Inland aeolian deposits of the Iberian Peninsula: Sand

Geomorphology 102 (2008) 207–220

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Inland aeolian deposits of the Iberian Peninsula: Sand dunes and clay dunes of theDuero Basin and the Manchega Plain. Palaeoclimatic considerations

M. Bernat Rebollal a,⁎, A. Pérez-González b,c

a Instituto Geológico y Minero de España, C/ Ríos Rosas, N° 23, 28003-Madrid, Spainb Departamento de Geodinámica, Facultad de Ciencias Geológicas, UCM, Avda. Complutense S/N, 28040-Madrid, Spainc Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Avda. de la Paz, N° 28, 09004-Burgos, Spain

⁎ Corresponding author.E-mail address: [email protected] (M. Bernat Reboll

0169-555X/$ – see front matter © 2008 Elsevier B.V. Aldoi:10.1016/j.geomorph.2008.05.009

A B S T R A C T
A R T I C L E I N F O
Article history:
This paper describes the lat Accepted 15 May 2007Available online 16 May 2008
Keywords:Sand dunesClay dunesUpper Pleistocene–HoloceneDuero BasinManchega PlainSpain

est research on the geomorphological characteristics, formation environment andchronology of the main inland aeolian deposits from the south-eastern Duero Basin (DB) and the ManchegaPlain (MP) of the Iberian Peninsula. Similarities and differences between the aeolian deposits of these twolocations are summarised. Wind deflation from the Guadiana and Júcar alluvial systems created the aeoliandeposits of the MP. These deposits are mainly composed of quartz sands. However, in the San Juan alluvialplain (MP) there is a large extent of clay dunes formed by exposure to prevalent winds of seasonal playa-lakes with salt and clay sediments. In the DB, wind remobilisation of the small particles from Quaternaryterraces and Tertiary arkosic sediments left aeolian deposits of quartz–feldspar sands. Textural parameters ofthe aeolian deposits show large variations depending on the location and the original deposit. Thus, in the DBthe aeolian sands derived from the deflation of fluvial sediments are better sorted and smaller in grain sizethan those created by the deflation of arkosic sediments. Morphologically, simple and compound parabolicdunes (U–V forms, hemicyclic, lobate and elongate), crescentic and linear dunes, climbing dunes and blowoutdunes have been recognized at both sites. Barchan and dome dunes are present only in the DB while “lunettelunette-clay dunes” are found only in the MP. In both locations, the large extent of aeolian sand sheets andthe predominance of simple and compound parabolic dunes indicates the active role of sparse vegetationcover in the formation of this aeolian system. In the DB, dunes were formed by southwest and west winds,while in the MP the aeolian morphologies indicate that the prevalent winds were west and northwest. Thechronology of the dune deposits is being determined with luminescence (TL-OSL) dating and MassSpectrometry Analysis (14C-AMS). In this way, the aeolian activity and stabilisation stages can be established,the latter well marked in the DB through soil A horizon development. Thus, the main sand dune formation inthe DB and the eastern regions of the MP occurred between 13.5 and 7 ka BP, during the cold and aridYounger Dryas episode and the Early Holocene. The clay dunes of the MP accumulated mainly from 29 to19 ka BP that corresponds with Heinrich events HE-3 and HE-2 and the Last Glacial Maximum. However, claydunes were also formed between 13.5 and 7 ka BP. In both locations, there have been reactivations of somesand deposits in the recent Holocene, with maximum activity around 5–2 ka BP and 0.5–0.2 ka BP. On theother hand, three marked stages of stabilisation of the DB aeolian system have been established with 14C-AMS, around 10.2, 6.2 and 1.2 ka BP. Finally, the main winds contributing to dune construction were alsoresponsible for the deflation processes with the formation of erosional depressions.

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1. Introduction

The aeolian deposits in the south-eastern Duero Basin (DB), to-gether with those associated with the River Guadiana in Extremaduraand those situated in the Manchega Plain (MP), constitute the threemost important inland aeolian complexes (Fig. 1) of the recentQuaternary in the Iberian Peninsula (Borja Barrera and Pérez-González, 2001). This paper carries out a geomorphological analysis

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of the aeolian deposits located in the south-east of the Duero Basin(Tierra de Pinares) and in the Manchega Plain (MP) through thecharacterisation and interpretation of the aeolian accumulation anddeflation morphologies.

The extensive sand accumulations in DB were known from themiddle of the 19th century. Casiano de Prado (1854,1862) and Cortázar(1891) proposed a fluvial origin. On the other hand, HernándezPacheco (1923a,b) declared their formation was unequivocally wind-related. Later, Bravard (1965) also recognized the capacity for deflationand transport of the sands bywind. During the 1970s, sedimentologicalwork was begun on these deposits (Aleixandre et al., 1971; Casas et al.,

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Fig. 1. Map of the Iberian Peninsula with the situation of the three zones with inland aeolian deposits. 1—SE of Duero Basin; 2—Manchega Plain; 3—Guadiana River in Extremadura.

208 M. Bernat Rebollal, A. Pérez-González / Geomorphology 102 (2008) 207–220

1972; Alcalá del Olmo,1972,1974), and studies carried out byAlcalá delOlmo contributed the most precise textural and mineralogicalmeasurements. Pérez-González (1982a) also studied the origin of theaeolian deposits and the deflation depressions in the tertiarysubstratum such as the one in Nava de Rey. Sedimentologicalinterpretations and the dating of the aeolian accumulations in themid-eastern part of Tierra de Pinares were performed by Temiño et al.(1997), Díez-Herrero and Bateman (1998), Bateman and Díez-Herrero(1999, 2001), Díez-Herrero et al. (2002) and García-Hidalgo et al.(2002). The works of Desir et al. (2003) and Gutiérrez-Elorza et al.(2005) on the origin and evolution of playa-lakes in the south-easternDB show that the wind deflation was responsible for the initialexcavation of the Quaternary alluvial cover and the subsequentdeepening of the bottom of the playa-lakes. Recently, detailedgeomorphological studies of the aeolian sheet and themain dunefieldsin the DB (Bernat Rebollal et al., 2003; Bernat Rebollal and Pérez-González, 2005) have included morphodynamic classifications andinterpretations of the aeolian accumulation and deflation forms. Theyalso analyse the environmental and chronological setting of theaeolian deposits.

With regard to the MP, the study and cartography of these aeoliandeposits and their morphology were carried out mainly by Pérez-González (1982b), who also tackled the problems of the clay dunes inthe alluvial plain of San Juan (Pérez-González et al., 1983). Themineralogical work carried out by Aleixandre et al. (1977) should alsobe pointed out, as well as the fact that the chronology of the aeoliandeposits has been studied more recently by Rendell et al. (1994, 1996)with luminescence techniques.

2. Regional setting

The aeolian sand sheets and dunefields in the DB are the mostextensive in the Iberian Peninsula and cover hundreds of squarekilometres, from the central sectors of the basin almost as far as thefoothills of the Central System, mainly in the region called as Tierra dePinares (Pine Land). They cover the lowlands and the páramos (highelevation surfaces onMiocene limestone) in the inland area of the basin.The sandy areas of aeolian origin in the DB cover terraces and Plio-Quaternary erosion surfaces, Tertiary sediments of several kinds

(conglomerate, sandy, silt and chalky facies) and Mesozoic–Paleozoicmaterials (slate, shale, quartz, granitoid, sandy dolomitic, dolomites,carbonates and marls) of the satellite mountain massifs of the CentralSystem. A number of dunefields can be distinguished within thesedeposits, amongwhichmention should bemadeof those in thepáramos(La Parrilla andMontemayor de Pililla: Fig. 2: Dfs-4), Arévalo (Fig. 2: Df-1),Cantalejo (Fig. 2: Df-3) and Sanchonuño–Lastras de Cuéllar (Fig. 2: Df-2).The latter, with 77 km2 is the most extensive and complex dunefield(Bernat Rebollal and Pérez-González, 2005).

In theMP the action of thewind has created a landscape composedof aeolian sand sheets and dunes which extend from the wetland ofTablas de Daimiel in the west (Fig. 3–4), as far as the west bank ofthe Júcar River, in the Picazo (Fig. 3), in the east, with a maximumlength of 145 km and a width of 8 km on the alluvial plain of San Juan(Fig. 3). These deposits mainly cover a Quaternary substratum madeup of the terraces of the alluvial systems of the Guadiana and the Júcarrivers.

