, Guide 51a
T. T. Alapieti and A. J. Kärki eds.
mained almost unaltered. Cumulus textures dyke swarms of similar age in other cratons.
are generally fairly well preserved as pseudo- These examples include the Jimberlana In-
morphs even in the completely altered intru- trusion (2420±30 Ma) in the Yilgarn Block,
sions, however, enabling determination of the Western Australia (McClay and Campbell,
cumulus stratigraphy. 1976) and the East Bull Lake Suite (2491-
Several compositionally distinctive 2441 Ma) in Ontario (Peck et al., 1993).
dyke swarms of age ~2440 Ma (Vuollo, The Great Dyke in Zimbabwe is somewhat
1994), which are characterized by relatively older, viz. 2579±7 Ma (Mukasa et al., 1998;
high MgO and Cr contents at intermediate Oberthür 2002). Dyke swarms emplaced at
SiO contents, low HFSE and TiO (mostly approximately the same time include, in addi-
2 2
below 0.5 wt.% TiO ), and relatively high Pd tion to the Fennoscandian dykes, the Scourie
2
(~20-40 ppb) (Alapieti et al. 1989), provide mafic dykes (2418 Ma) in Scotland (Heaman
the most likely parental magma composi- and Tarney, 1989), the Hearst-Matachewan
tions for certain Fennoscandian layered intru- dyke suite (2452 Ma) in the Superior Province
sions (Saini-Eidukat et al., 1997, Vogel et al., (Heaman, 1988), the Mysore dykes in south-
1998). Another characteristic feature of these ern India (Ikramuddin and Stueber, 1976),
intrusions is that they typically have , val- the Widgiemootha dyke suite in the Yilgarn
Nd
ues between 0 and –4, which are similar to Block (Glickson 1996) and the Vestfold Hills
those of the Stillwater Complex (Lambert et Complex (2424±72 Ma) in Antarctica (Col-
al., 1989), but slightly less negative than those lerson and Sheraton, 1986). An interesting ex-
of the Bushveld Complex (Sharpe, 1986). planation for this worldwide igneous activity
The emplacement of the 2.5-2.4 Ga lay- at the very beginning of the Proterozoic was
ered intrusions in Fennoscandia was part of provided by Glickson (1996), who correlated
the worldwide igneous activity at the begin- mantle-melting episodes with contemporane-
ning of Proterozoic, as suggested by the oc- ous mega-impact events.
currence of large layered intrusions and mafic
REFERENCES
ALAPIETI, T.T., 1982. The Koillismaa layered In Magmatic sulphides - the Zimbabwe volume.
igneous complex, Finland - its structure, miner- Edited by M.D. Prendergast and M.J. Jones. The
alogy and geochemistry, with emphasis on the Institution of Mining and Metallurgy, London,
distribution of chromium. Geological Survey of p.177-187.
Finland, Bulletin, 319, p.1-116.
ALAPIETI, T.T. and LAHTINEN, J.J., 2002.
ALAPIETI, T.T., FILEN B.A., LAHTINEN, J.J., Platinum-Group Element Mineralization in Lay-
LAVROV, M.M., SMOLKIN, V.F. and VOIT- ered Intrusios of Northern Finland and the Kola
SEKHOVSKY, S.N., 1990. Early Proterozoic Peninsula, Russia. In The Geology, Geochem-
layered intrusions in the northeastern part of the istry, Mineralogy and Mineral Beneficiation of
Fennoscandian Shield. Mineralogy and Petrol- Platinum-Group Elements. Edited by L.J. Cabri.
ogy, 42, p.1-22. The Canadian Institute of Mining, Metallurgy
and Petroleum, Special Volume, 54, p.507-546.
ALAPIETI, T.T., KUJANPÄÄ, J., LAHTINEN,
J.J. and PAPUNEN, H., 1989a. The Kemi Strati- ALAPIETI, T.T. and LAHTINEN, J.J., 1986.
form Chromitite Deposit, Northern Finland. Stratigraphy, petrology, and platinum-group
Economic Geology, 84, 1057-1077. element mineralization of the early Proterozoic
Penikat layered intrusion, northern Finland. Eco-
ALAPIETI, T.T., LAHTINEN, J.J., HÄN- nomic Geology, 81, p.1126-1136.
NINEN, E., PIIRAINEN, T.A. and SIVONEN,
S.J., 1989b. Platinum-group mineralization in the ALAPIETI, T.T. and PIIRAINEN, T.A., 1984.
marginal series of the early Proterozoic Suhanko- Cu-Ni-PGE mineralization in the marginal series
Konttijärvi layered intrusion, northern Finland. of the early Proterozoic Koillismaa layered igne-
9
Geological Survey of Finland, Guide 51a
ous complex, northeast Finaland. In Sulphide Canadian Society of Petroleum Geologists, 1988
deposits in mafic and ultramafic rocks. Edited by Joint Annual Meeting; Program with abstract, 13,
D.L. Buchanan and M.J. Jones. The Institution of p. A53.
