Perspectives of Kola Alkaline province

Zaitsev V.A.

GEOKHI RAS

 

 The Kola Alkaline Carbonatite Province (KACP), located in the northern Baltic Shield, consists of 20 akaline-ultramafic rock complexes, together with two giant nepheline syenite complexes (Lovozero and Khibiny). Alkaline massifs were formed during short time interval 360-380 Ma (Kramm et al. 1993, Downes et al., 2005). KACP located at the same place with Karelian-Kola paleoproterozoic alkaline province, which include Gremyakha-Vyrmes 1887 ± 58Ma (Sorokhtina et al., 2012) Soustov 1,884±6 Ma Tiksheozero (1999±5), Elet'ozero, and resently finded intrusions Gremikha (1955±11 Ma) Massives El’van’ and Spiridin-Ty, dated as (1668 and 1580 Ma) (Petrovsky et al., 2012). Archean alkaline province include Siilinjarvi (2600 Ma) Sakharyok (2613±35) also exist on the same territory (Zozulja, Bayanova, 2007).

Depth of carbonatite massifs formation was estimated by the microinclusion studies for Turiy Peninsula (1,5±0.5 km) Ozernaya Varaka (2,8±0,7 km), Kovdor (4,0±0,7 km), Vuorijarvi (4,7±0,8 km) and Afrikanda (5,4±0,8 km) (Epstein 1994). Calculated average erosion rate (during last 370 Ma) for this missives vary from 4 m/Ma for Turiy Peninsula to 14.5 Ma for Afrikanda. Pressure estimations by miroinclusions in Lovozero massif and Khibina massif (Kogarko, 1990) allow estimating erosion level as 3 km and 4.4 km, and erosion rate as 8.1 and 11.9 m/Ma respectively. Average erosion rate for Kola Peninsula can be estimated as 10.8 m/Ma (data for Turiy Peninsula, locqated inside Kandalakha graben was excluded).

Similar rate (12.7-13.4 m/Ma) was calculated using thermodynamic estimation of Sakhariok massif formations pressure (9,5-10 kbar) (Kozlovsky, 2001). It show more or less constant upwelling of territory during long time.

Geohpysical data provided by (Arzamastsev et al., 2001) allow estimating depth of the bottom for 18 massifs of KACP. Using this data we can estimate time, which will be necessary for erosion of each massif. It varies from 274 Ma for Africanda to 1443 for Lovozero massif and 1850 for Kovdor. Dependence between number of existing massifs and time may be described by the power law, conform the law of distribution of absolute ages of alkaline rocks and carbonatites around the Word (Zaitsev, 2012).

            It we will imagine that some geologist will try to study KACP when it will be the have same age as Karelian-Kola paleoproterozoic alkaline province now, he will find only the rests of Kovdor, and, probably, Lovosero massifs. We can also make another desigion, that when Karelian-Kola paleoproterozoic alkaline province was as yang as Kola Alkaline Carbonatite Province (1,5 By ago) it was much bigger then Kola Alkaline Carbonatite Province now.

 

 Bea F., Arzamastsev A., Montero P., Arzamastseva L. Anomalous alkaline rocks of Soustov, Kola: evidence of mantle-derived metasomatic fluids affecting crustal materials// Contributions to Mineralogy and Petrology February 2001, Volume 140, Issue 5, pp 554-566

Corfu F., Bayanova T.B., Shchiptsov V.V., Frantz N. U-Pb ID-TIMS age of the Tiksheozero carbonatite: expression of 2.0 Ga alkaline magmatism in Karelia, Russia// Central European Journal of Geosciences September 2011, Volume 3, Issue 3, pp 302-308

Downes et al., 2005 H. Downes, E. Balaganskaya, A.Beard R. Liferovichb, D. Demaiffe Petrogenetic processes in the ultramafic, alkaline and carbonatitic magmatism in the Kola Alkaline Province: A review// Lithos 85 (2005) 48–75

Epshein E.M. Geologial-petrological model and genetical features of ore-bearing karbonatite complexes. // Moscow, Nedra, 1994 – 256 p.

Kogarko L.N. Problemes of genesises of Arpaitic magmes//Moscow, Nauka, 1977

Koslovsky V.M. Formation of mineral paragenesises in alkaline rocks of Kuliok and Sakhariok massifs in Kola Penisula – 2001.Dissertation

Kramm, U., Kogarko, L.N., Kononova, V.A., Vartiainen, H., 1993.The Kola Alkaline Province of the CIS and Finland: precise Rb–Sr ages define 380–360 Ma age range for all magmatism. Lithos 30, 33– 44.

Petrovsky M.N. Petrovskaya L.S. Bayanova T.B. Basay A.B. Intraplate magmatism in geological history of Murmansk Neoarcheian craton// Modern problems of magmatism and metamorphism. Materials of Russian conference dedicated 150-annyary of F.Yu. Levinson-Lessing and 100- annyary of prof. G.M. Saranchina. 2012 pp123-127 (in Russian).

Sorokhtina N. V., Kogarko L. N., Shpachenko A. K., Groznova M. V., Kostitsyn, Yu. A.. Roshchina I. A, Gredina I. V. Geochemistry and age of the complex of alkaline metasomatic rocks and carbonatites of the Gremyakha-Vyrmes massif, Kola Peninsula// Geochemistry International  2012, Vol 50, Issue 12, pp 975-987

Zaitsev V.A. Alkaline rocks and astroblemes: comparable statistical analyses// Abstract of annual conference Ore potential of alkaline, kimberlite and carbonatite magmatism.// ONTI GEOKHI RAS, 2012 pp. 54-56

Zozulya D.R., Bayanova T.B. Indicatores of enreached mantle in archean carbonatiotes and alclaine rocks of Baltic and Greenland shields// abstracts of international conference Alkaline magmatizm of Earth and its ore potential, 2007