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This study uses luminescence and 14C accelerator mass spectrometry procedures to date relevant glaciofluvial and glacial deposits from the south-central and southeastern Pyrenees (Andorra–France–Spain). We distinguish two types of end-moraine complexes: (1) those in which at least a far-flung moraine exists beyond a frequently nested end-moraine complex (the most common) and (2) those in which a close-nested end moraine encompasses at least two glacial cycles. Both types formed within six distinctive glacial intervals: (1) A penultimate glacial cycle during Marine Oxygen Isotope Stage (MIS) 6 and older glaciofluvial terraces occurred beyond the range of the luminescence dating method. (2) An early glacial advance in MIS 5d (~97 −15/+19 ka) was followed by glacial retreat during MIS 5c (< 91 ± 9 ka). (3) The last maximum ice extent (LMIE) was in early MIS 4 (~74 ± 4.5 ka). (4) Unexpectedly, glaciers thinned during the second half of MIS 3 (~39 −6/+11 ka). (5) During the MIS 3–2 transition, glaciers subsequently fluctuated behind the LMIE limits. (6) The global last glacial maximum (LGM) started as early as ~26.6 ± 0.365 ka b2k, and the corresponding end moraines were built behind the LMIE limits or merged with it, forming close-nested moraines.

The Sierra de Gredos forms the central sector of the Central Range and extends for 155 km between the Sierra de Guadarrama to the east and the Sierra de Gata-Pena de Francia to the west, its highest peak being the Pico Almanzor (2591 m, 40° 14′ 46″ N and 5° 17′ 51″ W). The bedrock is mostly made up of granite rocks. The Sierra de Gredos has a Mediterranean–continental climate, with a clear increase in rainfall to the west due to its proximity to the Atlantic. Its glacial landscapes present a great variety of landforms, from small cirques in the massifs of the smaller summits and southern slopes, to large glacial valleys of lengths exceeding 10 km and plateau glaciers in the highest and western-most summits. The glacial evolution during the Late Pleistocene, since the maximum extent occurred before the global Last Global Maximum until the definitive disappearance of the glaciers, just at the beginning of the Holocene, is well known. Phases of glacial advance have also been clearly detected during the Oldest Dryas and, to a much more limited extent, during the Younger Dryas.

The Guadarrama and Somosierra mountain ranges form the eastern sector of the Iberian Central System and hosted numerous glaciers during the Late Pleistocene (MIS2). Glaciation was of low intensity with glaciers of small sizes, strongly controlled by the climatic context and the topography. This study analyses the shape, size, distribution and location of 96 cirques existing in these mountain ranges. In addition to the standard morphometric parameters and controlling factors (altitude, aspect and lithology) used in most studies, additional factors were considered here in relation to the pre-glacial relief and fracture network. The data were obtained and processed using ArcGIS 10.4 and relations between the parameters and controlling factors were evaluated using statistical methods. The results indicate that most are simple cirques, tending to isometry, with low vertical incision capacity, considerable variation in size and predominantly east-facing. In the context of the Iberian Peninsula and other European mountains, these cirques are among the most isometric, the lowest in height and present the least overdeepening. The development of these cirques has generally been the result of random combination of various factors. Thus: (i) the largest cirques are located at intermediate altitudes, with the headwall located on the main divides, at former torrential valley heads or at the headwalls of fracture corridor valleys, and are north-facing; (ii) the longest cirques are located at former torrential valley heads, on metamorphic bedrock (i.e. schists, slates) and on uniform slopes. Finally, the prevailing eastern aspects are explained by topoclimatic factors and are in agreement with previous studies, which have proposed a Circulation Weather Type (CWT) model throughout the Iberian Peninsula during the Last Glacial Period, similar to its current configuration.

