Search

The eastern Ebro basin is composed of an extensive irrigated plain, surrounded by rainfed slopes and wooden mountain ranges and open to the west to the agricultural western Ebro basin. The sea breeze generated at the coast is able to surmount the Catalan prelitoral range through its lowest heights, reaching the basin by its easternmost part. It is a well‐known feature in the region, called Marinada. A network of Automatic Weather Stations is used here to analyse a period of 19 years (2003–2021). A filtering procedure is developed which selects the events when the Marinada is present, based on detecting clear sky, weak wind conditions and the wind direction from the coast in the afternoon. The analysis of these days show that the Marinada propagates along the basin in the afternoon meanwhile observations of the specific humidity show a sudden increase as the temperature cools down, resulting on a cold and humid advection. It is also found that the timing of the arrival of the Marinada depends on the mesoscale/synoptical circulations already present in the region (westerlies or a thermal low). [ABSTRACT FROM AUTHOR]

The 40-km-long escarpment of the Ebro River valley to the north-west of Zaragoza (NE Spain) is a remarkable geomorphological feature and an important geoheritage locality. Being 30 to 150 m high, the escarpment exposes a complex evaporate-clastic succession of Early to Middle Miocene age, with alternating gypsum and mudstone/marl units, as well as halite beds at depth. The escarpment is a highly dynamic feature, extensively shaped by mass movements of different types, especially in sections where it is directly undercut by the Ebro River. It also hosts abundant evidence of salt and gypsum dissolution, contributing to ongoing instability. Diverse cultural heritage is associated with the escarpment, including an ancient Celtiberian settlement, medieval castles, abandoned villages, rock-cut churches and dwellings and ancient salt mines. Twenty-six possible geosites are identified, with six considered as most representative described in detail. Opportunities to develop the area for geotourism are presented, but these will be associated with challenges of properly managing steep, dynamic and fragile terrain. [ABSTRACT FROM AUTHOR]

In recent decades, the development of different analytical procedures applied to the study of archaeological lithic remains has allowed us to approach the territoriality of past societies. The application of geochemical tools has improved the study of lithic raw materials, allowing direct connections between archaeological samples and specific geological formations. In a similar way, the incorporation of GIS tools to the study of past mobility and territoriality has allowed to define which could have been the most probable routes used by past groups to stock up on rocks. In this paper, we present the results obtained after the geochemical study by Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) of lithic cherts found at Upper Palaeolithic human occupations at Cueva del Gato 2 (Épila, Zaragoza, Spain) as well as the least cost path routes obtained after GIS analyses. The Cueva del Gato 2 archaeological site is a large cave placed in the first foothills of the Iberian System, close to the Middle Ebro Basin, in Eastern Iberia. The archaeological work has revealed a long sequence of occupation with archaeological levels from the Bronze Age, the Ancient Neolithic and the Upper Palaeolithic. In this paper, we have focused on the study of level II, which has been dated in the range 21,000–23,000 cal BP. Results have demonstrated that past human groups from the Last Glacial Maximum knew and frequented the Sierra de Lanaja – Montes de Castejón lacustrine chert sources, outcropping in the Middle Ebro Basin. [ABSTRACT FROM AUTHOR]

The Monforte de Moyuela dam, also known as Ermita de la Virgen del Pilar dam, is a Roman reservoir built on a tributary of the Aguasvivas River (Ebro basin, Spain). A multidisciplinary study has been carried out to investigate this kind of Roman water infrastructure. It is the fifth‐highest dam (16.8 m) in the Iberian Peninsula and the seventh in the Roman Empire. The initial dam was built ca. 100 B.C.–10 A.D., probably in the period of Augustus, like other nearby Roman dams. It was quickly filled due to the extreme and generalized anthropic degradation in the basin during the Roman period. During the mid‐2nd century, the wall was increased in height and its final silting was dated to the early 7th century. The study of the opus caementicium mortars shows constructive differences between the initial and subsequent phases of the wall. These mortars provided charcoal for dating the two phases. In addition, the stratigraphic and edaphological study of the reservoir's sedimentary fill, together with the 14C ages, allowed us to reconstruct the two main activity cycles and the final siltation of the dam. Subsequently, the dam broke in two phases, which created the two stepped sections located on the current valley bottom. The data obtained allowed the creation of a geomorphological map and an evolutionary model of the valley showing the main differentiated stages, from the initial construction of the dam to its final opening. Although some remains of canals downstream of the dam have been identified, the use of this dam, which remained active for several centuries, still needs to be investigated in greater detail. [ABSTRACT FROM AUTHOR]

STRATEGY CCUS (Strategic Planning of Regions and Territories in Europe for Low‐Carbon Energy and Industry through CCUS) is a 3‐year project (2019‐2022) funded by the European Commission to support the development of low‐carbon energy and industry in eight regions of Southern and Eastern Europe by 2050. Among the three most promising regions selected was Ebro Basin (Spain) where local development plans (or scenarios) were defined for CO2 capture, utilisation and storage (CCUS) technologies implementation based on an industrial cluster approach. Potential regional impact analysis of these CCUS implementation plans was carried out based on the environmental impact assessment, social‐economics factors, social acceptance and in‐depth techno‐economic analysis. The Ebro Basin region is located at the north‐east (NE) of Spain and was selected based on its level of CO2 industrial emissions, estimated geological storage capacity and well‐defined transport network (pipelines, roads, rail and ports). The base scenario presented was built with the aim of covering the most extensive CO2 network but limited by the storage possibilities in the area. It covers the 15 largest emitters in the region, 3 storage sites and a complete transportation network including trucks, pipelines and ships. An alternative scenario was also proposed considering only those industries where CCUS technologies are already included in their decarbonisation strategy. The economic analysis of proposed scenarios is presented as an in‐depth set of key performance indicators (KPIs), as cost per tonne of CO2 avoided, allowing an effective comparison of the scenarios, understanding the real potential for CCUS implementation in the area and pointing out key needs for making it possible. © 2022 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons Ltd. [ABSTRACT FROM AUTHOR]

