Fadil, A., Vernant, P., McClusky, S., Reilinger, R., Gomez,
F., Sari, D. B., Mourabit, T., Feigl, K., and Barazangi, M.
Active tectonics of the western Mediterranean: Geodetic evidence for roll
back of a delaminated subcontinental lithospheric slab beneath the Rif Mountains,
Geology, 34(7), 529-532, 2006.
Surface deformation in Morocco derived from
five years of GPS survey observations of a 22-station network, four continuously
recording GPS stations, and four IGS stations in Iberia indicate roughly southward
motion (~3 mm/yr) of the Rif Mountains, Morocco relative to stable Africa. Motion
of the Rif is approximately normal to the direction of Africa-Eurasia relative
motion, which is predominantly strike slip, and results in shortening of the Rif
and subsequent crustal extension of the adjacent Alboran Sea region. The sense,
and the N-S asymmetry of the observed deformation (i.e., no evidence for north-directed
shortening in the Betic Mountains north of the Alboran Sea) cannot be easily explained
in terms of crustal plate interactions suggesting that dynamic processes below
the crust are driving the recent geologic evolution of the western Mediterranean.
The model that best fits the observations involves delamination and southward
roll back of the African lithospheric mantle under the Alboran and Rif domains.
This paper was published in Geology by the Geological Society of America (GSA),
and GSA retains the copyright.
Geological Society of America, P.O. Box 9140, Boulder, CO 80301-9140
to GSA abstract
Key Figures and Captions
Figure 3. Profile 1 and profile 2 (locations in Fig. 2). A
and D: Component of velocities and 1s uncertainties along the direction of plate
motion (normal to profile). B and E: Component of velocities and 1s uncertainties
normal to the direction of plate motion (i.e., parallel to profiles). Interseismic
deformation predicted by elastic block models is shown for three main hypothesized
plate boundaries (redKlitgord and Schouten, 1986; greenBird, 2003;
blueGutscher, 2004; see Fig. 1 for geometry). Thick pink line with thin
black line in the center is for a model with a central Rif block (see Fig. 4
for geometry). C and F: Topography and interpretative cross section along profiles
1 and 2. LVAlow-velocity and high-attenuation anomaly (Calvert et al.,
2000; Seber et al., 1996); CCcontinental crust; LMlithospheric mantle;