This study was funded by the LATESICE-CGL2016-78380-P, FINICES-PID2020-117685 GB-I00 and MED-REFUGIA-RTI2018-101714-BI00 (Plan Nacional I + D + I, Spanish Ministry of Science, Innovation and Universities) projects. This study was also funded by the OROMEDREFUGIA project (P18-RT-4963) from the Andalusian Office of Economy and Knowledge. Luelmo Lautenschlaeger was funded by the Spanish Ministry of Education, Culture, and Sports (FPU16/00676). We sincerely thank Dr. Guy Jalut for the constructive and helpful comments that improved our original draft. We would also like to sincerely thank Professor Eneko Iriarte, University of Burgos, Spain, for his help and advice in interpreting the geochemical records. We also thank the editor and the anonymous reviewers for their helpful comments and constructive suggestions that have significantly improved this manuscript., The Iberian Central System (ICS) is a clue region to reveal Mediterranean/Atlantic inferences over Iberia. We present a multidisciplinary study from western Spain conducted in the Navamuño depression (ND), covering the last 16.8 ka (cal BP). A reconstruction of the palaeotemperature from the resulting geochemical data highlights four cold and dry intervals, namely, the Oldest Dryas, Older Dryas, Intra-Allerød Cold Period (IACP), and the Younger Dryas, along with warmer intervals: the Bølling (14.7–14 ka) and the Allerød (12.9–12.6 ka); however, the Greenland Interstadial GI-1c (13.4–13.1 ka) is barely distinguishable in the ND. Despite the shortage of biomass to sustain fire, the earliest charcoals are from ~14.4–13.8 ka. Evidence of ash/dust events overprinting the geochemical background starts at ~13.8–12.8 ka. Significant fire activity in the Early Holocene at ~11.7–10.6 ka affected the ND, matching the westernmost ICS data. This period includes short oceanic spells inferred from Cl peaks at ~10.9–10.2 ka and three cold intervals at 11.4, 9.3, and 8.2 ka disrupted the progressive temperature increase. The Mid-Holocene showed a continuously increasing trend towards an arid climate, peaking at 4.2 ka under a pervasive dust influx from North Africa, which has prevailed since almost ~7.9 ka. A prominent volcanic event at ~6.8–5.8 ka is in Navamuño and Roñanzas (Asturias, N Spain; Gallego et al., 2013) identified from heavy metal-rich layer, synchronous with the last known eruption of the Calatrava volcanic field (South-Central Spain; Poblete-Piedrabuena et al., 2019). This volcanic eruption could affect many other regions half north of Iberia. The pervasive presence of oceanic aerosols in the last three millennia (2.8 ka ~ ) allowed the formation of a Cl-rich peat layer during the Ibero-Roman humid period ~2.1 ka, before a changing around ~0.4 ka toward colder and drier conditions at the Little Ice Age (LIA) period., Plan Nacional I + D + I, Spanish Ministry of Science, Innovation and Universities LATESICE-CGL2016-78380-P FINICES-PID2020-117685 GB-I00 MED-REFUGIA-RTI2018-101714-BI00, Andalusian Office of Economy and Knowledge P18-RT-4963, Spanish Ministry of Education, Culture, and Sports FPU16/00676

Geological and geophysical studies in complex valley troughs provide a key record for the reconstruction of paleoenvironmental conditions during the Quaternary. Here we present a study of the sedimentary infill of the El Cervunal kame complex or El Cervunal trough (Sierra de Gredos, Iberian Central System) by means of a combined interpretation of near-surface geophysical techniques supported by geomorphological and borehole data. A set of 1D and 2D near-surface geophysical methods, including electrical (Vertical Electrical Sounding and 2D Electrical Resistivity Tomography), seismic (2D Seismic Tomography and 1D Refraction Microtremor) and Magnetic Resonance Sounding techniques, were used to test their applicability in providing better insight on the infill nature and geometry. Because of greater sensitivity and higher resolution and coverage achieved with resistivity methods, the electrical resistivity has proven to be the most informative physical parameter, while seismic and magnetic resonance methods were complementary. The sedimentary infill was classified into three geophysical units and five sub-units with their geological interpretation. Unit 1 consists of a postglacial sedimentary sequence and includes alluvial-plain and alluvial-fan deposits. Units 2 and 3 below the postglacial unit were interpreted as glacial sequences including kame (glacigenetic and fluvio-glacial) and morainic deposits, respectively. Subsoil information combined with the geomorphological data enabled the partial reconstruction of the map-view geometry of the morainic bodies at the El Cervunal trough. The results suggest a complex evolution of the study area where erosive-sedimentary processes dominate, but also structural factors should be considered. At least five well-differentiated stages can be established to explain the occurrence of the trough infill: pre-glacial, maximum glacial extension, trough obturation, glacial retreat and periglacial-postglacial., This work was mainly supported by the Spanish Ministry of Science and Innovation (Spanish initials: MINECO; project CGL2016-78380-P) and UCLM Research Groups (Project 2020-GRIN-28992). The authors acknowledge the help received from the Sierra de Gredos Regional Park and the Consejería de Medio Ambiente of the Junta de Castilla y León (JCyL). Additional support comes from the Program I+D CARESOIL (S2018/EMT-4317) of the Comunidad Autónoma of Madrid