In both areas, the climate is Mediterranean-continental with hotdry summers, which are always hotter in the MP with an average of24–25 °C in July.Winter is much colder in the DBwith an average of 2–3 °C in January. Frequently extreme temperatures, with a minimum of−15 °C and a maximum of 40 °C are recorded in both zones. It rainsmore abundantly in autumn and spring, and the average rainfall inboth cases varies between 500 and 300 mm depending on location.This puts both areas within the limits of semi-arid conditions.Moreover, in the DB and MP there are prevailing winds from westand southwest with velocities higher than 4 m/s which are capable ofgiving rise to active aeolian processes with ripples, nebkhas andblowouts (Bernat Rebollal and Pérez-González, 2005; 2006a,b). Inaddition, these prevailing winds are most frequent from the end ofwinter until the middle of the summer (INM, 1988, 2002).

The vegetative landscape of the DB is characterised by the more orless continuous presence of a forest mass of resinous maritime pine(Pinus pinaster) and, to a lesser extent, stone pine (Pinus pinea). Thesenative pine forests (Calonge, 1987; Allué et al., 1995) were greatlyexpandedby reforestation in the secondhalf of theXIXcentury (Cortazar,1877, 1891) and especially from the 1940s onwards (ICONA, 1995) tobenefit the resin industry and in order to anchor the dunes. In contrast,the vegetative landscape of the MP is dominated by vineyards and, to a

Fig. 2. Geomorphological synthesis map of the SE Duero Basin (DB) with the main dunefields. Df-1: Arévalo, Df-2: Sanchonuño–Lastras de Cuéllar, Df-3: Cantalejo, Dfs-4: Páramosdunefields. Legend: 1—Dunefields; 2—Aeolian sand sheet; 3—Floodplains and lacustrine areas; 4—Floodplains and terraces of Duero and Pisuerga Rivers; 5—Fluvial terraces; 6—Pedimentdeposits; 7—Páramos and structural plains; 8—Mesozoic massif of Sepúlveda, 9—Paleozoic and Mesozoic substratum: erosion surfaces and residual landforms.

209M. Bernat Rebollal, A. Pérez-González / Geomorphology 102 (2008) 207–220

lesser extent, olive groves,with small pine replantedareas in theextremeeast of the MP (Peinado and Martínez, 1985).

3. Materials and methods

Detailed geomorphological cartography was made in the mostsignificant areas with a digital stereoscopic station. Dune morpholo-gies were identified, as well as other morphogenetic components,

fundamentally of the alluvial and lacustrine systems. Digital carto-graphywas incorporated into a Geographical Information System (GIS)and made it possible to perform spatial analyses and cartographicrepresentations leading to a morphodynamic classification of theaeolian forms. Digital Terrain Models were also carried out byrestitution techniques through digital photogrametric correlation(Fig. 4) and using topographic field data obtained by GPS survey. Thefield work consisted of verifying the cartography, morphometric

Fig. 3. Geomorphological synthesis map of the Manchega Plain (MP) with the more detailed studied areas: 1—San Juan alluvial plain; 2—San Clemente; 3: Casas de Haro–Júcar Rivercorridor; 4: Tablas de Daimiel. Legend: 1—Sandy aeolian sand sheets and dunes; 2—Clay dunes and aeolian sheets; 3—Playa-lakes; 4—Lakes and navas (intermittently floodedendorheic areas); 5—Peat deposits; 6—Floodplains and Valley bottoms; 7—Guadiana River alluvial system; 8—Rus River alluvial system; 9—Júcar River alluvial system; 10—Casas deIbáñez alluvial deposits; 11—Alluvial fans. 12—Karst landforms; 13—Paleozoic residual reliefs and mountains; 14—Erosional surfaces of the MP; 15—Erosional surfaces over Mesozoicsubstratum; 16—Structural surfaces; 17—Glacis.


measurements of the aeolian forms and recording coordinates andelevations with a GPS. The field work also consisted of taking samplesto analyse the sedimentology and establish chronologies of aeolianactivity and stabilisation. The chronologies were obtained by Qua-ternary TL Surveys (UK), the Dating and Radiochemistry Laboratory ofthe University Autonoma of Madrid (Spain) and BETA Analytic INC(USA) through luminescence techniques (TL-OSL) and Mass Spectro-metry Analysis (14C-AMS).

4. Mineralogy and texture characteristics

Two main granulometric facies (Table 1) can be distinguished inthe MP (Pérez-González, 1982b). One is, practically exclusive to thealluvial plain of San Juan (Fig. 3-1), with silt and clay content greaterthan 8% and frequently exceeding 30% (clay dunes). The secondcorresponds to the rest of the aeolian formations, inwhich the clay siltcontent is less than 5%. The sandy facies are mostly fine and medium-sized sand (0.125–0.5 mm), while very coarse (granules: 2–4 mm

Fig. 4. Digital representation example of a compound parabolic dune in the Sanchonuño–photogrammetric correlation in raster format; (2) Its geomorphological cross-section.

diameter) content is practically non-existent. The analysis of the silt–clay fraction in the clay dunes reveals a clear predominance of clayover silt. The average content of the silt fraction is near 12% while theaverage content of clay is 32%. In addition, the aeolian sands associatedwith the alluvial system of the Júcar River have a silt and clay contentwhich is always less than 4.5%.

The mineralogical composition (Aleixandre et al., 1977) of thesedeposits is essentially quartz grains (80–90%), together with feldsparand fragments of carbonates in similar proportions as secondaryminerals. The association of tourmaline (60%), zircon (16.5%) andstaurolite (10.5%) accounts for about 88% of the heavy fraction. Withregard to its morphology, there is a predominance of sub-roundedmatt grains, which suggests that they were transported only a shortdistance from the source area.

The compositional characteristics and the grain morphology of theaeolian sands in the MP reveal a nearby origin, located mainly in thealluvial systems of the Guadiana and the Júcar rivers, in the alluvialfans, in some endorheic areas and in the detrital Pliocene of the MP.

Lastras de Cuéllar dunefield (Duero Basin: Df-2): (1) The DTM obtained with digital

Table 1Summary of the mineralogy and texture characteristic of the Manchega Plain (MP)

Aeolian facies 1 Silt–clay aeolian facies(8–40% silt+clay)

2 Sandy aeolian faciesClay+siltb5%

San Juan alluvial plain(Central area)

Tablas de Daimiel(Western area)Casas de Haro–JúcarRiver (Eastern area)

Silt and clay averagecontents

Silt fraction=12%Clay fraction=32%

Sand grain size Fine and medium (0.125–0.5 mm)Sand mineralogy Light fraction: Primary: quartz grains (80–90%);

Secondary: feldspars and fragments of carbonatesHeavy fraction: association tourmaline (60%)+zircon(16.5)+staurolite (10.5%)

Grain morphology Predominance of sub-rounded matt surface

Mineralogy and morphometry from Aleixandre et al. (1977) and Pérez-González (1982b).


Thus, the more westerly accumulation of aeolian sands and dunes areon the leeward side of the wetland of the Tablas de Daimiel (RodríguezGarcía and Pérez-González, 2002). In the eastern sectors, the sandyaccumulations originated in the deflation of a wide elevated terrace ofthe Júcar River, which represents an alluvial system which formerlydrained towards the west (Pérez-González, 1982b). In contrast withthese groups of quartz sand dunes, with low silt and clay content (lessthan 5%), in the alluvial plain of San Juan a large extent of clay dunesand aeolian sheets has accumulated between Arenales de San Gregorioand Alcázar de San Juan.

In the DB (Table 2) only one sandy aeolian facies with a variable sizeof sand has been determined, thus, the textural characteristics of thedeposits fundamentally depend on the source areas; the sand from thefluvial deposits are better sorted and accumulate in fine-medium sizesof sand (0.125–0.5 mm), while little sorting has been done on thosewhich originate mainly in the Tertiary arkosic facies and are medium tocoarse. Aeolian deposits with coarser granulometry (very fine-pebbles:2–4 mm and fine-pebbles: 4–8 mm) predominate in the western andsouthwestern zones where the Tertiary arkosic substratum appearsmore frequently. In contrast, aeolian sands with finer granulometry arefoundmainly in the eastern zones where the fluvial substratum is moreextensive. In the aeolian deposits on the páramos, the greater distancefrom the source area and the topographic effect of the slopes thatconnect the lowlands with the páramos, leads a greater sorting of theaeolian sands (Bernat Rebollal and Pérez-González, 2005).

The aeolian sands of the south-eastern DB have an averagecomposition of light minerals made up of 62.5% quartz, 35% feldsparand 2.5% fragments of rocks and micas, while the fraction of heavyminerals is defined by the association of tourmaline–garnet–andalu-site, with an average composition of 35, 25 and 12% respectively(Alcalá del Olmo, 1972, 1974).

