This paper presents the characterisation of Pedra Cabaleira, a historically significant vernacular building stone from the Courel Mountains UNESCO Global Geopark (UGGp), Spain. Pedra Cabaleira presents a noticeable lithological and aesthetic contrast with the predominant lithologies in this UGGp in northwestern Spain. This stone has been historically used in religious and military buildings associated with the Order of Saint John of Jerusalem. This research aims to characterize the mineralogical, petrographic, and petrophysical properties of the stone to contribute to its valorisation as a significant vernacular building material in the context of the Courel Mountains UGGp. Field surveys identified three main lithotypes: a conglomerate (PC-1), a breccia (PC-2), and sandstone beds with intercalated clay-rich layers (PC-3). Analytical techniques included X-ray diffraction, optical petrography, scanning electron microscopy (SEM), mercury intrusion porosimetry, hydric properties, mechanical strength, and salt weathering tests, which revealed significant variations among these lithotypes. The results indicate that the conglomerate and the sandstone beds show the most favourable parameters for construction, with lower microporosity, higher strength, and better durability, while the clay-rich layers within the sandstone show weaker mechanical performance and higher susceptibility to weathering. The study highlights the interplay between geological heritage and built heritage, demonstrating the importance of locally sourced building materials in sustaining historical structures and promoting geotourism in the Courel Mountains UGGp and the potential of this stone to become a Heritage Stone.
This manuscript responds to the comment of García-Vázquez on our recent paper, especially regarding the decline in body mass of the Cantabrian brown bear during the Holocene. The observations of García-Vázquez are reviewed point by point, addressing methodological aspects, that is, the use of the Viranta equation, the mass estimation of the specimen SH5-97-T29-35 and radiocarbon dating, as well as her ethical questions about the use of previously published data. Re-evaluations show that (1) the errors noted do not significantly affect the original conclusions of Fidalgo et al. and, (2) the use of third-party data was carried out in compliance with both legal regulations and open science principles. The new analyses maintain the pattern of declining bear body size after 7000–4500 years ago, without any conclusive evidence to link this phenomenon to the introduction of firearms in historical times. Neither this nor any alternative hypotheses are discarded, though. The importance of integrative meta-analyses in data-poor contexts is highlighted, and their legitimacy in the framework of collaborative and open science is defended, provided that sources of data are cited.
Tearing at the edges of subducted slabs permits the migration of narrow orogenic arcs. Dynamic models predict that the active segment of subvertical tears migrates in the sense opposite subduction modifying the topography and tectonic regime along its path. However, the effects of slab tearing on surface deformation and landscape evolution, remains virtually unexplored. Here we show the landscape response to slab tearing, including drainage development and reorganization in the Betics, with analogies to the southern Caribbean arc. After approximately 400 km of slab tearing since 10 Ma the Betics show a transient topography with positive residual values over regions stripped from their subcontinental lithospheric mantle and negative anomalies outboard of the tear. The landscape evolves through crustal shortening and flexural uplift in the foreland of the active tearing segment producing land emergence and drainage development, with fluvial diversion around uplifting structures. Slab pull and orogen transverse extension inboard the active-tearing segment foster basin development followed by emergence and drainage reorganization by fluvial incision and capture. Mantle upwelling, flexural rebound and further extension affects teared regions, driving positive residual topography amplified in the footwall of extensional domes. Mantle flow around the slab drives uplift hundreds of km away from the slab edges.