A new record from a long sediment core (S3) in Navamuño (1505 m asl, western Iberian Central System) provides the reconstruction of the vegetation history and environmental changes in the region between 15.6 and 10.6 ka cal BP, namely during the Late Glacial and the early Holocene, using a multiproxy analysis (pollen-based vegetation and climate reconstruction, sedimentary macrocharcoals, loss-on-ignition, magnetic susceptibility and X-ray fluorescence (XRF) measurements). The results are then compared with other sequences from the Iberian Central System and the whole Iberian Peninsula in order to better understand the past dynamics of the main forest constituents. The pollen record shows a shift from open pine forests ∼15.6–14.7 ka cal BP (Oldest Dryas) to mixed open pine-birch woodlands ∼14.7–14.0 ka cal BP (Bølling). Woodlands were succeeded by a steppe-like landscape until ∼13.4 ka cal BP (Older Dryas), which was replaced again by high-mountain pine forests and riparian woodlands ∼13.4–12.6 ka cal BP (Allerød). A great development of cold steppe grasslands linked to the decline of birch woodlands is documented ∼12.6–11.7 ka cal BP (Younger Dryas). The early Holocene (11.7–10.6 ka cal BP) was characterized by a progressive reforestation of the study area by pine and birch forests in the highlands and oak woods in the lowlands. Temperate tree taxa (Carpinus betulus, Castanea sativa, Corylus avellana, Fraxinus, Juglans, Tilia, and Ulmus) were also common but likely at lower elevations. Pollen of Fagus sylvatica was already recorded during the Late Glacial and the early Holocene. The marked increasing local fire activity during the warmer and wetter Allerød oscillation could be related to a rise in tree cover, supporting the climatically driven character of these fires. Nevertheless, the strong increase in fire activity during the Younger Dryas would probably be related to growing tree and shrub mortality, as well as to the wet/dry biphasic structure of this stadial. The standard “Modern Analogue Technique” has been also applied to the Navamuño sequence to provide quantitative climate estimations for the Late Glacial and the early Holocene periods. This record is one of the few continental archives that show the climatic trend between the Late Glacial and the early Holocene in central Iberia, agreeing with many other regional records from the Western Mediterranean.

We present a detailed geomorphological map of the landform assemblages originated by the two major paleoglaciers of the Sierra de Gredos mountain range in the Spanish Iberian Central System. Based on previous works, our map focused on the features formed by Gredos and Pinar paleoglaciers during the last glaciation and subsequent glacial events. Based on a remote sensing analysis and exhaustive field surveys, we identified with great accuracy the local distribution of glacial, periglacial, mass movement, structural, fluvial, and lacustrine features. We recognized three main glacial geomorphological formations representing: (i) the maximum glacial extension reached (peripheral deposits); (ii) the culmination of glacial conditions (principal moraines) and (iii) the local glacial withdrawal (internal deposits). Our map offers a renewed spatial framework on which to conduct higher-resolution glacial chronologies, especially of Late Glacial and Holocene glacial activity, providing key information for performing future paleoclimatic reconstructions of the northern hemisphere mid-latitudes., This work was supported by the Spanish Ministry of Science and Innovation (Spanish initials: MINECO; project CGL2016-78380-P), University of Castilla–La Mancha Research Group (UCLM, project 2020-GRIN-28992) and the Chilean Ph.D. Fellowship CONICYT #21161417 and the ANID Millennium Science Initiative/Millennium Nucleus Paleoclimate

The only glaciers existing today in the Iberian Peninsula are small features located in the Pyrenees, though their number and extension has undergone significant changes over the Late Quaternary. The wide range of glacial landforms and deposits distributed across different Iberian ranges suggests the occurrence of several past periods with larger glacial systems. The objective of this research is to summarize the current knowledge on the spatial and temporal patterns of glacial activity in the Iberian mountains during the Late Quaternary. To this purpose, the chronological framework was divided in six periods: glaciations prior to the Last Glacial Cycle (Middle Pleistocene), Last Glacial Cycle (Late Pleistocene), Termination-1, Holocene, Little Ice Age (LIA) and present-day. The data were geographically divided considering the mountain systems where glacial evidence exists: Pyrenees, Cantabrian Range, NW ranges, Central Range, Iberian Range and Sierra Nevada. During Quaternary cold stages, ice accumulated in the head valleys of these mountain ranges and glaciers flowed down-valleys. In all cases, glaciers remained confined within the mountain systems and did not reach the surrounding lowlands. Depending on the combination of temperatures and moisture conditions, more or less ice was stored. In some ranges, there is evidence of Middle Pleistocene glaciations, one potentially correlating with marine isotope stage (MIS) 12 and another correlating with MIS 6 with glaciation dated to ca. 130-170 ka. However, most of the glacial records correspond to the Last Glacial Cycle and subsequent Termination. The maximum glacial expansion of this last Pleistocene glaciation stage occurred well before the global Last Glacial Maximum (LGM) between 30 and 60 ka in the Cantabrian Mountains and Pyrenees, at ca. 30 ka in Sierra Nevada and NW ranges, and (almost) synchronously to the LGM in the Central Range and Iberian Range. A massive glacial retreat occurred in all ranges at 19-20 ka, but the long-term deglaciation process was interrupted by cold intervals, such as the Oldest and Younger Dryas, which favoured glacial expansion in the highest mountains. Temperature increase recorded during the Holocene conditioned the melting of glaciers, which only reappeared in the highest massifs during the coldest periods, such as the LIA. However, post-LIA warming led to glacier disappearance in the Cantabrian Mountains, Sierra Nevada and most massifs of the Pyrenees, together with an accelerated shrinkage of the small glaciers still existing in this range at elevations near 3000 m.

This study explores the information gathered from the landscape transformation that occurred during the intense period of Roman hydraulic gold mining activity in northwest Spain. The Sierra del Teleno and its surroundings are characterised by the presence of Quaternary glacial and periglacial deposits and, locally, Neogene alluvial sediments, which were intensely mined by the Romans. However, the mining debris often obscures natural deposits, making their identification and description a challenging task. The aim of this study is to determine the existence of specific geomorphological features that can improve the identification of anthropic elements related to mining activity. River captures and widened drainage systems are among the most outstanding structures remaining, due to the extent and complexity of the work involved. However, other mining elements, such as anthropic modification of alluvial fans, moraine deposits and rock ridges are also evident in the landscape. In many cases, these remains are linked to the hydrologic infrastructure found in the area, which mainly comprises an extensive system of natural and man-made channels and distribution water-tanks. Difficulties arise in areas where no such structures are found. Thus, the use of geomorphic elements and patterns can help to distinguish natural and anthropic landforms. Using this approach, therefore, we have performed the first systematic and detailed analysis of the morphological imprint of Roman hydraulic gold mining activity on the landscape. These data will help piece together the puzzle of how the landscape was transformed by Roman mining activity, and can contribute to discussions surrounding the new epoch: The Anthropocene.

This contribution discusses the potential of UAV-assisted (unmanned aerial vehicles) photogrammetry for the study and preservation of mining heritage sites using the example of Roman gold mining infrastructure in northwestern Spain. The study area represents the largest gold area in Roman times and comprises 7 mining elements of interest that characterize the most representative examples of such ancient works. UAV technology provides a non-invasive procedure valuable for the acquisition of digital information in remote, difficult to access areas or under the risk of destruction. The proposed approach is a cost-effective, robust and rapid method for image processing in remote areas were no traditional surveying technologies are available. It is based on a combination of data provided by aerial orthoimage and LiDAR (Light Detection and Ranging) to improve the accuracy of UAV derived data. The results provide high-resolution orthomosaic, DEMs and 3D textured models that aim for the documentation of ancient mining scenarios, providing high-resolution digital information that improves the identification, description and interpretation of mining elements such as the hydraulic infrastructure, the presence of open-cast mines which exemplifies the different exploitation methods, and settlements. However, beyond the scientific and technical information provided by the data, the 3D documentation of ancient mining scenarios is a powerful tool for an effective and wider public diffusion ensuring the visualization, preservation and awareness over the importance and conservation of world mining heritage sites.

The Navamuño peatbog (Sierra de Béjar, western Spain) is a ∼14 ha pseudo-endorheic depression with boundaries defined by a lateral moraine of the Cuerpo de Hombre paleoglacier and fault-line scarps on granite bedrock. The stratigraphy of the Navamuño peatbog system is characterized here using borehole data to a depth of 20 m. An integrated interpretation from direct-push coring, dynamic probing boreholes and handheld auger drillings advances our knowledge of the Navamuño polygenetic infill. Correlating this data with those obtained in other studies of the chronology and evolutionary sequence of the Cuerpo de Hombre paleoglacier has enabled us to establish the sequence of the hydrological system in the Navamuño depression. During the Late Pleistocene (MIS2), the depression was dammed by the Cuerpo de Hombre glacier and fed by its lateral meltwaters, and was filled with glaciolacustrine deposits. The onset of the Holocene in Navamuño is linked to a flat, fluviotorrential plain with episodes of local shallow pond/peat bog sedimentation. This evolutionary sequence is congruent with the age model obtained from available radiocarbon dating, obtaining 19 ages from ∼800 cal yr BP (at depth 1.11 m) to ∼16800 cal yr BP (at depth 15.90–16.0 m). Finally, the sedimentary record enabled interpretation of the environmental changes occurring in this zone during the late glacial (from the Older Dryas to the Younger Dryas) and postglacial (Holocene) stages, placing them within the paleoclimatic context of the Iberian Peninsula and Mediterranean regions., This work was supported by the Spanish Ministry of Economy and Competitiveness (Projects CGL2013-44076-P and CGL2016-78380-P). The authors also wish to acknowledge the help and assistance of the Regional Environment Department (JCyL) and the Local Authority in the village of Candelario. Valenti Turu acknowledges grant ATC013 -and- 2015/2016 from the Government of Andorra.

