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Propagators and ridge jumps in a back‐arc basin, the West Philippine Basin
Author(s) -
Deschamps Anne,
Shinjo Ryuichi,
Matsumoto Takeshi,
Lee ChaoShing,
Lallemand Serge E.,
Wu Shiguo
Publication year - 2008
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.1365-3121.2008.00824.x
Subject(s) - geology , rift , structural basin , mantle (geology) , transform fault , ridge , gravity anomaly , fracture zone , seismology , seafloor spreading , paleontology , fault (geology) , geomorphology , oil field
We explore the tectono‐magmatic processes in the western West Philippine Basin, Philippine Sea Plate, using bathymetric data acquired in 2003 and 2004. The northwestern part of the basin formed through a series of northwestward propagating rifts. We identify at least five sequences of propagating rifts, probably triggered by mantle flow away from the mantle thermal anomaly that is responsible for the origin of the Benham and Urdenata plateaus. Gravitational forces caused by along‐axis topographic gradient and a ∼30° ridge reorientation appear to also be driving the rift propagations. The along‐axis mantle flow appears to be reduced and deflected along the Luzon‐Okinawa fracture zone, because the spreading system remained stable west of this major fault zone. North‐east of the Benham plateau, a left‐lateral fracture zone has turned into a NE–SW‐trending spreading axis. As a result, a microplate developed at the triple junction.