Sierra Nevada (Spain) is a mountain range thoroughly studied from a geological-geomorphological perspective due to its anomalously high local relief and the ongoing debate about its origin and geological structure. From the standpoint of slope dynamics, several studies have carried out, but it was not until last year that deep-seated gravitational slope deformations (DSGSDs) were described in this mountain range. Their recognition was facilitated by synergizing geomorphological assessments with data from two well-established techniques: Differential Synthetic Aperture Radar Interferometry (DInSAR) and Landscape Analysis using the normalized channel steepness index (ksn), a geomorphic index commonly used to outline landscape perturbations in tectonically-active mountain ranges. Systematic evaluation of ksn anomalies along rivers illuminated key DSGSD sectors that were studied in detail. This approach resulted in a novel inventory of 17 DSGSDs in the southwestern sector of the range, providing an initial figure of the widespread occurrence of large DSGSDs in Sierra Nevada. In a second phase, we conducted a detailed study of two slopes affected by DSGSDs in the Poqueira catchment, which provided new insights into Sierra Nevada’s DSGSDs. There, we characterized slope deformations by detailed morpho-structural mapping supported by fieldwork and interpretation of optical and LiDAR-derived imagery, resulting in morpho-structural maps and interpretative cross-sections. Collected data allowed setting up a series of 2DFEM multistage elasto-plastic models, parametrized by laboratory data and field rock mass assessment and validated with field evidence and DInSAR data. The studied cases are characterized by multiple nested landslides that become increasingly shallow, deformed, and active towards the valley. The geometry and kinematics of DSGSDs seem to be partially influenced by the orientation of foliation, indicating rock mass anisotropy, with dip slopes mainly exhibiting translational movements and anti-dip slopes demonstrating prevalence of rotational motions. We tested our initial hypothesis that these slope instabilities in the region were initiated because the development of fluvial incision, favored by the active tectonics and uplifting of the range. Preliminary findings of our analyses suggest that fluvial incision was a key trigger of DSGSDs in Sierra Nevada, but not the only one. Model simulations emphasize that, in addition to fluvial incision, rock mass anisotropy and long-term seismic activity played a crucial role in the onset and accumulation of large deformations of high slopes across the region, favoring the occurrence of significant mass movements. Considering this, rough estimates regarding the timing of incision and seismic activity suggest that initial DSGSD onset took place over a timescale of 104-105 years.
In this paper we present a detailed Quaternary evolution model of the Seine valley (France). The lower Seine valley contains very specific preserved morphological features (semi-entrenched meander cut-offs) and develops in a karstified chalky plateau (Normandy Chalk). Regional geomorphological features make it possible to combine geomorphological observations, petrological investigations as well as cross-dating analysis of fluvial sediments and karstic archives. We have reviewed former chronological data through a combination of different dating methods including ESR, U-series as well as palaeomagnetism. We also present here new dating results from both cave deposits and fluvial terrace sediments through the combined use of quartz ESR dating method and palaeomagnetism. The obtained results show river evolution extending over the entire Quaternary period. The gentle incision rate and its variations highlight the influence of climate and eustatic processes, hence a partially climate-induced uplift. Results also provide new chronological markers on the fluvial deposits for future archaeological research.
During the Holocene, Iberian ecosystems have changed dramatically in response to different biotic and abiotic drivers. Typically, the impact of these changes on ecosystems is assessed in terms of the variation of diversity in the communities that compose them. However, there are a wide variety of population-specific parameters of vital importance for the maintenance of the structure and health of these ecosystems. In this study, we have focused on the drastic decrease in body size (body mass) during the Holocene in three large mammal species in the Cantabrian Mountains. Namely, the brown bear ( Ursus arctos ), the chamois ( Rupicapra pyrenaica parva ) and the wild horse ( Equus ferus ferus ). The research combines the analysis of new findings with an exhaustive compilation of previously published data to assess changes in the body size of these species at different geographical (European, Iberian and Cantabrian Regions) and chronological scales (during the Quaternary – i.e. Pleistocene and Holocene). We aim at assessing the impact of anthropogenic and climatic factors on macromammal populations in the Iberian Peninsula, using new data obtained from the new archaeo-palaeontological site of Cueva de Llamazares (León, Spain). The results show that, although the final decline in body size during the Holocene occurred in the three species, each of them seems to have been driven by different factors. Bear populations seem more influenced by their mobility versus the potential impact of changing in human hunting dynamics, while changes in vegetation cover would have been most important for chamois, and the gradual effect of climate changes for horse populations. Research covering broad chronological ranges in the past helps understanding the present and future dynamics of these species, thus contributing to their conservation and management.
