Glacial evolution of the upper Gallego Valley (Panticosa mountains and ribera de Biescas, Aragonese Pyrenees, Spain)

lo^ Pi ineos, 138: 83 a 78, JACA; 1991 GLACIAL EVOLUTION OF THE UPPER GALLEGO VALLEY (PANTICOSA MOUNTAINS AND RIBERA DE BIESCAS, ARAGONESE PYRENEES, SPAIN)^ ENRIQUE SERRANO-CAÑADAS* ABSTRACT.- Glacial e olu ion in he uppe Gallego Valley has been es ablished by s udying e osional and deposi ional land o ms. Ten pulsa ions, ela ed o i e phases a e desc ibed: P emaximal (F. G. 0), a ibu ed o Middle Pleis ocene; Peniglacie , wi h h ee expanding pulsa ions (F.G. 1, 2 y 3), is a ibu ed o he Uppe Pleis ocene; Finipleniglacial wi h wo phases o dynamic (F.G. 4 y 5') and clima ic (F.G. 5) equilib ium associa ed wi h he Pleis ocene déglacia ion; high moun ain phase (F.G. 6 y 7), wi h wo mo phogene ic episodies; and he Holocene pulses om he Li le Ice Age. RESUMEN.- E olución glacia del Al o Gallego (Mon añas de Pan icosa y Ribe a de Biescas, Pi ineo a agonés). Se econs uye la e olución glacia del Al o Gallego a pa i del es udio de las o mas de e osión y acumulación glacia . Se desc iben diez pulsaciones, co espondien es a cinco ases mayo es: P emáximo (F.G.O.), a ibuido al Pleis oceno medio; Pleniglacia , con es pulsaciones de expansión (F.G. 1,2 y 3), del Pleis oceno ecien e; el Finipleniglacia ,con ases de equilib io dinámico (F.G. 4y 5')y climá ico (F.G. S), ligadas a la deglaciación pleis ocena; las ases de al a mon aña, con dos pulsaciones (F.G. 6 y 7), a ibuidas al Ta diglacia ; y las ases holocenas, de la Pequeña Edad del Hielo. RESUME.- É olu ion glaciai e de Hau Gallego (mon agnes de Pan icosa e Ri age de Biescas, Py énées a agonaises). On é udie l'é olu ion glaciai e du Hau Gallego à pa i de l'é ude des o mes d'é osion e accumula ion glaciai e. On déc i dix pulsa ions, co espondan à cinq phases majeu es: le P émaximun (F.G. 0), a ibué au Pleis ocene moyen; le Pléniglaciai e a ec ois pulsa ions d'expansion (F.G. 1, 2 e 3) a ibuée au Pleis ocene écen ; le Pini-pléniglaciai e a ec des phases d'équilib e dynamique (F.G. 4 e 5) e clima ique (F.G. 5), liées à la déglacia ion pleis ocene; les phases de hau e mon agne, a ec deux pulsa ions (F.G. 6 e 7) a ibuées au Ta di-glaciai e, e les phases holocénes, du Pe i Âge Glaciai e. Key wo ds: Py enees, glacial geomo phology, Pleis ocene, Holocene, gla- cial phases. 1 Recei ed Decembe , 1991. *Dep o. de Geog a ía, U banismo y O denación del Te i o io. Uni e sidad de Can ab ia. 39005-San ahde , Spain. ^ 83 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es PIRINEOS 138 The a eas shaped by glacie s in he high Gallego basin, include he Ribe a de Biescas and he Tena alley. Bo h a eas a e na u al egions o med by he mo phos uc u al compa imen a ion o he Py enean elie . The Ribe a de Biescas sp eads om he Val Ancha dep ession -made up o Eocene ma is o he Inne Ranges (Sie as In e io es). I includes a lysch uni , o med by he Eocene u bidi es. The Inne Ranges, Tendeñe a and Tele a, a e o med by limes ones wi h sand and dolomi ic in e cala ions. They a e a la ge mo phos uc u al ba ie sepa a ing he Ribe a o Biescas om he Tena Valley. . The Tena Valley is loca ed in he axil Py enees and is su ounded by he Inne Ranges, by he Pe mo iassic and olcanic ma e ials in he sou h and wes , and by he igo ous elie which o ms he B aza o, A ai ille, G an Facha, Balai ous and Fe a u as idge on no h and eas . Fig. 1. Loca ion o he s udy a ea in he Py enean ange. The alley mo phology is o ganized acco ding o ma e ial disposi ion, de onic limes