5. Aeolian forms

Morphologically in the MP (Fig. 5; Table 3) it is possible todistinguish, aeolian sand sheets, parabolic dunes in U and V of bothsimple and composed types, blowout dunes, crescentic and linear

Table 2Summary of mineralogy and texture characteristics of the Duero Basin (DB) aeolian deposit

Main aeolian areas Origin in Quaternary terraces

Mainly in eastern lowland and páramos aeolian dSand grain size Predominance of fine and medium size (0.125–0.5Mineralogy Light fraction: quartz (62.2%)+ feldspars (35%)+ca

Heavy fraction: Association, turmaline (32%)+garnGrain morphology Predominance of sub-rounded matt but with high

deposits of Miocene páramos

Mineralogy and grain morphology from Alcalá del Olmo (1972 and 1974).

dunes, climbing dunes, irregular dunes and clay dunes similar tolunettes as described for the first time in Australia (Hills, 1940) to theleeward of saline-clay playa-lakes. There are also deflation aeolianforms such as blowouts and wind-furrows. The maximum heights ofthe dunes have been measured in the alluvial plain of San Juan as 10–12 m, although normally the crests do not exceed 4–5 m.

The most characteristic aeolian accumulation forms in the DB areaeolian sand sheets and simple and compound parabolic dunes (Fig. 6;Table 4). Crescentic, barchan, dome and linear dunes, aswell as aeoliandestructive–constructive forms such as blowouts (simple blowoutsand blowout dunes) and wind-furrows have been also recognized. Thedunes with the largest dimensions are found in the dunefield of San-chonuño–Lastras de Cuéllar (Fig. 6-C) with dune heights of up to 24 m,kilometres long and hundreds of metres wide. However, the averageheight of the dunes is about 6–7 m, with widths of dozens of metresand lengths which do not usually exceed 500 m. The dunefield ofSanchonuño–Lastras de Cuéllar (Fig. 6-B; C) is also remarkable as it hasthe most morphological variety and complexity in all the DB, and theoverlapping and obliterations of several dunes which compose it arefrequent.

6. Interpretation and discussion on the main aeolian forms in theDuero Basin and the Manchega Plain

6.1. Aeolian sand sheets

The aeolian sand sheets covering 1500 and 400 km2 in the DB andthe MP respectively are the aeolian forms with the greatest extent.Due to the work of tree replanting and agriculture the surfacetopography has been quite altered. These are accumulations of sand(with clay and silt in the clay area of San Juan in the MP) with flat orslightly irregular morphologies which cover the substratum with athickness that varies between a few cm and 4–5 m in the DB andbetween 20 and 30 cm and 1.5 m in the MP. In both cases, they containisolated dune structures with insignificant morphology or withoutdefined avalanche faces, as well as deflation depressions of severalsizes. Good sections in quarries have only been located in the aeoliansand sheets in the DB. There, sets of coarse and very coarse sand havebeen observed and there are even very fine-pebbles and fine-pebblesof up to 8 mm in diameter. These deposits are interpreted as zibars(Cooke et al., 1973; Kocurek and Nielson, 1986), which are duneswithout avalanche faces made up of very coarse particles.

According to Kocurek andNielson (1986), there are a group of factorswhich condition the formation of the aeolian sand sheets. The presenceof disperse vegetation reduces the movement and the growth of thedunes, and encourages the accretion of horizontal sand sheets. Thissparse vegetationappears frequently in themarginsof deserts and in thesemi-arid steppes. In addition, if the subsurfacewater level is shallow orthere are periodic or seasonal floods, the formation of dunes is impeded.Furthermore, the most important control in the formation of extensiveareas of aeolian sheets in desert areas of the Sahara and Arabia is thelarge size of grain in the sedimentmoved by thewind (Breed et al.,1987;Khalaf, 1989). This factor has also been cited in the Canadian Arctic(Mckenna-Neuman and Gilbert, 1986), in the Mojave desert (Kocurek

s

Origin in Tertiary arkosic sediments

eposits. Mainly in west-southwest lowlands aeolian deposits.mm) Predominance of medium and coarse size (0.250–1 mm)

rbonates and micas (2.5%)et (25%)+andalucite (12%)fraction of subangular matt in lowlands and absence of subangular matt in aeolian

Fig. 5. Two representative areaswith aeolian forms of theManchega Plain (MP). A: Clay dunes of San Juan alluvialPlain. B: Sanddunes ofCasas deHaro–JúcarRiver corridor. Legend: 1—Claydunes; 2—Aeolian clay sheet and inter-dune areas; 3—Sand dunes; 4—Aeolian sand sheet and inter-dune areas; 5—Blowouts and wind-furrows; 6—Structural surface; 7—Alluvial fandeposits; 8—Floodplain or valley bottom of the Záncara River; 9—Júcar River Alluvial deposits (Terraces); 10—Wet and dry playa-lakes; 11—Dune crest; 12—Dune crest with indication ofslipface. 13—Undifferentiated crests of blowouts and dunes.


and Nielson, 1986) and in Australia (Mabbutt, 1980). In the DB and theMP there are two fundamental factors: the high amount of particles ofmedium and coarse size in the source areas and the presence in somezones of subsurface water tables, which, together with the open type orsteppe vegetation cover in the periods of greater aeolian activity(Rendell et al., 1994, 1996; Bateman and Díez-Herrero 1999 and 2001;Díez-Herrero et al., 2002) would have propitiated the formation of theaeolian sheets.

6.2. Parabolic dunes

Parabolic dunes such as those described in the DB and in the MPoccur in several environments: cold climates in the past and in thepresent (Filion and Morisset, 1983; Castel et al., 1989), in temperateclimates and wet tropical coasts (Cooper, 1958, 1967; Story, 1982; Pye,1982a; Flor,1983,1992), andon theboundaries of thehot deserts, in bothactive and stabilised zones (McKee, 1966; Bowler and McGee, 1978;Lancaster, 1983). In all these places there is a common denominatorwhich is the association of these types of dune with a certain level ofvegetative colonisation, which shows that this must play an importantfunction in their formation, by protecting the less mobile arms against

Table 3Summary of aeolian forms characteristics of the Manchega Plain (MP)

Main aeolianforms

Aeolian sand sheets: thickness ranging from 20–30 cm to 1.5 mSimple parabolic dunes. U–V, lobate and elongate forms.Compound parabolic dunes.“Linear dunes”Crescentic dunesMorphologies like “lunnete-clay dunes” down-wind of saltand clay playa-lakes.Dome and star dunesIrregular dunesTopographic dunes: Climbing and falling dunes.Deflation aeolian forms: Blowouts and wind-furrows

Aeolian formsizes

Max. height (10–12 m) in the San Juan alluvial plain. Average 6–7 m.Max. length (2000–4000 m) in the San Juan alluvial plain. Average400–600 m.Max. width (200–300 m). Average 50–60 m.

Dunefieldcharacteristics

In San Juan Alluvial Plain dunes are grouped in wide open dunefields,while in Casas de Haro–Júcar River dunes are found in small and closelongitudinal dunefields. In the San Juan alluvial plain there are wetinter-dune areas with playa-lakes and some morphologies like “pans”.

the action of the wind and allowing the central part to advance.However, their formation is also influenced by the humidity of the sandand the presence ofwater tables or vadose inter-phases near the surface(David, 1981). The speed of the wind is also a determining factor asstrongwinds are necessary to overcome the resistance of the vegetation(McKee, 1966).

GIS analysis in the DB and the MP indicates that there is apredominance of simple, compound and complex parabolic forms(Figs. 5, 6, 7), with a 74% of dune forms. The compound forms aremoreabundant in the DB and the complex forms are exclusive to thisgeographic area. These dunes usually show a certain asymmetry andin the majority of cases the arms located to the north or northwest ofthe central depression are more developed. This is related to thedifferences in the contribution of sediment due tomodifications in thedirection of the wind. A predominance of large-scale wedge-planarcross bed stratification (low angle, medium and high) can beappreciated in the DB parabolic dunes (Fig. 8), where laminationthickness varies frommillimetres to centimetres, and orientations anddips of lamination indicate wind transport directions consistent witheffective past winds inferred from dune morphologies. On the otherhand, the absence of good quarries and sections hinders the correctobservation of sedimentary structures in the MP.

In the DB and the MP, the genesis of the parabolic dunes fromblowouts (Figs. 5B,6A, and C) has left unmistakable signs in thedunefields studied, such as the windward (W and SW) deflationdepressions and in the central furrows of the parabolic dunes, whichare sometimes occupied by temporary or permanent waterloggedsurfaces. Another characteristic which refers back to the origin of theparabolic dunes are the sand belts which surround these erosivedepressions, as is the case of the Cotarra de Alba area (dunefield ofSanchonuño, Fig. 6-C: center-south), where there is a recent depres-sion surrounded by a belt of sand which is expanding and advancingtowards the leeward (E) and is forming an incipient parabolic dune. Asconcerns the wind regime, very one-directional winds produceelongate type parabolic dunes (Pye, 1982b, 1993; Filion and Morisset,1983; Gaylord and Dawson, 1987; Short, 1988) such as those mappedin the Arévalo and páramos dunefields (DB, Fig. 6-A, and D) and in theeastern area of the MP (Fig. 5-B). More variable winds tend to formhemicyclic and lunate type parabolic dunes (Pye, 1993) with shorterarms such as those in the majority of the dunefields studied in the DB(Fig. 6). The morphologies of the compound and complex dunes with“adherence-overlapping” characteristics (DB: Fig. 6-B, and C) indicate

Fig. 6. Four representative areas with aeolian forms in the south-eastern Duero Basin (DB) dunefields at the same scale. A: Arévalo dunefield (Fig.1: Df1); B: NE Sanchonuño–Lastras deCuéllar dunefield (Fig. 1: Df-2); C: SW and center of Sanchonuño–Lastras de Cuéllar dunefield (Fig. 1: Df-2); D: Páramo dunefield of La Parrilla (Fig. 1: Dfs-4). Legend: 1—Aeolian sandsheets and inter-dune areas; 2—Dune; 3—Blowouts,wind-furrows anddunedepressions; 4—Floodplain or valley bottom; 5—Nava (intermittentlyflooded endorheic area); 6—Lake; 7—Terrace; 8—Tertiary substratum (arkosic sands and limestones); 9—Slopes in Tertiary substratum; 10—Páramo surfaces on Miocene Limestone; 11—Dune crest; 12—Dune crest withindication of slipface; 13—Undifferentiated crests of dunes and blowouts.


that they have formed by coalescence and piling up of simple dunes atdifferent speeds. One special case of parabolic dunes involves complexparabolic ramps (García-Hidalgo et al., 2002), which are abundant inthe north-east (leeward) dunefield of Sanchonuño–Lastras de Cuéllar(Fig. 6-B: north-east). They consist of parabolic bodies with the frontmore or less cusped, with no internal depression and a very flattenedwindward side with parabolic, crescentic and blowout dunes. More-

over, the compound elongate parabolic dunes, which are veryabundant in the DB area of Arévalo (Fig. 6-A) and in the easternzone of the MP were formed by the evolution of a single body whichstretches in the direction of the dominant wind and their main armsare split by deep deflation furrows in several parallel or sub-parallelarms. Thus, arms in an incipient stage of separation can be observed asvery long wind-furrows (Fig. 6-A: center-north).

Table 4Summary of aeolian forms characteristics of the Duero Basin (DB)

Main aeolianforms

Aeolian sand sheets: thickness ranging from a few cm to 4–5 m.Simple parabolic dunes: U–V forms, hemicyclic, lunate, lobate,elongate, and parabolic ramps (without upwind central furrow)Compound parabolic dunes.Complex parabolic dunes including complex parabolic ramps.Crescentic dunes. Simple and complex. Crescentic with sinuosus crestare present too.Dome and barchan dunes.Irregular dunes.Topographic dunes: climbing dunes, with parabolic and crescenticforms.Deflation aeolian forms: Blowouts and wind-furrows.

Aeolian formsizes

Max. height (24 m) in Sanchonulo–Lastras de Cuéllar dunefield.Average 7–8 m.Max. length (2000–4000 m) Sanchonulo–Lastras de Cuéllar and Arévalodunefields. Average 300–500 mMax. width (700–900 m). Average 100–200 m

Dunefieldcharacteristics

Dunefields show usually dune-form zonation and contains dry andwetinter-dune areas, the latter with Navas (flood temporary endorheicareas) and lakes


6.3 . Crescentic dunes

GIS analysis indicates that crescentic dunes (Fig. 9) represent the15% of the dune forms mapped in the DB, and approximately the 9% intheMP. In the dunefields studied in the DB, the natural sinuosity of thecrescentic dunes that give them a linguoid-barchan aspect (Cookeet al., 1993) can be very marked and, in some cases can tend towardscompound en echelon parabolic forms (Fig. 6-D: center). This markedsinuosity of some crescentic dunes suggests that the vegetation playsan active role in the formation of these morphologies as the presenceof vegetation in the leeward side of the dunes would create a brakeand the unequalmovement of the dune progress. In the case of theMP,these types of dunes are straighter.

6.4. Linear dunes

These dune forms are scarce in the two areas analysed, but aremoreabundant and more developed in height and length (up to 2 km longand 10–12 m high) in the MP (Fig. 5-A). These morphologies can beclassified as sand ridges or vegetated linear dunes (Tsoar and Møller,1986), which are caused by winds with one main direction and where

Fig. 7. View from the windward side of a small simple parabolic dune with V-lobate type formthe Duero Basin (DB).

the vegetation intervenes as an active component in dune formation(these forms tend to converge in type Yand U forms towards leeward).The arrangement and relationship of some of thesemorphologies withother dune forms also suggest that they are the product of degradationof elongate parabolic dunes due to the advance and deflation of theconvex front, while the arms fixed by vegetation are transformed intoduneswith a linear aspect (Bernat Rebollal and Pérez-González, 2005).

6.5. Clay dunes and lunettes

The texture studies for the aeolian sheets andclaydunes in the alluvialplain of San Juan (MP) together with the morphological observationswhich have made possible to characterise forms similar to lunettes toleeward of playa-lakes as those described by Hills (1940), Bowler andMcGee (1978) and Holliday (1997), indicate that, as in the case of otherclay dunes (Price, 1963, 1968), these were formed by exposure toprevalent winds of seasonal playa-lakes with saline, silt and claysediments (Fig. 10). These morphologies are exclusive to this area of SanJuan alluvial plain in theMP.As concerns the rest of themorphologies, it ispossible that the clay products originated by deflation in the currentplaya-lakes covered already existing sand dunes and aeolian sand sheetsin the sameway as recent sands cover clay topographies in the southernborder of the large clay area of San Juan (Fig. 5-A: Extreme southwest).

6.6 . Barchan, dome and star dunes

In DB, barchan dunes are very scarce, small and always on the wind-ward margins of the dunefields (Fig. 6-C: southwest). Thus, they seem tobe associated to zones with a lower contribution of sand and which arevery exposed to the action of the wind, which would hinder thepermanence of the grains of sand and their accumulation. No dunes ofthis type have been observed or described in the MP. Furthermore, in theareas to thewindwardof thedunefieldsof theDB, small-sizeddome formshave been observedwith no defined avalanche faces. According toGarcía-Hidalgo et al. (2002), these dome forms could have constituted the initialphasesofduneconstructionwhichsubsequentlyevolved towardsbarchanand crescentic forms. In contrast, the star dunes have only been found inthe MP, and these are small, short forms (1–3 m) and are similar to hillswithmore or less rounded crestswith irregular armswhich radiate fromacentral point. These dune forms have been identified to the south of Al-cázar de San Juan (Fig. 3-1) and are associatedwith conical forms, while tothe east of Casas de Don Enrique are associated with parabolic forms.

. It can be observed the central deflation area. In the páramo dunefield of La Parrilla, in

Fig. 8. Nava de la Asunción quarry in a parabolic dune with soil evolution (E, Bt and Ck horizons). It can be also observed centimetric laminations with wedge-planar cross bed.Lamination surfaces indicate particles transport from southwest. Duero Basin (DB).


Existence of star dunes indicates periods with high variability in thewindsystem which contrasts with the strong single direction detected in theCasas de Haro–Júcar River corridor (Fig. 3-3) exposed in the elongateparabolic dunes constructed by the west winds.

6.7. Erosive depressions (blowouts and wind-furrows)

In the DB and in the MP, blowouts are found in the aeolian sandsheets and on the dune windward faces and crests (Fig. 11). Develop-ment ofwind erosive forms is related to the vegetation cover. The loss ofvegetation causes a decrease of the superficial roughness, and as a resultof this, an increase of the soil particle wind transport (Gutiérrez-Elorza,2001, 2005). The vegetation of the upper parts of the dunes tends toopen up as it suffers the effects of dry periods. This process isaccentuated by the efficient draining of the sand, and, thus, deflationwith the formation of blowouts occurring above all in these areas (Rutin,1983; Ahlbrandt et al.,1983; Thom et al.,1994).Morphometrically, thereare blowouts with metric and decametric dimensions, the most

Fig. 9. Slip face (dip: 15–20°) of crescentic dune (20 m high) and wet inter-dune area with podegraded lunate parabolic dune. Lastras dunefield in the Duero Basin (DB).

characteristic are the saucer-blowouts with 1:2 to 1:3 breadth–lengthratios and the trough-blowoutswith ratios of 1:4 (Fig.11). In some cases,their evolution to leewardproduces blowout duneswithparabolic formswhile in some trough-blowouts the concentration of the erosion at theend of the windward area forces these to enlarge or migrate towardsleeward (Hesp, 2002). This produces longdeflationdepressionsorwind-furrows, as can be seen in numerous depressions in the zones of studywhichpresentelliptical formswith a lengthenedmain axis (up todozensof metres) towards the NE and E determined by the dominant winds(SW and W) capable of producing aeolian deflation.

7. Internal dunefield organisation and inter-dune characteristics

In the MP the dune groupings are more open in the alluvial plain ofSan Juan. However, in the eastern zone, the dunefields are smaller butmuch more closed and with greater contact between the dune forms.Zoning in the distribution of the accumulation forms has been observedin theDB dunefields, in such away that thewindward areas (SWandW)

nd development. The foreground of the picture shows the upwind face (dip: 3–6°) of a

Fig. 10. Clay dune of lunette type with playa-lake deposits to windward in the western limit of the alluvial plain of San Juan in the Manchega Plain (MP).


in the dunefields have less developedmorphologies, with less complex-ity than the central zones and theedges to leeward (NE andE),where theprocesses of dune accretion predominate. This zoning is not seen in theMP where the dune forms are distributed more irregularly and with nodefined pattern in their morphological differentiation. The inter-dunespaces are typically low relief, topographically depressed zones situatedbetween the dunes with the same morphological and sedimentologicalnature as the aeolian sand sheets. Depending on the presence oftemporarily or permanently waterlogged zones, the inter-dune spacesare defined as wet or dry inter-dune areas. In the DB, the dunefields ofSanchonuño–Lastras de Cuéllar (Fig. 2: Df-2 and Fig. 6-B, C) and Canta-lejo (Fig. 2: Df-3) contain excellentexamples ofwet inter-duneareaswiththe formation of wet depressions as those in Navalayegua, Navalagrulla,Tenca and El Carrizal. The dunefields developed on the páramos and thewestern part of the low fields lack these wet inter-dune areas. Themorphologies of some of thewet depressionswith navas (intermittentlyflooded endorheic area) or lakes in the DB suggest that these may be aproduct of aeolian deflation as they clearly have a main axis in thedirection of the dominant winds from the SW or the W in concordancewith the dune forms and sedimentary structures analysed. The sameoccurs in the MP where, in the area of clay dunes in the alluvial plain of

Fig. 11. Degraded trough-blowout on the crest of a parabolic dune in the

San Juan, there are wet inter-dune depressions with the formation ofsaline playas or sebkhas which can be considered authentic pans (Fig. 5:A-center) due to their elliptical forms, with main axis in the direction ofthe dominant winds and dune rings to the leeward. Moreover, thepresence of shallow water tables in some zones of the aeolian system inthe DB and in the MP could have conditioned the periods of aeoliandeflation and accumulation (aeolian stabilisationwith highwater tables)as proposed by García-Hidalgo et al. (2002) for the eastern zone of theDB.

8. Chronology and environmental setting of the aeolian deposits

With regard to the chronologies, in both geographical areas data havebeen obtained through luminescence techniques by TL and OSL (Rendellet al., 1994, 1996; Díez-Herrero and Bateman, 1998; Bateman and Díez-Herrero, 1999, 2001; Díez-Herrero et al., 2002). Moreover, in the DB,dating has beenperformedwith 14C-AMS (Temiño et al.,1997) on periodsof stabilisation with the formation of soils (A horizons). More recently,the authors of this paper collected samples in conserved dune forms inthe MP and in the DB for chronologies with TL (Quaternary TL Surveys)and OSL (Dating and Radiochemistry Laboratory of University Autónoma

páramo dunefield of Montemayor de Pililla in the Duero Basin (DB).

Fig. 12.Medieval soil (black A-horizons) development between sand aeolian sequences indicating aeolian stabilisation in the Duero Basin (DB) Cantalejo dunefield (Fig. 2: Df-3). It hasbeen dated with 14C-AMS around 1.2 ka BP.


of Madrid). Quartz grains (2–10 µm) from the samples were used toobtain dating through TL techniques, whereas the feldspar grains (2–10 µm) also present in samples were used for dating with OSL.Furthermore, samples collected on A soil horizons intercalated (Fig. 12)in the aeolian sequences of the DB have been dated with 14C-AMS (BetaAnalytic Radiocarbon Dating Laboratory). Thus, 14C-AMS chronologieswere obtained with 2 Sigma calibrated results (95% probability). Asynthesis of all the dating carried out to date in the two areas under studyis given in Fig. 13, and with the published and unpublished data it ispossible to begin to establish the periods of aeolian activity andstabilisation in the inland areas of Spain. For an accurate setting ofthese periods, recent palaeoclimatic events identified by Walker et al.(1999), Cacho et al. (2001), Sánchez Goñi et al. (2002) and Sánchez Goñiand D'Errico (2005) have been used as reference in the present work.

The chronologies of the aeolian deposits (Fig. 13) generally point totheir formation during the transition period from the Late Pleistocene tothe Holocene, as in other aeolian deposits in the central and northernEurope(Castel et al., 1989; Kasse, 2002). During this period there wasextreme climatic variability defined isotopically in the sequence GRIP(Walker et al., 1999), also shown in the marine cores of the Alboran sea,Gulf of Cádiz and the NW Iberian margin (Cacho et al., 2001; SánchezGoñi et al., 2002; Sánchez Goñi and D'Errico, 2005). This climaticvariability was characterised by the cyclical nature of the Heinrichevents (HE) and Dansgaard–Oescher oscillations (D–O), so the warmeror inter-stadials periods are interspersedwithmore intense cold periodsof a longer duration (stadials). Thus, the nucleus of each Heinrich event(when the input of the Canadian ice-rafted detritus was at maximum)and also themaximum of the other D–O stadials, correspond to dry andcold periods in the central Iberian Peninsula (Sánchez Goñi et al., 2002),as is also demonstrated out by other palinological and chronologicalstudies in central Spain (Ruiz Zapata et al., 2000, 2003a, 2003b; Vegaset al., 2003). According to these palinological–chronological studies,vegetative changes occurred as an almost simultaneous response toclimatic oscillations, both in areaswith highmountains and those in lowlands, in such a way that, during the cold periods, the development offorests is limited, and an increase in steppe type herbaceous and bushvegetation is detected.

Dating of the aeolian deposits by luminescence indicates that themain sand dune development (Fig.13: yellowcolour) in theDB and in theeastern zone of the MP took place between 13.5 and 7 Ka BP during thecold and arid episodes of the Younger Dryas (GS-1 stadial) and around8 ka BP in the Early Holocene. The clay dunes in the MP (Fig. 13: paleorange colour) were accumulated mainly from the 29 to 19 ka BP,

associated to the Heinrich Events HE-3 and HE-2, and to the GS-2c andGS-2b stadials. Clay dunes alsowere formedbetween the13.5 and7kaBPat the same time as the sand dunes.Moreover, in both geographical areasthere was another period of wind activity with the formation of sanddunes in the recent Holocene, from5 to 2 ka BP (Fig.13: upper zone). Thiscoincides with the establishment of settlement and the expansion ofagriculture which took place during the Neolithic–Calcolithic period, theBronze and IronAges and the commencement of the Romanisation of theIberian Peninsula, between the 5th millennium and the 1st Century BC(Arribas,1967; Fortea Pérez andMartí Oliver,1977; Guiliane,1980) that isevidenced in the MP through the numerous fortified settlements in theBronze Age and the Mediterranean type intensive farming (Martín et al.,1993; Najera and Molina, 2004; Molina et al., 2005). Finally, the lastaeolian reactivation occurred between 0.5 and 0.2 ka BP coinciding withthe Little IceAge registered in Europe between theXVandXVIII centuries(Jones et al., 1998; Mann et al., 1998, 1999; Crowley and Kim, 1999;Crowleyand Lowery, 2000). On the otherhand, three aeolian stabilisationperiods characterised by the development of soil A horizons (Figs. 12,13)can be established in the DB around 10.2 ka BP, 6.2 ka BP (HoloceneClimatic Optimum) and 1.2 ka BP (Medieval warm period).

