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Topography of the Iberian peninsula showing the main traits of its landscape. Numbers indicate the average elevation of its different sectors.
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The present-day topography of the Iberian peninsula can be considered as the result of the MesozoicCenozo–ic tectonic evolution of the Iberian plate (including rifting and basin formation during the Mesozoic and compression and mountain building processes at the borders and inner part of the plate, during the Tertiary, followed by Neogene rifting o...
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The Iberian Peninsula, at the western end of the Alpine-Himalayan Belt, displays a complex structure with mountain ranges of diverse structural trends and sedimentary basins between them. The Iberian Peninsula also shows an elevated mean topography, the highest in Europe. In this short paper, we investigate the Alpine evolution of the Iberian Penin...
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... In addition, from the species P. duriense was described, all the populations of the Duero Basin were considered as P. duriense (Coelho, 1985). However, a survey based on morphological characters found that the population from Adaja Sub-basin was morphologically more similar to the populations from Tajo Basin (currently considered as P. polylepis) than to the populations from Duero Basin [108]. Therefore, based on the above, we support that the species P. polylepis is present in the Adaja River. ...
Environmental DNA (eDNA) metabarcoding has been increasingly used to monitor the community assemblages of a wide variety of organisms. Here, we test the efficacy of eDNA metabarcoding to assess the composition of Iberian freshwater fishes, one of the most endangered groups of vertebrates in Spain. For this purpose, we sampled 12 sampling sites throughout one of Spain’s largest basins, the Duero, which is home to approximately 70% of the genera and 30% of the primary freshwater fish in Spain. We sampled these sampling sites in the summer by using electrofishing, a traditional sampling method, and eDNA metabarcoding of river water samples using the mitochondrial 12S rRNA gene ( 12S ) as a marker. We also resampled four of these sampling sites in autumn by eDNA. We compared the results obtained through eDNA metabarcoding with those of electrofishing surveys (ones conducted for the present study and past ones) and assessed the suitability of 12S as an eDNA metabarcoding marker for this group of freshwater fishes. We found that the 12S fragment, analysed for 25 Iberian species, showed sufficient taxonomic resolution to be useful for eDNA approaches, and even showed population-level differences in the studied populations across the tissue samples for Achondrostoma arcasii . In most cases, a greater number of species was detected through eDNA metabarcoding than through electrofishing. Based on our results, eDNA metabarcoding is a powerful tool to study the freshwater fish composition in the Iberian Peninsula and to unmask cryptic diversity. However, we highlight the need to generate a local genetic database for 12S gene for such studies and to interpret the results with caution when studying only mitochondrial DNA. Finally, our survey shows that the high detection sensitivity of eDNA metabarcoding and the non-invasiveness of this method allows it to act as a detection system for species of low abundance, such as early invasive species or species in population decline, two key aspects of conservation management of Spanish freshwater fishes.
... This kind of geometry is relatively common in basins developed above a significant décollement level, as demonstrated in analogue models (Soto et al., 2008 and references therein). However, in comparison with other basins in the Tethys domain (for example, some of the Iberian and Pyrenean basins, Casas-Sainz et al., 2009;, we do not find in the High Atlas clear faults limiting the basin on both sides, and thickness changes are rather consistent with crustal stretching and (possibly) thermal subsidence, as proposed by El Harfi et al., (2006,2007), Guiraud (1998), etc. Since the existence of a décollement at the base of the Jurassic series favors the development of normal drags versus roll-over anticlines, at least in "confined", intracontinental basins , paleodips inferred for the extensional stage are in general very shallow, and associated with very large regional features. ...
... Similarities of the Central High Atlas with the Iberian basins do not extend to their particular structural features. The Iberian basins show an area of distributed deformation (Andeweg et al., 1999;Casas-Sainz & De Vicente, 2009;De Vicente et al., 2009Fernández-Lozano et al., 2011;Vergés et al., 2019) that encompasses a width of more than 300 km in most of the chain, with several dominant trends, both during extension and during compression (Antolín-Tomás et al., 2007;Simón, 2004Simón, , 2005. Conversely, the Atlas is an extremely long chain whose width only compares to the Iberian Chain in very particular zones such as the confluence with the Middle Atlas chain, maintaining an average width of less than 100 km in most of its length. ...