Streamflow in the Ésera and Upper Cinca Rivers (South Central Pyrenees) experiences alterations in the form of rapid pulses, commonly referred to as hydropeaks, associated with highly variable on‐demand hydropower production from flowing or stored water. A hydrological characterization of the hydropeaks in these two rivers was carried out to examine their distinct hydropeaking pattern during hydrologically contrasted years. The Ésera demonstrated a hydropeaking regime characterized by a high frequency and magnitude, while the Upper Cinca presented a regime with higher frequency but of lesser magnitude. Additionally, this study classified hydropeaks following the shapes proposed in previous studies and assessed their temporal distribution (frequency), timing, and magnitude. Results indicated that hydropeaks were different in shape and magnitude in both rivers; a Front Step pulse shape dominated in the Ésera whereas a Rectangle pulse shape was the most frequent in the Cinca. The Front Step shape had the highest ramping rates during the rising limb of the hydrograph and the shortest time to the maximum flow; whereas the Rectangle shape had higher duration and a larger volume of water released. Hydropeaks in the Ésera were less frequent (one per day) than in the Cinca (two per day). The river Ésera presented, in general, high‐magnitude hydropeaks, with double volume and duration, and three times larger up‐ramping rates and time between flow pulses. Overall, hydropeak shapes in the Ésera varied depending on the hydrological year and the season, while in the Cinca, shape distribution followed the same temporal pattern regardless of year and season; thus, hydropeaking in the Ésera appeared to be much more dependent on the annual hydrology (whether the year is wet or dry) than in the Cinca. Hydropeaking regimes were characterized based on three categories of variables: magnitude (flow‐based or hydrological variables), timing (duration), and frequency (occurrence). According to the variability of these variables, a total of three statistically significant groups were obtained in the Ésera, while two groups were identified in the Cinca. Hydropeaks can be statistically classified by their hydrological characteristics that in turn may have a direct effect on sediment entrainment and transport with implications to the ecological functioning of rivers. The different shape of the hydropeaks, however, will control the attenuation of the flows downstream and, consequently, the maintenance of the river's competence and capacity. This methodology provides a useful quantification of hydropeaking regimes to assess the potential impacts on physical and biological aspects of river systems. [ABSTRACT FROM AUTHOR]

This article presents a morpho-structural map at 1:50,000 scale of the confluence area between three regional units: (1) the Burgalesa Platform (Mesozoic; Cantabrian Mountains), (2) the Duero Basin and (3) the Ebro Basin (Cenozoic foreland basins). The map covers an area of 527 km2 in north Iberia. Additionally, structural lineaments such as joints are well preserved and documented in the Upper Cretaceous sediments of the Burgalesa Platform, represented by four main sets regarding their orientation. The foreland basins are incised in Miocene materials by rivers that have developed a complex drainage system controlling the deposition of the most recent alluvial sediments, following the four structural orientations. The map, together with the analysis of orthophotos and a Digital Terrain Model, and outcrop-scale observations, have led us to document the influence of the Miocene to present-day compression and strike-slip tectonic regime on the configuration of the drainage system and the geomorphological features.

To better understand the stratigraphic development of sedimentary systems, it is necessary to link the controls on sedimentary processes to the resulting deposits, which in turn allows predictions of stratigraphic architectures at a range of scales. We use a stratigraphic forward model to link the governing parameters to the distribution of deposits within a distributive fluvial system (DFS). The numerical model has been validated against outcrop observations to establish how the depositional processes needed to form the specific sedimentary system have been reproduced. We chose the previously studied Oligocene to Miocene Huesca DFS in northern Spain to investigate and calibrate the model. Additionally, downstream profiles from modern DFS in northern India, and hydrological measurements from the High Island Creek, Minnesota, USA, were used as input parameters for the model in addition to the outcrop data from the Huesca DFS. The resulting model adequately reproduced the real‐world system. Once validated, the analysis of the modelled DFS led to key findings, which expand our understanding of DFS stratigraphic architecture. Reservoir characteristics in radial DFS are dependent on the angle away from the meridian (straight line from the source through the apex to the distal zone of the DFS). The greater the angle is, the coarser the average grain size in the proximal zone is but the finer the average grain size in the medial and distal zones. Lateral variability of net to gross, sandbody thickness and number, and amalgamation ratio is greatest at the transition between the proximal and medial zone and is still significant in the distal part of the DFS. Stratigraphic forward modelling enhanced our understanding of DFS, which leads to reducing risk associated with exploration, production and storage of fluids in subsurface DFS. [ABSTRACT FROM AUTHOR]