As regards the wind regimes which intervene in the construction ofdunes in the DB, the dune morphology observed in the dunefields andthe sedimentary structures of these aeolian deposits indicate that thewinds responsible for the aeolian accumulation processes would bemainly west and southwest, alternating between very unidirectionalwindswhich favour the formation of elongate parabolic dunes andmorevariable winds whichwould be responsible for themore open parabolicforms (hemicyclic and lunate). On the other hand, the winds whichintervened in the construction of the dunes in theMPweremainlywest,northwest and, to a lesser extent, southwest. Winds from the west arealso inferred for the Younger Dryas in the center and north of Europefromaeolianrecords (BatemanandDíez-Herrero, 2001;Kasse, 2002) andnumerical simulations with a general model of the atmosphericcirculation (Isarin et al.,1997). The seasonality of the palaeowinds duringthis period is very difficult to deduce although some authors (McKenna-Neuman, 1993; Koster, 1995) suggest that the aeolian depositingprocesseswouldhave been intense during thewinter season, ashappensinpresentdayperiglacial environments (McKenna-Neuman,1989,1990).

9. Conclusions

In both locations, simple and compound parabolic dunes predomi-nate, the first originated from blowout evolution and the second formed

Fig. 13. Chronologies of the aeolian deposits and associated soils of the Duero Basin (DB) and the Manchega Plain (MP). Data source: 1—Díez-Herrero and Bateman(1998);Batemanand Díez-Herrero (1999, 2001); Díez-Herrero et al. (2002); 2—Rendell et al. (1994, 1996); 3—Temiño et al. (1997); 4—Bernat Rebollal and Pérez-González (unpublish). Verticalcoloured lines show the extreme values of the chronologies while the horizontal fine black line represents the central record value.


by theunionof simpleparabolic dunes. Thepredominanceof aeolian sandsheets and parabolic dunes, the presence of high winding crescenticdunes and possibly “vegetated linear dunes” indicate the active role of anopen vegetation cover in the formation of the aeolian systems.

Morphological observations and textural studies of MP clay dunesindicate that were formed by the exposure of seasonal playa-lakeswith salt and clay sediments to the prevailingwesterly winds, with theexclusive lunette-clay dunes as the main form resulting from thesetypes of aeolian processes. In addition, it may be possible that claymaterials, which originated from deflation of playas, covered previoussand dunes with a different morphology. Such sand deposits werepreviously created by deflation processes of the sandy substratum ofthe Guadiana River Quaternary alluvial system.

The old andnew luminescence datingof dune deposits indicates thatthe main aeolian activity with dune formation in the DB and the MPhappened in the cold stages of the Late Pleistocene and Early Holocene.Palinological and chronological studies in central Spain indicate that

development of forest vegetation is limited during these cold stages,whereas an increase of grass and bush stepparian vegetation has beendetected. This last determination is in agreement with the environ-mental characteristics required for the formation of the dunes andaeolian sand sheets.

The sand dune development in the DB and the eastern region ofthe MP occurred between 13.5 and 7 ka BP, during the GS-1 stadial(Younger Dryas) and the Early Holocene cold episode around 8 ka BP.

The clay dunes of the MP accumulated mainly between 29 and19 ka BP, during the Heinrich events HE-3 and HE-2 and the LastGlacial Maximum, but also were formed between 13.5 and 7 ka BP atthe same time as the sand dunes.

In both locations, there was a reactivation of some sand deposits inthe recent Holocene (5-0.2 ka), with maximum activity around 5–2 kaand 0.5–0.2 ka BP, and these most recent aeolian reactivations coincidewith agricultural expansion between the Neolithic and Romanisationperiods andwith theLittle IceAge inEurope.On theotherhand, there are


well identified stages of stabilisation (around 10.2, 6.2 and 1.2 ka BP) inthe DB that correspond with soil A horizon development which havebeen dated with 14C-AMS. These stabilisation stages without aeolianactivity apparently correspond with climatic optima.

In the DB, the main winds contributing to dune construction camefromwest and southwest, while in the MP there was a predominanceof those coming from the west and northwest. These winds were alsoresponsible for the deflation processes with the formation of saucer-blowouts, trough-blowouts and wind-furrows. Finally, morphologiescomparable to pans in the MP and some wet depressions in the DBwith main axes in the direction of the dominant winds, suggest thatthese landforms are a product of aeolian deflation.

Acknowledgements

We wish to express our more sincere gratitude for the GeologicalSurvey of Spain (IGME) and the Complutense University of Madridbecause of its support and economic financing that has made possiblethis research on the south-eastern Duero Basin and Manchega Plainaeolian deposits.We are also grateful to the revisionwork carry carriedout by M. Gutiérrez-Elorza, Xiaoping Yang, A.M. Harvey and M.T.Bardají, we estimate greatly their advices and suggestions that allowedthe improvement of this paper.

References

Ahlbrandt, T.S., Swinehart, J.B., Maroney, D.G.,1983. The dynamic Holocene dunefields ofthe Great Plains and Rocky Mountains basins, U.S.A. In: Brookfield, M.E., Ahlbrandt,T.S. (Eds.), Eolian Sediments and Processes. Elsevier, Amsterdam, pp. 379–406.

Alcalá del Olmo, 1972. Estudio sedimentológico de los arenales de Cuéllar (Segovia).Estudios Geológicos 28, 345–358.

Alcalá del Olmo, 1974. Estudio edáfico-sedimentológico de los arenales de la Cuenca delDuero. Tesis doctoral. Unpublished. Universidad Complutense de Madrid, Madrid,Spain.

Aleixandre, T., Benayas, J., Guerra, A., 1971. Procesos de movilización del hierro en algunossuelos de la región central española. Anales de Edafología y Agrobiología 30,1095–1111.

Aleixandre, T., Pinilla, A., Pérez-González, A., 1977. Caracterización mineralógica de lasdunas continentales de la Llanuramanchega. Actas III Reunión Grupo de Trabajo delCuaternario. Inst. Geología Aplicada, pp. 281–289.

Allué, M., Costa Tenorio, M., Moreno Sanz, M., 1995. Evaluación y descripción del paisajevegetal en Segovia. In: Abella Mardones, J.A. (Coord.), Paisajes Vegetales de Segovia(árboles, arbustos y montes de la provincia). Ed. Ayuntamiento de Segovia, CajaSegovia, Diputación Provinical, Fundación Nicomedes García y Junta de Castilla yLeón. Colección Hombre y Naturaleza (II).

Arribas, A., 1967. La edad de bronce en la Península Ibérica. In: Gómez Tabanera, J.M.(Ed.), Las raices de España. Instituto español de Antropología aplicada, Madrid.

Bateman, M.D., Díez-Herrero, A., 1999. Thermoluminiscence dates and palaeoenviron-mental information of the late Quaternary sand deposits, Tierra de Pinares, CentralSpain. Catena 34, 277–291.

Bateman, M.D., Díez-Herrero, A., 2001. The timing and relation of aeolian sanddeposition in central Spain to the aeolian sand record of NW Europe. QuaternaryScience Reviews 20, 779–782.

Bernat Rebollal, M., Perez-González, A., 2005. Campos de dunas y mantos eólicos deTierra de Pinares (Sureste de la cuenca del Duero, España). Boletín Geológico yMinero 116, 23–38.

Bernat Rebollal, M., Perez-González, A., 2006a. Procesos de erosión eólica en la Llanuramanchega. Tierra y Tecnología 28, 47–56.

Bernat Rebollal, M., Perez-González, A., 2006b. Actividad eólica actual y procesos erosivosen la Llanura manchega. In: Pérez Alberti, A., López Bedoya, J. (Eds.), Geomorfología yTerritorio: Actas de la IX Reunión Nacional de Geomorfología. Cursos e Congresos daUniversidade de Santiago de Compostela, vol. 171, pp. 147–162.

Bernat Rebollal, M., Pérez-González, A., Iglesias López, A., 2003. Una aproximación a ladistribución de dunas y mantos eólicos de Tierra de Pinares (sureste de la cuencadel Duero). In: Flor, G. (Ed.), Actas de la XI Reunión Nacional de Cuaternario, Oviedo,pp. 111–116.

Borja Barrera, F., Pérez-González, A., 2001. Formas y procesos eólicos. In: Goméz-Ortíz,A., Pérez-Gonzalez, A. (Eds.), Evolución reciente de la geomorfología española. Ed.Rueda, Barcelona-Madrid, pp. 289–318.

Bowler, J.M., McGee, J.W., 1978. Geomorphology of the Mallee region in semi-aridnorthern Victoria and western New South Wales. Proceedings of the Royal Societyof Victoria 90, 5–21.

Bravard, Y., 1965. Notas morfológicas sobre la Tierra de Pinares Segoviana. EstudiosGeográficos 27, 107–124.

Breed, C.S., McCauley, J.F., Davis, P.A., 1987. Sand sheets of the eastern Sahara and rippleblankets on Mars. In: Frostick, L.E., Reid, I. (Eds.), Desert sediments: ancient andmodern. Blackwell Scientific, Oxford, pp. 337–360.

Cacho, I., Grimalt, J.O., Canals, M., Sbaffi, L., Nick, J., Shackleton, N.F., Schönfeld, J., Zahn,R., 2001. Variability of the western Mediterranean Sea Surface temperature during

the last 25 000 years and its connection with the Northern Hemisphere climaticchanges. Paleoceanography 16, 40–52.

Calonge, G., 1987. El complejo ecológico y la organización de la explotación forestal enTierra de Pinares segoviana. Excma. Diputación de Segovia.

Casas, J., Leguey, S., Rodríguez, J., 1972. Mineralogía y sedimentología de los arenales querecubren el Terciario entre los ríos Pirón y Voltoya (Segovia). Estudios Geológicos28, 287–296.

Casiano de Prado, 1854. Note sur la constitution géologique de la province de Segovie.Bulletin de la SocieÂteÂ geÂologique de France XII, 330–338.

Casiano de Prado, 1862. Reseñas geológicas de la provincia de Ávila y de la parteoccidental de la de León. Junta general de Estadística. Comisión del Mapa Geológicode España. Madrid: Imprenta Nacional.

Castel, I.Y., Koster, E., Slotboom, R., 1989. Morphogenetic aspects and age of Late Holoceneeolian drift sands in Northwest Europe. Zeitschrift für Geomorphologie 33, 1–26.

Cooke, R.U., Warren, A., Goudie, A.S., 1973. Geomorphology in deserts. Baxford, London.Cooke, R.U., Warren, A., Goudie, A.S., 1993. Desert Geomorphology. University College

Press, London.Cooper,W.S., 1958. Coastal Sand Dunes of Oregon andWashington. Geological Society of

America, Memoir, p. 72.Cooper, W.S., 1967. Coastal Sand Dunes of California. Geological Society of America,

Memoir, p. 104.Cortázar, D., 1877. Descripcion fisica geologica y agrológica de la provincia de Valladolid.

Memoria de la Comisión del Mapa Geológico de España. Ed. Imprenta y Fundiciónde Manuel Tello, Madrid.

Cortázar, D., 1891. Descripción física y geológica de la provincia de Segovia. Memoria dela Comisión del Mapa Geológico de España. Ed. Imprenta y Fundición de ManuelTello, Madrid.

Crowley, T.J., Kim, K.Y., 1999. Modeling the temperature response to forced climatechange over the last six centuries. Geophysics Research Letters 26, 1901–1904.

Crowley, T.J., Lowery, T., 2000. Howwarmwas theMedievalwarmperiod?Ambio 29, 51–54.David, P., 1981. Stabilized dune ridges in northern Saskatchewan. Canadian Journal of

Earth Sciences 18, 286–310.Desir, G., Gutiérrez-Elorza, M., Gutiérrez Santolalla, F., 2003. Origen y evolución de

playas en una zona semiárida con arenas eólicas (región de Coca, Cuenca del Duero,España). Boletín Geológico y Minero 114, 395–407.

Díez-Herrero, A., Bateman, M.D., 1998. Interpretación paleoambiental y dataciónmediante luminiscencia del manto arenoso de la Tierra de Pinares oriental(Segovia). Geogaceta 24, 107–110.

Díez-Herrero, A., Bateman, M.D., López Sáez, J.A., Vegas, J., 2002. Procesos eólicostardiglaciares en la submeseta septentrional: cronología del manto arenoso de laTierra de Pinares oriental. In: Pérez-González, A., Vegas, J., Machado, M.J. (Eds.),Aportaciones a la geomorfología de España en el inicio del tercer milenio. InstitutoGeológico y Minero de España, Madrid, pp. 167–175.

Filion, L.,Morisset, P.,1983. Eolian landforms along the eastern coast of Hudson Bay, NorthernQuébec. In: Morisset, P., Payette, S. (Eds.), Tree-line ecology. Proc. northern Québec tree-line conf. Nordicana (Centre d'Études nordiques, Université Laval), vol. 47, pp. 73–94.

Flor, G., 1983. El complejo de dunas eólicas de la playa de Frouxeira (Meiras-Valdoviño,La Coruña). Cuadernos do laboratorio xeolóxico de Laxe 6, 155–187.

Flor,G.,1992. Tipología, catalogacióny tendencias de los procesosdeerosión/sedimentaciónen los campos dunares de la costa de Galicia (NW de España). Thalassas 10, 9–39.

Fortea Pérez, J., Martí Oliver, 1977. Cuestiones sobre la Neolitización en la PenínsulaIbérica, vol. 19. Revista de Occidente, pp. 2–7.

García-Hidalgo, J.F., Temiño, J., Segura, M., 2002. Holocene eolian sediments on thesouthern border of the Duero basin (Spain): origin and development of an eoliansystem in a temperate zone. Journal of Sedimentary Research 72, 30–39.

Gaylord,D.R., Dawson, P.J.,1987. Airflow–terrain interactions throughamountain gap,with anexample of eolian activity beneath an atmospheric hydraulic jump. Geology 15, 789–792.

Guiliane, J., 1980. La Chronologie du Néolithique iberique. Travaux de l'Institut d'ArtPhéhistorique, vol. XXII, pp. 231–244.

Gutiérrez-Elorza, M., 2001. Geomorfología climática. Ed. Omega. Barcelona.Gutiérrez-Elorza, M., 2005. Climatic Geomorphology. Developments in Earth Surface

Processes. Elsevier, Amsterdam.Gutiérrez-Elorza, M., Desir, G., Gutiérrez-Santolalla, F., Marín, C., 2005. Origin and

evolution of playas and blowouts in the semiarid zone of Tierra de Pinares (DueroBasin, Spain). Geomorphology 72, 177–192.

Hernández Pacheco, F., 1923a. Las arenas voladoras de la provincia de Segovia. Boletínde la Real Sociedad Española de Historia Natural 23, 211–216.

Hernández Pacheco, F., 1923b. Sobre médanos en Segovia. Boletín de la Real SociedadEspañola de Historia Natural 23, 217.

Hesp, P., 2002. Foredunes and blowout: initiation, geomorphology and dynamics.Geomorphology 48, 245–268.

Hills, E.S.,1940. The lunette, a new landformof aeolianorigin. AustralianGeographer 3,1–7.Holliday, V.T., 1997. Origin and evolution of lunettes on the High Plains, United States.

Geological Society of America Bulletin 108, 953–965.ICONA, 1995. Segundo Inventario Forestal Nacional (1986–1995). Castilla y León:

Segovia. Ed. Ministerio de Agricultura Pesca y Alimentación, Madrid.INM (Instituto Nacional de Meteorologia), 1988. Mapa Eólico Nacional. Ed. Ministerio de

Fomento, Madrid, Spain.INM (Instituto Nacional de Meteorologia), 2002. Rosas de Vientos 1971–2000. Ed.

Ministerio de Medio Ambiente, Madrid, Spain.Isarin, R.F.B., Rensen, H., Koster, E.A., 1997. Surface climate during the Younger Dryas in

Europe as inferred from aeolian records and model simulations. Palaeogeography,Palaeoclimatology, Palaeoecology 134, 127–148.

Jones, P.D., Briffa, K.R., Barnett, T.P., Tett, S.F.B., 1998. High-resolution palaeoclimaticrecords for the last millennium: interpretation, integration and comparison withGeneral Circulation Model control run temperatures. The Holocene 8, 455–471.


Kasse, C., 2002. Sandy aeolian deposits and environments and their relation to climateduring the last Glacial Maximum and Lateglacial in northwest and central Europe.Progress in Physical Geography 26, 507–532.

Khalaf, F.I., 1989. Textural characteristics and genesis of eolian sediments in the Kuwaitdesert. Sedimentology 36, 253–271.

Kocurek, G., Nielson, J., 1986. Conditions favourable for the formation of warn-climateeolian sand sheets. Sedimentology 33, 795–816.

Koster, E.A., 1995. Progress in cold climate aeolian research. Quaestiones Geographicae4, 155–163.

Lancaster, N.,1983. Controls ondunemorphology in theNamib sand sea. In: Brookfield,M.E.,Ahlbrand, T.S. (Eds.), EolianSediments andProcesses. Elsevier, Amsterdam, pp. 261–290.

Mabbutt, J.A., 1980. Some general characteristics of the aeolian landscapes. In: Storrier,R.R., Stannard, M.E. (Eds.), Aeolian Landscapes in the Semi-arid Zone of SouthEastern Australia. Australian Society of Soil Science, Inc., Riverina Branch, pp. 1–16.

Mann, M.E., Bradley, R.S., Hughes, M.K., 1998. Global-scale temperature patterns andclimate forcing over the past six centuries. Nature 392, 779–787.

Mann, M.E., Bradley, R.S., Hughes, M.K., 1999. Northern hemisphere temperatures duringthe past millennium: inferences, uncertainties, and limitations. Geophysics ResearchLetters 26, 759–762.

Martín, C., Fernández Miranda, M., Fernández Pos, M.D., Gilman, A., 1993. The BronzeAge of La Mancha. Antiquity 67, 23–45.

McKee, E.D.,1966. Structures of dunes atWhite Sands NationalMonument, NewMexico (anda comparisonwith structures of dunes formother selected areas). Sedimentology7,1–69.

Mckenna-Neuman, C., 1989. Kynetic energy transfer through impact and its role inentrainment by wind particles from frozen surfaces. Sedimentology 36, 1007–1015.

Mckenna-Neuman, C., 1990. Role of sublimation in particle supply for aeolian transportin cold environments. Geografisca Annaler 72A, 329–335.

Mckenna-Neuman, C., 1993. A review of aeolian transport processes in coldenvironments. Progress in Phisical Geography 17, 137–155.

Mckenna-Neuman, C., Gilbert, R., 1986. Aeolian processes and landforms in glaciofluvialenvironments of southeastern Baffin Island, NWT. In: Nickling, W.G. (Ed.), AeolianGeomorphology. Allen and Unwin, Boston, pp. 213–235.

Molina, F., Nájera, T., Aranda, G., Sánchez, M., Haro, M., 2005. Recent fieldwork at theBronze Age fortified site of Motilla de Azuer (Daimiel, Spain). Antiquity 79, ProjectGallery. http://antiquity.ac.uk/projgall/aranda/index.html.

Najera, T., Molina, F., 2004. La edad del Bronce en la Mancha: problemática yperspectivas de la investigación. In: Hernández, L., Hernández, M. (Eds.), La Edad delBronce en tierras levantinas y zonas limítrofes, Ayuntamiento de Villena, Alicante,pp. 531–540.

Peinado, M., Martínez, J.M., 1985. El paisaje vegetal de Castilla-La Mancha. Ed. Junta deComunidades de Castilla-La Mancha, Toledo, 230 pp.

Pérez-González, A., 1982a. El Cuaternario de la región central de la cuenca del Duero ysus principales rasgos geomorfológicos. “1a Reunión sobre la Geología del Duero”.Instituto Geológico y Minero de España, Salamanca, pp. 717–740.

Pérez-González, A., 1982b. Neógeno y Cuaternario de la Llanura manchega y susrelaciones con la cuenca del Tajo. Tesis doctoral, 179/82. Universidad Complutensede Madrid, Spain, 787 pp.

Pérez-González, A., Aleixandre, T., Pinilla, A., Gallardo, J., 1983. El paisaje eólico de lallanura aluvial de San Juan. Cuadernos do Laboratorio Xeolóxico de Laxe 5, 631–656.

Price, W.A., 1963. Physicochemical and environmental factors in clay dune genesis.Journal of Sedimentary Petrology 31, 245–255.

Price, W.A., 1968. Clay dunes. In: Fairbridge, R.W. (Ed.), The Encyclopedia of Geomorphol-ogy, pp. 126–128.

Pye, K., 1982a. Morphological development of coastal dunes in a humid tropicalenvironment, cape Bedford and cape Flattery, North Queensland. GeografiskaAnnaler 64A, 212–227.

Pye, K., 1982b. Morphology and sediments of the Ransay Bay sand dunes, HinchinbrookIsland,NorthQueensland. Royal SocietyofQueensland. Proceedings, vol. 93, pp. 31–47.

Pye, K., 1993. Late Quaternary development of coastal parabolicmegadune complexes innortheastern Australia. Sedimentology, vol. 16. Spec. Publs. Int. Ass., pp. 23–44.

Rendell, H.M., Calderón, T., Pérez-González, A., Gallardo, J., Millán, A., Townsend, P.D.,1994. Thermoluminiscence and optical simulated luminiscence dating of spanishdunes. Quaternary Geochronology (Quaternary Science Reviews) 13, 429–432.

Rendell, H.M., Pérez-González, A., Calderón, T., Benítez, P., 1996. Late Quaternary aeolianactivity in the Manchega plain, Central Spain. 8th International Conference ofLuminiscence an Electron Spin Resonance Dating. Canberra, Australia, pp. 220–221.

Rodríguez García, J.A., Pérez-González, 2002. Geomorfología de las Tablas de Daimiel ysu entorno. In: Pérez-González, A., Vegas, J., Machado, M.J. (Eds.), Aportaciones a lageomorfología de España en el inicio del tercer milenio, pp. 465–473.

Ruiz Zapata, M.B., Pérez-González, A., Dorado Valiño, M., Valdeolmillos Rodriguez, A., deBustamante, I., Gil García, M.J., 2000. Caracterización de las etapas áridas delPleistoceno Superior en la Región Central Peninsular. Geotemas 1, 273–278.

Ruiz Zapata, M.B., López Saéz, J.A., Vegas, J., López García, M.J., Pérez González, A., GilGarcía, M.J., Dorado Valiño, M.Y., Valdeolmillos, A., 2003a. Environmental changesduring the Late Glacial–Holocene transition in Sierra de Neila (Laguna GrandeLacustrine record, Spain). In: Ruiz Zapata, B., Dorado, M., Valdeolmillos, A., GilGarcía, M.J., Bardají, T., Bustamante, I., DeMartínez Mendizábal, I. (Eds.), Quaternaryclimatic changes and environmental crises in the Mediterranean Region. Serviciode Publicaciones de la Universidad de Alcalá. Alcalá de Henares, Spain, pp. 139–147.

Ruiz Zapata, M.B., Gil García, M.J., Dorado Valiño, M., Valdeolmillos Rodriguez, A., Vegas,J., Pérez-González, A., 2003b. Caracterización palinológica de los últimos grandeseventos fríos del últimoMáximo Glaciar en secuencias de la Península Ibérica. ActasII Congreso Argentino de Cuaternario y Geomorfología. Tucuman, pp. 165–176.

Rutin, J., 1983. Erosional processes on a coastal sand dune, De Blink Noordwijkerhout, TheNetherlands. Physical and Soils Laboratory, vol. 35. University of Amsterdam, p. 144.

Sánchez Goñi, M.F., D'Errico, F., 2005. La historia de la vegetación y el clima del últimociclo climático (OIS5-OIS1, 140.000-10.000 años BP) en la Península Ibérica y suposible impacto sobre los grupos paleolíticos. Ed. Museo de Altamira, Santander.Monografía 20, pp. 115–129.

Sánchez Goñi, M.F., Cacho, I., Turon, J.L., Guiot, J., Sierro, F.J., Peypouquet, J.P., Grimalt, J.O.,Shackleton, N.J., 2002. Synchroneity between marine and terrestrial responses tomillennial scale climatic variability during the last glacial period in the Mediterra-nean region. Climate Dynamics 19, 95–105.

Short, A.D., 1988. Holocene coastal dune formation in South Australia: a case of study.Sedimentary Geology 55, 121–143.

Story, R., 1982. Notes on parabolic dunes, winds and vegetation in northern Australia.CSRIO, Division of Water and Land Resources, Technical Paper. 43 pp.

Temiño, J., García-Hidalgo, J.F., Segura,M.,1997. Caracterizaciónyevolución geológica delsistema dunas-humedales de Cantalejo (Segovia). Estudios Geológicos 53, 135–143.

Thom, B.G., Hesp, P.A., Bryant, T., 1994. Last glacial “coastal dunes” in Eastern Australiaand implications for landscape stability during the Last Glacial Maximum. Palaeo111, 229–248.

Tsoar, H., Møller, J.T., 1986. The role of vegetation in the formation of linear sand dunes. In:Nickling, W.G. (Ed.), Aeolian Geomorphology. Allen and Unwind, London, pp. 75–95.

Vegas, J., Pérez-González, A., Ruiz Zapata, M.B., Gil-García, M.J., Dorado, M.,Valdeolmillos, A., López García, M.J., 2003. The GS-1/Younger Dryas event in theLaguna Grande Lacustrine record. Late Glacial–Holocene transition in the NWIberian Range, Spain. In: Valero-Garcés (Ed.), Limnogeology in Spain. ColecciónBiblioteca de Ciencias, CSIC, Ecología y Medio Ambiente, Zaragoza, pp. 238–304.

Walker, M.J.C., Björcket, S., Lowe, J.J., Cwynar, L.C., Johnsen, S., Knudsen, K.L., Wohlfarth,B., 1999. Isotopic events in the GRIP ice core: a stratotype for the Late Pleistocene.Quaternary Science Reviews 18, 1143–1150.

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Inland aeolian deposits of the Iberian Peninsula: Sand