Transverse Zonation and Latent Layering within the Ore Body of the Main Saranovskoe Deposit (the Western Urals, Russia)

Abstract

We present the results of a detailed study of the transversal geochemical zonation in the northern flank of the layered chromitites of the Main Saranovskoe deposit. The precision methods of chemical and mineralogical analysis of the core samples, as well as microprobe studies of chromite grains were used. The primary magmatic two level transverse zonation was established in the ore body. Zonation of the first level is characterized by decrease of Cr2O3 content along with ferrochromite and picrochromite minals, and increase of Al2O3 along with spinel and hercynite minals in the direction from the primary bottom of the ore body to the roof. Zonation of the second level appears as a hidden stratification within the ore body. It is characterized by a sinusoidal change of the component contents in chrome spinel. Magmatic zoning is complicated by the superposition of two processes: 1) metasomatic metamorphism with the release of the secondary chromemagnetite from chromite and origin of chrome chlorite from primary silicates, 2) hydrothermal processes with the formation of uvarovite-calcite veins. The obtained data allowed to detail the process of chromitite generation and to propose a model of ore formation. It supposes two types of stratification in the deposit: rhythmic with formation of ore layers and hidden within ore bodies.

Keywords

• Сарановское месторождение
• хромовые руды
• зональность рудного тела
• миналы руд
• расслоенность рудного тела
• тектономагматическая модель рудообразования