... This kind of geometry is relatively common in basins developed above a significant décollement level, as demonstrated in analogue models (Soto et al., 2008 and references therein). However, in comparison with other basins in the Tethys domain (for example, some of the Iberian and Pyrenean basins, Casas-Sainz et al., 2009;, we do not find in the High Atlas clear faults limiting the basin on both sides, and thickness changes are rather consistent with crustal stretching and (possibly) thermal subsidence, as proposed by El Harfi et al., (2006,2007), Guiraud (1998), etc. Since the existence of a décollement at the base of the Jurassic series favors the development of normal drags versus roll-over anticlines, at least in "confined", intracontinental basins , paleodips inferred for the extensional stage are in general very shallow, and associated with very large regional features. ...
... Similarities of the Central High Atlas with the Iberian basins do not extend to their particular structural features. The Iberian basins show an area of distributed deformation (Andeweg et al., 1999;Casas-Sainz & De Vicente, 2009;De Vicente et al., 2009Fernández-Lozano et al., 2011;Vergés et al., 2019) that encompasses a width of more than 300 km in most of the chain, with several dominant trends, both during extension and during compression (Antolín-Tomás et al., 2007;Simón, 2004Simón, , 2005. Conversely, the Atlas is an extremely long chain whose width only compares to the Iberian Chain in very particular zones such as the confluence with the Middle Atlas chain, maintaining an average width of less than 100 km in most of its length. ...
Previous works developed by our research group have shown that the Jurassic rocks of the Central high Atlas (CHA) have recorded a Cretaceous widespread remagnetization. In this chapter, a high resolution paleomagnetic study on 424 new paleomagnetic sites in Mesozoic units of CHA is presented. This work provides new information about the Cretaceous magnetic overprint of the CHA, as well as contributes to the knowledge of the geodynamic evolution of the Atlas. The new results confirm the extent of remagnetization throughout the study area (10,000 km2) in both carbonates (carried by magnetite) and red beds (carried by hematite) showing systematically normal polarity and an inter-folding acquisition. By using small circle techniques, the remagnetization direction (n = 531, Dec = 335.4°, Inc = 42.7° for carbonates and n = 62, Dec = 344.4°, Inc = 41.7° for red beds) and the age of acquisition (100 Ma ± 5 Ma for limestones) have been determined. The remagnetization properties in the carbonates and their paleomagnetic direction are maintained throughout the studied area and the different stratigraphic units. The small but statistically significant difference between the directions of remagnetization in carbonates and red beds suggests a delay in the acquisition in red beds. Remagnetization directions have been restored using small circle techniques, allowing to generate a set of 593 paleo-dips of the beds at 100 Ma. This valuable information has been used in Chap. “Kinematics of Structures and Basin Evolution in the Central High Atlas. Constraints from AMS and Paleomagnetic Data” to elaborate palinspastic reconstructions and to study the evolution of the different structures of the CHA. For this purpose, a new diagram (paleo-dip evolution diagram, PED) is here proposed.
... This kind of geometry is relatively common in basins developed above a significant décollement level, as demonstrated in analogue models (Soto et al., 2008 and references therein). However, in comparison with other basins in the Tethys domain (for example, some of the Iberian and Pyrenean basins, Casas-Sainz et al., 2009;, we do not find in the High Atlas clear faults limiting the basin on both sides, and thickness changes are rather consistent with crustal stretching and (possibly) thermal subsidence, as proposed by El Harfi et al., (2006,2007), Guiraud (1998), etc. Since the existence of a décollement at the base of the Jurassic series favors the development of normal drags versus roll-over anticlines, at least in "confined", intracontinental basins , paleodips inferred for the extensional stage are in general very shallow, and associated with very large regional features. ...
... Similarities of the Central High Atlas with the Iberian basins do not extend to their particular structural features. The Iberian basins show an area of distributed deformation (Andeweg et al., 1999;Casas-Sainz & De Vicente, 2009;De Vicente et al., 2009Fernández-Lozano et al., 2011;Vergés et al., 2019) that encompasses a width of more than 300 km in most of the chain, with several dominant trends, both during extension and during compression (Antolín-Tomás et al., 2007;Simón, 2004Simón, , 2005. Conversely, the Atlas is an extremely long chain whose width only compares to the Iberian Chain in very particular zones such as the confluence with the Middle Atlas chain, maintaining an average width of less than 100 km in most of its length. ...
