TY - JOUR

T1 - Assimilation of Carbonates by Mafic Magma: Fassaite Gabbro of the Olkhon Terrane (Western Baikal Region)

AU - Sklyarov, E. V.

AU - Lavrenchuk, A. V.

AU - Semenova, D. V.

N1 - This work was carried out under State Assignments of the Institute of the Earth’s Crust, Siberian Branch, Russian Academy of Sciences, and the Sobolev Institute of Geology and Mineralogy, Siberian Branch, Russian Academy of Sciences (project nos. 12204140044-2 and 122041400171-5).

PY - 2024/11

Y1 - 2024/11

N2 - Specific gabbro with the main rock-forming mineral of fassaite—alumina-rich (up to 12 wt % Al2O3) calcium pyroxene, typical of high-temperature metasomatic rocks, are characterized. In terms of the geochemical characteristics, the fassaite gabbros are close to the subalkaline monzogabbros of the Ust’-Krestovsky complex, which are widely distributed within the Krestovsky subterrane of the Olkhon terrane (Western Baikal region). At the same time, they differ sharply from the latter in having a higher content of CaO and MgO and a lower content of SiO2 and Al2O3. Fassaite gabbro composes several small bodies framed the Ust’-Krestovsky monzogabbro massif, without contacting the latter. A model of the formation of fassaite gabbro due to the assimilation of carbonate (crustal carbonate melts) by subalkaline mafic magma is proposed.

AB - Specific gabbro with the main rock-forming mineral of fassaite—alumina-rich (up to 12 wt % Al2O3) calcium pyroxene, typical of high-temperature metasomatic rocks, are characterized. In terms of the geochemical characteristics, the fassaite gabbros are close to the subalkaline monzogabbros of the Ust’-Krestovsky complex, which are widely distributed within the Krestovsky subterrane of the Olkhon terrane (Western Baikal region). At the same time, they differ sharply from the latter in having a higher content of CaO and MgO and a lower content of SiO2 and Al2O3. Fassaite gabbro composes several small bodies framed the Ust’-Krestovsky monzogabbro massif, without contacting the latter. A model of the formation of fassaite gabbro due to the assimilation of carbonate (crustal carbonate melts) by subalkaline mafic magma is proposed.

KW - Olkhon terrane

KW - assimilation

KW - carbonates

KW - fassaite

KW - gabbro

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85203184706&origin=inward&txGid=b243b920d81e5ecc047ddef907fc5a15

UR - https://www.mendeley.com/catalogue/06bb120c-1295-3e0d-944f-fc4e8f53b3cd/

U2 - 10.1134/S1028334X24603055

DO - 10.1134/S1028334X24603055

M3 - Article

VL - 519

SP - 1860

EP - 1867

JO - Doklady Earth Sciences

JF - Doklady Earth Sciences

SN - 1028-334X

IS - 1

ER -