Active slivering of oceanic crust along the Molucca ridge (Indonesia-Philippine): Implication for ophiolite incorporation in a subduction wedge?

Anne-Gaëlle Bader 1 Manuel Pubellier 2 Claude Rangin 2 Christine Deplus 3 Rémy Louat 4
1 Institut Français du Pétrole
2 LGE - Laboratoire de géologie de l'ENS
3 IPGP - Institut de Physique du Globe de Paris
4 IRD - Institut de Recherche pour le Développement
Abstract : A recent marine geophysical survey in the northern Molucca Sea revealed the structure to be that of a classical active convergent margin. We observe from west to east a volcanic arc (Sangihe), a forearc basin resting on an outer ridge (the Molucca ridge), which serves as a buttress for an accretionary wedge, and a composite downgoing plate (Snellius Ridge and Philippine Sea Basin). Gravity modeling indicates a strong negative anomaly above the wedge, which cannot be explained with reasonable density values. Modeling imposes a basement deepening and a rupture of the 700-km-long subducting lithosphere. This process individualized the lithospheric slab from the Snellius Ridge, which in turn was separated recently from the south Philippine Basin by the incipient Philippine Trench. This induces a deformation of the forearc region with backthrusting of the outer ridge and forearc basin, visible on bathymetry and seismic data. We extrapolate the tectonic emplacement of such oceanic blocks to the Oligocene times in order to explain the origin of the Pujada Miangas outer ridge as a sliver previously incorporated to the margin, and we discuss the possibility of this deformation process being fabric for terrane accretion.
Document type :
Journal articles
Complete list of metadatas
https://hal-insu.archives-ouvertes.fr/insu-01585936
Contributor : Eva Fareau <>
Submitted on : Tuesday, September 12, 2017 - 11:11:30 AM
Last modification on : Friday, April 5, 2019 - 8:21:54 PM
Long-term archiving on : Wednesday, December 13, 2017 - 2:23:36 PM

File

Bader_et_al-1999-Tectonics.pdf
Publisher files allowed on an open archive

Identifiers

Collections

INSU | ENS-PARIS | IPGP | IRD | PSL | USPC | UNIV-PARIS7

Citation

Anne-Gaëlle Bader, Manuel Pubellier, Claude Rangin, Christine Deplus, Rémy Louat. Active slivering of oceanic crust along the Molucca ridge (Indonesia-Philippine): Implication for ophiolite incorporation in a subduction wedge?. Tectonics, American Geophysical Union (AGU), 1998, 18 (4), pp.606-620. ⟨10.1029/1999TC900004⟩. ⟨insu-01585936⟩

Export

BibTeX TEI DC DCterms EndNote

Share

Metrics

Record views

145

Files downloads

183

Contact

support.ccsd.cnrs.fr
hal.support@ccsd.cnrs.fr
Logo CCSD