The article highlights the continuous production at Muruntau since 1967 and underscores its ownership and operation by the Uzbekistan state-owned Navoi Mining and Metallurgy Combinat. Muruntau’s journey from turquoise source to the world’s largest open-pit gold mine showcases the geological and mining prowess that defines this unparalleled gold deposit in the heart of Uzbekistan’s desert landscape.
The Muruntau gold deposit, nestled in the Qizilqum Desert of Uzbekistan, stands as the world’s largest open-pit gold mine. This article provides insights into the magnitude of this remarkable deposit, currently mined by Uzbekistan’s state-owned Navoi Mining and Metallurgy Combinat.
Discovering the treasure trove of Muruntau in 1958 marked a significant milestone, although the area had been historically known for turquoise since the Silk Road era. Systematic exploration in the 1950s revealed a substantial gold and arsenic geochemical anomaly, leading to the identification of the Muruntau deposit. The deposit’s richness became evident with the presence of auriferous quartz veins in surface exposures at the site, ultimately leading to the commencement of mining operations in 1967.
The Muruntau open pit, colossal in scale at approximately 3.5 by 2.5 km and reaching a depth of 560m (as of 2012), boasts an annual production estimated at two million ounces (56.7 tonnes). The gold resource within the Muruntau deposit, encompassing both production and reserves, is an astounding 170 million ounces (4,819 tonnes). This abundance results in an impressive reserves-to-production ratio of 85 years.
Tectonic Evolution of the Kyzyl Kum Area and Its Influence on Muruntau Gold Deposit Formation
The geological evolution of the Kyzyl Kum area, home to the renowned Muruntau gold deposit in Uzbekistan, is intricately tied to a series of tectonic events spanning different geological eras.
The Kyzyl Kum region comprises three primary tectonic units, with the oldest being the Besopan Formation—a metamorphosed Lower Palaeozoic rock shaped during the Caledonian orogeny. Over time, this basement underwent erosion, becoming the foundation for Devonian to Early Triassic sediments and volcanic rocks.
The Caledonian (Silurian) deformation left a lasting imprint on the Kyzyl Kum basement, manifesting in strong folding and the development of an axial planar cleavage. Isoclinal folds with east-striking axial planes suggest pre-basement deposition folding, with metamorphism reaching greenschist facies. Rubidium-Strontium dating places the Caledonian cooling age at approximately 401 million years.
Evidence of late Carboniferous deformation during the Hercynian orogeny is apparent north of Muruntau, where younger carbonate rocks thrust over older basement rocks. This thrusting event aligns with the change from shallow marine to terrestrial conditions at the top of the Carboniferous in the Karatau Range.
A significant Permo-Triassic deformation event, synchronized with a major unconformity, occurs north of Muruntau and is linked to the giant Karatau Fault. The fault exhibits right-lateral displacement and contributes to steeply-plunging Z-shaped folds.
Late Mesozoic and Tertiary deformation events, characterized by post-Tertiary open folds, further shape the geological landscape. Approximately 50 km southwest of the Muruntau deposit, these folds provide insights into the dynamic geological processes that have influenced the formation and evolution of this colossal gold deposit. Additionally, the Karatau Fault undergoes 70 to 100 kilometers of right-lateral movement during the late Mesozoic and early Tertiary, contributing to the complex geological history of the region.