ones and shales ollowing he he cinic s uc u es di ec ion. Mo eo e he Cau e e s g ani ic ba holi ic, —which includes he highes poin in he alley, he Balai ous peak a 3,150 m— and he Pan icosa's one. bo h exhibi ing hei espec i e me amo phic au eoles, complica e he elie c ea ing o og aphic kno s which each 3.071 m a. s. I. in In ie no-A gualas massi , which is o med by me apeli es and ma bles. 84 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es GLACIAL EVOLUTION OF THE GALLEGO VALLEY The Tena Valley is di ided in o wo main basins: he Gallego and Calda és. The la e descends om he g ani ic and me amo phic a eas o Pan icosa and In ie no massi s. Obse a ions on he glacial e olu ion o Tena Valley ha e mainly been pe o med in Calda és basin. The con ibu ions o his subjec in he Gallego basin began in he las cen u y wi h SCHRADER ( 1836) dealing wi h he uppe moun ain, while MALLADA (1878) and PENK (1885) deal wi h he glacial deposi ion land o ms and he la e al ob u a ion complexes o he Gallego Valley. These wo ks ha e been ollowed by VIDAL BOX (1933), PANZER (1948) and SOLÉ SABARIS (1942). The made a i s app oach wi hin he plu iglacia is heo y. Mo e de ailed s udies ca ied ou by FONTBOTÉ ( 1948), CASAS & FONTBOTÉ ( 1945) and BARRERÉ ( 1952, 1953, 1966 y 1975) pu he Qua e na y glacia ion p oblems in pe spec i e. Recen ly, MARTÍ-BONO (1977, 1978) and MENÉNDEZ & MARTÍ (1973) ha e wo ked on ch onological p oblems. O he con ibu ions a e he ca og aphic ones (BARRERÉ, 1966; GARCÍA RUIZ & PUIGDEFÁBREGAS, 1982; GARCÍA RUIZ, 1989), he INEGLA s udies on p esen glacie s (ALONSO e a/, 1983; MARTÍNEZ DE PISÓN & ARENILLAS, 1988) and o he s ecen ly made on he uppe moun ain phases, a diglacial and Li le Ice Age (CHUECA, 1989; SERRANO & AGUDO, 1989; SERRANO, 1990 a). 1. Glacial mo phology In he high Gallego he main mo phological ea u es a e he glacial land o ms, which a e insc ibed in he c aggy mo phos uc u al elie . The Pleis ocene glacie s ha e le he mos impo an ea u es and hey a e esponsable o he p esen glacial mo phology. 1.1. E osional land o ms These a e he land o ms p e ailing in he uppe Gallego landscape, ha ing caused he sha pes modi ica ions on he p eglacial mo phology. The la e only s ays in he axial di ides and in he u bidi ic uni s ( lysch a ea). The p eglacial opog aphy and, especially, he s uc u es led he glacial ac ion had condi iona ed is dynamics. The main ac o s in luencing on he di e en ypologies showed by he deposi ional land o ms a e size, al i udinal posi ion and he loca ion o he di e en mo phos uc u al uni s. They ac on ice s a us, size, lengh and endu ance. The glacial ci ques show di e en o ms. They a e usually wide, wi h la and o e deepened bo oms, which show a mode a e ice eed. Away om he highes peaks, ba ely o ganized land o ms, can be ound, mainly ela ed o p eglacial opog aphy and mo phos uc u es. T oughs would lead he ice h ough asymme ical alleys in he uppe s e ches, changing o sha pe and mo e pe ec oughs in he lowe ones. 85 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es PIRINEOS 138 >--._>. 1 ^^í^ 6 Ñ^^ 2 M Líí z ^^^ ^^- 4 9 OÍD ^ 10 12 13 Flg. 2. Geomo phologlcal diag am o he Senegüé-Sabiñánigo on al mo ainic complex. 1, i e s. 2, s uc u al hogback. 3, idges. 4, mo aines. 5, ill deposi s. 6, sca e ed mo ainic ma e ials. 7, glacio lu ial e ace. 8, lu ial e ace. 9, ob u a ion e ace. 10, "glacis". 11, ough walls. 12, esca pmen . 13, illage. 