Schematic tectonic reconstruction of the Aleutian SZI event (modified from Domeier et al., 2017). The collision of the Olutorsky arc with the trench of the south-dipping subduction of the Eurasia plate below the Pacific Plate is suggested to have caused a flip in subduction polarity, initiating the new Aleutian subduction zone. Shown are the new subduction zone (pink line), other active (solid purple lines) and inactive (dashed purple lines) subduction zones, spreading ridges (solid red lines), and transform faults (red dashed lines).
The Aleutian subduction zone initiation event formed today’s active Aleutian trench. The onset of the subduction zone likely occurred at around 53 Ma (Davis et al., 1989; Jicha et al., 2006) when the Pacific and Kula plates began to subduct northward, and at some point, under the overriding continental plates of northeast Siberia and North America.
The Aleutian SZI event was possibly instigated as a subduction polarity reversal associated with the arrival of an intraoceanic arc (Olutorsky arc) to the Okhotsk-Chukotka-Beringian margin of northeastern Asia and northwestern North America (Scholl, 2007; Domeier et al., 2017; Vaes et al., 2019), and therefore may have formed close to (i.e., at a distance of around 300 km) a pre-existing convergent plate boundary. Vaes et al. (2019) have speculated that the Aleutian trench may have exploited a pre-existing transform boundary in a possible backarc behind the Olutorsky arc. Those authors have furthermore pointed out that arc volcanics with ages of 54.4 Ma to 50.2 Ma have been dredged from the Beringian margin (Davis et al., 1989), and note that the Aleutian SZI event could also be seen as the outboard jump of that Beringian subduction zone.
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
- Seismic tomography VoteMap included
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