This chapter presents the results of numerous rock experiments carried out on Jurassic marine carbonates and red beds from the Central High Atlas, which have been affected by a regional remagnetization related to burial. As in other sedimentary rocks affected by chemical remagnetizations, the analyzed samples show a characteristic magnetic fingerprint. The dominant magnetic mineralogy of carbonates is composed of non-interacting uniaxial magnetite, in the superparamagnetic (SP) and stable single domain (SSD) states. Besides, a variable contribution of pyrrhotite is present in most of the samples. The combined presence of neoformed magnetite and pyrrhotite seems to be indicative that these rocks have reached temperatures around 200–250 °C, compatible with previous studies of illite crystallinity. ARM and IRM unmixing curves define a very characteristic pattern for remagnetized carbonates differentiated from other rocks types bearing magnetite. On the other hand, the high temperature susceptibility curves used to characterize the magnetic anisotropy studies show different contribution of paramagnetic and ferromagnetic (s.l.) minerals. Among paramagnetic phases, it is expected the presence of phyllosilicates and pyrite that can be the precursors of the neoformation of magnetite and pyrrhotite both during burial in natural conditions and in the different performed experiments. With regard to the ferromagnetic (s.l.) fractions, magnetite is the dominant phase with a minor contribution of pyrrhotite. In red beds, rock magnetic experiments show a dominance of hematite with different contribution of magnetite. In general, the susceptibility curves show a dominance of paramagnetic signal to the bulk susceptibility.
... This kind of geometry is relatively common in basins developed above a significant décollement level, as demonstrated in analogue models (Soto et al., 2008 and references therein). However, in comparison with other basins in the Tethys domain (for example, some of the Iberian and Pyrenean basins, Casas-Sainz et al., 2009;, we do not find in the High Atlas clear faults limiting the basin on both sides, and thickness changes are rather consistent with crustal stretching and (possibly) thermal subsidence, as proposed by El Harfi et al., (2006,2007), Guiraud (1998), etc. Since the existence of a décollement at the base of the Jurassic series favors the development of normal drags versus roll-over anticlines, at least in "confined", intracontinental basins , paleodips inferred for the extensional stage are in general very shallow, and associated with very large regional features. ...
... Similarities of the Central High Atlas with the Iberian basins do not extend to their particular structural features. The Iberian basins show an area of distributed deformation (Andeweg et al., 1999;Casas-Sainz & De Vicente, 2009;De Vicente et al., 2009Fernández-Lozano et al., 2011;Vergés et al., 2019) that encompasses a width of more than 300 km in most of the chain, with several dominant trends, both during extension and during compression (Antolín-Tomás et al., 2007;Simón, 2004Simón, , 2005. Conversely, the Atlas is an extremely long chain whose width only compares to the Iberian Chain in very particular zones such as the confluence with the Middle Atlas chain, maintaining an average width of less than 100 km in most of its length. ...
The anisotropy of magnetic susceptibility provides valuable information on the imprint of the different tectonic processes occurred in the Central High Atlas (CHA), complementing the structural analysis and paleomagnetic information. Different types of magnetic ellipsoids, related with extensional, diapiric or intrusive processes occurred during the Mesozoic, or with the Cenozoic compression, can be recognized. The predominance of one or another type of fabric varies spatially, and a transition can be observed from bedding-related fabrics in Western and Eastern sectors, to more abundant, modified magnetic fabrics in the Central sectors and in the Southern border of the CHA. Extensional fabrics are characterized by the orientation of the kmin axes normal to bedding and the kmax axes clustered in a NW–SE direction within the bedding plane. This direction represents the regional (and local) extension, perpendicular to the main faults. Compressional magnetic fabrics show their kmin axes in NW–SE or N-S directions and/or kmax axes sub-horizontal and clustered in the NE-SW direction, consistently with the shortening direction inferred from the trend of compressional structures (folds and thrusts). Compressional tectonic fabrics are unequivocally interpreted in areas showing regional cleavage. Magnetic lineations vertical or close to the bedding dip direction are found near thrust planes or near the core of narrow and tight anticlines and are related to transport direction or re-tightening of structures, in many cases nucleated in relation to salt tectonics features.