86 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es GLACIAL EVOLUTION OF THE GALLEGO VALLEY The e osional landscape is p oduced by a ela i ely mode a e bu pe sis en eed om he heads. E osional land o ms analysis shows h ee main di e en mo phogene ic phases: Fig. 3. Geomo phological design o The Gallego ough in Lanuza a ea. 1, ough walls. 2, mo aine. 3, slope sc ees. 4, allu ial an. 5, slides. 6, oches mou onées hills. 6, oad. 8, Lanuza ese oi . —The i s s age is only ep esen ed by he e ouches and unca ed idges in he Sia alley. These a e no connec ed o he majo o ms, and ha e been de eloped by an ice ongue coming om he Gallego Valley and ollowing a disappea ed opog aphy, i was a deposi ional glacial phase p e ious o ha which deposi ed he la e al mo aines and dug he Gallego basin. —The second s age was he mos impo an one because i c ea ed he g ea es e osional land o ms, he main o ms in he p esen mo phology. Du ing his pe iod he glacie s made he Gallego, Bola ica, Ripe a, Yene i o, Calda és and Gallego oughs. The ci ques complex which ed hese basins was also o ganized. —The las s age ac ed only in he uppe moun ain, whe e he ci ques appea o e deepened and emodela ed as ough o ms (Ibones, Azules, Xuans y La aza) and he e osional land o ms show impo an changes in ice dynamics. This phase is e y ecen and he ci ques c ea ed du ing he p e ious one we e' nodela ed in de ail. 1.2. Deposi ional land o ms They ha e li le en i y on he landscape, appea ing as de ail land o ms which a e mainly loca ed in ma ginal a eas. 87 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es PIRINEOS 138 1.2.1. The on al and on la e al complexes The a e placed a he bo om o he bo om o he alleys and ci ques a di e en in e als, om 800 m a.s.l. in Senegüé up o 2.600 m in he In ie no massi . a) The mo ainic complex o Senegüé-Sabiñánigo. This is a g oup o land o ms o igina ed by he glacial on a di e en s ages. I is o med by: he on al mo aine o Senegüé, buil by a sup aglacial ill; he glacio lu ial e ace o Au in, linked o he mo aine o which i is joined beyond Sabiñánigo a a single le el + 15 m o e he p esen halweg; and he mo aine o Au in, damaged, and o med by a sup aglacial ill. Abo e his he e a e some sca e ed mo aine emnan s in he Sa ué dep ession a 870 m. They a e connec ed o he Lá ede la e al mo aine. Such emnan s and a glacio lu ial e ace a + 3 m. abo e he p esen channel in he Sa ué dep ession poin ou a p e ious episode linked o he phase which o igina ed he on al complex. b) The mo ainic complex o Lanuza-Pan icosa. The e a e la e al mo aines and di e se mo ainic emnan s s ay in Gallego and Calda és alleys a 1,300 m. They poin ou he exis ence o a glacial on whose on al pa s ha e been des oyed by he p oglacial and pos glacial p ocesses. The Lanuza la e al mo aine is o med by a lodgemen ill which suppo s a sup aglacial ill abo e i . Bo h a e bu ied by s a i ied slope sc ees. In Pan icosa he mo ainic emnan s, o med by a sup aglacial ill, a e e y damaged. They a e deepe and ha e wide ob u a ion deposi s. c) F on al complexes in high moun ain. The appea loca ed a in e als in oughs and ci ques. In Amales, In ie no, Pecico, Pun a Za a, Xuans, Le e o and Espelunz he e a e complexes a 2,300 m a.s.l. whose ea u es a e pa ially dis u bed. In hese ci ques, abo e he p e ious complexes, be ween 2,400 and 2.500 m a.s.l., he e a e emnan s o on al mo aines. Almos all o hem a e small and loca ed a he oo o he cli s. Highe abo e, he e a e only mo ainic complexes in he highe and be e exposed ci ques. We can ind g oups o med by wo o h ee a cs in he In ie no, Pun aZa a,Tendeñe a and Sabocos. In he lowe ci ques he mo ainic land o ms ha