Numerous sedimentary fans on Mars have been studied to better understand the early martian hydrological system. Of particular interest is to estimate the duration of fluvial activity from alluvial fan size by dividing deposit volume by bankfull sediment flux. However, such a calculation requires an intermittency factor—a parameter relating sediment discharge from channel‐filling (bankfull) floods to the long‐term mean sediment discharge—which is poorly constrained. Here, we investigated fluvial fan deposits from the Oligocene–Miocene Caspe Formation, Spain, as an analog to fans on Mars because it has exhumed channel belts that create sinuous ridges in the modern topography, similar to those observed on Mars that are used for paleohydraulics. We made measurements of the thicknesses of dune and bar cross sets within exhumed channel belts at nine field sites to reconstruct bankfull channel depth (∼1.4 m) and bankfull sediment flux (∼0.48 m3/s). We estimated total bed‐material sediment volume of the fan (362 km3) from stratigraphic thickness, the area containing exhumed channel belts, porosity and sand fraction. Combined with previous constraints on depositional timespan (∼6 Myr), we calculated a sediment‐transport intermittency factor of 0.004 (range: 0.0004–0.04). Our approach can be applied to Mars by using remote sensing measurements of fluvial ridge morphology, which indicates the possibility of long depositional timespans exceeding millions of years for martian fans. Plain Language Summary: We examined Oligocene‐Miocene river deposits in the Guadalope‐Mattaranya fan (Ebro Basin, Spain) as an analog for river deposits on Mars that potentially represent long durations of river activity. Similar to deposits on Mars, the Guadalope‐Mattaranya fan has been differentially eroded creating networks of branching, sinuous ridges that represent former river channel belts. Based on measurements of river bar and dune deposits, we estimated that the ancient rivers were sand‐bedded and 1.4 m deep and that they carried a bankfull sediment discharge of 0.48 m3/s. Using these data, we calculated that the entire fan could have been built in as little as 24,000 years if there was continuous bankfull flow in the rivers. However, in reality, the fan was built over 6 million years, highlighting the vast amount of time that sediment transport was inactive. Applying a similar fraction of intermittent sediment transport to case studies on Mars suggests that martian river systems could have been intermittently persistent for millions of years. Key Points: Guadalope‐Matarranya fan in the Ebro Basin, Spain, is a large fluvial fan with fluvial ridges similar to fans on MarsFluvial ridges are exhumed channel belts from rivers 1.4 m deep, with sediment‐transport intermittency factor of 0.004 (range: 0.0004–0.04)If martian depositional rivers had similar intermittency, some persisted at least millions of years [ABSTRACT FROM AUTHOR]

Stratigraphic and sedimentological study of distal alluvial and lacustrine deposits in the Plana de la Negra-Sancho Abarca area (western-central Ebro Basin, NE Iberia) within the early and middle Miocene allows five main lithofacies to be characterized and mapped within two tectosedimentary units, construction of a sedimentary facies model and discussion on allogenic controls on sedimentation. In this area, the boundary between tectosedimentary units T5 and T6 appears to be conformable and is marked by the change from dominant clastics to carbonates. Correlation of the studied outcrops with nearby sections that already had magnetostratigraphic and biostratigraphic data allows the studied succession to be dated from C5Dr to C5Cn (Burdigalian-Langhian), placing the boundary T5/T6 at ca. 16.1-16.05Ma. Seven vertical facies sequences document deposition of distal alluvial clastics and palustrine and lacustrine carbonates. Sandstones and mudstones represent low-sinuosity channels and lateral and terminal splays by unconfined flows runnig across the alluvial plain, associated to the Pyrenean-derived Luna fluvial system. The carbonates contain charophytes, ostracods, bivalves and gastropods, indicating deposition in 2-4m deep lakes. Laminated carbonate facies record reworking of shore carbonates and the influx fine-siliciclastic sediment offshore. Abundant bioturbation and desiccation features indicate episodic submergence and subaerial exposure. Four main episodes of alluvial and associated palustrine/lacustrine facies belt shifts are identified. Alluvial deposition in the studied T5 unit is related to low lake level conditions, rather than to a Pyrenean uplift. The maximum extent of the freshwater carbonates occur at the base of unit T6. This is consistent with conditions of increasing humidity of the Middle Miocene Climatic Optimum.

This article presents a morpho-structural map at 1:50,000 scale of the confluence area between three regional units: (1) the Burgalesa Platform (Mesozoic; Cantabrian Mountains), (2) the Duero Basin and (3) the Ebro Basin (Cenozoic foreland basins). The map covers an area of 527 km2 in north Iberia. Additionally, structural lineaments such as joints are well preserved and documented in the Upper Cretaceous sediments of the Burgalesa Platform, represented by four main sets regarding their orientation. The foreland basins are incised in Miocene materials by rivers that have developed a complex drainage system controlling the deposition of the most recent alluvial sediments, following the four structural orientations. The map, together with the analysis of orthophotos and a Digital Terrain Model, and outcrop-scale observations, have led us to document the influence of the Miocene to present-day compression and strike-slip tectonic regime on the configuration of the drainage system and the geomorphological features. [ABSTRACT FROM AUTHOR]

The Sauveterrian is an industrial complex barely known in Spain. We have a little over a dozen known stratigraphic sequences, and there are very few studies about their industries. In this sense, there are many open research questions: a) about its chronological framework; b) its technological characterisation; c) its connection with the previous epipaleolithic traditions; d) its temporal evolution; and e) its relationship with the Sauveterrian industries of Western Europe. In this state of knowledge we present the main results from the study of raw materials, technology and typology of the sauveterrian levels from two upper and middle Ebro sites: Atxoste (Basque Country) and Peña 14 (Aragon). The reconstruction of the lithic industry production and management strategies carried out allows us to offer an initial characterisation of these industries in the upper and middle Ebro, and offers a good opportunity to re-evaluate this complex and reflect on how it fits into the industrial dynamics of the Iberian Peninsula, the changes and continuities it represents and its meaning. [ABSTRACT FROM AUTHOR]

Evaluation of karst hazards benefits from the integration of different techniques, methodologies and approaches. Each one presents a different signature and is sensitive to certain indicators related to karst hazards. In some cases, detailed analysis permits the evaluation of representativeness either from isolated approaches or by means of integrated analyses. In this study, we present the evaluation of an area with high density of karstic collapses at different evolutionary stages through the integration of surficial, historical, geomorphological and geophysical data in order to finally define the evolutionary model for karst activity development. The obtained dataset permits to identify different steps in sinkhole evolution: (i) cavities and open sinkholes, (ii) filling of these cavities, with materials having different signatures, (iii) the progression from collapses to subsidence sinkholes and (iv) enlargement through collapses in marginal areas of previous sinkholes. The presence of different stages of this evolutionary model permits to determine their own signatures that can be of application in contexts where analysis cannot be so systematic and also to evaluate the definition of the marginal areas of previous sinkholes as the most hazardous sectors.

The Upper Eocene fish‐bearing deposits of the Terminal Complex of the Plana de Vic (Ebro Basin, Catalonia, NE Spain) and its fish assemblage are analysed in detail from a stratigraphic and sedimentological point of view. Moreover, the taphonomic features and taxonomy of the fishes are studied for the first time. Fishes belonging to the families Clupeidae, Synodontidae, and an indeterminate percomorph have been identified, including a new lizardfish taxon, Ausonasynodus almerai gen. et sp. nov. The fish specimens are preserved in finely laminated limestones, resulting from the development of microbial mats on the seafloor. The presence of these microbially induced biolaminations favoured the good preservation of the fossil material. The combination of the stratigraphic and sedimentological context of the studied deposits, together with the taphonomic and paleobiological information obtained from the fishes, suggest that they were likely deposited in a shallow marine setting, probably in restricted or protected areas, under arid climatic conditions. [ABSTRACT FROM AUTHOR]

Environmental water uses and their social values have been mostly overlooked in traditional water management over the last few decades, and recently, the maintenance of environmental flows has been considered a key issue in water policies. Addressing the more sustainable management of water resources involves introducing new water allocation policies. However, these policies are often associated with tradeoffs across sectors, stakeholders, and spatial locations. This study aims to evaluate the tradeoffs and political economy aspects of allocating water among economic water uses and environmental flows in water-scarce river basins. An empirical analysis has been conducted in the Ebro River basin (Spain) as a case study, where an intense debate on the environmental flow allocation of the Ebro mouth is taking place. The study uses a hydroeconomic model that includes the major water uses in the Ebro to analyze the effects of different water allocation policies under combinations of water availability and environmental flow scenarios. The results of this study highlight the importance of assessing the opportunity costs and political implications of reallocating water from economic activities to the environment under impending climate change impacts. Moreover, the results indicate that well-functioning water allocation policies should be not only economically efficient but also socially acceptable to reduce the likelihood of failure of water reallocation to the environment. [ABSTRACT FROM AUTHOR]

Abstract The study of fluvial network rearrangement provides a key to understand past and future landscape evolution. Large perturbations of hydrographic basins such as the change from endorheism to exorheism have repercussions in the steady or disequilibrium state of the basins and their drainage divides. Such transitions from internal to external drainage imply a major lowering of the geomorphological base level causing a major retreating knickpoint wave that separates the upstream low-relief area (inherited from the endorheic period) from the downstream incised area. Subsequently, the water divide migrates to reach an equilibrium in which erosion rates at both sides of the divide are similar. Previous fluvial analyses suggest that both the Duero and Ebro drainage networks, the two largest catchments in Iberia, experienced a change from endorheism to exorheism sometime between the Late Miocene and the Pliocene. Fluvial capture evidence argues for a Pliocene westward migration of the Ebro-Duero divide implying an area decrease for the Duero fluvial network (victim) in favor of the Ebro (aggressor). We used river profiles, knickpoint distribution and Chi-map calculation to understand the different degree of erosion of the Duero and the Ebro catchments and the dynamics of their drainage network. The results show an equilibrated Ebro drainage network in contrast with a disequilibrium in the erosional state of the Duero drainage, which remains reorganizing and adapting to the newly-imposed Atlantic base level. We identified at least two knickpoint wave trains in the Duero drainage resulting from the onset of exorheism: a fast-propagating wave through the cover and a low-propagating wave affecting the bedrock. Field evidence and topographic analysis suggest a westward migration of the Ebro-Duero divide, resulting in an ongoing headward erosion of the Ebro against the Duero catchment. Chi analysis provides the degree of disequilibrium of the drainage network indicating a large-scale aggressor role for the Duero and a victim role for the Ebro. We interpreted this seeming contradiction as the result of a different time scale perspective: local divide observations indicate a victim Duero in the short-term, whereas basin-scale dynamics support a victim role for the Ebro fluvial network in the long-term (multi-million-year time-scales). Highlights • The Ebro Basin is closer to equilibrium than the Duero Basin, which remains adapting to the Atlantic base-level. • We suggest a fast-propagating knickpoint wave through the cover and a low-propagating wave affecting the bedrock. • The rate of knickpoint retreat on the cover is twice as high as the rate of retreat on the bedrock. • Local divide dynamics argue for a victim Duero at short-term and basin-scale dynamics argue for a victim Ebro at long-term. [ABSTRACT FROM AUTHOR]