Landslide research has benefited greatly from advances in remote sensing techniques. However, the recent increase in available data on land surface movement provided by InSAR techniques can lead to identifying only those areas that were active during data acquisition as hazardous, overlooking other potentially unsafe areas or neglecting landslide-specific geological settings in hazard assessments. Here, we present a case study that serves as a reminder for landslide researchers to carefully consider the geology and geomorphology of study areas where complex active movements are detected using InSAR technology. In an area extensively studied using InSAR and UAV-related techniques, we provide new insights by applying classical approaches. The area is the coastal stretch of La Herradura, and its importance lies in the fact that it has served as an illustrative example in the Product User Manual of the European Ground Motion Service, a platform that provides ground motion data on a European scale. Our approach is to revisit the area and carry out qualitative geological and geomorphological assessments supported by UAV surveys and GIS spatial analysis on a broader scale than previously published investigations. Our classical approach has yielded the following new observations, crucial for risk assessment and land management: active landslides identified by InSAR techniques since 2015 are bodies nested within large mass movements that affect entire slopes. A variety of processes contribute to slope dynamics, such as large slumps, marble rock spreading and block sliding, and surface rock falls and topples. The revised delineation of the landslide bodies reveals an area almost five times larger than previously mapped. These new findings in a well-known area highlight (1) the importance of updating and downscaling previous maps and (2) the ongoing importance of classical fieldwork and desk studies as basic complements to modern InSAR analyses.
In this work we presented the landspy Python library and its QGIS user interface. This Python library allows to perform landscape analysis from Digital Elevation Models (DEMs); extraction and analysis of the drainage network, calculation of some of the most used indices and metrics in tectonic geomorphology and a real-time knickpoint analysis. In its first release allows the computation of drainage networks and channels gradients (chi metric, Hack indexes, knickpoint analysis), river profile analysis, and hypsometry. The base Python library contains classes to read and manipulate raster and grids. To compute the drainage network, the flow is modelled as a directed acyclic graph (DAG), a novel approach that has demonstrated to be more efficient that the traditional methods based on the D8 algorithm. Results can be exported as raster / vector formats or viewing directly in QGIS as temporary layers. The QGIS interface allow using the library without programming knowledge through interactive toolboxes and windows. The user can analyze different kind of channel profiles (longitudinal profile, chi-elevation, logarithmic area-slope, and ksn profile) directly through an interactive window that synchronizes with QGIS current map. This allow a real-time knickpoint evaluation and analysis without needing to use different programs, thus constituting a power tool to the spatial analysis of drainage network anomalies. We will show an example of use in the Rif Cordillera (northern Morrocco), where tectonic play an important role in the configuration and evolution of drainage networks.
Geographic Information Systems (GISs) cover a wide range of Earth and environmental science disciplines that have become essential for spatial data management, easing the digital transformation needs of our society. Despite the usefulness of GISs, they remain underutilised in academia, and many students do not understand the possibilities that these tools offer. To familiarise university students with the potential of GISs, we designed 11 short clips (less than 5 min long) recorded by Earth scientists with diverse backgrounds who shared their work experience with GISs to solve real-world problems. Through these short clips, we emphasised not only the multidisciplinary uses of GISs but also provided professional references for undergraduate students, including societal aspects such as gender equality, national and international mobility, private-to-public-sector transitioning, and different family circumstances. As a result, the students expressed their interest in the applications of GISs, many of which were completely new to them, highlighting the potential of GISs in terms of entrepreneurship and their usefulness in mitigating global change. Thus, we were able to transfer knowledge from research to university education and foster spatial data management skills in Earth science.
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 sedimentary 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. Speleothems and fossils reveal coast emersion between 3.5/2.4 and 0.65 Ma. Granada coast is older than nearby shores uplifted during the last 200 ka. Chronological differences suggest local subsidence impacting the Granada coast. Quaternary extensional faults would cause the coastal subsidence. image
An updated and complete landslide inventory is the starting point for an appropriate hazard assessment. This paper presents an improvement for landslide mapping by integrating data from two well-consolidated techniques: Differential Synthetic Aperture Radar (DInSAR) and Landscape Analysis through the normalised channel steepness index ( k sn ). The southwestern sector of the Sierra Nevada mountain range (Southern Spain) was selected as the case study. We first propose the double normalised steepness ( k snn ) index, derived from the k sn index, to remove the active tectonics signal. The obtained k snn anomalies (or knickzones) along rivers and the unstable ground areas from the DInSAR analysis rapidly highlighted the slopes of interest. Thus, we provided a new inventory of 28 landslides that implies an increase in the area affected by landslides compared with the previous mapping: 33.5% in the present study vs. 14.5% in the Spanish Land Movements Database. The two main typologies of identified landslides are Deep-Seated Gravitational Slope Deformations (DGSDs) and rockslides, with the prevalence of large DGSDs in Sierra Nevada being first revealed in this work. We also demonstrate that the combination of DInSAR and Landscape Analysis could overcome the limitations of each method for landslide detection. They also supported us in dealing with difficulties in recognising this type of landslides due to their poorly defined boundaries, a homogeneous lithology and the imprint of glacial and periglacial processes. Finally, a preliminary hazard perspective of these landslides was outlined.
