Тип публикации: статья из журнала
Год издания: 2008
Идентификатор DOI: 10.1016/j.rgg.2007.10.007
Ключевые слова: intrusive traps, structural type, large-scale complex, Siberian Platform, craton, formation mechanism, geomorphology, hot spot, igneous intrusion, intraplate process, isotopic ratio, lithosphere, magmatic differentiation, magmatism, mantle plume, rare earth element, tectonic evolution, trap (geological structure), Eurasia, Russian Federation
Аннотация: The Oneka intrusive complex, recognized on prospecting for hydrocarbons in the western Siberian Platform, in the northern half of the Bakhta megablock (Tunguska syneclise), holds a special position among the known and new large-scale manifestations of intrusive trap magmatism. During the process, original data on the distribution oПоказать полностьюf traps in the 4.2 km thick platform cover were obtained. Diverse in morphology and size, the intrusions are of the same genesis, composition, and character of intrachamber differentiation and form a "framework" igneous complex in the northern half of the Bakhta megablock. This complex occupies an area of about 40,000 km(2). It is an intricate tectonomagmatic superstructure, with the volume of magmatic material estimated at 50,000 km(3). Results of petrochemical and geochemical studies, multispectra and REE ratios, and isotope ratios Sr-87/Sr-86 (0.70558-0.70580) suggest that diverse rocks of the Oneka intrusive complex were, most likely, formed from a primary picritoid magma, which underwent deep-level differentiation and was slightly contaminated with rocks of the crust and platform cover. The comprehensive study of the massif and results of numerical modeling show that the formation of such tectonomagmatic structures is closely related to the processes of intraplate magma formation in the craton lithosphere. The large Oneka intrusive complex, like other similar manifestations of Permo-Triassic trap ( and alkaline-ultrabasic) magmatism of the Siberian Platform, can be considered projections of hotspots recording the evolution of the Siberian superplume. (C) 2008, IGM, Siberian Branch of the RAS. Published by Elsevier B. V. All rights reserved.
Журнал: RUSSIAN GEOLOGY AND GEOPHYSICS
Выпуск журнала: Vol. 49, Is. 5
Номера страниц: 297-309
ISSN журнала: 10687971
Место издания: AMSTERDAM
Издатель: ELSEVIER SCIENCE BV