Abstract Rhus asymmetrica sp. nov. from the lower Oligocene of Cervera (Catalonia, Spain) is characterized by a trifoliate leaf with a symmetric sessile apical leaflet and asymmetric lateral leaflets. The apical leaflet displays a serrate margin and decurrent base with pinnate primary venation, craspedodromous secondary venation and an irregular reticulate tertiary framework. The lateral leaflets show a rounded base with a secondary basal vein in the distal part of the lamina, while the proximal part is straight or concave. Formerly, these specimens were accommodated within Rhus pyrrhae Unger. However, detailed study of the R. pyrrhae holotype has led us to emend its diagnosis to include its brochidodromous secondary venation pattern, which differs clearly from the venation pattern of the new species. Additionally, a number of leaf morphotypes from the Cervera palaeobotanical site that were erroneously attributed to Rhus by former authors have been segregated and related to Acer and Toxicodendron. The extant species R. aromatica displays the closest foliar structure to R. asymmetrica sp. nov. However, differences in the leaf morphology suggest that the new species grew under distinct palaeoclimatic conditions: (1) R. asymmetrica sp. nov. bears glands at the tips of the teeth of the lateral leaflets while R. aromatica is devoid of these glands. This character would help to prevent excessive evapotranspiration; (2) lateral leaflets of R. asymmetrica sp. nov. are asymmetric while in R. aromatica they are symmetric, suggesting that R. asymmetrica sp. nov. grew under a greater environmental stress than R. aromatica ; (3) R. asymmetrica sp. nov. displays fewer teeth with a larger tooth-area than R. aromatica. This would indicate growth under a warm climate with low seasonal contrast. These features are compatible with an open woodland habitat under subtropical palaeoclimatic conditions. Highlights • Rhus asymmetrica sp. nov. from the Oligocene of the Iberian Peninsula is described. • Living North American R. aromatica displays the leaf closest to R. asymmetrica. • Differences in leaf characters of R. asymmetrica and its NLR are climate-sensitive. • Glands in lateral leaflets teeth of R. asymmetrica point out to water stress. • R. asymmetrica shows few and large teeth as a response to warm and arid climate. [ABSTRACT FROM AUTHOR]

Constraining the way in which continental deformation is accommodated in time and space is essential to reconcile past plate movements with geological observations. Kinematic reconstructions of the Iberia‐Europe plate boundary are still debated. Here we focus on an inverted Mesozoic rift basin, the Cameros basin, which is part of the Iberian chain. We use a combination of detrital low‐temperature thermochronological techniques to define the time‐temperature evolution of the basin from Mesozoic rifting to Cenozoic collision. Zircon fission‐track analyses of Oligocene–Miocene sedimentary rocks yield two main age populations at ~170 ± 10 and ~100 ± 10 Ma, reflecting (i) an Early Jurassic thermal event related to the Atlantic‐Alpine Tethys opening and (ii) an Albo‐Cenomanian thermal event related to the Bay of Biscay opening. Thermal modeling of combined zircon fission‐track, apatite fission‐track, and apatite (U‐Th‐Sm)/He data reveals that collision‐related cooling of the Cameros basin started during the Paleocene (~60 Ma). A second cooling/exhumation phase of the basin is recorded from 35 to 25 Ma. Initial cooling occurred after a protracted postrift period characterized by persistence of high geothermal gradients, a feature also recognized in the Pyrenees. Our results show that the Iberian chain shared the same Early to Late Jurassic tectonothermal evolution with the Atlantic‐Alpine Tethyan rifted margins. From the Albian onward, the thermal evolution of the Cameros basin was very similar to that of the Pyrenees. This study shows that the preservation in mountain ranges of a succession of rifting events provide important clues for plate reconstructions. Key Points: Iberian Range thermal history provides record of the tectonic evolution of the Iberia‐Europe plate boundaryZircon grains cooled during rifting events are preserved in the Ebro basin detrital recordDiachronous Iberian Range and Pyrenean rifting events recorded the same Albian thermal anomaly and metamorphism [ABSTRACT FROM AUTHOR]

I report the first observation of the symbiotic relationship between a serpulid polychaete and a larger foraminifer, Discocyclina, from the Eocene of the Ebro Basin (NE Spain). Discocyclina tests are the larger and most abundant element of the fossil assemblage in a limestone bed within a fan delta series, and seems to be a preferred substrate by the serpulid larvae to settle. The bioimmuration of the serpulid tube within the foraminiferal test shows that the polychaetes attached and grew on living foraminifers, which continued growing after the serpulid’s death. The foraminifer could benefit from the filtering activity of the serpulid, although in some cases the serpulid attachment caused an anomalous growth of the foraminiferal test. Some foraminifer individuals survived to two, possibly three successive episodes of serpulid attachment, which suggests a life span of 1-3 years for this Discocyclina species, similar to that of recent hyaline larger foraminifers such as Amphistegina or Paleonummulites. This sheds new light on the paleobiology of this type of larger foraminifers without recent counterparts that thrieved during Late Cretaceous and Paleogene times. [ABSTRACT FROM AUTHOR]

The Ebro Basin constitutes the central part of the southern foreland of the Pyrenees. It was endorheic during the Cenozoic and accumulated sediments. By the end of the Miocene, erosion and river incision reconnected the basin to the Mediterranean Sea, establishing a post-opening drainage network. Those rivers left terraces that we study in this work. We first synthesize previous works on river terraces that are widely dispersed in the basin. We provide new age constraints, up to 3 Ma, obtained thanks to cosmogenic nuclides using both profile and burial methods. We derive a unified fluvial terrace chronology and a homogenized map of the highest terraces over the entire Ebro Basin. The dated terraces labeled A, B, C, D, and E are dated to 2.8 ± 0.7 Ma, 1.15 ± 0.15 Ma, 850 ± 70 ka, 650 ± 130 ka, and 400 ± 120 ka, respectively. The chronology proposed here is similar to other sequences of river terraces dated in the Iberian Peninsula, around the Pyrenees, and elsewhere in Europe. The oldest terraces (A, B, C) are extensive, indicating they form a mobile fluvial network while from D to present, the network was stable and entrenched in 100 to 200 m-deep valleys. The transition from mobile to fixed fluvial network is likely to have occurred during the Middle Pleistocene Transition (MPT, between 0.7 and 1.3 Ma), when long-period/high-intensity climate fluctuations were established in Europe. We estimate that between 2.8–1.15 Ma and present, the incision rates have tripled.

