How did the mineral-rich Bolivian tin belt form?

The Bolivian tin belt is a metallogenetic province located in the Cordillera Oriental of Bolivia that is rich in tin, tungsten, silver, and base metals. Its mineral enrichment stems from fluids expelled by peraluminous magmas, which are created through the partial melting of continental crust. This geological process shares features with collisional orogens, pointing to unique tectonic interactions between the South American and Nazca plates.

What we know

• The Bolivian tin belt is situated in the Cordillera Oriental of Bolivia and contains reserves of tin, tungsten, silver, and base metals. [2]
• Mineralization within the belt formed episodically, starting in the Triassic with the youngest known mineralizations dating to the Miocene. [2]
• Mineral enrichment is driven by fluids expelled from peraluminous magmas formed by the partial melting of metasedimentary rock, gneiss, and Lower Paleozoic pelitic rock. [2]
• The geology of Bolivia comprises a variety of lithologies, separating a mountainous western area affected by subduction from eastern stable platforms and shields. [5]

Where to go next

• how we knowWhat metals are found in the Bolivian tin belt?
• how it workedHow do tectonic plates influence South American metallogeny?
• whereWhat is the geology of the Cordillera Oriental?
• compared withHow does the Southeast Asian tin belt compare?
• what followedWhat role did tin mining play in Bolivia's history?
• an unexpected connectionWhy do Andean volcanoes share features with Himalayan collisions?Peraluminous magmas are typically rare in the Andes and more characteristic of collisional orogens like the Himalayas, suggesting unexpected collision-like events in South America.

Sources

• [1]Bolivian tin belt (Wikidata Q39087295) · CC0 1.0
• [2]Bolivian tin belt · CC BY-SA 4.0
• [3]Southeast Asian tin belt · CC BY-SA 4.0
• [4]Bolivia · CC BY-SA 4.0
• [5]Geology of Bolivia · CC BY-SA 4.0