Crustal thinning in the Southwestern Iberia Margin

González, A.; Torné, Montserrat; Córdoba, Diego; Vidal, N.; Matias, L.; Díaz, Jordi

doi:10.1029/96gl02299

Cited by 46 publications

(53 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Southwest from Cape San Vicente, a strong low-velocity anomaly is imaged. The crustal structure obtained by González et al (1996) using seismic refraction and wide-angle reflection data along a 350 km NE-SW oriented transect, reveals a strong but continuous crustal thinning from 30 km onshore Iberia to less than 15 km at the southwestern end of the profile. In addition, they performed 2D gravity modelling to validate the crustal structure obtained from seismic data.…”

Section: Discussionmentioning

confidence: 99%

Seismic anisotropy and velocity structure beneath the southern half of the Iberian Peninsula

Serrano

Hearn

Morales

et al. 2005

Physics of the Earth and Planetary Interiors

View full text Add to dashboard Cite

Travel times of 11,612 Pn arrivals collected from 7675 earthquakes are inverted to image the uppermost mantle velocity and anisotropy structure beneath the southern half of the Iberian Peninsula and surrounding regions. Pn phases are routinely identified and picked for epicentral distances from 200 to 1200 km. The method used in this study allows simultaneous imaging of variations of Pn velocity and anisotropy. The results show an average uppermost mantle velocity beneath the study area of 8.0 km/s. The peninsular area covered by the Iberian massif is characterized by high Pn velocity, as expected in tectonically stable regions, indicating areas of the Hercynian belt that have not recently been reactivated. The margins of the Iberian Peninsula have undergone a great number of recent tectonic events and are characterized by a pronouncedly low Pn velocity, as is common in areas greatly affected by recent tectonic and magmatic activity. Our model indicates that the Betic crustal root might be underlined by a negative anomaly beneath the southeastern Iberian Peninsula. In the Atlantic Ocean, we find a sharp variation in the uppermost mantle velocities that coincides with the structural complexity of the European and African plate boundary in the Gulf of Cadiz. Our results show a very pronounced low-velocity anomaly offshore from Cape San Vicente whereas high velocities are distributed along the coast in the Gulf of Cadiz. In the Alboran Sea and northern Morocco, the direction of the fastest Pn velocity found is almost parallel to the Africa-Eurasia plate convergence vector (northwest-southeast) whereas to the north, this direction is almost parallel to the main trend of the Betic Cordillera, i.e. east-west in its central part and north-south in the curvature of the Arc of Gibraltar. This suggests that a significant portion of the uppermost mantle has been involved in the orogenic deformation that produced the arcuate structure of the Betic Cordillera. However, we assume that the Neogene extension had no major influence on a lithospheric scale in the Alboran Sea. Our results also show a quite complex pattern of anisotropy in the southwest Iberian lithospheric mantle since the relationship between the direction of fastest Pn velocity and major Hercynian tectonic trends cannot be directly established.

show abstract

Section: Discussionmentioning

confidence: 99%

Seismic anisotropy and velocity structure beneath the southern half of the Iberian Peninsula

Serrano

Hearn

Morales

et al. 2005

Physics of the Earth and Planetary Interiors

View full text Add to dashboard Cite

show abstract

“…The faults identified along the western Algarve Basin coincide in location (see triangle on the seabed in Fig. 14) with a sudden rise in the Moho that trends NW-SE (based on the profiles of González et al, 1996 andSallarès et al, 2011;Fig. 18a).…”

Section: Accepted Manuscriptmentioning

confidence: 99%

“…Points with numbers indicate the depth to the base of the crust from the compilation of Diaz et al (2016). The western limit of the Gulf of Cadiz (GoC) segment of the margin is marked by the GorringeGoC transfer zone along the transition from continental to ocean domains defined by González et al, (1996) and Sallarès et al (2011). The eastern limit of the margin segment is located along the GoC-Betic transfer zone, across which Mesozoic thickness drops (dashed contours indicate Mesozoic thickness in this area from the map in Fig.…”

Section: Accepted Manuscriptmentioning

confidence: 99%

Crustal structure of the SW Iberian passive margin: The westernmost remnant of the Ligurian Tethys?

et al. 2017

View full text Add to dashboard Cite

At present, the SW Iberian margin is located along the convergent Iberia-Nubia plate boundary. In Mesozoic times, the margin was located at the triple junction of the Ligurian Tethys, Central Atlantic and Northern Atlantic. The characterization of its crustal structure has allowed us to propose a configuration for this triple junction and to determine the role that this transform margin played within the plate kinematic system. In this paper we present an integrated study based on the interpretation of a 2D regional multichannel seismic survey consisting of 58 profiles, tied with onshore geology and exploratory wells, and on gravimetric modeling performed over four NW-SE trending profiles.

show abstract

“…Based on tomographic images, Gutscher et al [2002] proposed an active eastward subduction process beneath the Arc of Gibraltar, and suggested that oceanic lithosphere may still be present in the presumed fore arc region in the central Gulf of Cadiz. On the other hand, modeling of deep seismic sections, involving wide-angle and near-vertical reflection observations [Gonzáles et al, 1996;González-Fernández et al, 2001], as well as free-air gravity data [Gràcia et al, 2003] indicate a Hercynian type continental crust below the Gulf of Cadiz, which is progressively thinning from $30 km near the coastline to $20 km in the central and western parts of the Gulf.…”

Section: Introductionmentioning

confidence: 99%

Crust‐mantle coupling in the Gulf of Cadiz (SW‐Iberia)

Stich

Mancilla

Morales

2005

Geophysical Research Letters

View full text Add to dashboard Cite

[1] In the Gulf of Cadiz and Cape St. Vincent region at the SW-Iberian margin, seismic catalogues report seismicity down to $100 km depth. According to structural models for the region, this includes earthquakes that occur in the uppermost continental mantle. We invert regional waveforms to estimate moment tensors and centroid depths for moderate earthquakes, obtaining eight solutions (Mw 3.8 to 5.3) between 6 and 60 km depth. Moment tensor solutions and previous source estimates show predominately reverse and strike-slip faulting style with $NNW-SSE oriented P-axes, close to plate convergence between Africa and Eurasia. We obtain similar stress tensor estimates from crustal and upper mantle earthquakes, both with sub-horizontal, $NNW s 1 -axes. This indicates analogous deformation in both domains, and that earthquakes are unrelated to any subduction process.

show abstract

Crustal thinning in the Southwestern Iberia Margin

Cited by 46 publications

References 11 publications

Seismic anisotropy and velocity structure beneath the southern half of the Iberian Peninsula

Seismic anisotropy and velocity structure beneath the southern half of the Iberian Peninsula

Crustal structure of the SW Iberian passive margin: The westernmost remnant of the Ligurian Tethys?

Crust‐mantle coupling in the Gulf of Cadiz (SW‐Iberia)

Contact Info

Product

Resources

About