naa a22 4500 510736378 CHVBK 20180411083011.0 cr unu---uuuuu 180411e20130701xx s 000 0 eng 10.1134/S1075701513040053 doi (NATIONALLICENCE)springer-10.1134/S1075701513040053 Origin of Au-bearing rodingite in the Karabash massif of alpine-type ultramafic rocks in the southern Urals [Elektronische Daten] [V. Murzin, D. Varlamov, Yu. Ronkin, S. Shanina] The rodingite belt in the Karabash massif situated 40 km north of Miass is continuously traced for 2.5 km along its central part. Rodingites bear up to 1% sulfide disseminations and gold particles with high Cu content (up to 40 wt %) throughout the belt. The central part of the rodingite belt is especially rich in gold, which was mined at the Zolotaya Gora (Gold Mountain) deposit. The Au-bearing rodingite belt is zonal and was formed during three stages. The inner zone is composed of chlorite-andradite-diopside rock of the first stage, which is crosscut by diopside veinlets of the second stage and calcite veinlets of the third stage. The intermediate zone consists of fine-grained chloritolite of the first stage and coarse-grained chlorite veinlets of the second stage. The outer zone of the metasomatic column is occupied by antigorite and chrysotile-lizardite serpentinites. No relict rocks or minerals of the replaced protolith have been established except sporadic Cr-spinel grains. Native gold was being deposited during all periods of rodingite formation. In terms of the currently adopted concept of evolution of the Ural Foldbelt, the Sm-Nd isochron age of rodingite estimated at 369.4 ± 8.8 Ma corresponds to the period of collisional compression of Silurian-Devonian oceanic and island-arc complexes and upward pushing out of a block of the melanocratic basement underlying these complexes. A proposed model of rodingite formation is based on ore mineralogy, REE geochemistry, and thermobarogeochemical and isotopic study of minerals. It is suggested that in contrast to the barren bimetasomatic rodingite replacing dikes, the studied rodingite are considered to be fissure veins accompanied by metasomatic alteration of host serpentinite. The estimation of initial isotopic composition of fluid components indicates that the ore-bearing fluid is of metamorphic origin (δDfl = −4 to −13‰ and δ18Ofl = 5.9 to 8.3‰). The fluid was formed as a product of dehydration of oceanic serpentinite at the base of melanocratic rocks and related gabbroids that moved out to the surface. These rocks were a source of gold and other components (Ca, Al, Ti, Cu, Ni, REE, P, etc.). Pleiades Publishing, Ltd., 2013 Murzin V. Institute of Geology and Geochemistry, Ural Branch, Russian Academy of Sciences, Pochtovyi per. 7, 620075, Yekaterinburg, Russia aut Varlamov D. Institute of Experimental Mineralogy, Russian Academy of Sciences, ul. Institutskaya 4, 142432, Chernogolovka, Russia aut Ronkin Yu Institute of Geology and Geochemistry, Ural Branch, Russian Academy of Sciences, Pochtovyi per. 7, 620075, Yekaterinburg, Russia aut Shanina S. Institute of Geology, Komi Scientific Center, Ural Branch, Russian Academy of Sciences, ul. Pervomaiskaya 54, 167982, Syktyvkar, Russia aut Geology of Ore Deposits Springer US; http://www.springer-ny.com 55/4(2013-07-01), 278-297 1075-7015 55:4<278 2013 55 11477 https://doi.org/10.1134/S1075701513040053 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S1075701513040053 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Murzin V. Institute of Geology and Geochemistry, Ural Branch, Russian Academy of Sciences, Pochtovyi per. 7, 620075, Yekaterinburg, Russia aut NATIONALLICENCE 700 1- Varlamov D. Institute of Experimental Mineralogy, Russian Academy of Sciences, ul. Institutskaya 4, 142432, Chernogolovka, Russia aut NATIONALLICENCE 700 1- Ronkin Yu Institute of Geology and Geochemistry, Ural Branch, Russian Academy of Sciences, Pochtovyi per. 7, 620075, Yekaterinburg, Russia aut NATIONALLICENCE 700 1- Shanina S. Institute of Geology, Komi Scientific Center, Ural Branch, Russian Academy of Sciences, ul. Pervomaiskaya 54, 167982, Syktyvkar, Russia aut NATIONALLICENCE 773 0- Geology of Ore Deposits Springer US; http://www.springer-ny.com 55/4(2013-07-01), 278-297 1075-7015 55:4<278 2013 55 11477 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer