a review of glacial geomorphology and chronology in northern spain timing and regional variability during the last glacial cycle abstract in this paper we synthesize the research in glacial geomorphology and geochronology in northern spain with special attention to the evidence of local glacier maximum extent earlier than the global lgm of mis 2 18 21 ka bp more accurate models of glacier evolution have been defined based on limnogeological geochronological and geomorphological data in the pyrenees osl optically stimulated luminescence surface exposure and radiocarbon dating techniques have identified end moraines and fluvial terraces corresponding to mis 6 about 170 ka and even to mis 8 about 260 ka and also established the timing of the last local glacial maxima as prior to global lgm mis 4 ca 50 70 ka during the global lgm a smaller re advance occurred but glaciers reached different extents in the central and the eastern pyrenees in nw iberia radiocarbon and osl techniques point to local glacial maximum prior to ca 26 ka 38 ka and probably synchronous with 45 ka although some bias might have been introduced by the dating procedures this review demonstrates that in both regions the local maximum extent occurred prior to the global lgm the asynchronies between the glacial maxima chronologies in the different mountain ranges of northern spain suggest that local climate factors exert a strong control on mountain glacier dynamics

chronological and geomorphological investigation of fossil debris covered glaciers in relation to deglaciation processes a case study in the sierra de la demanda northern spain abstract in this study fossil debris covered glaciers are investigated and dated in the sierra de la demanda northern spain they are located in glacial valleys of approximately 1 km in length where several moraines represent distinct phases of the deglaciation period several boulders in the moraines and fossil debris covered glaciers were selected for analysis of 10 be surface exposure dating a minimum age of 17 8 2 2 ka was obtained for the outermost moraine in the san lorenzo cirque and was attributed to the global last glacial maximum lgm or earlier glacial stages based on deglaciation dates determined in other mountain areas of northern spain the youngest moraines were dated to approximately 16 7 1 4 ka and hence correspond to the gs 2a stadial oldest dryas given that the debris covered glaciers fossilize intermediate moraines it was deduced that they developed between the lgm and the oldest dryas coinciding with a period of extensive deglaciation during this deglaciation phase the cirque headwalls likely discharged large quantities of boulders and blocks that covered the residual ice masses the resulting debris covered glaciers evolved slowly because the debris mantle preserved the ice core from rapid ablation and consequently they remained active until the end of the late glacial or the beginning of the holocene for the san lorenzo cirque and the holocene thermal maximum for the mencilla cirque the north facing part of the mencilla cirque ensured longer preservation of the ice core

last deglaciation in northwestern spain new chronological and geomorphologic evidence from the sanabria region abstract geomorphologic mapping morphometric analysis of glacial features and sedimentologic characterization of glacial deposits together with gis management have led to reconstruction of the glacial evolution of the tera valley glacier sanabria lake basin nw spain after the local glacial maximum moreover a structural analysis of the bedrock fracture network based on a detailed map containing 898 fractures has been used to evaluate the influence of bedrock geology in the development of the glacier pattern a detailed model of the deglaciation has been constructed by complementing the geomorphologic evidence with the chronological and sedimentologic study of a drilling core retrieved from the eastern subbasin of sanabria lake in 2004 according to this model 10 episodes of glacier front retreat and stabilization took place after the local glacial maximum subsequently a proglacial lake was established in the eastern subbasin of current sanabria lake fed by ablation waters coming from the glacier front retreat the proglacial activity was extended from a minimum age of 25 6 to 14 3 ka bp in which the sedimentation of organic rich muds took place until 13 1 ka bp subsequently around 13 1 to 12 2 ka bp a short advance of the tera glacier is inferred from the deposition of coarser and less organic sediments after this date the glacier front would have retreated to the headwaters of the tera valley sedimentologic and chronological data from another core retrieved in a moraine dammed deposit indicate that a marginal lake would have been active since at least 22 ka bp until at least up to 10 5 ka bp to the north of sanabria lake these results suggest a local glacial maximum prior to the global lgm and therefore new evidence of an early deglaciation in sw europe

late glacial and post glacial deposits of the navamuno peatbog iberian central system chronology and paleoenvironmental implications abstract the navamuno peatbog sierra de bejar 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 navamuno 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 navamuno 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 navamuno 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 navamuno 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

karst landscape evolution in the littoral area of the bay of biscay north iberian peninsula the western pyrenean area contains extensive karst areas however their genesis and development are still mostly unknown in this work we make a general description of the karst landscape in different karst areas 1 rasa type 2 cone type karst and 3 alpine type karst the first two types are present in the littoral area where geomorphological evolution mostly depends on sea level and climatic changes we focused our study in two karst areas of the littoral cone type karst we correlate different caves created from different stable water table levels three representative caves are studied in detail studying their stratigraphic record based on allostratigraphy finally we dated the different phases of speleothem formation in the three caves using all this information we defined four stable paleowater table levels at 50 150 220 and 350 m asl controlled by sea level changes and isostatic uplift events the lowest level is the youngest with an age of c 1 ma we discovered that the interior of the three caves display very similar endokarst allostratigraphic sequences characterized firstly by an erosion phase a fluvio karst input flowstone speleothem formation and finally dripping speleothem formation the chronological data shows a correlation between these phases and pleistocene climatic phases the erosion phase is related to the falling sea level fluviokarst detrital input is related to cold glacial stages and the formation of speleothems is related to the warmest interglacial moments and high sea level periods

a spatio temporal landslide inventory for the nw of spain bapa database abstract a landslide database has been created for the principality of asturias nw spain the bapa base de datos de argayos del principado de asturias principality of asturias landslide database data collection is mainly performed through searching local newspaper archives moreover a bapa app and a bapa website http geol uniovi es bapa have been developed to obtain additional information from citizens and institutions presently the dataset covers the period 1980 2015 recording 2063 individual landslides the use of free cartographic servers such as google maps google street view and iberpix government of spain combined with the spatial descriptions and pictures contained in the press news makes it possible to assess different levels of spatial accuracy in the database 59 of the records show an exact spatial location and 51 of the records provided accurate dates showing the usefulness of press archives as temporal records thus 32 of the landslides show the highest spatial and temporal accuracy levels the database also gathers information about the type and characteristics of the landslides the triggering factors and the damage and costs caused field work was conducted to validate the methodology used in assessing the spatial location temporal occurrence and characteristics of the landslides

timing of last deglaciation in the cantabrian mountains iberian peninsula north atlantic region based on in situ produced 10 be exposure dating abstract the last glacial termination led to major changes in ice sheet coverage that disrupted global patterns of atmosphere and ocean circulation paleoclimate records from iberia suggest that westerly episodes played a key role in driving heterogeneous climate in the north atlantic region we used 10be cosmic ray exposure cre dating to explore the glacier response of small mountain glaciers ca 5 km2 that developed on the northern slope of the cantabrian mountains iberian peninsula an area directly under the influence of the atlantic westerly winds we analyzed twenty boulders from three moraines and one rock glacier arranged as a recessional sequence preserved between 1150 and 1540 m above sea level a s l in the monasterio valley redes natural park results complement previous chronologic data based on radiocarbon and optically stimulated luminescence from the monasterio valley which suggest a local glacial maximum local gm prior to 33 ka bp and a long standing glacier advance at 24 ka coeval to the global last glacial maximum lgm resultant 10be cre ages suggest a progressive retreat and thinning of the monasterio glacier over the time interval 18 1 16 7 ka this response is coeval with the heinrich stadial 1 an extremely cold and dry climate episode initiated by a weakening of the atlantic meridional overturning circulation amoc glacier recession continued through the bolling allerod period as indicate the minimum exposure ages obtained from a cirque moraine and a rock glacier nested within this moraine which yielded ages of 14 0 and 13 0 ka respectively together they suggest that the monasterio glacier experienced a gradual transition from glacier to rock glacier activity as the amoc started to strengthen again glacial evidence ascribable to the younger dryas cooling was not dated in the monasterio valley but might have occurred at higher elevations than evidence dated in this work the evolution of former glaciers documented in the monasterio valley seems consistent with previous 10be chronologies reported in other mountain ranges of the iberian peninsula which have been recalculated according to a common production rate and scaling scheme however the re evaluation of published 10be chronologies has highlighted the fact that glacial evidence previously ascribed to the younger dryas might be more limited than previously thought and the need for additional studies to characterized the extent of glaciers during the younger dryas cooling

a cave lion panthera spelaea skeleton from torca del leon nw iberia micromammals indicate a temperate and forest environment corresponding to gi 11 mis 3 abstract the torca del leon site asturias nw spain discovered in 2014 provided an interesting fossil assemblage including a p spelaea partial skeleton and a rich micro mammal community with palaeoenvironmental significance the bone accumulation was formed in a karstic cave that acted as a natural trap as indicated by the geomorphology of the cavity connected to a 16 m deep shaft and the lack of signs of human or carnivore activity on the bones the large mammal assemblage is composed of carnivores of which the most striking is the partial skeleton of the cave lion an exceptional find for this region which allowed a detailed comparative study its skull and teeth retained features of systematic relevance which agree with its ascription to p spelaea sexing of the specimen points to it possibly being from a male whose body weight was estimated at 360 kg other identified large mammals in the site include p pardus and canis lupus the rich small mammal assemblage comprising 14 taxa allowed inferring that the environment during site formation corresponded to a mature forest developed under humid and temperate conditions located at just 15 km from the glacial fronts of the cantabrian mountains ams dating yielded 43 0 0 5 cal ka bp coinciding with greenland interstadial gi 11 a warming event poorly known in nw iberia coeval with the onset of the regional glacial retreat occurred after the local glacial maximum of 45 ka this episode is also coeval with the middle to upper paleolithic transition in northwestern iberia

a multiple dating method approach applied to the sanabria lake moraine complex nw iberian peninsula sw europe new evidence in the nw region of the iberian peninsula w42 n6 w of a glacial advance coeval with the global last glacial maximum lgm of the marine isotope stage 2 has been identified through a dataset of exposure ages based on 23 10 be concentration measurements carried out on boulder samples taken from a set of latero frontal moraines results span the interval 19 2e15 4 10 be ka matching the last deglaciation period when iberia experienced the coldest and driest conditions of the last 25 ka and are consistent with lateglacial chronologies established in other mountain regions from sw europe the extent of the lgm stade identified in this work is similar to the local maximum ice extent stade recorded and dated as prior to 33 ka using radiocarbon and optically stimulated luminescence this work showcases how multiple dating approaches and detailed geomorphological mapping are required to reconstruct realistic palaeoglacier evolution models

applying the aabr method to reconstruct equilibrium line altitudes from the last glacial maximum in the cantabrian mountains sw europe abstract 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

palaeoglaciation of parque natural lago de sanabria northwest spain abstract detailed geomorphological mapping provides evidence for at least three phases of glaciation in the parque natural lago de sanabria in northwest spain the most extensive glaciation was characterised by a large plateau ice cap a combination of geomorphological evidence and glacier modelling indicates that this ice cap covered an area of more than 440 km 2 with a maximum ice thickness of c 300 m and outlet glaciers reaching as low as 1000 m this represents the largest ice mass in iberia outside the pyrenees and one of the largest in the mountains of southern europe and the mediterranean region radiocarbon dates from the base of lacustrine sequences appear to suggest that the most extensive phase of ice cap glaciation occurred during the last cold stage weichselian with deglaciation occurring before 14 15 ka 14 c bp a second phase of glaciation is recorded by the moraines of valley glaciers which may have drained small plateau ice caps whilst a final phase of glaciation is recorded by moraines in the highest cirques

deglaciation in the central pyrenees during the pleistocene holocene transition timing and geomorphological significance abstract in this study we document deglaciation in a sector of the southern central pyrenees the panticosa massif and the upper gallego and ossau valleys using cosmic ray exposure cre dating methods which were applied to samples from high altitude polished rock steps and rock glacier boulders the obtained cre dates show a coherent spatial distribution and confirm results previously obtained in this study area thus demonstrating the reliability and robustness of the method the results of analyses based on two distinct isotopes 10 be and 36 cl are consistent although the error is higher for results based on the 36 cl isotope the study provides evidence for ice extent in the high gallego valley during the oldest dryas with glacial advance until the bottom of the valleys although the main glacier tongues remained disconnected from each other during this period the extent of glacier advance was directly related to the elevation of the associated summits the younger dryas glaciers were constrained to cirques or very short ice tongues and dating of the polished rock steps indicates that the ice masses were present until the first millennium of the holocene the brazato rock glacier developed at the beginning of the holocene and remained active until the holocene thermal optimum because of the protective effect of large masses of blocks and boulders

paleoenvironmental evolution of picos de europa spain during marine isotopic stages 5c to 3 combining glacial reconstruction cave sedimentology and paleontological findings abstract in glaciated areas the environmental evolution before mis 2 is usually poorly constrained mainly due to the later glacial erosion during the global last glacial maximum lgm however in carbonate areas karst caves can preserve records of pre lgm paleoenvironment we studied a cave 1350 m altitude to establish the paleoenvironmental evolution of a glaciated karst area in picos de europa sw europe for this objective a glacial reconstruction cave sedimentology analyses and macro and micromammal remains are com bined with ten u th osl and ams 14c ages the paleo glacial reconstruction indicates glaciers descended down to 810 1040 m of altitude covering an area of 36 18 km2 in the surroundings of covadonga lakes during the glacial local maximum with the equilibrium line altitude located at 1524 36 m the geomorphological study of the cave and the u th and osl dates reveal the presence of three allochthonous alluvial sediment sequences at 132 135 98 60 and ca 36 ka these last two sequences would come from the erosion of fluvioglacial sediments including teeth fragments of pliomys coronensis p lenki an unusual species in high areas of nw spain during the upper pleistocene in addition remains of chamois rupicapra pyrenaica dated in 37 33 cal ka bp constitutes the oldest evidence of chamois above 800 m asl in the region all the presented data indicate the development of alpine glacier free areas covered by fluvioglacial sediments at ca 1450 m altitude at 98 60 and 37 33 ka corresponding to glacial retreat stages

comparison of oxygen isotope records from the gisp2 and grip greenland ice cores recent results1 2 from the greenland ice core project grip summit ice core suggest that the climate in greenland has been remarkably stable during the holocene but was extremely unstable for the time period represented by the rest of the core spanning the last two glaciations and the intervening eemian inter glacial here we present the complete oxygen isotope record for the greenland ice sheet project 2 gisp2 core drilled 28 km west of the grip core we observe large rapid climate fluctuations throughout the last glacial period which closely match those reported for the grip core however in the bottom 10 of the cores spanning the eemian interglacial and the previous glacia tion there are significant differences between the two records it is possible that ice flow may have altered the chronological sequences of the stratigraphy for the bottom part of one or both of the cores considerable further work will be necessary to evaluate the likelihood of this and the extent to which it will still be possible to extract meaningful climate information from the lowest sections of the cores

glacial geomorphic study of the thajwas glacier valley kashmir himalayas india abstract glacial geomorphic studies provide vital information to make inferences about the effect of glacial advance and retreat on the geomorphology of an area in the present study glacial geomorphic landforms of the thajwas glacial valley in the upper reaches of the indus kashmir himalayas were mapped using geospatial technology validated with gps based field observations and ground photography the glacial geomorphic landforms were digitized using aster dem 30 m resolution landsat etm satellite imagery 30 m resolution and google earth 1 m resolution data results showed that google earth imagery supported by field validation is very useful for the interpretation of glacial geomorphic landscapes and relief features at micro and meso scales however morphometric characteristics of landforms are best obtained using dem overlaid onto the landsat etm satellite data glaciers in the valley are presently confined along the south and southwestern slopes however the significant role played by glaciers in shaping the geomorphic landforms and their subsequent preservation within the scenic landscape under the late quaternary climatic conditions are remarkably evident the glacial geomorphic landforms especially terminal moraine glacial trough and cirques observed in the valley aided the reconstruction of palaeo glacial setting of the area morphology shape and location of terminal and lateral moraine ridges were used to establish the palaeo glacial extents glacial volume and the number of glacial advances of the thajwas glacier the maximum elevation of the lateral moraines was used to define the former equilibrium line altitude ela the greater rock excavation to form a large valley during the last glacial maximum might have induced isostatic rock uplift exhumation in the glacier source area it is observed that the concomitant retreat of the north facing glacial cirques has played an important role in expanding the glacial valley and limiting the topographic relief

age and significance of the quaternary cemented deposits of the duje valley picos de europa northern spain abstract cemented calcareous breccias appear in the picos de europa cantabrian mountains spain resting on glacially abraded surfaces and covered by moraines u th dating of the calcite coating the clasts was successful in two samples the oldest one indicating that the breccias accumulated during or prior to marine isotope stage mis 11 and the youngest indicating later cementation during mis 8 the former introduces a limit for the age of the glaciation preceding the breccias which cannot correspond to an event younger than mis 12 this is the oldest absolute age so far obtained for intercalated glacial interglacial deposits of the iberian peninsula

geomorphology and quaternary stratigraphy the roles of morpho litho and allostratigraphy abstract the subdivision and ordering of quaternary sediments and landforms is very often based on geomorphology quaternary landforms such as moraines river terraces palaeoshorelines and indeed any other landform can be arranged and ordered in time based on their relative position in the landscape morphostratigraphy is the subdivision of sedimentary units primarily on the basis of surface form whilst surface form is often used as a criterion for separating sedimentary units morphostratigraphy also usually incorporates lithological criteria to aid stratigraphical subdivision and morpho and lithostratigraphy are often interlinked in quaternary science however another approach allostratigraphy has increasingly been applied to subdivide and order quaternary sediment landforms allostratigraphy uses discontinuities to subdivide sedimentary successions allostratigraphy enables lateral variations in lithology to be included within the same stratigraphical unit furthermore it enables lithologically similar sediments stacked on top of each other to be divided into separate units based on discontinuities this paper examines the applications of morpho litho and allostratigraphy to subdivide sediment landform assemblages and critically reviews their role in quaternary stratigraphy

mountain glaciation and paleoclimate reconstruction in the picos de europa iberian peninsula sw europe abstract geomorphic mapping and stratigraphic analysis of a lake core document the late quaternary glacial history of the central and eastern massifs of the picos de europa northwestern spain the distribution of glacial deposits indicates that at their most advanced positions glaciers occupied 9 1 km2 extended as far as 7 km down valley and had an estimated equilibrium line altitude ela ranging between 1666 and 1722 m radiocarbon dating of sediment deposited in a lake dammed by moraines of this advance show that the maximum glacial extent was prior to 35 280 440 cal yr bp this advance was followed by two subsequent but less extensive late pleistocene advances recorded by multiple moraines flanking both massifs and sedimentary characteristics in the lake deposits the last recognized glacial episode is the 19th century maximum extent of small little ice age glaciers in the highest cirques above 2200 m

sequence and chronology of the cuerpo de hombre paleoglacier iberian central system during the last glacial cycle abstract 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 10 be 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

late pleistocene glaciers in greece a new 36cl chronology abstract glaciers formed in the highest mountains of greece during the late pleistocene but the timing of glacier maxima is poorly understood this paper presents 27 36cl terrestrial cosmogenic nuclide exposure ages from glacial boulders on mount tymphi 2497 m a s l 40on in epirus northwest greece these ages address both a significant geographical gap in mediterranean glacial chronologies and a temporal gap in the glacial history of this region by targeting the previously undated late pleistocene record late pleistocene glaciers were restricted to the cirques and upper valleys of mount tymphi terminal and lateral moraines between 1700 m and 2050 m a s l mark the extent of late pleistocene glaciers on the southern side of mount tymphi moraines marking the maximum extent of late pleistocene glaciation date to 29 0 3 0 ka and 25 7 2 6 ka taking the oldest ages as most representative of moraine emplacement glaciers had retreated to the high cirques by 24 5 2 4 ka during heinrich stadial 2 rock glaciers formed under cold and drier conditions during this period of glacier retreat this 36cl dataset complements published u series ages from secondary calcites in glacial sediments below 1700 m elevation which demonstrate more extensive middle pleistocene glaciations in mis 6 and mis 12 a late pleistocene glacier maxima on mount tymphi at 25 7 29 ka is in good agreement with well preserved outwash sediments dating to 24 28 ka in the voidomatis river record downstream and is consistent with the ioaninna basin pollen record indicating cool and wet conditions most favourable for glacier growth at 25 30 ka

dynamics of mediterranean late quaternary fluvial activity an example from the river ebro north iberian peninsula abstract late pleistocene and holocene fluvial evolution of the upper river ebro miranda basin north spain is analysed using geomorphological sedimentological and optical dating techniques maximum regional crustal uplift of 0 98 m ka approximately helped preserve a suite of terraces in the miranda basin 5 river terraces t1 5 were identified and their formation attributed to mis 6 t 1 mis 5d t 2 mis 4 t 3 mis 2 t 4 mis 1 t 5 alluvium deposited in terraces t 1 t 2 t 3 and t 4 is well sorted clast supported gravels whereas the t 5 deposit is exclusively composed of silt gravels were deposited during cold and dry periods when reduced vegetation cover on hillslopes increased sediment supply to the trunk river silt was deposited in overbank settings under warmer and wetter climate conditions when vegetation cover stabilised hillslopes and restricted sediment supply it also resulted in lower peak discharge and reduced flow velocities over vegetated floodplains the chronological sequence of terraces indicates that incision occurred during climatic transitions we conclude that the upper river ebro responded to fluctuations in sediment supply and discharge controlled by late quaternary climate cycles

permafrost conditions in the mediterranean region since the last glaciation the relatively warm climate conditions prevailing today in the mediterranean region limit cold geomorphological processes only to the highest mountain environments however climate variability during the late pleistocene and holocene has led to significant spatio temporal variations of the glacial and periglacial domain in these mountains including permafrost conditions here we examine the distribution and evolution of permafrost in the mediterranean region considering five time periods last glaciation deglaciation holocene little ice age lia and present day the distribution of inactive permafrost derived features as well as sedimentary records indicates that the elevation limit of permafrost during the last glaciation was between 1000 m and even 2000 m lower than present permafrost was also widespread in non glaciated slopes above the snowline forming rock glaciers and block streams as well as meter sized stone circles in relatively flat summit areas as in most of the northern hemisphere the onset of deglaciation in the mediterranean region started around 19 20 ka the ice free terrain left by retreating glaciers was subject to paraglacial activity and intense periglacial processes under permafrost conditions many rock glaciers protalus lobes and block streams formed in these recently deglaciated environments though most of them became gradually inactive as temperatures kept rising especially those at lower altitudes following the younger dryas glacial advance the early holocene saw the last massive deglaciation in mediterranean mountains accompanied by a progressive shift of permafrost conditions to higher elevations it is unlikely that air temperatures recorded in mediterranean mountains during the holocene favoured the existence of widespread permafrost regimes with the only exception of the highest massifs exceeding 2500 3000 m lia colder climate promoted a minor glacial advance and the spatial expansion of permafrost with the development of new protalus lobes and rock glaciers in the highest massifs finally post lia warming has led to glacial retreat disappearance enhanced paraglacial activity shift of periglacial processes to higher elevations degradation of alpine permafrost along with geoecological changes

little ice age glaciation and current glaciers in the iberian peninsula little ice age lia glacier advance has been registered in three of the main iberian high mountain areas pyrenees picos de europa and sierra nevada during the lia three different glacial env

late pleistocene climate of the northern iberian peninsula new insights from palaeoglaciers at fuentes carrionas cantabrian mountains

palaeoenvironmental studies in nw iberia cantabrian range vegetation history and synthetic approach of the last deglaciation phases in the western mediterranean abstract at the north western limit of the mediterranean basin in the mediterranean oceanic transition zone the multidisciplinary study of two palaeolakes villaseca and la mata province of leon provides data on the last deglaciation the juxtaglacial lakes were formed during a deglaciation phase of the last cold stage weichselian wurm estimated from the regional and pyrenean chronological data between circa 48 ka and 32 ka ka 1000 years ago their drainage occurred circa 17 ka and 15 ka respectively during the definitive glacial retreat phases these results provide evidence for a glacial maximum extension preceding the global last glacial maximum lgm and an early deglaciation comparisons with the pyrenean data show that in the most important glacial basins of the pyrenean cantabrian range glaciers were still present at middle elevation circa 18 20 ka the final deglaciation did not happen until around 16 ka during the period 48 13 3 ka along the pyrenean cantabrian range three stages can be distinguished in the deglacial processes between circa 48 and 32 ka the deglacial retreats were contemporaneous with d o events 12 to 6 between circa 32 ka and 18 ka major sedimentary modifications were rare two of them are synchronous with d o 4 and 3 a glacial readvance also occurred during this period along the pyrenean cantabrian range between 18 and 17 ka major sedimentary changes and an increase in the 18o records of the ngrip ice core record are synchronous between 15 and 13 3 ka glacial retreats and sedimentary changes are synchronous with the climatic improvement observed from the end of the oldest dryas to the end of the bolling allerod period these correspondencies suggest relationships between the deglacial processes in the western mediterranean and the palaeoenvironmental events in the north atlantic region during the last glacial interglacial transition during the full glacial period the pollen data indicates dominant steppic environments the oldest dryas was not a constant cooling phase and from around 15 5 ka the pollen data indicates a slight warming during the holocene until circa 2040 cal bp mixed oak forests developed and pine was a prominent component of the cantabrian landscape then the forests were destroyed due to mining agriculture and fire and this favoured the extension of heathland

constraining the age of superimposed glacial records in mountain environments with multiple dating methods cantabrian mountains iberian peninsula abstract numerous cases of timing differences between glacier advances recorded in mountain environments have been documented over the last decade usually suggesting potential age conflicts between the different dating techniques the frequent use of a single technique to date numerically a given glacial sequence makes it difficult to address to what extent age differences can be an artifact related to biased numerical age results or a paleoclimate signature here we present a new set of 43 numerical ages based on three dating techniques 10be surface exposure dating radiocarbon and optically stimulated luminescence that complement the chronology of pleistocene glacial advances in the porma valley in the central cantabrian mountains of spain results compliment previous chronologies in the area supporting an important glacial advance during marine isotope stage 3 stage iia 56 ka that culminated with the last glacial maximum advance stage iib 33 24 ka of mis 2 in response to increased rainfall and solar insolation minima glacier fronts reached elevations as low as 1130 m a s l possibly without overriding evidence related to the previous pleistocene glacial maximum extent glacier recession in the cantabrian mountains started at 21 20 ka ago after the global lgm we suggest that the recession was initiated by increased insolation followed by hyper cool and dry conditions during heinrich stadial 1 in response to meltwater discharges in the north atlantic