Sediment-filled caves, conduits and voids are common in many karst regions. These voids and the sediment they contain are important palaeoclimatic and palaeoenvironmental archives, but often have an adverse impact on en-gineering projects, mineral extraction and hydrogeology. Most studies into fluvial sedimentation in karst aquifers have focussed on more traditional karst areas. However, the nature and extent of fluvial sedimentation within caves and conduits in the important Upper Cretaceous Chalk Group aquifer (NW and Central Europe), and their impacts are less well known. This is principally due to a lack of accessible Chalk caves with exposed 3D sed-iment archives for study. Fortunately, the discovery of the World's longest Chalk cave system by underground quarrying at Caumont in the Seine valley near Rouen, northern France, has exposed numerous sediment sections along 2.4 km of passage. Detailed analysis of the stratigraphy, mineralogy, sedimentology, provenance and the chronology of the exposed sediments including the novel use of Gamma-ray spectrometry, reveals complex stra-tigraphy and lateral facies distribution along a karst conduit. The depositional model comprises five allostratigraphical units since the mid-Chibanian, separated by periods of erosion. The units are derived from hyper-concentrated and sediment-laden flows, and include thalweg, channel, slackwater, backswamp speleothem facies and debris flow deposits that are interbedded. Speleothems precipitated during MIS 7, 6, 5e and 1. During MIS 7-6, detrital sediments filled almost all Chalk conduits, similar to other caves in the European Atlantic Margin, coevally with the Penultima (Saalian) Glacial Cycle and a maximum of the Earth ec-centricity. Detrital sediments are derived from the erosion of local Chalk bedrocks as well as metamorphic and igneous rocks of remote areas, such as Morvan massif and Massif Central. The depositional model is consistent with the conception of the Chalk as a karst aquifer. Significant sediment aggradation caused upwards dissolution (paragenesis), conduit occlusion and subsequent genesis of new conduits by flow diversion, potentially altering the functioning of the chalk aquifer and the interpretation of Chalk hydrogeology (e.g., dye-tracing tests).& COPY; 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).
The Punta Lucero III cave is a natural trap where abundant vertebrate remains were accumulated during the Meghalayan (Late Holocene). To better understand the paleoenvironmental conditions in which this record was accumulated, the micromammal assemblage, comprising a minimum number of 1396 individuals belonging to 19 taxa, was studied using the Mutual Ecogeographic Range and the Habitat Weighting Method. Throughout similar to 2600 years, the micromammal community's quick turnover reflected a shift from patchy forests and humid meadows to open, shrubbier grasslands. The Late Holocene Thermal Maximum's humid and mild climatic con-ditions underwent a cooling and aridification phase, coeval with the Iron Age Cold Epoch. These concluded in a slight temperature rising, coeval with the Roman Warm Period. Macromammals experienced a shift from wild populations to domestic herds. Therefore, this work discusses a broader context for this mammalian turnover from a human cultural perspective.
El Olivo Cave (Pruvia de Arriba, Llanera, Asturias, Spain) is a small karst cave located in the Aboño River basin and formed in the Cretaceous limestone of the Mesozoic cover of the Cantabrian Mountains (north of the Iberian Peninsula). It contains an important upper Pleistocene sedimentary, archaeological, and paleontological record, with abundant technological evidence and faunal remains. The archaeological record shows a first occupation that could correspond to the Middle Paleolithic and a second occupation in the Middle Magdalenian. The stratigraphic sequence inside and outside the cave was studied with geoarchaeological methodology. In this paper, the lithostratigraphic sequence is analyzed, and the data from the granulometric, mineralogical, edaphological, and radiometric analyses are presented. The results of these analyses enable an accurate interpretation of both the lithostratigraphy of the deposit and the processes responsible for its formation and subsequent evolution. The available numerical dates allow us to locate the first sedimentation episode in the cave in OIS 7a, in the Middle Pleistocene, the base of the outer fluvial sedimentation in the cold OIS 3a stage of the Upper Pleistocene and the Magdalenian occupation in the Last Glacial Maximum (OIS 2) at the end of the Late Pleistocene.
