Tectonic and Volcanic Processes in Andean Systems

The Andes represent one of the world’s most active continental margins, where the eastward subduction of the Nazca Plate beneath South America has driven over 200 million years of mountain building and arc volcanism. Convergence rates and slab geometry vary along strike, yielding segments of flat-slab subduction, steep-angle descent and localized slab tears. These variations control the distribution of thick- and thin-skinned deformation in the orogenic belt, the migration of magmatic arcs and the formation of high-relief plateaux such as the Altiplano. Volcanism ranges from basaltic to rhyolitic compositions, reflecting interaction between mantle melts, subducted sediments and continental crust. Tectonic shortening produces fold-and-thrust systems in the foreland, basement uplifts beneath volcanic centres and backarc extension where slab rollback occurs. The resulting landscape is a tapestry of active volcanoes, ignimbrite fields, fault-bounded basins and deep crustal roots. Andean processes not only pose seismic and volcanic hazards to tens of millions of people but also contribute essential minerals, regulate regional climate and influence carbon cycling through volcanic degassing.

Research from Nature Portfolio

Recent studies have revealed that large-scale deep-mantle structures can preserve evidence of past slab-tearing events that shaped the configuration of Andean subduction. Integrated analysis of seismic tomography and geological records indicates that an Early Mesozoic slab rupture facilitated shifts in magmatic loci and triggered intraplate extension in regions equivalent to the Neuquén Basin. This insight illustrates how slab tears can modulate arc activity and crustal deformation over geological timescales, offering a model for interpreting spatial variations in modern Andean volcanism and tectonics.

Tectonic and Volcanic Processes in Andean Systems publication trend

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

Technical terms

Subduction: The process by which one tectonic plate descends beneath another into the mantle.

Orogeny: A mountain-building event driven by tectonic plate convergence and crustal deformation.

Slab tear: A discontinuity or rupture in a subducting plate that alters mantle flow and magmatic patterns.

Thin-skinned deformation: Upper-crustal folding and thrusting detached above a weak décollement layer, leaving basement undeformed.

InSAR (Interferometric Synthetic Aperture Radar): A remote-sensing technique that measures ground deformation by comparing radar images taken at different times.

References

1. Does the Mineral Composition of Volcanic Ashes Have a Beneficial or Detrimental Impact on the Soils and Cultivated Crops of Ecuador?. Toxics (2023).
2. Surface and mantle records reveal an ancient slab tear beneath Gondwana. Scientific Reports (2019).
3. Unrest at Domuyo Volcano, Argentina, Detected by Geophysical and Geodetic Data and Morphometric Analysis. Remote Sensing (2019).
4. U–Pb dating of carbonate veins constraining timing of beef growth and oil generation within Vaca Muerta Formation and compression history in the Neuquén Basin along the Andean fold and thrust belt. Marine and Petroleum Geology (2021).