1. Subduction initiation causes broad upper plate extension: The Late Cretaceous Iran example.
- Author
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Moghadam, Hadi Shafaii and Stern, Robert J.
- Subjects
- *
SUBDUCTION , *BACK-arc basins , *LITHOSPHERE , *OPHIOLITES - Abstract
Subduction initiation (SI) requires the sinking of one plate beneath another and this exerts extensional stress on the overlying plate. How broad a region is affected by SI-related extension is unclear because most of the clearest SI examples– such as Izu-Bonin-Mariana arc– are deep under the ocean. A major SI event is recorded in the Late Cretaceous forearc ophiolites of Iran, related to the subduction of Neotethyan oceanic lithosphere beneath Eurasia. This caused extreme extension of the Iranian plate, up to ~1000 km away from the proto-trench and generated a series of back-arc oceanic basins, sedimentary basins, and core complexes and exhumed high-P rocks. The Late Cretaceous Iran example shows that SI can cause strong extension over a much wider region of the overriding plate than heretofore imagined and offers an accessible natural laboratory for studying SI processes. This understanding also provides an attractive new explanation for the origin of the South Caspian Sea. • Subduction initiation (SI) is a mechanism for forming Neotethyan ophiolites. • Ophiolites of Iran show SI exerts extensional stress on the overlying plate. • SI-related extension can affect broad regions of the overriding plate. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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