Cave temperature is a parameter of major importance for palaeoclimate studies based on speleothems since most proxies used are temperature-dependent. The general assumption that cave temperature reflects the mean annual surface atmosphere temperature (SAT) over the cave is based on a limited number of specific studies, and detailed mechanisms supporting this link are not properly described. Eagle Cave, in Spain, was used to understand the detailed mechanisms connecting SAT and cave temperature. A monitoring programme conducted from 2009 to 2011 allows the characterization of the thermal dynamics in the cave air. In the studied karstic environment thermal conduction is the main mechanism responsible for transferring the ground temperature signal to the cave. The calculated thermal diffusion coefficient is 0.756×10 −6 ±0.013 m 2 s −1 . The SAT signal is recorded at the cave with a delay ranging from ~3 to 11 yr, depending on the thickness of the bedrock over the ceiling (5–18 m). A cave cooling of 2 °C has been recorded since mid-1970s, when cave temperature measurements were made. The application of a model exclusively based on thermal conduction of SAT does not reproduce the observed thermal changes. However, vegetation cover over the cave was modified dramatically during recent decades. This impacts ground temperature due to the changes in exposure to insolation and the modification of soil properties, which is eventually recorded in the cave. The incorporation of changes in vegetation cover in the model provides a realistic thermal reconstruction. The impact of vegetation cover was much more significant than SAT in order to explain the large thermal change in the cave over past decades. Thus, the cooling in Eagle Cave during past decades is mainly controlled by a variable decoupling from mean annual SAT as a result of the afforestation over the cave. The effect of this thermal decoupling on speleothem δ 18 O records is potentially significant and should be considered when performing accurate palaeoclimate reconstructions.

Rock tablets of known weight were buried in the soil of a karst region in Central Spain to evaluate the carbonate weathering during a period of a year. The experiment was conducted at two different soil depths: 5–10 and 50–55 cm from the surface. The parental rock used in the experiment is composed of dolomite and magnesite with variable proportion of accessory minerals and minor elements. Soil mineral and chemical composition as well as its texture was also characterized. Meteorological conditions at the site together with temperature and CO2 in both soil levels were monitored. Sets of tablets were retrieved after 6 and 12 months of the start of the experiment to account for seasonal weathering. Different lithologies do not exhibit significant differences in weathering, although a large inter-sample variability is attributed to variable size and distribution of the porosity. Results show an enhanced weathering during the wet and cold season that accounts for 78 ± 1% of the total annual weathering. Rock tablets examined under scanning electron microscopy prior and after exposure to natural environment show that most of the material lost occurred along cracks, edges or large pores. Although dissolution is a common process, most of the weathering is due to crystal detachment. Rock tablets at the depth of 5–10 cm were weathered 68 ± 1% more than those set at 50–55 cm from the surface. Higher soil moisture and concentration of CO2 were found deeper in the soil, which likely enhanced the dissolution of carbonate. However, physical weathering dominated weight loss of rock tablets at both soil depths; especially at the 5–10 cm level where soil thermal and moisture cycles were more frequent and greater. Denudation rate calculated from the 12 months set provides values of 2.48 ± 1.07 μm/yr and 1.75 ± 0.66 μm/yr at the depths of 5–10 and 50–55 cm, respectively. Since the conditions at the average contact between soil and bedrock are similar to those at the 50–55 cm depth, we consider that this is a more reliable denudation rate for the studied location during the studied period. The calculated weathering rate suggests that denudation has a limited contribution to the thinning of bedrock over caves at this site. Therefore, we consider that the formation of unroofed caves in this region most likely results from the thinning of bedrock cover over caves due to collapse of blocks from their ceilings.

During the Holocene a series of tufa sediments were deposited from a karstic spring along the Trabaque Canyon, central Spain. A long-term lowering of the water table caused the location of the spring to be displaced from the upper sector of the canyon during the early Holocene to the lower sector in the late Holocene. This progressive shift was in response to decreased precipitation in the region. The depositional environments and their geomorphologic relationships were characterized. Thus, five morphosedimentary units (MSUs) were identified within the Holocene tufa deposits. Erosive episodes were recognized between MSUs and, as most of the MSUs partially overlap, the older ones are perched in relation to the younger ones. The chronology of the MSUs is based on 14C dates, and stable isotopes and total organic carbon content provided environmental information during the period of tufa sedimentation. The successive dissection episodes in the Trabaque Canyon tufa deposits took place during transitioning climate conditions from the relatively wet early Holocene to the more arid late Holocene. During this transitional period in the mid-Holocene, wet phases alternated with more arid conditions, causing the largest hydrological regime gradients in the Holocene. Thus, the four erosive episodes causing tufa dissection in Trabaque during the Holocene are interpreted as the result of abrupt transitional periods towards arid conditions.

The morphometrical analysis of gnammas (weathering pits) in granite landscapes has been used to establish the relative chronology of recent erosive surfaces and to provide the weathering history in a region. To test the validity of gnammas as relative chronometer indicators, and the reliability of the obtained weathering record, two sites have been studied in Serra da Estrela, Portugal. The first site is within the limits of the glacier that existed in these mountains during the last glaciation, whereas the second site is located in an unglaciated sector of the mountains, which preserves a longer record of weathering in the bedrock surface. The number of gnamma weathering phases recorded in the latter site (8) is larger than those from the former (6). Correlation between both measurement stations based on morphometrical criteria is excellent for the younger six weathering phases (1 to 6). Consequently, the parameter used for relative chronology (δ-value) has been verified to be age dependent, although absolute values are modulated by microclimate due to altitude variations. The weathering record was essentially duplicated once the surfaces at both sites were exposed, demonstrating the reliability of gnamma evolution as a post-glacial environmental indicator for the region.

