Lesser Antilles subduction zone initiation

Schematic tectonic reconstruction of the Lesser Antilles SZI event (modified from van Benthem et al., 2013 and Boschman et al., 2014). Subduction of the North and South America plates beneath the Caribbean plate was probably already active earlier on. At 58–39 Ma, subduction jumped eastwards, creating the new Lesser Antilles subduction zone. Shown are the new subduction zone (pink line), other active (solid purple lines) and inactive (dashed purple lines) subduction zones, and transform faults (red dashed lines).

The Lesser Antilles SZI event that formed the present-day Lesser Antilles subduction zone likely occurred between 59–38 Ma (Boschmann et al., 2014), with the North and South American plates subducting below the Caribbean plate. However, there is a debate on the nature of this event, which also represents the transition from the Greater Caribbean Arc to the Lesser Antilles subduction zone. The break in the slab, revealed by seismic tomography (van Benthem et al., 2013), along with the age gap between the Aves Ridge and the Lesser Antilles Arc and the start of the formation of the Barbados Accretionary Prism (Boschman 2014) suggests episodic subduction. Other interpretations consider continuous subduction during the narrowing of the arc and suggest that the arc has jumped 50–250 km from the Avis ridge to the Lesser-Antilles arc during continuous subduction roll-back and the consequent opening of the Grenada and Tobago basins (together) as a forearc basin (e.g., Aitken et al., 2011). Due to the widening forearc, the Avis ridge became inactive. In this scenario, the SZI event of the Lesser Antilles is the same as that of the Greater Caribbean arc, which might have happened sometimes between 120 to 88 Ma. This earlier event is not considered here any further.

The Lesser Antilles SZI event might be an episodic event that followed from a previously active, but subsequently extinct, subduction zone; it is suggested that the active arc from the Aves ridge transitioned to, and formed, the Lesser Antilles arc during the mentioned time span (Boschmann et al., 2014).

For more details on the geologic record, corresponding plate reconstruction, and seismic tomography, see the SZI Database.

• Creators: Fabio Crameri, Valentina Magni, Matthew Domeier, Ágnes Király, Grace Shephard
• This version: 17.06.2025
• License: Attribution-ShareAlike 4.0 International (CC BY-SA 4.0)
• Specific citation: These graphics from Crameri et al. (2020) are available via the open-access s-ink.org repository.
• Related reference: Crameri, F., V. Magni, M. Domeier, G.E. Shephard, K. Chotalia, G. Cooper, C. Eakin, A.G. Grima, D. Gürer, A. Király, E. Mulyukova, K. Peters, B. Robert, and M. Thielmann (2020), A transdisciplinary and community-driven database to unravel subduction zone initiation, Nature Communications, 11, 3750. doi:10.1038/s41467-020-17522-9

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