Instituto Geológico y Minero de España

Hispaniola accommodates a significant portion of the present‐day convergence between Caribbean and North American plates. Located in southern Hispaniola, the Neogene Enriquillo basin is bounded by the Neiba and Bahoruco mountain ranges. The role of active individual faults and fault systems in this basin is not well understood, particularly their geometry and kinematics, slip rates and seismic activity. Knowing this information is important to characterize the active deformation pattern in southern Hispaniola, but it is also crucial to estimate the regional seismic hazard. Here, we analyze GPS geodetic data and seismicity and present the results of fault mapping of the Enriquillo basin based on tectonic field observations, radiocarbon and luminescence dating, remote sensing and regional magnetic data. These observations indicate that WNW to NW‐trending thrust faults and associate large‐scale folds, as well as minor strike‐slip and normal faults, have been active both in the Tertiary rocks within the mountain ranges and in the basin margins along the Quaternary. Inversion of fault‐slip data establishes that a NE‐directed shortening has controlled the formation of these structures. We propose a regional kinematic model in which the present‐day kinematics of each main fault depend strongly on its orientation with respect to the regional stress tensor. Computed seismic hazard defines a map pattern for the peak ground acceleration elongated to the main seismotectonic fault zones. Regions around the southwest Sierra de Neiba, the western Enriquillo basin and the northwest Sierra de Bahoruco, where peak ground acceleration exceed 500 cm/s², have a high seismic hazard.

Cape Welchness is an uncovered ice area on Dundee Island (north-east of the Antarctic Peninsula), mostly covered by Holocene-age glacial-glaciomarine deposits of up to 70 m in depth. In some areas, rocks from the Trinity Group and the Gustav Group outcrop. Syngenetic cryounits with an active layer development of 0.8 m and ice content ranging from 6% to 15%, increasing with depth, have been detected. Epigenetic units develop an active layer of up to 1.25 m (6–16% ice content), with similar depth values. Along the coastal zone, cryopeg reaches nearly 8 m in depth, alternating between ice, fresh water and saline water. The low and high plains exhibit extensive areas of open talik. In the low plain, a suprapermafrost summer aquifer with a thickness of 1.25–1.50 m develops. Glacial-fed creeks discharge 98% of the water input, while snow-fed creeks contribute only 0.04 Hm ³ /month. The ponds are divided into those fed by glaciers (linked to open talik) and those fed by precipitation (linked to closed talik). Creeks have an average salinity of 198 mg/l, lakes 190 mg/l and groundwater 223 mg/l. This study focuses on the area of the new Petrel Base, designed to enhance Argentine logistics.

This study investigates the selection of volcanic rocks from the El Metate and Urutzen volcanoes for the traditional crafting of metates, focusing on the physical and mechanical properties that determine their suitability. Through comprehensive analyses, including slake durability tests and assessments of porosity, permeability, and uniaxial compressive strength, we identify specific rock groups that exhibit optimal characteristics for metate fabrication. Our findings reveal that the quarries currently exploited for metate production (samples 11-13) use rocks with petrophysical properties like those of the ancient, abandoned quarries of Taleminuchi (El Metate lava flow 7, samples 9-10). Despite all rocks under study falling within the same porosity range and featuring ink-bottle type pores, significant differences in pore distribution have been found to govern essential properties such as permeability and compressive strength, which are critical for the manufacture of metates. This research emphasizes the importance of selecting rocks with a balanced set of physical properties to ensure the durability and efficiency of metates. The study not only enhances our understanding of traditional tool crafting but also establishes a practical framework for selecting ideal volcanic rocks for metate manufacturing, echoing the deep-rooted knowledge inherited from ancestral craftsmanship practices. Through the lens of modern scientific analysis, we bridge the gap between traditional wisdom and contemporary material selection, underscoring the enduring relevance of these ancient practices in the today society.

This paper deals with the detailed analyses of magnetic fabrics, accompanied by stable isotopic composition and microscopic observations, in centimetric and metric scale authigenic carbonate concretions embedded in the Eocene flysch deposits of the Southwestern Pyrenees. Sampling was focused in the carbonate concretions, (in both metric and centimetric scale), in the marls lateral and nearby to the concretions and in the marls located several meters away from the concretions. The inverse magnetic fabrics (k max axes cluster perpendicular to bedding plane) detected in these concretions constitute a fast methodology to uncover the presence of iron-carbonate minerals and the paleoenvironmental significance of their authigenic origin. The subfabric analyses indicate that magnetite is present in all four types of samples with normal magnetic fabric (k min axes perpendicular to bedding). Paramagnetic fabric (low temperature anisotropy of magnetic susceptibility when magnetic susceptibility increases ~ 3.8 times the one at room temperature) overlaps the room temperature magnetic fabric. The microscope observations reveal that iron-enriched dolomite is the main carrier of the inverse fabric in the carbonate concretions at room temperature. The stable isotopic composition indicates minor differences between the Eocene marls and the carbonate concretions and, when compared with previous data, they suggest a marine pore water origin due to bacterial activity during burial. We relate the early diagenetic growth of the concretions to an enhancement in bacterial activity driven by the increased terrigenous and terrestrial organic matter supply during the Middle Eocene Climate Optimum (MECO), a period of global warming.

