TY - JOUR

T1 - Stable isotope (C, O, H) characteristics and genesis of the Tazheran brucite marbles and skarns, Olkhon region, Russia

AU - Doroshkevich, Anna

AU - Sklyarov, Eugene

AU - Starikova, Anastasia

AU - Vasiliev, Vladimir

AU - Ripp, German

AU - Izbrodin, Ivan

AU - Posokhov, Viktor

N1 - Publisher Copyright: © 2016, Springer-Verlag Wien.

PY - 2017/6/1

Y1 - 2017/6/1

N2 - Stable isotope compositions are examined for brucite marble and Mg-skarn that occur in the southern part of the Tazheran massif, Olkhon region, Russia. Brucite marble exhibits a narrow range in δ18O of +23.3 to +26.2 ‰ and shows carbon isotope depletion of −1.9 to −4.4 ‰) as compared with the country dolomite isotope compositions (+2.0 to +2.4 ‰) which is explained by both decarbonation processes and participation of fluids depleted in 13C. The emplacement of brucite marble was accompanied by the formation of endo- and exoskarn at the contact between syenite and brucite marble. δ18O profiles across the contact show a typical decrease towards the syenite side interpreted as the result of fluid/rock interaction and influx of magmatic fluids. Finally, we discuss the mechanisms of brucite marble emplacement and consider three possible ways of producing these rocks: (1) injection of dolomite with subsequent transformation to periclase marble and then to brucite marble; (2) injection of periclase marble with a following replacement of periclase by brucite or injection of brucite marble; (3) crustal water-rich carbonate melt. We favor models 2 and 3 and discuss their strengths and weaknesses.

AB - Stable isotope compositions are examined for brucite marble and Mg-skarn that occur in the southern part of the Tazheran massif, Olkhon region, Russia. Brucite marble exhibits a narrow range in δ18O of +23.3 to +26.2 ‰ and shows carbon isotope depletion of −1.9 to −4.4 ‰) as compared with the country dolomite isotope compositions (+2.0 to +2.4 ‰) which is explained by both decarbonation processes and participation of fluids depleted in 13C. The emplacement of brucite marble was accompanied by the formation of endo- and exoskarn at the contact between syenite and brucite marble. δ18O profiles across the contact show a typical decrease towards the syenite side interpreted as the result of fluid/rock interaction and influx of magmatic fluids. Finally, we discuss the mechanisms of brucite marble emplacement and consider three possible ways of producing these rocks: (1) injection of dolomite with subsequent transformation to periclase marble and then to brucite marble; (2) injection of periclase marble with a following replacement of periclase by brucite or injection of brucite marble; (3) crustal water-rich carbonate melt. We favor models 2 and 3 and discuss their strengths and weaknesses.

KW - Brucite marble

KW - Decarbonation

KW - Fluid depleted in C

KW - Fluid-rock interaction

KW - Olkhon collision system

KW - Skarn

KW - Stable isotopes

KW - Tazheran gabbro-syenite massif

KW - CONTACT-METAMORPHISM

KW - SYSTEM

KW - Skam

KW - FRACTIONATION

KW - MINERALS

KW - INTRUSION

KW - SELF-ORGANIZATION

KW - OXYGEN

KW - BAIKAL REGION

KW - Fluid depleted in C-13

KW - CARBONATE

KW - WALL ROCK

UR - http://www.scopus.com/inward/record.url?scp=84990891518&partnerID=8YFLogxK

U2 - 10.1007/s00710-016-0477-8

DO - 10.1007/s00710-016-0477-8

M3 - Article

AN - SCOPUS:84990891518

VL - 111

SP - 399

EP - 416

JO - Mineralogy and Petrology

JF - Mineralogy and Petrology

SN - 0930-0708

IS - 3

ER -