![]() RUSSIAN JOURNAL OF EARTH SCIENCES VOL. 4, NO. 1, PAGES 35–75, doi:10.2205/2002ES000080, 2002
Petrology of the Europe-Largest Burakovka early Paleoproterozoic layered pluton (Southern Karelia, Russia)A. V. Chistyakov, E. V. Sharkov, T. L. Grokhovskaya, O. A. Bogatikov, and G. N. Muravitskaya Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry (IGEM), Russian Academy of Sciences, Moscow, Russia N. G. Grinevich Karelian Geological Survey, Petrozavodsk, RussiaAbstract
[1] The Burakovka layered pluton of basic and mafic rocks is the largest intrusive
massif in the Baltic Province composed of Si- and Mg-rich boninite-like rocks. The pluton consists
of two individual bodies, each having its own internal structure, and contacting each other in their
apical parts, known as the Aganozero and Shalozero-Burakovka bodies. Both bodies have a similar
rock sequence including five differentiated zones (upward): mafic rocks, pyroxenite, gabbro norite,
pigeonite gabbro norite, and magnetite gabbro diorite (the latter found only in the Shalozero-Burakovka
Body). Being generally similar to each other, these bodies differ notably in the styles of
their cumulate stratigraphy and, to a lesser extent, in composition.
The pluton is distinguished by the presence of markers - singular interlayers of high-temperature
mafic cumulates emplaced in the sequence of lower-T formations. Their origin is
believed to have been associated with the intrusion of fresh magma portions into the crystallizing
magma chambers. The same mechanism is believed to have been responsible for a macrorhythmic
pattern found in the southeastern portion of the Shalozero-Burakovka intrusive body.
Using chemical and mineralogical data, it is shown that the bodies discussed were derived
from similar high-Si and high-Mg magmas, except that the Aganozero Body was emplaced 50
million years later than the Shalozero-Burakovka intrusion: the former was dated (Sm-Nd isochron)
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Received 8 February 2002; published 12 March 2002. Keywords: petrology, Paleoproterozoic layered pluton, mafic rocks. ![]() Citation: Chistyakov, A. V., E. V. Sharkov, T. L. Grokhovskaya, O. A. Bogatikov, G. N. Muravitskaya, and N. G. Grinevich (2002), Petrology of the Europe-Largest Burakovka early Paleoproterozoic layered pluton (Southern Karelia, Russia), Russ. J. Earth Sci., 4, No.1, 35-75, doi:10.2205/2002ES000080. Copyright 2002 by the Russian Journal of Earth Sciences Powered by TeXWeb (Win32, v.2.0). |