... This kind of geometry is relatively common in basins developed above a significant décollement level, as demonstrated in analogue models (Soto et al., 2008 and references therein). However, in comparison with other basins in the Tethys domain (for example, some of the Iberian and Pyrenean basins, Casas-Sainz et al., 2009;García-Lasanta et al., 2017), we do not find in the High Atlas clear faults limiting the basin on both sides, and thickness changes are rather consistent with crustal stretching and (possibly) thermal subsidence, as proposed by El Harfi et al., (2006,2007), Guiraud (1998), etc. Since the existence of a décollement at the base of the Jurassic series favors the development of normal drags versus roll-over anticlines, at least in "confined", intracontinental basins (Soto et al., 2008), paleodips inferred for the extensional stage are in general very shallow, and associated with very large regional features. ...
... Similarities of the Central High Atlas with the Iberian basins do not extend to their particular structural features. The Iberian basins show an area of distributed deformation (Andeweg et al., 1999;Casas-Sainz & De Vicente, 2009;De Vicente et al., 2009Fernández-Lozano et al., 2011;Vergés et al., 2019) that encompasses a width of more than 300 km in most of the chain, with several dominant trends, both during extension and during compression (Antolín-Tomás et al., 2007;Simón, 2004Simón, , 2005. Conversely, the Atlas is an extremely long chain whose width only compares to the Iberian Chain in very particular zones such as the confluence with the Middle Atlas chain, maintaining an average width of less than 100 km in most of its length. ...
From the application of the magnetic techniques (Anisotropy of Magnetic Susceptibility and paleomagnetism) it can be seen that to determine the age (and origin) of structures in the Moroccan Central High Atlas is not straightforward from geometrical features only and that similar structures can have different origins, or that the two limbs of a particular structure can have developed at different times. A classification of structures is proposed showing all these possibilities. As a general rule, many structures were initiated before compression and, with local exceptions associated with salt structures, paleo-dips were shallow at the remagnetization stage. This has allowed the restoration of structures and the characterization of the overall geometry of the atlasic basin as a narrow, steer’s head strongly subsiding basin whose geometry strongly conditioned its tectonic inversion during the Cenozoic compressional stage. As a synthesis, the Central High Atlas constitutes a good example of intra-plate chain in which different models of basin formation (continental rifting, salt tectonics, transtension) and inversion (thrust tectonics, transpression, buttressing and internal deformation…) can be tested and visualized.
... The Mesozoic evolution of Iberia was governed by widespread rifting periods along its northern, eastern and western margins, ending with the continental break-up along the Bay of Biscay, Lingurian-Thetys and Atlantic plate boundaries, 115 respectively (Salas and Casas, 1993;Casas-Sainz and de Vicente, 2009;Vergés et al., 2019). As a result, shallow to deep marine sedimentary basins formed at the main rifting zones (Fig. 2a): These are: (1) the intracratonic Iberian basin, represented nowadays by the Iberian Range, Maestrat basin, Cameros Massif and Catalan Coastal Ranges (Salas and Casas, 1993;Vergés and Fernàndez, 2006), (2) the Basque-Cantabrian-Aquitanian-Pyrenean basin, which currently forms the Basque-Cantabrian basin and the Pyrenees (Vergés and Fernàndez, 2006;Soto et al., 2008;López-Gómez et al., 2019), (3) the Atlantic Margin 120 rift basins, represented onshore by the Lusitanian basin (Rasmussen et al., 1998), and (4) the Atlantic-Lingurian-Tethys linkage zone, which currently forms the external Prebetic and Subbetic cordilleras within the Betic System (García-Hernández et al., 1980;Peper and Cloetingh, 1992) and the Algarve basin (Ramos et al., 2016;. ...