e usually been subs i ued by ock glacie s loca ed a he bo om o he ci ques and a he oo o he cli s. d) La e al complexes. In he Tena Valley he e a e la e al mo aines a 1,800 m a.s.l. in he Es i iacha and Cos e a O denal. They su ound he Pan icosa and Lanuza lowe complexes and a e e y damaged. These land o ms and deposi s in ol e he la ges size eached by he glacie s in he alley. The Ribe a de Biescas la e al complexes a e loca ed in Lá ede, Oli an, Ba benu a, La Sia, Los Fo cos, Asieso, El Pue o, Sob emon e and Escue . They a e la ge han hose in Tena Valley and a e loca ed in la e al alleys pe ched o e he ough. The a e o ganized as ob u a ion complexes whe e he subglacial ill, sup aglacial ill and lacus ine ob u a ion deposi succesion exis s. All o hem a e co e ed by hillside deposi s. The la e al a cs a e well p ese ed: i e in Sia, h ee in Oli an, h ee in Escue and wo in Sob emon e. All o hem a e he mos impo an la e al mo ainic and ob u a ion complexes 88 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es GLACIAL EVOLUTION OF THE GALLEGO VALLEY and a e loca ed a di e en heigh s. The deposi ionai ea u es, sedimen wea he ings and land o ms o he deposi s allow us o a ibu e he main land o ms o he same glacial s age. We can ela e hem o he on al complex o Senegüé-Sabiñánigo. In La Sia and Espie e alleys he e a e e osional ea u es and ewo ked mo ainic ma e ial sca e ed on he ancien bo om o he alleys. They a e co e ed by lacus ine and slope ma e ials. These ea u es allow us o iden i y a glacia ion p e ious o he emnan s o e osional and deposi ionai land o ms in he Ribe a de Biescas. 2. Glaciomo phological dynamics and e olu ion 2.1. The P e-maximun phase The blocks and megablocks sca e ed h ough he Espie e and La Sia alleys a e o glacial o igin. They may be classi ied as emnan s o ill o p oglacial deposi s bu hey a e nei he ela ed o he main glacial land o ms no o he exis ing deposi s. In Yese o hey a e all loca ed o e he ancien bo om o he alley he e is also a lacus ine complex. The alley bo om deposi s include sca e ed g ani ic blocks and a o ma ion cons i u ed by sup aglacial ill co e ed by lacus ine and slope deposi s. These sedimen a y eco ds and e osional land o ms poin o a s age p e ious o he main glacial land o ms. This is mainly deduced om: he mul iple p ocesses which ha e ac ed on hem wi h ewo ked mo ainic ma e ial included in ecen ly al e ed ancien hillside deposi s; he lack o well p ese ed land o ms; hei uneasy connec ion wi h he majo glacial phase; and hei ela ionship wi h he p eglacial opog aphy. They a e emnan s coming om an ancien , p e ious o he pleniglacial, cold phase. One can assume ha hey we e c ea ed on a di e en mo phology o he p esen and Pleniglacial ones and ha hey may be ela ed o he Pleis ocene and o one o i s cold phases. 2.2. The Pleniglacial: ice maximal expansion The combina ion o mo phos uc u al cha ac e is ics, opog aphy and exposu e has p oduced se e al dymanjc a eas, wi h he mos ac i e glacie s coming om he highes di ides. The no he n exposu e is o g ea impo ance in he o ma ion o ci ques in e e y massi . The la ge mo phos uc u al ba ie o he Tele a and Tendene a Ranges is he clea es example, as hey show a sha p di e ence be ween hei sou he n and no he n slopes. The pleniglacial land o ms show déglacia ion since he glacial maximum pe o med by episodies ha gi e i a discon inuous cha ac e . Du ing his pe iod, in he s abiliza ion maximum one, he glacie should ha e been 300 m deep in Ribe a de Biescas, 400 m in San a Elena and 600 in Tena Valley. 