@article{fdi:010064228,
  title = {{C}rustal structure of the eastern {A}lgerian continental margin and adjacent deep basin : implications for late {C}enozoic geodynamic evolution of the western {M}editerranean},
  author = {{B}ouyahiaoui, {B}. and {S}age, {F}. and {A}btout, {A}. and {K}lingelhoefer, {F}. and {Y}elles-{C}haouche, {K}. and {S}chnuerle, {P}. and {M}arok, {A}. and {D}everchere, {J}. and {A}rab, {M}. and {G}alve, {A}. and {C}ollot, {J}ean-{Y}ves},
  editor = {},
  language = {{ENG}},
  abstract = {{W}e determine the deep structure of the eastern {A}lgerian basin and its southern margin in the {A}nnaba region (easternmost {A}lgeria), to better constrain the plate kinematic reconstruction in this region. {T}his study is based on new geophysical data collected during the {SPIRAL} cruise in 2009, which included a wide-angle, 240-km-long, onshore-offshore seismic profile, multichannel seismic reflection lines and gravity and magnetic data, complemented by the available geophysical data for the study area. {T}he analysis and modelling of the wide-angle seismic data including refracted and reflected arrival travel times, and integrated with the multichannel seismic reflection lines, reveal the detailed structure of an ocean-to-continent transition. {I}n the deep basin, there is an similar to 5.5-km-thick oceanic crust that is composed of two layers. {T}he upper layer of the crust is defined by a high velocity gradient and {P}-wave velocities between 4.8 and 6.0 km s(-1), from the top to the bottom. {T}he lower crust is defined by a lower velocity gradient and {P}-wave velocity between 6.0 and 7.1 km s(-1). {T}he {P}oisson ratio in the lower crust deduced from {S}-wave modelling is 0.28, which indicates that the lower crust is composed mainly of gabbros. {B}elow the continental edge, a typical continental crust with {P}-wave velocities between 5.2 and 7.0 km s(-1), from the top to the bottom, shows a gradual seaward thinning of similar to 15 km over an similar to 35-km distance. {T}his thinning is regularly distributed between the upper and lower crusts, and it characterizes a rifted margin, which has resulted from backarc extension at the rear of the {K}abylian block, here represented by the {E}dough {M}assif at the shoreline. {A}bove the continental basement, an similar to 2-km-thick, pre-{M}essinian sediment layer with a complex internal structure is interpreted as allochthonous nappes of flysch backthrusted on the margin during the collision of {K}abylia with the {A}frican margin. {T}he crustal structure, moreover, provides evidence for {M}iocene emplacement of magmatic intrusions in both the deep basin and the continental margin. {B}ased on the crustal structure, we propose that the eastern {A}lgerian basin opened during the southeastward migration of the {E}uropean forearc before the collision, along a {NW}-{SE} elongated spreading centre that ran perpendicular to the subduction trend. {S}uch an atypical geometry is explained by the diverging directions of the subduction rollback during the backarc opening: eastward for the {C}orsica-{S}ardinia block, and southward for the {K}abylian blocks. {T}his geometry of the forearc can be interpreted as the surface expression of a slab tear at depth, which is responsible for atypical magmatism in the overlying backarc oceanic basin.},
  keywords = {{T}omography ; {C}omposition of the oceanic crust ; {C}ontinental margins ; divergent ; {A}frica ; {AFRIQUE} ; {ALGERIE}},
  booktitle = {},
  journal = {{G}eophysical {J}ournal {I}nternational},
  volume = {201},
  numero = {3},
  pages = {1912--1938},
  ISSN = {0956-540{X}},
  year = {2015},
  DOI = {10.1093/gji/ggv102},
  URL = {https://www.documentation.ird.fr/hor/fdi:010064228},
}