Evaporites flow in the solid state under relatively low differential stress, and have unique mechanical properties compared to other sedimentary rocks. Worldwide, they control the structural and stratigraphical architecture of many basins and orogens in ancient and active tectonic settings. Moreover, they host mineral deposits and play key roles in petroleum systems because they typically act as seals due to their low-permeability, and their flow produce structural hydrocarbon traps such as folds and faults in their encasing rocks. Additionally, evaporite structures can be used as subsurface storage sites for Geo-energy applications and nuclear waste. The systematic characterization of subsurface evaporite structures is thus key for the development of geoscience-based technologies to address societal challenges. Owing to their value, massive amounts of surface and subsurface information about (among others) the stratigraphy, structure, geochemistry, and petrophysical properties of evaporite structures and their surrounding rocks have been acquired by earth scientists, petroleum and mining exploration companies, and geological surveys. However, the data often appear segregated (i.e., in the form of database fragments, scientific articles and unpublished reports), not systematically organized, and sometimes not fully accessible. This contribution presents the Iberian Evaporite Structure DataBase (IESDB), the first comprehensive assessment that focuses on evaporite structures carried out in any region of the world. The IESDB includes information and figures for 150 evaporite structures and their surrounding rocks inventoried in Spain and Portugal, and is sourced from other six thematic databases and more than 1,500 published and unpublished scientific documents. The database targets undeformed to slightly deformed evaporite successions, outcropping and buried diapirs, evaporite-cored anticlines, evaporite-detached thrusts, and allochthonous evaporite bodies. Collated data include information about the structure, stratigraphy, event chronology, surface and subsurface data availability, mining activity, and key bibliographic references. The IESDB follows the FAIR principles of database management (Findable, Accessible, Interoperable and Reusable) and is presented as an interactive webpage and an open-access database, where indexed structures can easily be selected from a map or browser and filtered by a search engine. The IESBD intends to be a useful resource for teaching (i.e., pointing out examples of exceptional evaporite outcrops), academic and industry research (i.e., identifying knowledge deficits on specific structures or tectonic settings), and for the sustainable exploration and appraisal of mineral resources and Geo-Energy applications (i.e., representing a terminus a quo for site selection and suitability assessment). The framework provided by the IESDB is an opportunity to enhance the scientific research on Iberian evaporite structures in Spain and Portugal and to take advantage of their scientific and economic potential to tackle important societal challenges faced by these countries. The IESDB is freely available at https://iesdb.eu and the datasets can be downloaded from https://doi.org/10.20350/digitalCSIC/14586 (González-Esvertit et al., 2022).
... The feasible figures for extension and compression in the central-eastern Iberian Chain Seillé et al., 2015) do not leave much space for vertical movements. Crustal thinning and associated basement faulting can account for subsidence during the Mesozoic, while recovery of such thinning piling up an extra crustal thickness (Casas-Sainz & De Vicente, 2009) would correspond to the Cenozoic shortening stage. ...
Many works in the last decades underline the role of evaporites, not just as a conditioning factor but as the engine for subsidence and eventually basin inversion. The western Mediterranean alpine ranges are being investigated in this regard because of the presence of discontinuous units of Permian to Triassic evaporites, deposited in the western Tethys basins. This work presents a thorough analysis of two particular structures (Cañada Vellida and Miravete anticlines) in the intraplate Maestrazgo basin (eastern Iberian Chain, Spain) in which evidence to support their reinterpretation as salt‐driven structures has been recently reported. Our analysis includes (i) a comprehensive stratigraphic and structural study of the folds along their entire trace, (ii) the compilation of thickness and distribution of evaporite–bearing and supraevaporite units, paying special attention to changes in thickness of units in relation to anticlines, and (iii) the study of fault patterns, sometimes in relation to the mechanical stratigraphy. All three aspects are also documented and discussed on a regional scale. The new data and interpretations reported here reinforce the extensional origin of the Late Jurassic–Early Cretaceous basins, and the role of regional extensional tectonics as the responsible for the development of first‐order syn‐sedimentary normal fault zones driving the formation and evolution of sub‐basins. These basins were subsequently inverted and deformed, including the formation of complex, box‐geometry anticlines that, in their turn, controlled deposition in Cenozoic basins. The review of the arguments that support the alternative of salt tectonics for the origin of such anticlines has allowed us to delve into the sedimentary and tectonic evolution of the inverted extensional basins, and to propose a specific model for the development of these faulted anticlines. The role of salt levels and other interlayered detachments in the structuring of sedimentary basins and their inversion is also pondered. The observations in the eastern Iberian Chain reported here have implications to assess ongoing reinterpretations in terms of salt tectonics in other alpine basins and ranges of the western Mediterranean.
