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Style of rifting and the stages of Pangea breakup
Author(s) -
Frizon de Lamotte Dominique,
Fourdan Brendan,
Leleu Sophie,
Leparmentier François,
Clarens Philippe
Publication year - 2015
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1002/2014tc003760
Subject(s) - geology , rift , paleontology , large igneous province , passive margin , cretaceous , permian , continental margin , plate tectonics , lithosphere , mantle plume , tectonics , earth science , magmatism , structural basin
Pangea results from the progressive amalgamation of continental blocks achieved at 320 Ma. Assuming that the ancient concept of “active” versus “passive” rifting remains pertinent as end‐members of more complex processes, we show that the progressive Pangea breakup occurred through a succession of rifting episodes characterized by different tectonic evolutions. A first episode of passive continental rifting during the Upper Carboniferous and Permian led to the formation of the Neo‐Tethys Ocean. Then at the beginning of Triassic times, two short episodes of active rifting associated to the Siberian and Emeishan large igneous provinces (LIPs) failed. The true disintegration of Pangea resulted from (1) a Triassic passive rifting leading to the emplacement of the central Atlantic magmatic province (200 Ma) LIP and the subsequent opening of the central Atlantic Ocean during the lowermost Jurassic and from (2) a Lower Jurassic active rifting triggered by the Karoo‐Ferrar LIP (183 Ma), which led to the opening of the West Indian Ocean. The same sequence of passive then active rifting is observed during the Lower Cretaceous with, in between, the Parana‐Etendeka LIP at 135 Ma. We show that the relationships between the style of rifts and their breakdown or with the type of resulting margins (as magma poor or magma dominated) are not straightforward. Finally, we discuss the respective role of mantle global warming promoted by continental agglomeration and mantle plumes in the weakening of the continental lithosphere and their roles as rifting triggers.