Литосфера (Feb 2016)
Ophiolites of Mariinsky complex at east and west frames of Revdinsky Massif
Abstract
Fragments of the ophiolites of the Mariinsky complex of eastern and western framing of the Revdinskiy massif have been compared. At the eastern framing rocks of Mariinsky complex are main dolerites of sheeted dike complex, whch intruded basaltic pillow lavas, and were provenanced by back-arc spreading. This conclusion is confirmed by study of the composition of accessory chrome-spinels. Minor geochemical differences of dolerites of sheeted dike complex and basaltic pillow lavas have been demonstrated. In sheeted dike complex acide dikes of andesite-dacites were investigated. At the western framing of the Revdinskiy massif rocks of Mariinsky complex are main amphibolites and green schists, which were origin by metamorphism of basic rocks of the upper part of ophiolite section. Relic interlayers of cataclastic metagabbros differing from the host amphibolite by geochemical characteristics were found in the amphibolites at Mt. Lysaya. Amphibolites of the western framing of the Revdinskiy massif are intermediate position between the oceanic basalts and back-arc spreading basalts and differ from rocks of eastern framing by some geochemical characteristics (high TiO2, absence of highly visible Ta-Nb-minimum etc.), that indicates its origin by different geodynamic settings and probably different age.