Pseudoscorpions, one of the earliest terrestrial lineages dating back to the Middle Devonian period ( c . 385 Ma), have a limited fossil record mainly as inclusions in amber. The available fossils are mostly from the Cenozoic era, making it challenging to comprehensively understand their evolutionary history and diversification over time. Here, we report the first fossils of the order from Spanish Lower Cretaceous (upper Albian) ambers. Two new genera and species in the family Garypinidae are described from Álava amber (Peñacerrada II outcrop, Álava Province): Cretogarypinus zaragozai gen. et sp. nov. and Ithioreolpium alavensis gen. et sp. nov. Remarkably, the holotype of Cretogarypinus zaragozai shows preservation of internal soft tissues. The variability observed in the arolium of both fossil garypinids serves as compelling evidence for the hypothesis of diphyletism within the clade, which was already well established before the Early Cretaceous. Additionally, an incomplete specimen consisting of an isolated palp ascribed to the family Pseudogarypidae (extant genus Pseudogarypus Ellingsen), is described from San Just amber (Teruel Province). These findings represent the earliest occurrences of the families Garypinidae (superfamily Garypinoidea) and Pseudogarypidae (superfamily Feaelloidea) in the fossil record. They not only contribute to our understanding of a diverse pseudoscorpion fauna in Spanish amber but also offer valuable insights into divergence time estimations for pseudoscorpion families and potentially for biogeographic studies.

Distributed acoustic sensing (DAS) is an innovative technology with great potential for acquiring seismic data sets in urban areas. In this work, we check the suitability of a DAS data set acquired in Granada (Spain) for retrieving subsurface reflectivity from ambient noise. The fiber‐optic is a pre‐existing underground telecommunication cable that crosses the city from Northwest to Southeast. We use a 10 hr recording of strain rate from a 2020 experiment to obtain seismic reflections using the autocorrelation method. We compare the DAS results with reflections obtained from seismic ambient noise recorded in nine seismometers deployed close to the fiber‐cable for 7 days in November 2022. The novel approach proposed in this study for the identification of the reflections is to use autocorrelations after bandpass filtering for specific central frequencies and to check the stability of the signals over a broad frequency band. Microtremor Horizontal to Vertical Spectral Ratio (MHVSR) measurements at a total of 14 stations, five of them outside the city, help to constrain the reflection interpretation. These include one station at the borehole that reaches the basement in the Granada Basin crossing all the Cenozoic units. We use the legacy sonic log to obtain a relationship between frequencies of MHVSR peaks and depth. Autocorrelation and MHVSR methods give consistent results delineating bedrock depth deeper than 1,000 m in Granada. These results confirm that DAS can provide valuable subsurface information in urban areas.

The Spanish historical earthquake catalog reveals a significant number of destructive earthquakes (≥ ${\ge}$Mw 6.0) that have occurred along the Eastern Betic Shear Zone (EBSZ), a major active fault system at the Eastern Betic Cordillera. However, during the last century, seismic activity in this region has been characterized by the absence of large‐magnitude events, complicating yet underlining the importance of understanding active fault interaction in the EBSZ. In this work, we focus on the northeastern half of the EBSZ and apply a similar method to Yazdi et al. (2023, https://doi.org/10.1029/2023tc007917). We model a series of consecutive earthquakes (≥ ${\ge}$ IEMS ${\mathrm{I}}_{\mathsf{EMS}}$VII; > ${ >}$Mw 5.0) between the 17th ${17}^{\text{th}}$ and 19th ${19}^{\text{th}}$ centuries occurring along the Alhama de Murcia, Carrascoy and Bajo Segura faults, and assess their coseismic impact as well as explore the evolution of Coulomb stress changes due to the postseismic viscoelastic relaxation on the surrounding faults. Our results support a stress‐triggering connection between subsequent events and shed light on identifying the responsible faults for some. Our findings indicate that 1673 Mw 6.0 Orihuela and 1674 Mw 6.2 Lorca earthquakes, seemingly unrelated, could have both contributed to the forthcoming > ${ >}$Mw 5.0 earthquake clustering along the Carrascoy fault. We show that attributing the 1829 Mw 6.6 Torrevieja earthquake to the Bajo Segura fault better describes the occurrence of earthquake sequences between the mid‐19th ${19}^{\text{th}}$ and early 20th ${20}^{\text{th}}$ centuries. Finally, we propose the Alhama de Murcia and the Carrascoy faults as responsible initiators for the early 20th ${20}^{\text{th}}$ ‐century earthquake sequence in the Segura Medio valley. These findings provide valuable insights for seismic hazard modeling in the region.

