Crustal structure of the SW-Moroccan margin from wide-angle and reflection seismic data (the DAKHLA experiment) Part A: Wide-angle seismic models
|Author(s)||Klingelhoefer Frauke1, Labails Cinthia1, 2, Cosquer Emmanuel1, Rouzo Stephane1, 3, Geli Louis1, Aslanian Daniel1, Olivet Jean-Louis1, Sahabi M.4, Nouze Herve1, Unternehr P.5|
|Affiliation(s)||1 : IFREMER, Lab Marine Geophys & Geodynam, F-29280 Plouzane, France.
2 : NGU Geol Survey Norway, N-7491 Trondheim, Norway.
3 : Inst Phys Globe, Paris, France.
4 : Univ El Jadida, Fac Sci, El Jadida 24000, Maroc, Morocco.
5 : Total Explorat Prod Geosci, F-92078 Paris, France.
|Source||Tectonophysics (0040-1951) (Elsevier), 2009-04 , Vol. 468 , N. 1-4 , P. 63-82|
|WOS© Times Cited||44|
|Keyword(s)||Ocean continent transition, Keyword wide angle seismic, Southern Moroccan margin|
|Abstract||A total 1500 km of seismic reflection and wide-angle profiles were acquired off the southern Moroccan margin during the DAKHLA cruise, a joint project of Ifremer, the Universities of Brest, El Jadida and Lisbon and Total. The shots along two profiles parallel to the margin and two profiles perpendicular to the margin were also recorded by ocean bottom seismometers (OBS). The profiles perpendicular to the margin were additionally extended on land using 14 stations on the northern profile and 11 stations on the southern profile. Modelling of the reflection and wide-angle seismic data reveals a 10 km deep sedimentary basin including two high velocity carbonate layers. Lateral crustal thinning is observed from a 27 km thick crystalline continental crust to a 7 km thick oceanic crust occurring over less than 100 km. The crystalline continental crust can be divided into two distinct layers of 12 and 15 km thickness. The oceanic crust east of the magnetic anomaly M25 displays higher velocities in layer 3 than west of the magnetic anomaly. The change in seismic velocity suggests a possible link to changes in accretionary processes of the oceanic crust. Some regions show seismic velocities between 6.8 and 7.4 km/s which could be explained by slightly elevated mantle temperatures during accretion of the crust.|