Subduction initiation without magmatism: The case of the missing Alpine magmatic arc
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Date
2018-12-01Type
- Journal Article
ETH Bibliography
no
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Abstract
Models of orogens identify subduction of oceanic crust as the key mechanism leading to continental collision. Such models, based inter alia on thermobarometric and geochronological evidence preserved in high-pressure metamorphic rocks and subduction-related magmatism, have been used to explain the convergence of Europe and Adria in the Cretaceous–Cenozoic and the subsequent Alpine orogen. Here, we review the metamorphic, igneous, and sedimentary record of the past 300 Ma of the Alpine orogen to show that there is no evidence of igneous activity during subduction initiation and prograde high-pressure metamorphism, leading to an ∼50 Ma hiatus in magmatism, or “arc gap.” The closure of rift basins forming the Piemont-Liguria ocean did not follow a classical Wadati-Benioff–type subduction. Instead, subduction initiation at passive margins allowed for the accretion of the hydrated portion of the subducting plate within an orogenic wedge as subduction of dry subcontinental lithosphere inhibited magmatism during subduction initiation and ocean closure. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000310657Publication status
publishedExternal links
Journal / series
GeologyVolume
Pages / Article No.
Publisher
Geological Society of AmericaOrganisational unit
09656 - Chelle-Michou, Cyril / Chelle-Michou, Cyril
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ETH Bibliography
no
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