Category: Aleutian

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Aleutian SZI Events

Aleutian subduction zone initiation

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).
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, starting around 53 Ma as a subduction, marked the formation of the Aleutian trench as the Pacific and Kula plates began subducting. This event possibly involved a subduction polarity reversal linked to the Olutorsky arc’s arrival, influencing regional tectonic activity and magma production along northeastern Asia and northwestern North America.