Introduction to the Pre-Mesozoic Geology of Iberia

Dallmeyer, R. D.; García, Ernesto Martínez

doi:10.1007/978-3-642-83980-1_1

Cited by 26 publications

(25 citation statements)

References 4 publications

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“…In Fig. 6, an extensive area of the central and western Iberian Peninsula is covered by the Variscan Iberian massif, a large, old and geologically stable block of continental lithosphere (Dallmeyer and Martínez García, 1992). This area is characterized by high Pn velocity, as expected in tectonically stable regions, emphasizing the fact that they are areas that have not recently been reactivated.…”

Section: Discussionmentioning

confidence: 81%

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

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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.

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Section: Discussionmentioning

confidence: 81%

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

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show abstract

“…2). The Palaeozoic sediments reflect the development from rifting to passive margin and finally to a foreland fold and thrust belt (Dallmeyer and Martı´nez-Garcı´a, 1990; Aramburu and Bastida, 1995). The Variscan tectonics began in Late Carboniferous time with the emplacement of regional thrusts and folds, followed by later fracturing.…”

Section: Geological Settingmentioning

confidence: 98%

Massive hydrothermal dolomites in the southwestern Cantabrian Zone (Spain) and their relation to the Late Variscan evolution

Gasparrini

Bechstädt

Boni

2006

Marine and Petroleum Geology

109

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“…It is subdivided in the Cantabrian, West-Asturian-Leonese, Galacian-Castillan, Ossa-Morena, and South Portuguese zones (see a recent overview in Dallmeyer and Martinez Garcia, 1990). The Cantabrian Zone is subdivided into the allochthonous Asturian-Leonese and the autochthonous Palentine domains.…”

Section: Location Stratigraphymentioning

confidence: 99%

Internal structure and depositional environment of Late Carboniferous mounds from the San Emiliano Formation, Cármenes Syncline, Cantabrian Mountains, Northern Spain

Samankassou

2001

Sedimentary Geology

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Well-exposed mounds are common in limestone of the Late Carboniferous San Emiliano Formation, Cantabrian Mountains (Northern Spain). They occur as obvious primary topographic features. Careful study of the mound intervals and surrounding strata revealed the internal structures of mounds and the factors controlling their growth. The substrate (2 -3 m) of the mounds consists of greyish to reddish, bedded oolitic and oncolithic packstone and grainstone. Crinoids, fragments of the alga Epimastopora, and, rarely, bryozoans are present. Ooids and oncoids indicate a wave-dominated high-energy environment. Presence of quartz indicates the influence of terrigenous siliciclastic input. Mound intervals (6 -12 m thick) are characterized by skeletal -microbial boundstone. Donezellid algae, agglutinated worm tubes, and calcisponges are the dominant fossils. Smaller foraminifers, gastropods, and brachiopods are also present. A peloidal-clotted matrix is characteristic and accounts for more than 30% of the mound volume. Intraframe pores are mainly filled by peloidal sediment and early marine cement. Intermound strata are approximately one-third as thick as time equivalent mounds. Mound fossils (algae, agglutinated worm tubes, and sponges) are uncommon. However, intermound strata are generally more diverse than the mounds, containing fusulinids, smaller foraminifers, bryozoans, gastropods, crinoids, and bioclasts. Some of these fossils have micritic envelopes. Bedded packstone and grainstone, 3 -6 m thick, with siliciclastic debris, rugose corals, and chaetetid sponges characterize the capping facies. Coated grains and small ooids are uncommon. This facies indicates shallowing to a higher energy environment and/or a higher input of siliciclastics, inhibiting mound growth. Mounds are interpreted to have accreted in a quiet environment below wave base. This position is comparable to the depositional environment inferred for many Late Paleozoic mounds described elsewhere, e.g., from Texas and New Mexico, Canadian Archipelago, and Carnic Alps in Austria. Mound relief is explained by (1) accumulation of peloidal-clotted sediments limited to boundstone and probably related to microbial activities, (2) widespread marine cementation within this area, and (3) low export of mound fossils to intermound areas. The position of the mounds within the sequence, and their initiation, size and termination, seem to be mainly controlled by sea-level fluctuations and siliciclastic input. D

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Introduction to the Pre-Mesozoic Geology of Iberia

Cited by 26 publications

References 4 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

Massive hydrothermal dolomites in the southwestern Cantabrian Zone (Spain) and their relation to the Late Variscan evolution

Internal structure and depositional environment of Late Carboniferous mounds from the San Emiliano Formation, Cármenes Syncline, Cantabrian Mountains, Northern Spain

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