Jotabeche has generated rhyodacite rocks. The Negro Francisco ignimbrite is rhyolitic while the Jotabeche ignimbrite itself is of rhyodacitic composition. Specific SiO2 concentrations are 65-70% for Negro Francisco while the caldera complex has 68-72%. The Jotabeche Norte stratovolcano has a concentration of 60% and is considered to be hornblende andesite in terms of composition. Overall, all rocks fit the K rich calc alkaline pattern. Au-rich porphyry deposits are found on Jotabeche's flanks. Diorites are also found but the only weak erosion and thick late Miocene rock cover bury them. Other mineralizations are found between Jotabeche and the Salar de Maricunga.