late quaternary glacial phases in the iberian peninsula abstract 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

mass balance and equilibrium line altitudes of glaciers in high mountain environments abstract the mass balance characteristics of glaciers in high mountain environments complicate the relationship between glacier equilibrium line altitudes elas and climatic variables such as precipitation and air temperature therefore methods of ela reconstruction employed in low relief environments are commonly not applicable in high mountains or require some modification we review the concept of the ela with reference to the mass balance of a range of glacier types found in high mountain regions we examine the applicability of several commonly used methods of ela reconstruction for different glacier types and propose some general principles to guide the choice of appropriate methods

timing and new geomorphologic evidence of the last deglaciation stages in sierra nevada southern spain abstract the main objective of this research is to improve knowledge of the deglaciation stages in sierra nevada southern spain by applying 36cl cosmogenic exposure dating to 28 samples from moraine and fossil rock glacier boulders and glacial polished surfaces in 5 glaciated valleys around veleta peak 3396 m asl 37 03 02 n 3 20 54 w the results show that shortly before the last glacial maximum lgm and during the lgm the heads of the glacial valleys were occupied by ice tongues with possible glacial transfluence between the valleys after 19 ka a major glacial regression started but glaciers during the oldest dryas od expanded again and refilled the valley bottoms the glacial advances of the pre lgm lgm and od formed polygenic moraine systems during the bolling allerod the glaciers receded and probably disappeared thereafter the valley bottoms remained ice free during the younger dryas yd small glaciers developed again but only in cirques shaped on east facing slopes subsequently these glaciers started retreating towards their valley heads and finally disappeared completely with the onset of the holocene rock glaciers developed inside the deglaciated cirques on the eastern slopes of some valleys but only under the most active and protected headwalls did large complex rock glaciers develop and remained active until the mid holocene

environmental evolution in the picos de europa cantabrian mountains sw europe since the last glaciation abstract the western massif of the picos de europa latitude 43 n longitude 4 5 w includes some of the highest peaks in the cantabrian mountains this massif was heavily glaciated during the last glaciation though the post glacial environmental evolution is still poorly understood using a complementary geomorphological and sedimentological approach we have reconstructed the environmental events occurred in this massif since the last pleistocene glaciation the geomorphological distribution of glacial landforms suggests the occurrence of four main glacial stages maximum glacial advance glacial expansion after the maximum advance late glacial and little ice age moreover a 5 4 m long sedimentary sequence was retrieved from the karstic depression of belbin providing a continuous record of the paleoenvironmental conditions in this area since the last glaciation until nowadays this section suggests that the maximum glacial expansion occurred at a minimum age of 37 2 ka cal bp significantly prior to the global last glacial maximum subsequently periglacial processes prevailed in the mid lands of the massif until glaciers expanded between 22 5 and 18 7 ka cal bp following the melting of the glaciers a shallow lake appeared in the belbin depression lake sediments do not show evidence of a cold stage during the late glacial when moraine systems formed at higher locations the terrestrification of this lake started at 8 ka cal bp and the area turned into grassland at 4 9 ka cal bp the existence of charcoal particles in the sediments of belbin sequence reveals the onset of human occupation in the massif through the use of fire activity for grazing purposes finally the presence of moraines inside the highest northern cirques shows evidence of the last glacial phase that occurred during the little ice age cold event since then the warming climate has led to the melting of these glaciers and periglacial processes prevail in the high lands of the massif

research history on glacial geomorphology and geochronology of the cantabrian mountains north iberia 43 42 n 7 2 w abstract the study of glacial geomorphology in the cantabrian mountains a mountain range that extends 460 km along the northern coast of the iberian peninsula sw europe started late in the 19th century and continues nowadays with a growing number of research papers however the number and timing of glaciations remains poorly understood partially due to the still limited number of numerical ages its southerly location and proximity to the atlantic ocean make this mountain range potentially sensitive to past climate fluctuations this work updates the glacial knowledge evolution for the whole range from the queixa invernadoiro massif to the basque mountains reviewing i the history of glacial research since the late 19th century ii the methodological approaches applied to reconstruct both the spatial extent and timing of past glacial stages and iii the main geomorphological and geochronological evidence reported until date including glacial features attributed to the last glacial cycle last 120 ka and previous glaciations according to current knowledge glaciers extended over the cantabrian mountains covering a total area of 3150 km2 showing asymmetric development conditioned by variations of the topographic configuration and moisture supply along the range available geochronology based on radiocarbon optically stimulated luminescence and terrestrial cosmogenic nuclides suggests the occurrence of at least 2 glacial advances during the last glacial cycle i a glacial maximum stage that took place at a minimum age of 36 45 ka marine isotope stage 3 and ii a second glacial advance at 19 23 ka mis 2 in some areas the extent of the glacier tongues during the second glacial advance was comparable to previous glacial maximum and was followed by glacial retreat conditions with formation of recessional moraines asynchronous glacial maximum conditions have been reported only for the castro valnera mis 4 3 numerical ages and queixa invernadoiro mis 6 1 numerical age massifs until now finally geomorphological evidence reported in picos de europa has been attributed to prior glaciations and correlated to cold conditions recorded during mis 12 and mis 22 based on a very limited number of numerical ages