We present the first results of the MORPHOMED project, in order to deepen the chronology, uplifting rate, and tectonic forcing of different sectors of the Betic Cordillera since the Pliocene. Our initial morphotectonic analysis in the Western Betics, at the active termination of the Betic dextral STEP fault, highlights the location of active orogen-parallel normal faults cutting Pliocene marine sediments, uplifted above 600 masl, and Quaternary alluvial fans. The morphometric study we carried out includes normalized river steepness (ksn) and other geomorphic indices calculated in GIS using our own code designed in python. The fieldwork developed comprises the identification of uplifted Pliocene marine deposits, faulted alluvial fans and remnants of uplifted planation surfaces. The alluvial fans are related to travertine deposits older than 350 ka, which would be associated with hot springs. Geochronological studies involve previous and new U-Th dating on travertines and speleothems from caves in the high areas. The preliminary morphometric analyses reveal the occurrence of knickpoints that coincide with normal faults affecting marine Pliocene deposits and alluvial fans. These fans show vertical displacement of more than 20 m and their age remains unknown albeit the associated travertines are being dated. These results support previous works concerning of active tectonics in the Central and Western Betic Cordillera and they will serve to define new active faults, driving tectonic uplift of the Western Betics, which are the key to understand the landscape evolution forced probably by deep mantle rooted tectonics like slab tearing and edge delamination.
The provenance of medieval building stones links historic constructions with their quarrying areas, thereby revealing medieval trade routes and the spatial organization of past societies. In northern France, the Duchy of Normandy played a significant role in the medieval history of Europe, situated at the centre of the disputes between the English and French kingdoms. However, the historical documentation from this period is scarce, particularly in terms of the quarrying industry. Our study aims to define the quarrying areas and their diffusion zones and map the territorial organization of Eastern Normandy during the 10th-14th centuries. A multidisciplinary procedure using archaeological, geological and geochemical techniques was designed to establish the provenance of Normandy Chalkstone. First, we obtained a representative assembly of building stones by the selection and strategic sampling of 22 buildings. Second, we determined areas of chalk bedrock from a geological map rendered through GIS and sampled chalkstones from natural outcrops and quarries. In total, 118 samples from buildings, quarries and natural outcrops were characterized via optical microscopy and geochemical analyses for major, minor and trace elements (XRF, ICP-MS and ICP-OES), as well as for Sr-87/Sr-86 isotope ratios (MC-ICP-MS). The application in situ of pXRF analysis allows for the identification of Normandy Chalkstone sources preserved in archaeological sites. The results indicate that all chalkstones came from five local varieties of Normandy Chalkstone and one of Shelly Limestone imported from nearby regions. The suitability of chalkstone as construction material was evaluated in situ using a sclerometer, which revealed that the singular and local geological features of the chalkstone make it suitable for walling. Our study demonstrates the development of a prominent and relatively continued quarrying industry over the 10th to 14th centuries in Eastern Normandy. The main quarrying areas were constituted of three chalkstone diffusion zones that run coevally with smaller and apparently sporadic quarries. The chalkstone diffusion was strongly related to the occurrence of singular and local geological resources and the stone transport system, which favoured the use of effective fluvial and maritime navigation for transport over 50 km from the quarrying areas.
The 87Sr/86Sr isotope ratio in Normandy chalkstones has been measured by LC-MC-ICP-MS to help identify the quarries employed in the construction of medieval monuments.
Predicting the response of rocky coasts to different erosional agents remains a great challenge at present. The episodic and discontinuous nature of the instability processes typical of hard bedrocks makes it difficult to make predictions based on observations over short research periods. This work aims to contribute to the understanding of the geomorphological evolution of rocky cliffs by means of a case study of a geologically complex cliff (developed on quartzite and slate) located on the Atlantic coast of Spain. The analysis of high-precision topographic models and orthophotographs, the use of geomatics techniques and geomorphological characterization have made it possible to define a model of the cliff behaviour. The results indicate that the structure of the bedrock determines the type of instability processes affecting the cliff and the morphology of the associated deposits. Lithology is the other main conditioning factor: while slate is easily eroded, quartzite offers greater strength and its detached blocks act as an effective natural defence element protecting the cliff and slowing down the coastal retreat. The evolution model established for this cliff explains the absence of retreat in the study period (2003–2022) and confirms the important role of local factors in cliff evolution.