Encyclopedia of Astrobiology

2015 Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James (Jim) CleavesII, Daniele L. Pinti, José Cernicharo Quintanilla, Daniel Rouan, Tilman Spohn, Stéphane Tirard, Michel Viso

Sagduction

  • Nicholas ArndtEmail author
Reference work entry
DOI: https://doi.org/10.1007/978-3-662-44185-5_1400

Definition

This term refers to the return of crustal material into the  mantle in downward-moving diapirs (large teardrop-shaped masses of ductile material) composed of dense metavolcanic and metasedimentary rock. The hypothesis has two sources. First, some authors attribute the dome-and-basin structure of Archean granite-greenstone belts (examples are observed in the  Pilbara Craton, Western Australia) to vertical tectonics involving upward- and downward-directed diapirs. Second, some authors believe that  plate tectonics could not have operated on a hot early Earth and that thus another mechanism must have operated to recycle oceanic crust back into the mantle.

See Also

Copyright information

© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.ISTerre, Université Grenoble AlpesGrenobleFrance