Influence of Host Marble Rocks on the Formation of Intrusive Alkaline Rocks and Carbonatites of Sangilen (E. Siberia, Russia)

Anatoly V Nikiforov,Nikolay A Polyakov,Amina M Sugorakova,Elena O Dubinina,Aylan K Khertek

doi:10.3390/min11070666

Anatoly V Nikiforov, Nikolay A Polyakov + Show 3 more

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https://doi.org/10.3390/min11070666

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Abstract

The study of the O and C isotope composition of calcite from nepheline syenites, ijolites and carbonatites of the Chik intrusion and the intrusions of the Erzin–Tarbagatay group of Sangilen (Eastern Siberia, Russia) showed derivation from alkaline melts enriched with a carbonate component from the host marbleized sedimentary rocks. The calculations showed that about 40% of the initial mass of carbonates involved in the interaction with silicate melts have remained after decarbonation. During the assimilation of the carbonate, an oxygen isotope exchange took place between the residual carbonate material and the silicate phase. Crystallization products of such hybrid magmas are carbonatite veins, calcite-rich nepheline rocks and their pegmatites with a calcite core.

Highlights

It is assumed that typical carbonatites, for example, in the Paleozoic complexes of Fennoscandia, occurred due to the multistage evolution of a single silicate–carbonate magma generated from a mantle source at low degrees of partial melting [1,2,3,4]
The clearest example is the Vitim, Sangilen or Kuznetsk Alatau alkaline provinces (Eastern Siberia, Russia), where, among a large number of alkaline intrusions, there are some complexes with carbonatites: Petropavlovsky in Kuznetsk Alatau, Chik and Kharly on Sangilen and Saizhensky on Vitim [8]
In this paper, using the example of the Chik and Kharly intrusions of the Sangilen, we show that the original silicate melts were significantly enriched by a carbonate component from the host sedimentary rocks, resulting in the formation of carbonatite veins and calcite-rich (>25%) nepheline-bearing rocks

Summary

Introduction

It is assumed that typical carbonatites, for example, in the Paleozoic complexes of Fennoscandia, occurred due to the multistage evolution of a single silicate–carbonate magma generated from a mantle source at low degrees of partial melting [1,2,3,4]. The identification of the source of carbonates is generally simple, as, for example, in the intrusions of the Maimecha-Kotuiskaya province (Eastern Siberia, Russia) [7]. When carbonatites are sharply subordinate to alkaline rocks, identification is difficult. The clearest example is the Vitim, Sangilen or Kuznetsk Alatau alkaline provinces (Eastern Siberia, Russia), where, among a large number of alkaline intrusions, there are some complexes with carbonatites: Petropavlovsky in Kuznetsk Alatau, Chik and Kharly on Sangilen and Saizhensky on Vitim [8]

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