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Till macrofabric and grain-size analysis of glacial diamictons and landforms present in several valleys of the Serra da Estrela Mountains in central Portugal were used to interpret till types and to reconstruct the glacial paleoprocess history of this mountainous region. Supraglacial melt-out and flow tills are dominant in this range. Supraglacial melt-out tills, representative of periods of glacial stability and stagnation followed by recession, present weaker fabric data and coarser, poorly sorted sediments. Flow tills, mainly representative of glacial stability followed by recession, present crude layering, and soft-sediment deformation structures with moderate fabric data and coarser to fine, poorly sorted sediments. Glacial diamictons affected by post-glacial paraglacial activity in the form of landslides were also observed in three valleys. These present weaker to moderate fabric data and coarser, poorly sorted sediments. These glacial diamictons and landforms are of particular importance in the reconstruction of the glacial dynamics and history of the Serra da Estrela Mountains due to a scarcity of chronological data based on absolute dating methods. These mountains also represent the southernmost Atlantic range in Europe where significant glaciation took place, which makes it an interesting area to investigate mountain glacial dynamics in low elevation humid Atlantic coastal ranges and compare it with other Atlantic ranges.

The Montes de Leon (northwest Spain) include the Aquilanos Mountains (2142 m), the Teleno Mountains (2182 m), and the Sierra de la Cabrera (2121 m), which are Paleozoic mountains with a predominance of slate and quartzite. During the maximum glacial advance, 94 small cirque and valley glaciers (up to 9 km long) occupying c. 116 km2 were formed in this area. Although the glacial development was similar in the three mountain ranges, the conservation of the landforms is very uneven. On the western slope of La Cabrera and in the Aquilanos Mountains, the steep slope and the greater presence of slate favored erosion, and only a few moraines have been preserved, although cirques and troughs are still present. The preserved moraines in the Teleno and the east of La Cabrera (Vizcodillo) present a less steep gradient, allowing us to observe three glacial stages. The first two show similar development, with glaciers occupying the headwaters of the valleys. The third appears in the highest and best-oriented cirques, with moraines over 1700 m. Some of the moraines were excavated for gold in Roman times, and others have been destroyed by current-day slate mining.

Relict rock glaciers are widespread in the Cantabrian Mountains, with more than 250 lobate, tongued‐shaped and complex landforms identified. Located mostly within glacial cirques, facing north and northeast, these landforms are indicative of the distribution of ancient permafrost. Macro‐fabric analysis allows us to reconstruct the past dynamics of these landforms. Surface macro‐fabric analysis of 34 rock glaciers including both ridge and furrows was performed. The orientation and dip of 50 clasts was determined in each case. All data were plotted in equal‐area stereograms and the eigenvalue method was used for statistical analysis of the data. The data show weak fabric shapes, with the transitional and the girdle shapes being the most representative, with 67.6% of the samples studied. The main fabric direction (eigenvalue S1) is found in 40–60% of the clasts, and only 11.7% present values ≥0.60. Clast concentration density in the stereograms gives concentrations

Deglaciated mountainous areas are usually affected by a great range of paraglacial processes that involve progressively denudation of glacial imprints. This study focuses on paraglacial processes and glacial landform preservation in six zones located in two catchments of the Cantabrian Mountains (NW Spain). These zones are adjacent but display important topographic, lithologic and glaciation style differences. An analysis of how these variables conditioned the intensity and diversity of paraglacial processes in these zones was investigated through a detailed study of their relief, lithology and paleo glacier surface using GIS. A comprehensive cartography of paraglacial landforms was also accomplished, considering landslides, alluvial fans and rock glaciers that show signs of having been conditioned by glaciation. Moraines and debris-mantled slopes were also included in the analysis to examine their grade of preservation depending on the studied variables. Data comparison show that differences in glaciation style influenced paraglacial processes. In the ancient icefield area, relief modification by glacial action was limited and scarce paraglacial processes occur. By contrast, in the upper areas located in the southern ranges where an alpine-style of glaciation was installed, paraglacial processes were very active, generating many rock glaciers. Lithology explains some paraglacial landforms distribution: 1) Landslides are associated with incohesive (sandy and shale) rocks; 2) Rock glaciers mainly occur in quartzite areas; 3) In limestone areas subterranean drainage contributes to glacial landscape preservation, but suffosion dolines affect some glacial deposits. Topography is also a key factor in paraglacial processes: 1) Moraines are well-preserved in gently sloping valleys, but rare in the steeper where they are usually transformed into moraine (or debris)-mantled slopes; 2) Alluvial fans are more frequent in the steeper valleys, but more dissected by postglacial river action. 3) Elevation and orientation show little influence on paraglacial landforms, except in the generation of some periglacial features such as rock glaciers.

