Tectonic Processes and Geological Evolution in the Northern Andes

The Northern Andes form a complex mosaic of interacting plates and microblocks, where subduction of the Nazca and Caribbean plates beneath South America drives mountain building, magmatism and seismicity. The separation of the Central and Eastern Cordilleras by intermontane basins records successive pulses of crustal shortening, uplift and erosion since the Late Cretaceous. Variations in slab dip and the presence of tears in the subducting plates control patterns of deformation and mantle flow beneath the range. In the north, the North Andes microplate accommodates oblique convergence and hosts prominent strike-slip systems, while farther south flat subduction has led to eastward migration of volcanism and uplift of the Eastern Cordillera. Processes such as lithospheric delamination, foundering of dense mantle keel and slab flattening have punctuated the evolution of coastal ranges and interior massifs, notably the Sierra Nevada de Santa Marta. Surface processes respond in turn to tectonic forcing, with erosion rates, sediment export and river steepness mapping active uplift and revealing transient disequilibria. Together, these interactions shape topography, influence seismic hazards and govern the distribution of natural resources across a domain of profound global significance.

Research from Nature Portfolio

Recent studies have illuminated how lithospheric removal beneath Colombia’s Bucaramanga seismic nest may drive intermediate-depth seismicity. High-resolution tomographic imaging reveals a high-velocity anomaly at 130–167 km depth, coincident with clustered earthquakes. Numerical hydromechanical models suggest that dense lower lithosphere detaches and “drips” into the mantle, enhancing fluid release from the subducting slab and triggering seismicity through dehydration embrittlement. This mechanism links deep lithospheric dynamics to seismic hazard in a key Andean segment.

Tectonic Processes and Geological Evolution in the Northern Andes publication trend

The graph below shows the total number of articles in tectonic processes and geological evolution in the northern andes across all publications each year (not limited to Nature Index journals).

Technical terms

Delamination: Gravitational removal of dense lower lithosphere from beneath the crust, leading to foundering of a mantle “drip”.

Cosmogenic nuclide erosion rate: Measurement of surface denudation using isotopes produced by cosmic rays in exposed rocks, used to infer uplift.

Channel steepness: Metric of river gradient corrected for drainage area, reflecting tectonic uplift or climatic variation.

Bouguer gravity anomaly: Variations in Earth’s gravity field after correction for topography and latitude, indicating density contrasts in the crust and mantle.

Slab flattening: Shallowing of the subducting plate’s angle beneath the overriding plate, often leading to inland migration of deformation and magmatism.

Thermochronology: Study of cooling histories of rocks to determine uplift and exhumation rates via temperature-sensitive mineral systems.

Non-isostatic forces: Forces other than simple buoyant support (isostasy), such as dynamic pressure in the mantle, which influence surface elevation.

References

1. Erosion rate maps highlight spatio-temporal patterns of uplift and quantify sediment export of the Northern Andes. Earth and Planetary Science Letters (2023).
2. Lithospheric delamination as the driving mechanism of intermediate-depth seismicity in the Bucaramanga Nest, Colombia. Scientific Reports (2023).
3. Lithosphere Removal in the Sierra Nevada de Santa Marta, Colombia. Journal of Geophysical Research: Solid Earth (2024).
4. On the interaction of the North Andes plate with the Caribbean and South American plates in northwestern South America from GPS geodesy and seismic data. Geophysical Journal International (2018).