Abstract—

The Chernogorskoe gem-quality scapolite deposit, which is attributed to a new genetic type, is described. It is located in the Central Pamirs (Tajikistan), in the Sary-Dzhilga Formation of the Muzkol Group (PR₁). Host rocks include metamorphosed mafic–ultramafic formations of the Kukurt complex, among which harzburgite was the first discovered. Albitite lenses host gem-quality scapolite mineralization. They were formed by the metasomatic replacement of nepheline syenite. This reaction was accompanied by a decrease in the volume of solid phases by 14% and the appearance of voids. Albitite bodies form a lenticular nesting structure, have crosscutting contacts, and make up amphibolite, which metasomatically replaces melanocratic gabbroid and partially altered harzburgite. Gem-quality scapolite is localized in 28 albitite lenses; the walls of their voids are encrusted with columnar purple scapolite. The sequence of processes at the studied deposit is as follows: formation of melanocratic gabbroids with small nepheline syenite bodies → metasomatic development of amphibolite after the former and albitite with voids after the latter → growth of columnar scapolite on voids walls → crystallization of gem-quality scapolite in voids.

中文翻译：

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Chernogorskoe宝石级方沸石矿床的地质（塔吉克斯坦中部帕米尔斯）

摘要-

描述了归因于一种新的遗传类型的切尔诺戈尔斯科宝石级闪锌矿矿床。它位于Muzkol集团（PR ₁）的Sary-Dzhilga组中的中帕米尔（塔吉克斯坦））。宿主岩包括库库特岩体的变质的镁铁质-超镁铁质岩层，其中首先发现了钙长石。Albitite镜片具有宝石级的方沸石矿化作用。它们是由霞石正长岩的交代置换形成的。该反应伴随着固相体积的减少14％和空隙的出现。菱铁矿体形成一个透镜状的嵌套结构，具有横切接触，并组成了角闪石，后者在交代作用上替代了黑克拉通辉石和部分变质的方沸石。宝石品质的方柱石位于28个方钠石镜片中；空洞的墙壁上覆盖着圆柱状的紫色蓝宝石。研究矿床的过程顺序如下：