The article presents the 1:25,000-scale geomorphological map of the upper reaches of the Curueño River, on the southern slope of the Central Cantabrian Mountains, NW Spain. The study area spans approximately 125 km2 and corresponds to the 1:25,000-scale Spanish National Topographical Map Sheet 104-I of Lugueros. The area is moderately mountainous with elevation ranging from 1100 to 2100 m.a.s.l. The main landforms are river gorges, karst, and glacial landforms. The map legend contains 78 elements divided into 9 groups: litho-structural, polygenic, karst, fluvial, glacial, periglacial, nival, gravitational, weathering, and anthropic forms. The map was prepared using Esri ArcGIS with the Universal Transverse Mercator (UTM, Zone 30) projection. In addition, a database and style set were created for each landform with the goal of using this set of symbols in other areas and performing complementary mapping of geologic and geomorphologic risk, protection of natural geoheritage, land-use classification, and applied geomorphology.

Changes in land use related to mining in the north-western mountains of Spain are analysed. We studied 15 representative types of mining activity in the Sil River basin (Leon province), including three types of mineral resources: gravel, roofing slate and coal. We use colour orthopothos of 2014 to calculate areas occupied by dumps, lagoons, open pits, auxiliary construction and access roads in mines. Also areal photographs of 1956–1957 were used to measure land uses in these years. In all cases the extraction of mineral resources by surface mining has caused the destruction of the former topography, and these alterations are irreversible. The new post-mining topography represents a drastic change in the landscape and land use in these areas. Areas occupied by coal and slate mining (around 1500 ha.) are significantly greater than gravel quarries (74 ha.). Waste material is greater in slate mining (69%) and coal mining (44%) than in gravel mining (8%). Former agricultural areas now occupied by mining were more extensive in gravel quarries (44%) than in slate quarries (10%) and coal mines (6%) because of the gentler topography in the areas where the gravel quarries are located. In six cases mining are located in natural protected areas and in other cases alter and/or eliminate valuable geological heritage.

Till macrofabric and grain-size analysis of glacial diamictons and sequences present in several valleys of the Serra do Geres Mountains in the Northwestern Iberian Peninsula were used to interpret ...

A total of 156 glacial cirques located on two different areas in the Cantabrian Mountains (NW Spain) were identified and measured in order to continue and expand the study of these large‐scale erosional forms in European mountains. Environmental variables that may explain cirque distribution (altitude, aspect and lithology), and their most important morphometric features (area, length (L), width (W), headwall height (H), and L/W, L/H and W/H indices), are analysed. Statistical analysis has been applied as indicators of contrast (ANOVA) and association (correlation and regression). Conglomerate analysis (CLUSTER) has been used to discriminate cirque groups based on their morphometric variables. Results show that cirques occur at lower altitudes in the Upper Sil River basin area than in the Montana Central area due to a lower former equilibrium line altitude (ELA) position. In the Upper Sil River basin, environmental variables appear to have had a strong influence on the location and size of cirques...