Chert from the limestones and marly limestones of Castelltallat Formation (Ebro Basin) was widely used throughout prehistoric times in north-eastern Iberia to produce stone tools due to its properties and accessibility. A rough estimate indicates that this rock—either as raw material or as lithic products—was distributed mainly to the north of the outcrops, over an area of 6000-8000 km2. However, other rocks in the area have similar characteristics which can lead to confusion in the interpretation of its prehistoric use and distribution. In order to establish useful archaeometric criteria for differentiating this chert from other similar, the Castelltallat chert is characterised in petrographic, mineralogical and geochemical terms. The chert nodules are found to be homogenous at the macroscopic and microscopic level, with a significant presence of bioclasts, thus indicating they might be formed in a freshwater lake environment by the early diagenetic replacement of carbonates in shallow waters. The mineralogical composition is homogeneously uniform and of a flint type, characterised by an almost exclusive predominance of quartz, without any opaline phases, and a variable proportion of moganite. The iron oxide content is very low, whereas its chemical composition is unusually high in uranium which correlates positively with carbonate content and negatively with silica. Archaeometrical parameters are provided to reach a proper identification of tools knapped with this chert. This way, chert from Castelltallat Formation turns out to be a valuable lithological marker to evaluate the range of mobility of the human groups who lived in the north-eastern Iberia and their contacts with neighbouring areas. [ABSTRACT FROM AUTHOR]

This work aims to bring to light the great wealth of mammal and avian tracksites of the Cenozoic of the southern margin of the Pyrenees and the northern Ebro Basin (Aragon, northeast Spain) by designing a palaeoichnological itinerary that includes the main tracksites. Scientific research in these fields is currently being carried out with very interesting preliminary results, given the poor ichnofossil record in the Palaeogene worldwide. In addition to its scientific importance, however, we want to emphasize the value of this palaeontological heritage as a tourist and educational resource and also the geoconservation work carried out on the tracksites. In some of these sites (Fondota, Sierra de Luna and La Playa Fósil), conservation and adaptation activities have been undertaken over the last few decades. These activities have allowed people to access and visit these tracksites, thus promoting them as socioeconomic assets of this region. [ABSTRACT FROM AUTHOR]

Abstract: In the early 20th century, when extensive areas of land were transformed from rainfed to irrigated agriculture, there was a severe lack of scientific and technical literature available on the effects of applying water to saline soils. This was the case of the Violada Irrigation District located in a semiarid region of NE Spain whose transformation started in the 1940s. We discuss the use of agronomical expertise and the limited knowledge of soils available prior to the transformation, the favorable and unfavorable scenarios encountered during the transformation, and the final success of irrigation despite the initial soil salinization and water logging. We attribute the technical success to the fact that gypsum is common in the soils and geological materials, and to the continued drainage efforts. Failures in the irrigation of saline lands are a frequent subject of discussion in the scientific literature; contrariwise, we present the history of a successfully irrigated district after 70 years. [ABSTRACT FROM AUTHOR]

Pollutants' dynamics in rivers flowing through industrial areas is linked to the entrainment and transport of contaminants attached to solid particles. The transport of sediment is mainly associated to high discharges and flood episodes, and these events constitute one of the main factors causing fluxes of buried pollutants in rivers. We performed a field study in the lower River Cinca (Ebro basin, Northeast Spain) to quantify the mobilization and transfer of several contaminants present in the river bed sediments. We focused on contaminants previously identified (PCBs, DDXs, PBDEs, HBCDs and PFRs) to occur in the river. River bed sediment samples were collected during low flows and a subsequent sampling campaign was used to capture sediment borne contaminants during a flood event. Water samples were taken at the same locations as the static sediment samples and used to determine the suspended sediment concentrations and the contaminants content (i.e. mass of contaminant per sediment mass unit) during the event. We estimated mass fluxes for both sediment and pollutants, and determined that sediment transport followed a clockwise hysteresis. This is typically observed in high flow events after dry summer periods. With sediments there was a large mobilization of PFRs (36 kg in 48 h in one of the main tributaries) and PCBs not previously observed in the static sediment. Observed contaminant load ranges during the two-day sampling campaign were: PCB (34–152 g), DDT (12–213 g), PBDE (50–1740 g), HBCD (0–2.2 g) and PFR (2410–35,895 g). An environmental risk assessment was carried out by comparing the pollutant concentrations found in the sediments with the Canadian quality guidelines (ISQC), showing a significant noncompliance for PCBs in dynamic sediments. Our results point out to the need of a regular assessment of the downstream transfer of the sediment-borne pollutants in drainage basins historically affected by intense industrial activities and associated contamination. [ABSTRACT FROM AUTHOR]