The Cuerpo de Hombre paleoglacier occupies the upper sector of the Cuerpo de Hombre river basin, located on the northwest slope of the Sierra de Bejar Mountains (Iberian Central System). At the stage of the maximum ice extent during the last glacial cycle, this paleoglacier was one of the longest tongues emerging from the Sierra de Bejar plateau glacier. The study of the morphostratigraphic succession and the geometric and genetic relations between the geomorphological indicators of this paleoglacier has revealed its evolutionary sequence during the last glacial cycle. The comparison between this sequence and the one previously established by a regional evolutionary pattern shows that although they both coincide in general terms, some stages/substages of this pattern must be corrected or more clearly defined. The absolute chronology of the different stages was obtained using terrestrial cosmogenic nuclides (10Be). The maximum ice extent of Cuerpo de Hombre paleoglacier has been dated to ∼25.0 ka (MIS2 and concurrent with the LGM). This chronology coincides with date obtained for other paleoglaciers in the Iberian Central System, but is slightly more modern than the regional chronology estimated as most likely for the maximum ice extent in these areas. Subsequent to reaching the maximum extent, the glacier had a retreat (minimum age ∼20.6 ka), followed by another stage of expansion or readvance, after which it stabilised until the start of the deglaciation stage (∼17.8 ka). In all previous work, the deglaciation stages in the Iberian Central System have been described as one continuous recession process. However, in the Cuerpo de Hombre paleoglacier, all the data point to stabilisations of considerable magnitude, and particularly to another stage of readvance of the glacier. Based on its chronology (minimum age ∼11.1 ka) and its evolutionary significance, this new readvance has been correlated with the Older Dryas stadial. Finally, the evolutionary context marked by the indicators and its chronology confirm that the whole of the Late Glacial sequence identified in Cuerpo de Hombre can be correlated with the traditionally established in northern Europe (climatic periods or stadials and interstadials): Oldest Dryas-Bolling-Older Dryas-Allerod-Younger Dryas. The minimum ages obtained for the cold periods (stadials) in this sequence in the Cuerpo de Hombre paleoglacier are (respectively): ∼17.5 ka, ∼13.9 ka and ∼11.1 ka. This complete sequence of the Late Glacial Period, including the stadials Older and Younger Dryas, had not been previously identified in any of the paleoglaciers in the Iberian Central System.

The Jerte Valley is a northeast-southwest tending graben located in the mountainous region of west central Spain (Spanish Central System). Mass movements have been a predominant shaping process on the Valley slopes during the Quaternary. Present day activity is characterized as either ‘first-time failure’ (shallow debris slides and debris flows) or ‘reactivations’ of pre-existing landslides deposits. A delineation of landslide hazard zoning within the Valley has been carried out by using the detailed documentation of a particular event (a debris slide and a sequel torrential flood, which occurred on the Jubaguerra stream gorge), and GIS techniques. The procedure has had four stages, which are: (1) the elaboration of a susceptibility map (spatial prediction) of landslides; (2) the elaboration of a map of ‘restricted susceptibility’ in the particular case of slopes that are connected to streams and torrents (gorges); (3) the elaboration of a digital model which relates the altitude to the occurrence probability of those particular precipitation conditions which characterized the Jubaguerra event and (4) the combination of the probability model with the ‘restricted susceptibility map’, to establish ‘critical zones’ or areas which are more prone to the occurrence of phenomena that have same typology as this one.

During the deglaciation stages of the last glacial period a rock avalanche took place on the glacier that occupied the upper sector of the Cuerpo de Hombre Valley (Sierra de Bejar). The material displaced during the avalanche fell onto the ice, was transported by the glacier and later deposited as supraglacial ablation till. The cause of the avalanche was the decompression of the valley slopes after they were freed from the glacier ice (stress relaxation). Reconstruction of the ice masses has been carried out to quantify the stress relaxation that produced the collapse. The rock avalanche took place on a lithologically homogeneous slope with a dense fracture network. The avalanche left a 0.4 ha scar on the slope with a volume of displaced material of 623 ± 15 × 103 m3. The deposit is an accumulation of large, angular, heterometric boulders (1–100 m3 in volume) with a coarse pebble-size matrix. The avalanche can be explained as a relaxation process. This implies rock decompression once the glacier retreat left the wall ice free (debuttressing). Calculations show that the avalanche took place where the decompression stresses were highest (130–170 kPa). In the Spanish Central System paleoglaciers the largest accumulation of morainic deposits occurred after the glacial maximum and the earliest stages of the ice retreat. The process described here is used as an example to formulate a hypothesis that the largest accumulations of tills were formed in relation to enhanced slope dynamics once some glacier retreat had occurred.