We present the characterization of the sources of vibration in the open-pit Riotinto mine (southern Spain), based on the data recorded by a dense seismic network of 30 stations located along a 1-km long segment of a tailings dam. We describe the most common transient signals detected, including local and distant earthquakes, blasting and vehicles. The time variations in the amplitude of the 10–40 Hz frequency band are then used to define three phases of activity during the recording period. The phase with the highest seismic amplitudes is observed during a time interval of five weeks, coinciding with the civil works carried out for the regrowth of the dam, necessary to correctly capture the continuously increasing amount of tailings. In the last three months of operation of our network, the seismic noise is dominated by the deposition of tailings into the pond, enabling the use of seismic data to monitor into detail the evolution of the deposition process.

The mountainous karst massif in the Sierra de las Nieves (southern Spain) and the adjacent large outcrops of subcontinental mantle peridotites provide this area with a distinctive geodiversity that has contributed to the recent declaration of the zone as the new Sierra de las Nieves National Park. In addition, the Alpine tectonic interaction between the peridotites and the carbonate formations originated an important fault, the Turquillas fault, that has conditioned the existence of two tectonic blocks in the karst massif, one uplifted with respect to the other. Also, in the uplifted block, the fault has contributed to the generation of Z-supercaves, which are defined in this paper as caves with more than 1000 m of development in the vertical or Z dimension. Sima GESM with 1100 m of depth is the only Z-supercave known in the giant geologic structure of the Gibraltar Arc, which speaks on the infrequent and exceptionality of the generation of these underground geomorphological systems. The task of this paper is to present a detailed study of the Turquillas fault and its influence in the surface and underground geomorphology and hydrogeology and in particular its influence and implications in the development of the deep karst system defined as the Z-supercave. It is hoped that this study will contribute to identify the necessary conditions for the development of these extraordinary geomorphic systems which are of great international relevance in the major mountain ranges of the world with high relief karst and deep karst systems.

This research studies the characteristics of snow-covered area (SCA) from two vastly different sensors: optical (Moderate-Resolution Imaging Spectroradiometer, or MODIS, equipped on board the Terra satellite) and radar (Synthetic Aperture Radar (SAR) on-board Sentinel-1 satellites). The focus are the five mountain ranges of the Iberian Peninsula (Cantabrian System, Central System, Iberian Range, Pyrenees, and Sierra Nevada). The MODIS product was selected to identify SCA dynamics in these ranges using the Probability of Snow Cover Presence Index (PSCPI). In addition, we evaluate the potential advantage of the use of SAR remote sensing to complete optical SCA under cloudy conditions. For this purpose, we utilize the Copernicus High-Resolution Snow and Ice SAR Wet Snow (HRS&I SWS) product. The Pyrenees and the Sierra Nevada showed longer-lasting SCA duration and a higher PSCPI throughout the average year. Moreover, we demonstrate that the latitude gradient has a significant influence on the snowline elevation in the Iberian mountains (R² ≥ 0.84). In the Iberian mountains, a general negative SCA trend is observed due to the recent climate change impacts, with a particularly pronounced decline in the winter months (December and January). Finally, in the Pyrenees, we found that wet snow detection has high potential for the spatial gap-filling of MODIS SCA in spring, contributing above 27% to the total SCA. Notably, the additional SCA provided in winter is also significant. Based on the results obtained in the Pyrenees, we can conclude that implementing techniques that combine SAR and optical satellite sensors for SCA detection may provide valuable additional SCA data for the other Iberian mountains, in which the radar product is not available.