... Ramírez & Chaparro Sabina, 1989;Ramírez et al., 1982). In the westernmost part of the Southern Plateau, Precambrian-Paleozoic substrates are most common (Casas-Sainz & de Vicente, 2009). Given these geological and geographical features, Plio-Pleistocene fossil assemblages identified in the region are found mostly associated with either the fluvial deposits of the Tagus and Upper Guadiana basins or the karstic sedimentary infilling systems in the easternmost part (García-Martínez, 2019). ...
We present the discovery of a Middle Pleistocene fossil assemblage at Los Villares locality (Ruidera, Ciudad Real, Castilla-La Mancha), which has possible evidence of associated human activity. The potential of the site has been evaluated through multidisciplinary research including taxonomy, anatomy, deep learning, and direct dating of fossil remains. A surface study carried out in 2017, over a very limited area (2 m2) on the slope of one of the Ruidera lakes led to the discovery of more than 50 fossil specimens, including cranial (mainly teeth) and postcranial remains. This rich assemblage is dominated by the remains of Caprinae, although the presence of some small or medium carnivore remains also stands out. The identification of a cut mark, tested with Convolutional Neural Networks, suggests the presence of human activity within the bone assemblage. Several fossils were directly dated using a multi-technique approach involving radiocarbon, U-Th, and ESR methods. The results constrain the fossil assemblage to between 300 ka and 400 ka, positioning Los Villares as one of the first Middle Pleistocene localities identified in the Upper Guadiana basin, on the Southern edge of the Southern Iberian Plateau. These promising initial results show the great potential of the site to contribute to filling a gap of knowledge in the Pleistocene archaeo-paleontological record of the Iberian Peninsula. Nevertheless, we also acknowledge the need for systematic excavations in the future, not only to obtain a better idea of the lateral and stratigraphic extension of the fossil assemblage and its complete taxonomic composition, but also to confirm the human presence at the site.
... Several studies have reported on the genetic structure of freshwater fauna associated with connections between the Tagus Basin and adjacent basins (e.g., Alagón, Alberche and Lozoya rivers; Carmona et al., 2000;Casas-Sainz & De Vicente, 2009;Doadrio, 1988;Pérez-González, 1980;Sousa-Santos et al., 2007). Although recent connections may be explained as a consequence of the tectonic activity in the region (Goy et al., 2020), there are no geological studies that support a recent connection between the western Alagón sub-basin (Tagus Basin) and the Águeda sub-basin (Duero Basin), despite the close proximity of some of their river headwaters (in some cases, as little as 150 m of linear distance). ...
We studied the population genetic structure of Cobitis vettonica, an endangered freshwater fish species endemic to the Iberian Peninsula, in order to propose a biogeographic model of the responses of species to the multiple changes that occurred in the Iberian hydrological system during the Quaternary period. We also deciphered the relationship of C. vettonica with its sister species C. paludica, particularly in sympatric areas, and provide genetic information for conservation purposes. To achieve this goal, we analyzed both mitochondrial and nuclear data (the cytochrome b and the nuclear recombination activating 1 genes) and a battery of single-nucleotide polymorphisms (SNPs) of 248 individuals of C. vettonica or C. paludica from 38 localities, including some sympatric ones, covering the entire distribution area of C. vettonica. We highlight the important role played by the hydrogeomorphological processes and climatic changes that occurred in the Iberian Peninsula during the Quaternary on both the population structure of C. vettonica and its relationship with its sister species C. paludica. Our results support the genetic introgression of populations at the eastern limit of the distribution of C. vettonica. Furthermore, we postulate genetic introgression in sympatric areas. Finally, we propose the establishment or expansion of four Operational Conservation Units (OCUs) for C. vettonica, and highlight the threat faced by its populations due to the low level of genetic diversity detected for some of its populations and genetic introgression with C. paludica, which could eventually displace C. vettonica, resulting in a loss of diversity in this species.