Mountain glaciers respond directly to changes in precipitation and temperature, thus their margin extent is a high-sensitivity climate proxy. Here, we present a robust Be-10 chronology for the glacier maximum areal extent of central Spain paleoglaciers dated at 26.1 +/- 1.3 ka BP. These glaciers reached their maximum extent several thousand years earlier than those from central Europe due to the increased precipitation within a cold period between 25 to 29 ka BP, as confirmed by a local speleothem record. These paleoclimate conditions impacted the maximum extent of mountain glaciers along the western and central Mediterranean region. The cause and timing of the enhanced precipitation implies a southward shift of the North Atlantic Polar Front followed by storm tracks in response to changes in insolation via orbital parameters modulation. Thus, these mountain paleoglaciers from the Mediterranean region record an ocean-continent climate interaction triggered by external forcing.

Weathering phases recorded by gnammas: Response to comments by Norwick, Pages 400–401

Pollen data from three sequences (CH, PD and CbN) in the Gredos Range (Spanish Central System) have been presented. These data record the evolution of vegetation from the 7000 BP (Holocene). The most important results are summarized in the domain of the pine forest and the change in the local forest composition. Then, the forests of Betula and Corylus, developed until 3000 BP, are replaced by deciduous and evergreen Quercus. At this time and only in the sequence CH, presence of Cedrus and Fagus has been detected. From approximately 1000 BP, takes place an important decrease in arboreal taxa, mainly of Pinus associated with the expansion of Ericaceae and Poaceae, in response to an increase in both temperature and anthropogenic activities.

During the last glaciation (Late Pleistocene) Sierra de Béjar hosted a plateau glacier with two morphologies: a plateau icefield and a Plateau icecap. The former developed in the southern sector and was formed by a set of valley glaciers coalescent in the upper sectors. The later occupied the northern sector of the range, being a non-confined dome-shaped ice mass, which was favoured by the plateau morphology of the bedrock. The detailed study of the glacier morphology in Sierra de Béjar has conducted to identify reliable indicators to reconstruct the ice masses during the Glacial Maximum (MG). These indicators were used to calculate different morphologic, dynamic and chronologic paramenters, very useful in unravelling the glacier evolution and to extract paleoclimate interpretations. Based on the new data, the edges of the plateau glacier were established around 2100 m above sea level, its extension was of 57.4 km2 and the maximum thickness ranges from 80 and 130 m along the summits of the range. During the period of maximum extension of the glacier (MG) the plateau had a morphology close to an icecap, whereas with the onset of glacier retreat the ice mass reduced and the glacier become a truly icefield. Finally, during successive stages of retreat the glaciers were individualized and become valley and cirque glaciers. The on-going research regarding the chronology of the glacier maximum (MG) based on 10Be dates, that consider samples from Duque-Trampal, Endrinal and Cuerpo de Hombre glaciers from Sierra de Béjar, provides preliminary dates of 27.2 ± 2.7 and 26.2 ± 0.8 ka BP for the maximum extent of the plateau glacier in this area.

During the period of deglaciation of the last glacial cycle, a rock avalanche tooks place in the cliffs of Los Hermanitos (Cuerpo de Hombre Valley, Sierra de Béjar). The material displaced during the avalanche fells over the ice, was transported towards the glacier front and later on deposited as a supraglacial meltout till. The origin of the avalanche is the result of a decompression in the slopes of the valley after they have been liberated of the glacier ice (paraglacial stress relaxation). Based on geomorphological data and the implementation of a GIS, the reconstruction of ice masses during the main glacier stages have been carried out in order to quantify the stress relaxation that produced the collapse.

The present study focuses on the importance of visitors in Eagle Cave temperature, a tourist cavern in Ávila, central Spain. Cave air temperature was measured during a year and natural and anthropogenic thermal effects were identified. Eagle Cave has a rather stable temperature around 15.6ºC with an annual cycle which amplitude is

On this work there are provided new data regarding the till deposits corresponding three valleys of glacier-related origin at the Sierra de Béjar. Given that these deposits are located out of what up to the moment has been considered as a glacier dominium, their interest is essential as they permit set the sketch of the evolutionary sequence of ice on these mountains. Such a schedule, which is itself the main aim of this work, is integrated on an interpretative model that of glacier history and evolution on these areas, which main pillars are the existence of both ice caps and ice fields, as well as a stage of maximum extension of glaciers previous to his maximum balance. On relation to the ice caps, the previous statements regarding the data obtained on diverse sectors of the Béjar, Nava and Gredos ranges have clearly demonstrated their presence. Therefore, we will just need to integrate on the evolutionary sketch the new type of glaciers to those traditionally described on the mountains, that is, the circus, slopes and valley ones. On respect to the new limit of the maximum ice extension, there is determined through the till deposits located out of the glacier dominium defined by the best developed moraine ; such moraine is the one that traditionally has been considered o the whole of the Sierra de Gredos as the main one (representing the maximum ice extension). This sketches, initially considered as an exceptional and isolated fact (only quoted on the ancient glacier valley of the Serrá Gorge), is validated on the present work through the data obtained on the valleys of ancient glacier of the Culebrón, Endrinal and Cuerpo de Hombre.