Although the frequency of pastoral activities involving vertical sheep mobility has decreased over the last century, this is a herding strategy still used in the Ebro basin, where animals move from overwintering valley locations up to the Pyrenees from late spring to early autumn. Such practice allows herders to avoid the worst climatic conditions, seasonally balancing the great contrast between ecological zones in this region, from dry lowland Mediterranean steppe to wet mountain subalpine grasslands. As recent regional archaeological works have suggested, the altitudinal movement of flocks may have begun with the first early Neolithic groups settled in this territory. Here we investigate through stable isotope analyses one of the last flocks that still performs this activity. Sheep specimens were analyzed by sequential analyses (δ13C and δ18O) in bioapatite of tooth enamel, allowing detection of seasonal changes. Tooth series are interpreted according to rainfall distribution, seasonal patterns in δ 18O of meteoric water, vegetation changes and δ13C values in pastures along the altitudinal gradient in the area. Vertical movements in sheep sequential series are recognized by an inverse relationship between δ13C and δ18O values. Monthly δ18O values in meteoric water obtained in valley and mountain locations describe the same type of seasonal oscillation, with high values during the warm months and low values during the cold months. Pastures analyzed along the altitudinal gradient showed a decrease in δ13C values with altitude, linked to the seasonal availability of precipitation and vegetation differences among locations. These results define a new analytical and conceptual framework for the interpretation of archaeological samples in this region. [ABSTRACT FROM AUTHOR]

Abstract: Single‐station autocorrelations of seismic ambient noise allow to obtain the shallow subsurface reflection response without the need of any active source or earthquake. Recently, crustal‐scale studies successfully applied this method to map the crust‐mantle boundary. These studies employed different processing methodologies to stabilize and identify the weak‐amplitude reflections. Here we also analyze noise autocorrelations but use higher‐frequency bands to map the basement of the Ebro Basin in Spain. This basin has a nonuniform basement structure due to its complex evolution. We tested two autocorrelation methods (the classical and phase cross correlation) to retrieve the P wave reflection response for seismic broadband stations located in the basin. The phase correlation approach is amplitude unbiased since based on the instantaneous phase coherence of analytic signals. It is insensitive to the background seismicity from the Pyrenees and other noise and proved to be the more efficient approach to retrieve P wave reflections from the Paleozoic basement. The detected signals per station are quite stable and show only a small time variability. We also show that sidelobes caused by the convolution of a delta pulse at zero time lag with the effective noise source time function do not affect our measurements and compare the measured noise autocorrelations with synthetic data for lithological profiles from neighboring wells. The a priori information from well data was essential to identify the signals and to finally map the discontinuity in between and beyond the well positions. Our final result is a comprehensive map of the Paleozoic basement in the Ebro Basin. [ABSTRACT FROM AUTHOR]

In arid lands, irrigation is necessary for agriculture to be profitable. However, the nature of soils and parent materials is significant enough to trigger permanent management limitations and the loss of important investments, as happened in some areas of the Flumen irrigation district in the Central Ebro Basin, NE Spain. We studied the distinct soil characteristics of a salt-affected agricultural plot and its recurrent problems from the last 30 years. We describe and discuss the prominent features of this soil and their effects on plant life and agricultural management. The evidence of post-irrigation salt-related effects is documented together with the water and soil salinity monitoring records. The presence of varved Holocene sediments comprising alternating clays and carbonate-rich silt with high levels of salinity and sodicity, together with a shallow saline water table, were found to be the key unfavorable conditions. Despite a noticeable decrease in sodium adsorption ratio (SAR) from 1999 to 2015 and a reduction in soil salinity down to a steady state after rice paddy cultivation, SAR and alkalinity remained high enough to hamper irrigated agriculture. Only the native plant Puccinellia festuciformis thrives in the studied plot. The article presents and discusses chemical features―analytical data―and morphological features―pictures and descriptions―that are seldom reported and interpreted together in the scientific or technical literature about irrigation of sodic soils, often limited to chem data. The paddy field studied is deemed representative of the most unfavorable soils for agriculture in the irrigated districts of the Ebro valley. [ABSTRACT FROM AUTHOR]

Discussing the transition from Mesolithic to Neolithic requires a definition for the archaeological record. In the Ebro Basin the typical archaeological sites, rock shelters, have been considered in a simplified way as hunting grounds, but advances in research indicate that they were in fact multi-purpose habitats with varied activities, tight control of resources and a comprehensive exploitation of the area. Our hypothesis is that Mesolithic societies were sedentary with a complex social organisation. For this reasons, we reject the concept of Mesolithic peoples with pottery which is applied to records which do not contain the whole Neolithic package. We know that versatility is one of the characteristics that defines these settlements whith a) all the steps in the lithic chaîne opératoire , b) a wide variety of objects, c) the use for hunting, butchery, fur making, woodworking, bone, plants and so on. In terms of wildlife, the description of an individual animal as domestic is not always easy to extrapolate from anatomical criteria, but an in-depth analysis does not discard this possibility either in the rockshelters. The prehistory of the Ebro Basin seems to indicate that their historical narrative began in the transition towards a production economy: in the balance between the archaeological record and historical logic it makes sense to assess ground-breaking processes of Neolithisation in comparison with participatory models of local communities. [ABSTRACT FROM AUTHOR]

