The Cerro Galán caldera, located in northwestern Argentina in the Central Andean Volcanic Zone of the Andean continental margin volcanic arc of South America, is often cited as an example of one of the largest caldera-forming “super eruptions” on Earth. No super-eruptions have been witnessed in human history; little is known concerning their frequency, eruption mechanisms and emplacement processes of erupted material. This thesis uses new geochemical and petrological techniques combined with mapping and stratigraphy to shed new light into these relatively unknown features of Cerro Galán and other supervolcanic eruptions. The Cerro Galán volcanic system has erupted at least nine crystal-rich ignimbrites from ~6 to 2 Ma. Starting with the earliest eruption, these consist of the Blanco Ignimbrite (date unknown; volume ~10 km3), the Merihuaca Formation Ignimbrites, consisting of the Lower, Middle and Upper Members (~5.1 to 4.9 Ma; total volume ~65 km3), the Pitas Ignimbrite (~4.8 Ma; 190 km3), the Real Grande Ignimbrite (~4.7 Ma; 390 km3) and the Vega Ignimbrite (~4.5 Ma; volume unknown). Together, these ignimbrites are known as the Toconquis Group and were exclusively deposited from the south-west to the north of the modern caldera. There was then a hiatus in ignimbrite eruptions until the Cueva Negra Ignimbrite (~3.8 Ma; 50 km3) was deposited to the east of the caldera, followed by the climactic eruption of the Cerro Galán Ignimbrite (CGI; ~2.1 Ma; 630 km3) which is found radially around the caldera. The eruption of the CGI facilitated a caldera collapse event, producing the modern volcano-tectonic depression preserved today. Collapse occurred via a piecemeal trapdoor process with the hinge located along the eastern margins of the caldera. Post-CGI resurgence uplifted the central portion of intracaldera fill to produce a resurgent dome; this period also witnessed small-volume pyroclastic surges and ignimbrite eruptions (