Paragenetic relations of minerals in the Snezhnoye ruby deposit, Muzkol-Rangkul anticlinorium, Central Pamir

Background. The mineral association of ruby in the Snezhnoye deposit is represented by 7 rock-forming and 19 accessory minerals. Here, all minerals vary in their composition due to isomorphism. The conducted paragenetic analysis of minerals from marble-hosted ruby deposits identified four groups of rocks. Out of them, three groups are divided into series according to the dominant mineral: plagioclase, scapolite, and mica associations. The fourth group comprises monomineralic ruby. The studied minerals exhibit 16 parageneses, including two-, three-, and four-mineral forms. The diversity and uneven manifestation of paragenesis is determined by the variable chemical composition of protolith (bauxite-like sediment), the metamorphogenic transformation of which led to the emergence of Snezhnoye and other deposits.Aim. To identify paragenetic relations between rock-forming minerals of ruby-bearing deposits.Materials and methods. The methods of paragenetic analysis, the foundations of which were developed by D.S. Korzhinsky, were used. Three groups of inert elements were selected from the actual mineral and chemical compositions of the Snezhnoye ruby deposits and other ruby-bearing objects of the Muzkol series: (1) Si, (2) Al, and (3) the sum of Ca, Mg, Na, and K. Mineral compositions were calculated in terms of 100% and plotted on triangular diagrams. Then, on the basis of observations in samples and sections on the diagrams, the parageneses were connected by tie-lines for analysis.Results. The conducted paragenetic analysis of minerals from marble-hosted ruby deposits identified four groups of rocks. Out of them, three groups are divided into series according to the dominant mineral: plagioclase, scapolite, and mica associations. The fourth group comprises monomineralic ruby. The studied minerals exhibit 16 parageneses, including two-, three-, and four-mineral forms. The diversity and uneven manifestation of paragenesis is determined by the variable chemical composition of protolith (bauxite-like sediment), the metamorphogenic transformation of which led to the emergence of Snezhnoye and other deposits.Conclusion. The use of paragenetic analysis when investigating the metamorphogenic ruby deposit under study produced reliable results, which were further tested at nearby deposits and occurrences. The obtained materials can be used when prospecting new marble-hosted deposits of the Muzkol metamorphic series.

Central Pamir, Muzkol-Rangkul anticlinorium, Snezhnoye ruby deposit, paragenesis, ruby, plagioclase, scapolite, muscovite, phlogopite, margarite