The Ebro Basin constitutes one of the most representative territories in SW Europe for the study of prehistoric societies during the Pleistocene-Holocene transition. The correlation of palaeoenvironmental and geomorphological proxies obtained from sedimentary records with chronologically well-constrained reference archaeological sites has allowed defining this time frame precisely, such that three main pilot areas haven been broadly depicted: the Alavese region, the Pre-Pyrenees and the Bajo Aragón. Overall, the human imprint in the Ebro Basin was rare during the Upper Palaeolithic, but more visible from the Upper Magdalenian (14500–13500 cal BP) to Neolithic times (up to 5500 cal BP). Local environmental resources were continuously managed by the prehistoric communities in the different areas of study. In fact, the Ebro Basin acted during those millennia as a whole, developing the same cultural trends, industrial techniques and settlement patterns in parallel throughout the territory. However, some gaps exist in the 14 C frequency curve (SCDPD curve). This is partially related to prehistoric sites in particular lithologies and geological structures that could have partly been lost by erosional processes, especially during the Early Holocene. In addition, this gap also parallels the reconstructed climate trend for the Pre-Pyrenean and the Bajo Aragón areas, which are defined by high frequencies of xerophilous flora until ca. 9500 cal BP, suggesting that continental climate features could have hampered the presence of well-established human communities in inland regions. The interdisciplinary research (archaeology, geomorphology and palaeoclimatology) discussed in this paper offers clues to understand the existence of fills and gaps in the archaeological record of the Ebro Basin, and can be applied in other territories with similar geographic and climate patterns. [ABSTRACT FROM AUTHOR]

Copyright of Boletín Geológico y Minero is the property of Instituto Tecnologico Geominero De Espana and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We present the results of prospecting in the NE of the Iberian Peninsula, with the aim of identifying the siliceous sources potentially used by the populations that occupied the marginal basins of the Ebro depression during the Middle and Upper Palaeolithic. We intend to define the main characteristics of the cherts in the region studied, taking into account the palaeoenvironment in which silicifications are mainly formed, and the premise that siliceous rocks acquire the attributes of enclosing rocks. The cherts studied are the products of early diagenesis by replacement of carbonate and evaporite sediments. Petrological analyses show that they are made up of microquartz, with high proportion of fibrous forms silica, carbonates, ferric oxides and evaporite relicts. In the future, these characteristics will be useful for ascribing archaeological materials in both geological and geographical terms.

Evaluation of karst hazards benefits from the integration of different techniques, methodologies and approaches. Each one presents a different signature and is sensitive to certain indicators related to karst hazards. In some cases, detailed analysis permits the evaluation of representativeness either from isolated approaches or by means of integrated analyses. In this study, we present the evaluation of an area with high density of karstic collapses at different evolutionary stages through the integration of surficial, historical, geomorphological and geophysical data in order to finally define the evolutionary model for karst activity development. The obtained dataset permits to identify different steps in sinkhole evolution: (i) cavities and open sinkholes, (ii) filling of these cavities, with materials having different signatures, (iii) the progression from collapses to subsidence sinkholes and (iv) enlargement through collapses in marginal areas of previous sinkholes. The presence of different stages of this evolutionary model permits to determine their own signatures that can be of application in contexts where analysis cannot be so systematic and also to evaluate the definition of the marginal areas of previous sinkholes as the most hazardous sectors. [ABSTRACT FROM AUTHOR]

Satellite remote sensing is a powerful tool to map flooded areas. In recent years, the availability of free satellite data significantly increased in terms of type and frequency, allowing the production of flood maps at low cost around the world. In this work, we propose a semi-automatic method for flood mapping, based only on free satellite images and open-source software. The proposed methods are suitable to be applied by the community involved in flood hazard management, not necessarily experts in remote sensing processing. As case studies, we selected three flood events that recently occurred in Spain and Italy. Multispectral satellite data acquired by MODIS, Proba-V, Landsat, and Sentinel-2 and synthetic aperture radar (SAR) data collected by Sentinel-1 were used to detect flooded areas using different methodologies (e.g., Modified Normalized Difference Water Index, SAR backscattering variation, and supervised classification). Then, we improved and manually refined the automatic mapping using free ancillary data such as the digital elevation model-based water depth model and available ground truth data. We calculated flood detection performance (flood ratio) for the different datasets by comparing with flood maps made by official river authorities. The results show that it is necessary to consider different factors when selecting the best satellite data. Among these factors, the time of the satellite pass with respect to the flood peak is the most important. With co-flood multispectral images, more than 90% of the flooded area was detected in the 2015 Ebro flood (Spain) case study. With post-flood multispectral data, the flood ratio showed values under 50% a few weeks after the 2016 flood in Po and Tanaro plains (Italy), but it remained useful to map the inundated pattern. The SAR could detect flooding only at the co-flood stage, and the flood ratio showed values below 5% only a few days after the 2016 Po River inundation. Another result of the research was the creation of geomorphology-based inundation maps that matched up to 95% with official flood maps.

We introduce the first map of density data in Northeastern Spain which can help in the interpretation of gravimetric surveying. The background map is a simplified version of the Geode continuous geological cartography (scale 1:200.000) of the Iberian Range and Ebro basin. These maps are synthetic and homogeneous maps based on previous 1:50,000 scale geological maps (MAGNA). The map uses the ETRS89 datum and UTM coordinates (30T northern zone) and covers an area of 140,000 sq km. The compiled data shown in the map come from previous papers of the region (≈ 700 points) as well as from more than 800 additional points developed in the course of an exploratory project focused on the underground characterization of a potential CO2reservoir in the so-called ‘Linking Zone'. The new data accomplish some basic criteria; they are accurately georeferenced and lithology, stratigraphic age and other technical details about the measurements (e.g. means and error) and methods are fully displayed. [ABSTRACT FROM PUBLISHER]