New Floian and early middle Darriwilian brachiopod assemblages of the San José Formation of the Eastern Cordillera of Peru are presented. A new genus and species, Apurimella santiagoi , and two new species, Phragmorthis henrylunae and Nocturnellia ashaninka , are described. The assemblages also contain additional characteristic taxa demonstrating links with other proto‐Andean localities (Peruvian Altiplano, Argentinian Eastern Cordillera, Famatina) as well as with some localities of Baltica (Estonia, Ingria, Norway), Ganderia (Anglesey, Tramore, Indian Bay, Summerford, Miramichi), peri‐Laurentia (Mayo, Svalbard) and Laurentia (Klamath Mountains). Those shared genera indicate dynamic faunal exchanges between the Peruvian Eastern Cordillera and these terranes during the Early–Middle Ordovician transition, suggesting active brachiopod dispersal mechanisms across the Rheic and Iapetus oceans. These connections seem to have still been active by the middle Darriwilian, as suggested by the presence of Phragmorthis in the Darriwilian assemblages of Cuyania and Laurentia. Similarly, the new Peruvian Nocturnellia species is of particular interest, given that this genus is likely to have originated in South China during the Floian, but extended its distribution to Avalonia and to high‐latitude peri‐Gondwana by the Dapingian. It thrived there until the middle Darriwilian, but by that time had also reached the proto‐Andean margin either via Avalonia across the Rheic Ocean or along the Gondwanan coast from high‐latitude settings. All of these occurrences improve our knowledge of Early–Middle Ordovician brachiopod faunas of the northern Central Andean Basin and their relationships with contemporaneous faunas worldwide.

Thermogenesis in plants is the ability to raise their temperature above that of the surrounding air through metabolic processes, and is especially detected in reproductive organs. Warming benefits plants by facilitating the transmission of odours and compounds that attract insects. As a result, these plants increase their odds of being pollinated by the attracted insect. Modern thermogenesis has been reported in extant cycads and a small number of angiosperm lineages. Although thermogenesis is not directly preserved in the fossil record, it can be inferred by examining extant thermogenic plant lineages and comparing their features with those of the fossil record. We suggest that thermogenesis has probably occurred in seed plants for at least the past 200 million years, long before the origin of angiosperms. Thermogenesis in plants is an important factor that facilitated entomophilous pollination by enhancing the attraction of insects, complementary to other factors, thereby participating in the success of the two groups of organisms and providing many facets of past and recent reproductive biology for future exploration.

The identification of extreme wave events' deposits is of the main importance in the contexts of global warming and coastal geohazards. Specifically, improving the knowledge of this phenomenon is extremely relevant for high populated volcanic oceanic islands. In this paper, we analyse two extreme wave event deposits located on a coastal platform formed by lavas from the 1730-1736 Timanfaya eruption in Lanzarote Island (Spain). The first one consists of a boulder ridge parallel to the coast of approximately 750 m in length and 7 m asl in elevation. These are accumulations of non-cemented large boulders and sands that extend about 150 m inland from the intertidal zone. The boulders are of basaltic composition, heterometric, sub-rounded to angular, and they reach sizes up to 3 m of major axis. They are imbricated both inland and seaward, indicating a strong inundation and backwash. The second deposit is a small outcrop of boulders of equal composition and sizes up to 1 m of major axis, reaching an elevation up to 6 m asl, and has been correlated with the former deposit.

The investigation of triggers causing the onset and intensification of Northern Hemisphere Glaciation (NHG) during the late Pliocene is essential for understanding the global climate system, with important implications for projecting future climate changes. Despite their critical roles in the global climate system, influences of land-ocean interactions on high-latitude ice sheets remain largely unexplored. Here, we present a high-resolution Asian dust record from Ocean Drilling Program Site 1208 in the North Pacific, which lies along the main route of the westerlies. Our data indicate that atmosphere-land-ocean interactions affected aeolian dust emissions through modulating moisture and vegetation in dust source regions, highlighting a critical role of terrestrial systems in initiating the NHG as early as 3.6 Myr ago. Combined with additional multi-proxy and model results, we further show that westerly wind strength was enhanced, mainly at low-to-middle tropospheric levels, during major glacial events at about 3.3 and 2.7 Myr ago. We suggest that coupled responses of Earth’s surface dynamics and atmospheric circulation in the Plio-Pleistocene likely involved feedbacks related to changes in paleogeography, ocean circulation, and global climate.

