| Registro completo |
| Provedor de dados: |
ArchiMer
|
| País: |
France
|
| Título: |
Quasi-3D seismic reflection imaging, and wide-angle velocity structure of nearly amagmatic oceanic lithosphere at the ultra-slow spreading Southwest Indian Ridge
|
| Autores: |
Momoh, Ekeabino
Cannat, Mathilde
Watremez, Louise
Leroy, Sylvie
Singh, Satish C.
|
| Data: |
2017-12
|
| Ano: |
2017
|
| Palavras-chave: |
Amagmatic
Ultraslow mid-ocean ridge
3-D seismic
Tomography
Detachment fault
Damage zone
|
| Resumo: |
We present results from 3D processing of 2D seismic data shot along 100 m-spaced profiles in a 1.8 km wide by 24 km long box during the SISMOSMOOTH 2014 cruise. The study is aimed at understanding the oceanic crust formed at an end-member mid-ocean ridge environment of nearly zero melt supply. Three distinct packages of reflectors are imaged: (1) south-facing reflectors which we propose correspond to the damage zone induced by the active axial detachment fault. Reflectors in the damage zone have dips up to 60° and are visible down to 5 km below the seafloor; (2) series of north-dipping reflectors in the hanging wall of the detachment fault. These reflectors may correspond to damage zone inherited from a previous, north-dipping detachment fault, or small offset recent faults, conjugate from the active detachment fault, that served as conduits for isolated magmatic dykes; (3) discontinuous but coherent flat-lying reflectors at shallow depths (< 1.5 km below the seafloor), and at depths between 4 and 5 km below the seafloor. Comparing these deeper flat lying reflectors with the wide-angle velocity model obtained from ocean bottom seismometers (OBSs) data next to the 3D box shows that they correspond to parts of the model with P-wave velocity of 6.5-8 km/s suggesting that they occur in the transition between lower crust and upper mantle. The 4-5 km layer with crustal P-wave velocities is interpreted as primarily due to serpentinization and fracturation of the exhumed mantle-derived peridotites in the footwall of active and past detachment faults.
|
| Tipo: |
Text
|
| Idioma: |
Inglês
|
| Identificador: |
https://archimer.ifremer.fr/doc/00411/52215/52943.pdf
https://archimer.ifremer.fr/doc/00411/52215/52944.pdf
https://archimer.ifremer.fr/doc/00411/52215/52992.jpg
https://archimer.ifremer.fr/doc/00411/52215/52993.jpg
https://archimer.ifremer.fr/doc/00411/52215/52994.jpg
https://archimer.ifremer.fr/doc/00411/52215/52995.jpg
https://archimer.ifremer.fr/doc/00411/52215/52996.jpg
DOI:10.1002/2017JB014754
https://archimer.ifremer.fr/doc/00411/52215/
|
| Editor: |
Amer Geophysical Union
|
| Formato: |
application/pdf
|
| Fonte: |
Journal Of Geophysical Research-solid Earth (2169-9313) (Amer Geophysical Union), 2017-12 , Vol. 122 , N. 12 , P. 9511-9533
|
| Direitos: |
2017 American Geophysical Union. All rights reserved.
info:eu-repo/semantics/openAccess
restricted use
|