spatial and temporal variability of periglaciation of the iberian peninsula abstract active periglacial processes are currently marginal in the iberian peninsula spatially limited to the highest mountain ranges however a wide variety of periglacial deposits and landforms are distributed in low and mid altitude environments which shows evidence of past periods of enhanced periglacial activity the purpose of this paper is to summarize the present knowledge of past periglacial activity in the iberian peninsula the chronological framework takes four main stages into account the last glaciation deglaciation holocene and present day processes this study focuses on the highest massifs pyrenees cantabrian range nw ranges central range iberian range sierra nevada as well as other lower elevation environments namely the central iberian meseta during the last glaciation the periglacial belt extended to much lower altitudes than today reaching current sea level in the nw corner of the iberian peninsula a wide range of geomorphological landforms and sedimentary records is indicative of very active periglacial processes during that phase in some cases related to permafrost conditions i e block streams rock glaciers most of the inactive landforms and deposits in low and mid elevations in iberia are also related to this phase the massive deglaciation of the iberian massifs was caused by a gradual increase in temperatures the deglaciation phase was only interrupted by a short period with colder conditions the younger dryas that reactivated periglacial processes in the formerly glaciated cirques of the highest lands specifically with the widespread development of rock glaciers during the holocene periglacial processes have been only active in the highest ranges shifting in altitude according to temperature regimes and moisture conditions the little ice age saw the reactivation of periglacial activity in lower elevations than today currently periglacial processes are only active in elevations exceeding 2500 m in the southern ranges and above 2000 2200 m in the northern massifs higher in sierra nevada in the south of iberian peninsula

explosive cyclogenesis and large scale circulation changes implications for atmospheric blocking abstract large scale circulation changes attending explosive surface cyclogenesis are quantitatively examined in two cases selected from recent winter seasons both cases feature a rapidly deepening surface cyclone over the western atlantic ocean but changes in the 500 mb geopotential height field near the cyclone differ in each case one event during january 1977 is characterized by the retrogression of an anticyclonic vortex blocking high in the 500 mb height field downstream of the surface cyclone the second case in february 1978 is distinguished by the formation of a 500 mb cyclonic vortex cutoff low upstream of the surface cyclone but no downstream anticyclonic vortex is observed the retrogression of the january 1977 block over the atlantic ocean coincides with the migration of a 500 mb synoptic scale perturbation associated with the surface cyclone from a planetary scale trough over north america toward a planetary scale ridge over europe in the february 1978 case the blocking cyclo

the last deglaciation in the picos de europa national park cantabrian mountains northern spain a sedimentological and geochemical study of the lago enol sequence cantabrian mountains northern spain together with detailed geomorphological mapping provides a first record of glacier evolution and climate change over the last 40 ka in the picos de europa national park the enol glacier retreated from its maximum extent prior to 40 ka bp as demonstrated by the onset of proglacial lacustrine sedimentation in two glaciated depressions the comella hollow to the north before 40 ka bp and the lago enol before 38 ka bp these results support previous evidence that the maximum extent of southern european glaciers occurred earlier than in northern europe alternation of homogeneous and laminated proglacial sediments during the glacier retreat illustrate a dynamic glacial evolution during the marine isotope stage mis 3 40 26 ka bp a slight warming is detected at 26 ka ago with the change from proglacial sediments in a lake located in contact to the glacier to glaciolacustrine sedimentation in a non contact or distal lake finally the onset of organic rich sediments took place at 18 ka ago this last transition occurred in two phases similarly to the north atlantic last termination suggesting a link between north atlantic deep water formation oscillations and palaeohydrological variability in the cantabrian mountains copyright 2009 john wiley sons ltd

quaternary glacial evolution in the central cantabrian mountains northern spain abstract the glacial evolution of the cantabrian mountains is not well known previous studies have focused on the extent of the glacial maximum and the presence of younger features in several massifs recently efforts have been made to date glacial periods particularly the glacial maximum this work presents a reconstruction of the glacial evolution in the cantabrian mountains providing data on the environmental characteristics and timing of the different stages from the quaternary glacial maximum to the little ice age the study area covers 3000 km 2 between the 4 58 w and 3 34 w and includes eleven massifs of the central area of the cantabrian mountains the selected sectors have an atlantic and atlantic mediterranean transitional climate and include the highest massifs above 2600 m and low altitude glacierised massifs lower than 2000 m glacial extent and evolution have been reconstructed on the basis of detailed geomorphological and morphostratigraphic mapping the equilibrium line altitude palaeo ela has been estimated for the different stages of each tongue the ela has been assessed by the aar and modified kurowski methods and altitude methods have been considered a numerical chronological framework is proposed using 17 ams radiocarbon and one osl data obtained in lake and bog deposits from three massifs four main glacial stages have been differentiated between 38 000 bp and the little ice age they correspond to different cold environments and the number of glacial stages varies from one to four among the different massifs conclusions are analysed in the context of the quaternary glacial evolution of other iberian mountains