Mining and Metallurgy, London, p.123-131.
HEAMAN, L.M. and TARNEY, J., 1989. U-Pb
AMELIN, YU.V., HEAMAN, L.M. and SE- baddeleyite as gas for the Scourie dyke swarm,
MENOV, V.S., 1995. U-Pb geochronology of Scotland: evidence for two distinct intrusion
layered mafic intrusions in the eastern Baltic events. Nature 340, p.705-708.
Shield: implication for the timing and duration of
Paleoproterozoic continental rifting. Precambrian HUHMA, H., CLIFF, R.A., PERTTUNEN, V.
Research, 75, p.31-46. and SAKKO, M., 1990. Sm-Nd and Pb isotopic
study of mafic rocks associated with early Pro-
BALASHOV, YU, VETRIN, V.R. and ZOZU- terozoic continental rifting: the Peräpohja schist
LUA, D.R., 1996. Age correlation of overprinted belt in northern Finlad. Contributions to Mineral-
processes in peralkaline granites of Kola Penin- ogy and Petrology, 104, p.369-379.
sula and volcanic episodes in Pechenga-Varzuga
paleorift. In Fennoscandian Geological Correla- HUHMA, H., MUTANEN, T., HANSKI, E. and
tion. Edited by Yu.B. Bogdanov, V.V. Ivanikov WALKER, R.J., 1996. Sm-Nd, U-Pb and Re-
and N.B. Philippov. Fennoscandian Geological Os isotopic study of the Keivitsa Cu-Ni-bearing
Correlation. 1st International Conference, 8-11 intrusion, Northern Finland. In The 22nd Nordic
September 1996, St.Petersburg. Abstract Volume. Geological Winter Meeting, Turku, January 8-11,
p.112. 1996. Abstracts, p.72.
BUIKO, A., LEVCHENKOV, O., TURCH- IKRAMUDDIN, M and STUEBER, A.M., 1976.
ENKO, S. and DRUBETSKOI, E., 1995. Geol- Rb-Sr ages of Precambrian dolerite and alkaline
ogy and isotopic dating of the early Proterozoic dykes of Southeast Mysore State, India. Lithos, 9,
Sumian-Sariolian Complex in northern Karelia p.235_241.
(Paanajärvi-Tsipringa structure). Stratigraphy and ILJINA, M., 1994. The Portimo Layered Igneous
Geological Correlation, Vol. 3 (4), p.16-30 (in Complex, with emphasis on diverse sulphide and
Russian). platinum-group element deposits. Acta Univer-
sitatis Ouluensis. Series A, Scientiae Rerum
COLLERSON, K.D. and SHERATON, J.W., Naturalium 258, p.1-158.
1986. Age and geochemical characteristics of
a mafic dyke swarm in the Archaean Vestfold
Block, Antarctica: Interferences about Protero- KOUVO, O., 1977. The use of mafic pegmatoids
zoic dyke emplacement in Gondwana. Journal of in geochronometry. In European Colloquium
Petrology, 27, p.853-886. Geochronology, Cosmochronology, Isotope
Geology, 5th Pisa, Italy, 5-10 September, 1977,
DEDEEV, A.V., KHASCHKOVSKAYA, T.N. Abstracts, unpaginated.
and GALGIN, A.S., 2002. The PGE Mineraliza-
tion of the Monchegorsk Layered Intrusion of the LAHTINEN, J., 1985. PGE-bearing copper-
Kola Peninsula. In The Geology, Geochemistry, nickel occurrences in the marginal series of the
Mineralogy and Mineral Beneficiation of Plati- early Proterozoic Koillismaa Layered Intrusion,
num-Group Elements. Edited by L.J. Cabri. The northern Finland. In Nickel-Copper Deposits of
Canadian Institute of Mining, Metallurgy and the Baltic Shield and Scandinavian Caledonides.
Petroleum, Special Volume, 54, p.569-577. Edited by H. Papunen and G.I. Gorbunov. Geo-
logical Survey of Finland, Bulletin, 333, p.161-
GLICKSON, A.Y., 1996. Mega-impacts and 178.
mantle-melting episodes: test for possible cor-
relations. AGSO Journal of Australian Geology LAMBERT, D.D., MORGAN, R.J., WALKER,
and Geophysics, 16, p.587-607. S.B., SHIREY, R.W., CARLSON, M.L., ZIEN-
TEK, MI.L. and KOSKI, M.S., 1989. Rhenium-
HEAMAN, L.M., 1988. A precise U-Pb zircon osmium and samarium-neodynium isotopic
age for a Hearst Dyke, Geological Association of systematics of the Stillwater Complex. Science
Canada, Mineralogical Association of Canada, 244, p.1169-1174.
10