Magmatism and Volcanism in Central Andean Systems

The Central Andean margin is defined by the oblique subduction of the Nazca Plate beneath South America, generating one of the most active continental arcs on Earth. Magmatism here spans a spectrum from mantle-derived basalts to voluminous silicic ignimbrites, reflecting progressive crustal differentiation and magma storage in mid-crustal reservoirs. Tectonic processes including slab steepening, flat-slab segments and variations in convergence rate control heat input, fluid release and melt generation. The Altiplano-Puna plateau hosts the largest imaged magma accumulation—the Altiplano-Puna Magma Body—which contributes both to episodic surface uplift and to the thermal structure of the overriding plate. Volcanic outputs range from long-duration, low-flux eruptions to catastrophic flare-ups that build ignimbrite sheets and caldera complexes. These events influence regional topography, geothermal systems and mineralisation. Research has also elucidated the role of deep crustal processes such as delamination and mush reorganisation in modulating magmatic pulses. Understanding magmatism and volcanism in this segment is central to hazard assessment, resource exploration and insights into continental crustal growth in convergent settings.

Research from Nature Portfolio

Recent analyses of a 35-Myr volcanic geospatial database for the 22.5–29° S arc segment have quantified magmatic addition rates, revealing an order-of-magnitude increase during flare-ups compared with steady-state conditions and a lag of approximately 8–12 Myr between major slab perturbation and peak magma flux. Geodetic and gravity modelling of the Altiplano-Puna Magma Body has demonstrated that magmatic intrusion drives long-wavelength doming, with melt volumes that match seismic tomography estimates and suggest magmatic addition can rival lithospheric removal in elevating the plateau. High-resolution seismic velocity imaging across the Puna Plateau has further shown that plutonic-to-volcanic volume ratios exceed 30:1, implying significant construction of intermediate to silicic crust and advancing our understanding of continental crust generation at Cordilleran margins.

Magmatism and Volcanism in Central Andean Systems publication trend

The graph below shows the total number of articles in magmatism and volcanism in central andean systems across all publications each year (not limited to Nature Index journals).

Technical terms

Magmatic flare-up: A transient interval of greatly elevated magma production and eruption flux.

Steady-state magmatism: Long-term background volcanic activity at comparatively stable magma flux rates.

Isostatic compensation: Lithospheric adjustment to mass changes in the crust or mantle to maintain gravitational equilibrium.

Altiplano-Puna Magma Body (APMB): A vast mid-crustal silicic magma reservoir beneath the Altiplano-Puna plateau.

Seismic attenuation tomography: A method that images subsurface melt and fluids by mapping energy loss of seismic waves.

U–Pb zircon dating: A technique measuring uranium decay in zircon crystals to determine magmatic crystallisation ages.

Volcanic Explosive Index (VEI): A logarithmic scale quantifying eruption magnitude based on erupted volume and plume height.

References

1. Magmatic addition rates differentiate periods of steady-state versus flare-up magmatism in the Central Andean arc. Communications Earth & Environment (2023).
2. Surface uplift in the Central Andes driven by growth of the Altiplano Puna Magma Body. Nature Communications (2016).
3. Hydrothermal Fluids and Where to Find Them: Using Seismic Attenuation and Anisotropy to Map Fluids Beneath Uturuncu Volcano, Bolivia. Geophysical Research Letters (2023).
4. Geochronological imaging of an episodically constructed subvolcanic batholith: U-Pb in zircon chronochemistry of the Altiplano-Puna Volcanic Complex of the Central Andes. Geosphere (2016).
5. La gran erupción de hace 4.2 ka cal en Cerro Blanco, Zona Volcánica Central, Andes: nuevos datos sobre los depósitos eruptivos holocenos en la Puna sur y regiones adyacentes. Estudios Geológicos (2019).
6. Velocity structure beneath the southern Puna plateau: Evidence for delamination. Geochemistry Geophysics Geosystems (2013).
7. Thermomechanical modeling of the Altiplano-Puna deformation anomaly: Multiparameter insights into magma mush reorganization. Geosphere (2017).