| Инд. авторы: | Chernyshov A.I., Nozhkin A.D., Mishenina M.A. |
| Заглавие: | Petrogeochemical typification of the ultramafic rocks from the Idar greenstone belt, Kan block, East Sayan |
| Библ. ссылка: | Chernyshov A.I., Nozhkin A.D., Mishenina M.A. Petrogeochemical typification of the ultramafic rocks from the Idar greenstone belt, Kan block, East Sayan // Geochemistry International. - 2010. - Vol.48. - Iss. 2. - P.118-139. - ISSN 0016-7029. - EISSN 1531-8397. |
| Внешние системы: | DOI: 10.1134/S0016702910020023; SCOPUS: 2-s2.0-77951941145; |
| Реферат: | eng: The ultramafic rocks of the Kan block, East Sayan, are confined mainly to the Idar greenstone belt. In terms of formational affiliation, they are subdivided into two groups: magmatic (Kingash Complex) and residual (Idar Complex) ones. The magmatic ultramafic rocks compose hypabyssal and subvolcanic bodies, which are represented by rocks of dunite-wehrlite-picrite association with cumulate textures. Uninterrupted chemical variations of the magmatic ultramafic rocks indicate subsequent magmatic differentiation of parental picritic melt in the intermediate deep-seated chambers and emplacement of its derivatives in the crystallization site. Differentiation leads to proportional increase of all rare-earth and other incompatible elements. The residual ultramafics occur as boudined dunite-harzburgite bodies showing metamorphic granoblastic textures. They have more homogenous chemical composition close to those of ophiolite complexes, which represent strongly depleted mantle rocks brought to the upper lithospheric levels via deep-seated thrusts. Residual ultramafics differ from magmatic rocks in notably lower contents of some trace and rare earth elements. © Pleiades Publishing, Ltd., 2010.
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| Ключевые слова: | igneous geochemistry; magmatic differentiation; mantle source; ophiolite; parent body; petrogenesis; Sayan Mountains; Russian Federation; ultramafic rock; trace element; rare earth element; greenstone belt; formation mechanism; emplacement; chemical composition; Rocks; Trace elements; Textures; Rare earth elements; Geochemistry; Wehrlite; Ultramafic rocks; Ophiolite complex; Mantle rocks; Magmatic rock; Lithospheric; Incompatible element; Harzburgites; Greenstone belts; Chemical variations; hypabyssal rock; Chemical compositions; |
| Издано: | 2010 |
| Физ. характеристика: | с.118-139 |