Abstract
Fe–Ti oxides (magnetite, Ti-magnetite, ilmenite, and associated high-Al spinel) in the ferrogabbroids of the Middle Paleoproterozoic Elet’ozero syenite–gabbro intrusion are intercumulus minerals usually surrounded by coronitic rims of two types. The first type usually represents multilayer amphibole–biotite ± olivine coronas along contacts of Fe–Ti oxides with cumulus moderate-Ca plagioclase and more rarely, clinopyroxene. Two-layer rim is developed in contact with high-Ca plagioclase; the inner rim consists of pargasite and spinel, while the outer rim is made up of sadanagaite and spinel. The second type is represented by two-stage coronitic textures developed along boundaries of olivine and Fe–Ti oxide clusters with plagioclase. Initially, the olivine was surrounded by orthopyroxene rim, while Fe–Ti oxides were rimmed by pargasite with thin ingrowths of high-Al spinel (hercynite). At the next stage, the entire cluster was fringed by a common symplectite reaction rim, the composition of which also depended on the composition of plagioclase matrix: the spinel–sadanagaite rim was formed in contact with high-Ca plagioclase, while pargasite–muscovite–scapolite rim was formed in contact with moderate-Ca plagioclase. The formation of the outer rims occurred after hydration of the inner parts of coronas around olivine and oxides within the clusters. It is suggested that the Fe–Ti oxides and surrounding coronitic rims were microsystems formed by crystallization of drops of residual hydrous Fe-rich liquid.
Similar content being viewed by others
References
A. N. Bogachev, S. I. Zak, G. P. Safonova, and K. A. Inina, Geology and Petrology of the Elet’ozero Massif of the Gabbroid Rocks of Karelia: Geology, Petrography, Petrology, and Metallogeny (AN USSR, Moscow–Leningrad, 1963) [in Russian].
B. Charlier and T. L. Grove, “Experiments on liquid immiscibility along tholeiitic liquid lines of descent,” Contrib. Mineral. Petrol. 164, 27–44 (2012).
R. A. Cox and A. Indares, “Transformation of Fe–Ti gabbro to coronite, eclogite and amphibolite in the Baie du Nord segment, Manicouagan Imbricate Zone, eastern Grenville Province,” J. Metamorph. Geol. 17, 537–555 (1999).
J. K. Jakobsen, I. V. Veksler, C. Tegner, and C. K. Brooks, “Crystallization of the Skaergaard Intrusion from an emulsion of immiscible iron- and silica-rich liquids: evidence from melt inclusions in plagioclase,” J. Petrol. 52 (2), 345–373 (2011).
A. A. Kukharenko, M. P. Orlova, and E. A. Bagdasarov, Alkaline Gabbroids of Karelia (LGU, Leningrad, 1969) [in Russian].
A. A. Polkanov, N. A. Eliseev, E. N. Eliseev, and G. N. Kavardin, Gremyakha–Vyrmes Massif on the Kola Peninsula (Nauka, Leningrad, 1967) [in Russian].
E. V. Sharkov, B. V. Belyatsky, M. M. Bogina, A. V. Chistyakov, V. V. Shchiptsov, A. V. Antonov, and E. N. Lepekhina, “Genesis and age of zircon from alkali and mafic rocks of the Elet’ozero Complex, North Karelia,” Petrology 23 (3), 259–280 (2015).
E. V. Sharkov. Formation of Layered Intrusions and Related Mineralization (Nauchnyi Mir, Moscow, 2006) [in Russian].
V. V. Shchiptsov, “Industrial minerals of the Tikshozero- Eletozero alkaline ultramafic-carbonatitic and alkaline gabbroic complexes in Karelia, Russia,” in 12 SGA Biennial Meeting Mineral Deposits Research for a High Tech World. Uppsala, Sweden, 2013, Proceedings 4, 1781–1783 (2013).
I. V. Veksler, A. M. Dorfman, A. A. Borisov, R. Wirth, and D. B. Dingwell, “Liquid immiscibility and the evolution of basaltic magma,” J. Petrol. 48, 2187–2210 (2007).
C. Y. Wang and M. I. Zhou, “New textural and mineralogical constraints on the origin of Hongge Fe–Ti–V oxide deposits, SW China,” Miner. Deposita 48 (6), 787–798 (2013).
P. R. Whitney and J. M. McLelland, “Origin of biotite–hornblende–garnet coronas between oxides and plagioclase in olivine metagabbros from Adirondack Mountains, New York,” Contrib. Miner. Petrol. 82, 14–41 (1983).
M.-F. Zhou, W. T. Chen, C. Y. Wang, S. A. Prevec, P. P. Liu, and G. Howarth, “Two stages of immiscible liquid separation in the formation of Panzhihua-type of Fe–Ti–V oxide deposits, SW China,” Geosci. Front. 4 (5), 481–502 (2013).
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © E.V. Sharkov, A.V. Chistyakov, 2017, published in Geokhimiya, 2017, No. 6, pp. 513–526.
Rights and permissions
About this article
Cite this article
Sharkov, E.V., Chistyakov, A.V. Coronitic textures in the ferrogabbroids of the Elet’ozero intrusive complex (northern Karelia, Russia) as evidence for the existence of Fe-rich melt. 1. Types of coronas. Geochem. Int. 55, 535–547 (2017). https://doi.org/10.1134/S0016702917060076
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S0016702917060076