This paper describes the determination of sheet erosion rates by using dendrogeomorphological methods on exposed tree roots. Two sites on the northern slope of the Guadarrama Mountains, Central Spain, were studied: a popular trail in a Scots pine forest (Senda Schmidt, Valsaı´n) growing on granites and gneisses, and an open holm-oak forest on granitic slopes (Monterrubio). These sites were selected because they showed high denudation morphologies due to accelerated soil-erosion processes caused by human influence (trampling by continuous trekking and overgrazing), resulting in exposed roots. The method applied is based on the morphological pattern of roots, defined by the growth-ring series of the sampled roots. In order to confirm the validity of the criteria used and to make the estimations of erosion more accurate, several anatomical indicators of exposed and nonexposed Pinus sylvestris roots were characterized. The study entailed a statistical analysis of exposure time and erosion depth. The influence of environmental factors affecting the variation in velocity of the erosion processes was also examined. With a significance level of 95%, the mean erosion rates were in the range of 1.7–2.6 mm/year (29– 44 t/ha/year) on Senda Schmidt over the last 101 years, and 1.1–1.8 mm/year (19–31 t/ha/year) in Monterrubio over the last 42 years. Using a multifactor analysis of variance, we observed a change in the erosion rates as a function of position on the path along Senda Schmidt. In Monterrubio, however, we reached no significant conclusions, apart from an inverse relationship between erosion and slope gradient that was difficult to interpret. Climate conditions in Senda Schmidt and the accuracy of dating Scots pine indicate that the evaluation on P. sylvestris roots is fairly reliable, which is not the case for oak roots. Although this paper is based on the application of an existing method, its novelty lies in being the first attempt in Spain to estimate dacceleratedT sheet erosion rates (due to recreational activities and overgrazing) using dendrogeomorphological techniques, supplemented by anatomical indicators for P. sylvestris.

Landform-based physiographic maps, also called land systems inventories, have been widely and successfully used in undeveloped/rural areas in several locations, such as Australia, the western United States, Canada, and the British ex-colonies. This paper presents a case study of their application in a developed semi-urban/suburban area (Segovia, Spain) for land use planning purposes. The paper focuses in the information transfer process, showing how land use decision-makers, such as governments, planners, town managers, etc., can use the information developed from these maps to assist them. The paper also addresses several issues important to the development and use of this information, such as the goals of modern physiography, the types of landform-based mapping products, the problem of data management in developed areas, and the distinctions among data, interpretations, and decisions.

The geometric and genetic characterization of the Navamuño depression peatland system (Iberian Central System) is presented here using results from a geophysical survey. This depression is a ~30 ha pseudo-endorheic flat basin over granitic bedrock. Three geophysical techniques were used to map the subsurface geology, and identify and describe the infill sequence: shallow seismic refraction (SR), Magnetic Resonance Sounding (MRS) and electrical resistivity measurements (VES and ERT). The three main geoelectrical layers (G1, G2, G3) identified in previous research, have also been identified in the present work. Using the data obtained in this new research we have been able to analyse these three geological layers in detail and reinterpret them. They can be grouped genetically into two sedimentary units: an ancient sedimentary body (G3), of unknown age and type, beneath an Upper Pleistocene (G2) and Holocene (G1) sedimentary infill. The facies distribution and geometry of the Upper Pleistocene was examined using the Sequence Stratigraphy method, revealing that the Navamuño depression was an ice-dammed in the last glacial cycle resulting in glaciolacustrine sedimentation. A highly permeable sedimentary layer or regolith exists beneath the glaciolacustrine deposits. Below 40 m depth, water content falls dramatically down to a depth of 80 m where unweathered bedrock may be present. The information obtained from geophysical, geological and geomorphological studies carried out in this research, enabled us to consider various hypotheses as to the origin of this depression. According to these data, the Navamuño depression may be explained as the result of a transtensional process from the Puerto de Navamuño strike-slip fault during the reactivation of the Iberian Central System (Paleogene-Lower Miocene, Alpine orogeny), and can be correlated with the pull-apart type basins described in these areas. The neotectonic activity of this fault and the ice-dammed processes in these areas during the Last Glacial Cycle (MIS2) were the main causes of recent sedimentary infill in this depression., This work was supported by the Spanish Ministry of Economy and Competitiveness (Projects CGL2013-44076-P and CGL2016-78380-P).