Cueros de Purulla

Cueros de Purulla is a volcano in Argentina. It consists of a lava dome and an associated ignimbrite. A large eruption dated to c. 7820 BP deposited ash into the Valles Calchaquies.
Geography and geomorphology.
The volcano lies in Catamarca Province of Argentina southeast of Antofagasta de la Sierra. Cerro Blanco volcano lies south of Cueros de Purulla.
It is the northern of two lava domes which lie at the southern end of the Sierra de Calalaste. The dome is accompanied by ignimbrites and a debris deposit consisting of obsidian lies at the foot of the dome. Two volcanic fallout units are associated with Cueros de Purulla. A lower fallout unit consisting of lapilli and volcanic ash extends several kilometres from the volcano, and remnants occur as far as from it. The upper unit is formed by ignimbrites and pyroclastic density current deposits.
Composition and ores.
Volcanic rocks erupted at Cueros de Purulla include rhyolite. Mineralogically, the rocks contain allanite, amphibole, apatite, biotite, clinopyroxene, epidote, feldspar, ilmenite, magnetite, muscovite, quartz, titanite and zircon. For the past five millennia, the volcano has been used as a source of obsidian, which occurs at in the form of blocks and nodules of various colours, and is of high quality. Reportedly, gold and silver can be found at the volcano.
Eruption history.
The lava dome at Cueros de Purulla is 400,000 ± 100,000 years old. A large eruption occurred during the Holocene, 7820 years before present (i.e. about 5870 BC). Deposits from this eruption form the Cerro Paranilla Ash in the Calchaquí Valleys. The eruption was highly explosive, forming a buoyant cloud and depositing tephra as far as Cafayate in the Salta Province.