quaternary regional evolution based on karst cave geomorphology in picos de europa atlantic margin of the iberian peninsula abstract alpine caves have attracted considerable geomorphological paleoenvironmental and hydrogeological interest since climate glaciations relief uplift fluvial incision and karst aquifer control their evolution in the atlantic margin of the iberian peninsula picos de europa mountains is among of the most important karst areas of the world containing some of the deepest caves explored today in addition these mountains represent a reference site for the study of the last glacial cycle in the sw of europe this work aims to reconstruct the pliocene quaternary evolution of this region based on geomorphological and geochronological research u th and al be carried out in four alpine caves cave geomorphological mapping evidences that 12 km of studied caves are made up of 47 vadose canyons and shafts 45 phreatic epiphreatic conduits organised in six cave levels and 7 breakdown modified passages their deposits are characterized by speleothems including flowstones that represent ancient cave pavements fluvial terrace deposits with allochthonous clasts slackwater deposits related to cave floods and debris deposits produced by breakdown one 26al 10be burial age indicates a minimum age of 2 1 0 5 ma for the caves origin allowing estimation of the mountain uplift at 0 15 0 25 mm a 1 since the late pliocene twenty eight new 234u 230th ages and another six previous speleothem ages give ages ranging from mis 8 to 1 the speleogenetic model comprises six phases of regional evolution phase 1 main development of cave levels with se directed phreatic flow in the nw of picos de europa in a karst partially or totally covered by the detrital permian mesozoic cover presently eroded phase 2 erosion of the permian mesozoic cover and onset of vadose conditions before 260 ka in a karst affected by fluvial captures phase 3 cave infill during 220 145 ka probably caused by the erosion of stephanian detrital outcrops phase 4 erosion of cave infill during 125 45 ka phase 5 apparent pause in the speleothem formation during 45 25 ka related to dry and cold regional conditions phase 6 reactivation of the speleothem precipitation since 25 ka regional climate fluvial incision and the ancient presence of detrital outcrops at the surface appear to have been the main factors that controlled the cave evolution and regional geomorphological evolution throughout pliocene and quaternary times

topographic lithologic and glaciation style influences on paraglacial processes in the upper sil and luna catchments cantabrian mountains nw spain abstract 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

glacial chronology environmental changes and implications for human occupation during the upper pleistocene in the eastern cantabrian mountains abstract interest in the evolution of pleistocene glaciers environmental change and human occupation in southern europe is now growing thanks to the availability of fresh dating in different mountains the demise of neanderthals in the north of the iberian peninsula and the expansion of anatomically modern humans took place between 40 and 30 ka mis3 under cold and wet climatic conditions hypotheses differ regarding the migration and demise of neanderthals relating to environmental human or cultural factors the aim of this study is to establish glacial evolution in the eastern cantabrian mountains related to environmental changes and climatic evolution during the mis3 and mis2 and human occupation including the neanderthals demise the study is based on glaciomorphology by glacial reconstructions morphostratrigraphic sequences equilibrium line altitude estimation numerical dating 14 c ams and osl palaeoclimate sequences and human occupation three glacial stages during mis3 and mis2 have been established s i took place during mis3 in a cold and wet environment associated with snowfall coming from cold humid masses from the n nw and sw and available dates place s i at 42 31 ka s ii was characterised by shorter and thicker glaciers which point to a cold dry and more stable climate and this is coetaneous with the european last glacial maximum s iii was a brief period still poorly dated but attributed to the late glacial characterised by small glaciers housed at altitude and absent from lower mountains a lack of harmony has been detected between environmental cooling and population and this may have been a response to environmental changes in n and nw europe neanderthals disappeared from the cantabrian region at the time of the s i glacial advance during a cold and wet period at the end of the mis3 if they had adapted to environmental changes including abrupt cold events h6 h5 with important environmental consequences factors other than environmental ones may have been the cause the weight of the cultural hypothesis seems more likely in view of the environmental changes glacial evolution and the continuity of oceanic climates

glacial origin for cave rhythmite during mis 5d c in a glaciokarst landscape picos de europa spain abstract laminated slackwater deposits have been identified in many karst caves related to fluvial and lacustrine sedimentation however sedimentological evidence rarely supports a glacial origin for these deposits which was proposed by previous studies the torca la texa shaft is located in a glaciokarst area that comprises numerous slackwater type deposits piled up in fining upward sequences a basal sandy erosive layer and millimeter sized laminated rhythmite with interbedded flowstone characterize these sequences fining upward layers of carbonate silt clay and minor quartz sand deposited in flooded conduits define the rhythmite lamination the presence of allochthonous minerals indicates that the rhythmite sediment comes from the glacial erosion of nearby carbonate mountains two 234u 230th radiometric ages dated the rhythmite deposits around 109 and 95 ka coinciding with relative cold periods included in the mis 5d c these cold periods were marked by a high annual seasonality immediately after the glacial local maximum extension in agreement with a varve type deposit the combination of these sedimentological mineralogical geomorphological and paleoclimate information indicates that the rhythmite should be introduced into the studied cave during the summer melting of the glaciers which produced the recharge of the karst aquifer triggering cave floods in addition punctual glacier collapses would also have their imprint in the slackwater sequences with thicker coarser and erosive sand deposits and the spring blocking by glaciers may have promoted floods inside the cave therefore the studied rhythmite can be interpreted as glacial varves decanted during the relatively cold climate conditions