Producción Científica, Landforms resulting from the interaction between paleo-glaciers and karst are studied by using the Sierra de los Grajos (Cantabrian Mountains) as a model. This area contains glacial landforms that have not interested geomorphologists due to their low altitude (Peña Castillo is about 1857 m a.s.l.), the absence of glacial cirques and the scarcity of large moraines. However, the prevalence of groundwater flow and chemical dissolution has favoured the preservation of glacial landforms. Lateral and frontal moraines show three main glacial stages and other minor glacier stabilization phases, with the paleo-ELA oscillating between 1650 and 1760 m. Moraines are combined with depressions and sinks resulting from subglacial karstic drainage. This convergence of forms and processes is an exception in the Cantabrian Mountains, where postglacial erosion has usually eroded the frontal moraines and the proglacial sediments. In the case of the Sierra de los Grajos, despite the underground drainage and preservation of many glacial deposits on karstic landforms, an outwash-plain was formed. These proglacial sediments and others from non-karstified areas filled the depressions of the preglacial terrain located at their edges. The main glaciokarstic landforms have been mapped and a sedimentological analysis of the outwash plain was made in order to reconstruct the glacial dynamics of this area., Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (projects CGL2016-76215-R and CGL2015-65569-R)

The La Balouta Valley, located in the extreme SW region of the Las Médulas Natural Monument and UNESCO World Heritage Site (León, Spain), is one of the largest gold-mining sites developed by the Romans more than 2,000 years ago when excavating a thick series of red Miocene sediments in the area. The main determining feature of the La Balouta Valley, especially if we compare it with the Sil River Valley of which it is a tributary, is its status of a non-functional valley. It is a dry paleo-valley with a flat bottom and is characterized by limited surface water runoff and the presence of small cavities, channels, and residual karst topography. Variscan structures that form the structural framework of the study area underwent long-term erosion and supported deep sediment accumulation in the area during the Miocene, reaching depths of more than 100 m. A portion of these sediments accumulated over a karst, as indicated by karst channels that exhibit total and locally partial filling with red sediments similar to those mined at Las Médulas roughly 2 km further to the east. The presence of gold particles in one of the sediment samples and the identification of several characteristics common of formations mined by the Romans lead us to deem the La Balouta Valley an ancient paleokarst that was initially fossilized by deposition of red Miocene sediments and subsequently excavated via historical mining activities, which formed its current characteristics. In La Balouta, natural and anthropogenic processes have produced a unique cultural landscape that is reflective of systematic gold mining of sediments on the NW Iberian Peninsula by the Romans.

Fabric and grain-size analysis of eight deposits present in the Upper Sil River Basin palaeoglacial system of northwest Spain were used to interpret till types and to reconstruct the glacial paleoprocess history of this region. They are represented by lodgement, deformation, and melt-out tills. The first, representative of glacial advance stages, present cluster fabrics and are generally composed of poorly sorted and finer sediments. Melt-out and deformation tills, representative of stages of glacial stability followed by fast recession, present transitional to girdle fabrics and are composed of poorly sorted coarser sediments. In any case, multiple criteria, including lithological, clast-shape, or structural data, support these directional and grain-size observations. These sequences, most of them located in the snout area of the Sil palaeoglacier, are important in the reconstruction of glacial dynamics due to poor preservation of landforms related to the maximum glacial advance. This palaeoglacial syste...

Several glaciers developed in the Cantabrian Mountains (NW Spain) during the last glacial maximum (LGM). In the last 15 years, several studies of glacial geomorphology have increased the knowledge about the limits of the glaciation, but little data are available about many valleys, especially on the northern slope, due to extensive postglacial erosion. In this study, we apply the AABR method to reconstruct palaeo-equilibrium-line altitudes (ELAs) in eleven palaeo-glaciers that are considered to be representative of the different areas of the range. To reduce the ambiguity in the palaeo-ELA values caused by local factors, we analysed medium and large glaciers (4.7 to 65.5 km2) except for the Sil complex glacier, which was the largest glacier in northwestern Spain (445 km2). The palaeo-ELAs during the local LGM ranged between 1000 and 2000 m and had a similar pattern to the present-day winter precipitation and summer temperatures.

New data about the glacial geomorphology of Cardano valley (North of Palencia province, Spain) are presented. Using AABR (Area Altitude Balance Ratios) method we have estimated the ELA position in the last maximum advance at 1840 m. Instead of this high altitude, the great surface above this altitude permitted the development of an important glacier. Numerous erosional and depositional forms are widespread in the valley, and many of them are recognized for the first time.