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The Alps in the Cretaceous: a doubly vergent pre‐collisional orogen
Author(s) -
Zanchetta Stefano,
Garzanti Eduardo,
Doglioni Carlo,
Zanchi Andrea
Publication year - 2012
Publication title -
terra nova
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.353
H-Index - 89
eISSN - 1365-3121
pISSN - 0954-4879
DOI - 10.1111/j.1365-3121.2012.01071.x
Subject(s) - geology , cretaceous , paleontology , rift , cenomanian , subduction , continental margin , passive margin , dike , seismology , tectonics
Terra Nova, 24, 351–356, 2012 Abstract Current palaeotectonic models see the Alps chiefly as a collisional orogen, with the Southalpine retrobelt developed only as a post‐collisional feature. New structural and geochronological data show, instead, that the continental margin of Africa‐Adria was being structured as a doubly vergent orogen during subduction of Alpine Tethys in the Cretaceous, tens of million years before collision with Europe. Subduction is envisaged here to have nucleated in the latest Albian/Cenomanian within the attenuated Adriatic margin. Most continental slivers exhumed as eclogites in the axial part of the Cretaceous orogen contain gabbros and relics of HT/LP metamorphic rocks, indicating inheritance from Permian to Jurassic rifting. Cretaceous shortening in the Southalpine retrobelt is indicated by several lines of evidence, including orogen‐derived turbidites and syn‐sedimentary compressional activity since the Cenomanian, Upper Cretaceous pseudotachylytes dating major S/SE‐verging thick‐skinned thrusts, and widespread fold‐and‐thrust deformation cut by Eocene plutons and dikes.