A magnetic fabric study was carried out in Permo-Triassic continental sedimentary red beds from the Cadí Basin (Eastern Pyrenees). These rocks were deposited on the top of a volcanic sequence when the regional tectonic regime changed from transtension to extension. Standard paleomagnetic cores (cylinders), cubes and irregular fragments were obtained for this study in 25 sites distributed throughout the basin. The “fragment methodology”, using oriented irregular fragments in claystones, is demonstrated to be successful and replicable. The aims of this study are (i) to interpret the magnetic fabrics in red beds according to sedimentary or tectonic models; (ii) to establish the relationship between the magnetic fabrics in the sedimentary red beds and the magnetic fabrics previously obtained in the underlying volcanic series, and (iii) to compare magnetic fabrics in continental sediments with other basins of the same age to interpret the tectonic scenario in the Iberian plate during Permian and Triassic times. The results obtained reveal a primary magnetic fabric that recorded a syn-sedimentary stretching in two nearly perpendicular directions, WNW-ESE and N-S, linked to basin development. Other sedimentary and tectonic factors, such as paleocurrents and deformation derived from the Alpine compression did not have a significant influence on the development of magnetic fabrics. The geodynamic scenario of the Iberian plate during Late Permian to Triassic times can be explained according to regional trajectories of extensional stress due to the activity of the North-Pyrenean fault zone.

This paper introduces and evaluates the effectiveness of borehole ovalization analysis, a methodology designed to predict the natural stress field by examining deformations in vertical boreholes. The reliability of this approach has undergone rigorous testing across multiple boreholes within soft argillaceous formations, revealing several key observations. First, the results obtained demonstrate a notable correlation with hydrofracturing measurements, enhancing the overall credibility of the methodology. Second, the ratio of horizontal to vertical stress (σH/σh) is found to be contingent on the selected value of the breakout angle (θ), introducing a nuanced variable into the predictive framework. This insight emphasizes the importance of considering breakout angle variability in stress field predictions. Finally, the cohesion of the rock mass emerges as a pivotal factor that significantly influences the estimation of the horizontal stress magnitude (σH). This finding underscores the necessity of accounting for rock mass cohesion when applying borehole ovalization analysis for stress field predictions. Additionally, this paper conducts a meticulous comparative analysis by contrasting its results with findings from three hydrofracturing profiles conducted in distinct boreholes. Through this comparative approach, a more comprehensive understanding of the methodology's strengths and limitations is unveiled, contributing to the ongoing discourse on accurate stress field predictions in subsurface geomechanics.

In carbonate coastlines, karst studies have traditionally focused on reconstructing Quaternary coastal uplift and sea level oscillations. However, their potential for investigating coastal subsidence remains unexplored in regions with limited sedimen-tary records and scientific monitoring. In line with this, our study delved into the utility of karst research for deciphering the Quaternary evolution of the Granada coast in southern Spain-a shoreline marked by a conspicuous scarcity of records and information regarding recent tectonic movements. The current labelling data and the absence of evidence for uplift led to the hypothesis that the Granada coast may be susceptible to subsidence, though this conjecture remained unconfirmed. While submerged marine terraces were clearly identified, they were previously interpreted as consequences of sea-level oscillations. Our multidisciplinary approach integrated karst vadose features, biostratigraphy, and the dating of 22 speleothems to address the potential uplifting or subsiding dynamics of the Granada coast. The findings indicated that the Granada coast experienced emersion between 3.5/2.4 Ma and 650 ka ago. Notably, this uplift predated similar occurrences in neighbouring coastal regions to the W and E, which occurred within the last 200-180 ka. These disparities in timing cannot be solely attributed to sea-level fluctuations, suggesting the involvement of the tectonic activity during the Quaternary. The tectonic likely led to the emergence of the Granada coast and its karstification, followed by subsidence. Furthermore , we identified the extensional faults that caused the coastal subsidence, previously documented in studies conducted in nearby regions. However, until now, their specific impact on the Granada coast had not been comprehensively stated. In summary, our research introduces a novel application of classical karst investigations in the understanding coastal subsidence and the extensional active tectonic. By comparing vadose cave ages with established chronologies in adjacent coastal areas, this approach sheds light on the complex tectonic evolution of coastal regions.

The Iberian Peninsula is a key region for unraveling human settlement histories of Eurasia during the period spanning the decline of Neandertals and the emergence of anatomically modern humans (AMH). There is no evidence of human occupation in central Iberia after the disappearance of Neandertals ~42,000 years ago until approximately 26,000 years ago, rendering the region “nobody’s land” during the Aurignacian period. The Abrigo de la Malia provides irrefutable evidence of human settlements dating back to 36,200 to 31,760 calibrated years before the present (cal B.P.) This site also records additional levels of occupation around 32,420 to 26,260 cal B.P., suggesting repeated settlement of this territory. Our multiproxy examination identifies a change in climate trending toward colder and more arid conditions. However, this climatic deterioration does not appear to have affected AMH subsistence strategies or their capacity to inhabit this region. These findings reveal the ability of AMH groups to colonize regions hitherto considered uninhabitable, reopening the debate on early Upper Paleolithic population dynamics of southwestern Europe.