89 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es PIRINEOS 138 SRANITOS (3R) CALIZAS ARENISCAS ESOUISTOS PIZARRAS PCRMOTRIAS (PTI PRESENCIA DE GRANITOS DEPÓSITOS MORRENICOS Fig. 4. Li hology o he mo aine deposi s in he s udy a ea. 1, g ani es. 2, limes ones. 3, sands ones. 4, schis s. 5, shales. 6, Pe mo iasic ma e ials. 7, g ani e p esence. 8, mo ainic deposi s. 9, glaciolacus ine deposi s. 90 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es GLACIAL EVOLUTION OF THE GALLEGO VALLEY The S udy o he sedimen s in he ills p o ides in o ma ion on he ice ongue dynamics and i s o igin. So we can dis inguish be ween he land o ms associa ed wi h he Gallego ma e ials and hose ela ed o he Inne Ranges, mainly in El Pue o alley. Sedimen analysis also shows he ela ionships be ween he Pan icosa ice la e al complex and he Bola ica and T a enosa ice on al complex ( ig. 4). The au och onous ma e ials play a majo ole, hough always lowe in he sup aglacial ill. The p esence o g ani es in he eas side o he glacie and he absence o e y li le p esence on he wes e n is a e y impo an ac o . Mo eo e , i shows he poo mix u e kep by he di e en masses inside he glacie . This ac , e y common in he glacial ongues all o e he wo ld, dec eases in he glacie on . He e ice mel ing p ocesses encou age he mixing o he sedimen s, con i ming he mo ainic cha ac e o he Au in on al deposi s (Fig. 5). 102 , 702 701 TAMAÑO DE ARENAS A enas g uesc TAMAÑO DE CANTOS PETR06RAF1A m 5 4 5 i 1 O Km. Fig. 5. C oss-sec ion o he Senegüé lu ioglacial plain and sedimen ological da a. The land o ms ela ed o he pleniglacial phase a e he mos impo an ones in glacial mo phology. They a e mos ep esen a i e in he uppe Gallego basin. They cons i u e a la ge numbe o deposi ion and e osion land o ms. We can di e en ia e: A maximal expansión pulse (F.G. 1 ) ma ked 91 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es GLACIAL EVOLUTION OF THE GALLEGO VALLEY In he same way, he Pleniglacial would ha e i s maximum be o e 38,000 B.P., wi h a e ac ion and equilib ium pe iods da ed be ween 25,000 and 24,000 B.P. I would include he quie e ac ion phases. F om his poin on he degla ia ion s a s in he lowe a eas. 3.3. Finiglacial e ac ion We ha e di ided his phase in o di e en episodes: Bubal and Ripe a ha e a dynamic cha ac e while Lanuza, has a clima ic one. This las phase is he so-called "disjunc ion phase" by BARRERÉ (1963) because he glacial (3>^ Fig. 9. Glacial ex ension du ing he Finiplels ocene e ac ion, Lanuza phase (F.G. 5). 1, idges. 2, ou wash low channels. 3, glacial ongue. 97 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es PIRINEOS 138 ongues s ayed de ini ely sepa a ed and enclosed inside he moun ains. Some simila e ac ion pe iods ha e been poin ed ou in he A iège (TAILLEFER, 1985), Ando a (VILAPLANA, 1985), PALLARS (BRU e a/., 1985), Ribago za (ViLAPLANA, 1983) and Benasque Valley (MARTÍNEZ DE PISÓN, 1989). The iniglacial e ac ion was p oduced a e he las s opping pe iod, da ed abou 26,000-24,000 B.P. (MARDONES, 1982; ANDRIEU e a/., 1988), These au ho s belie e ha a p og essi e e ac ion un il i s e ea o he uppe alleys was p oduced abou 16,000-15,000 yea s B.P. 3.4. High moun ain phases 3.4.1. High moun ain expansion The mo aine p esence is widely de ec ed in he high moun ain a eas o he Py enees. S a ing om he glacie ex ension and si ua ion, we a ibu e hese land o ms, o he Ta diglacial, making an ex apola ion om he exis ing bibliog aphy (TAILLEFER, 1968; SERRANO, 1989). I s ch olonogy has been es ablished be ween 13,000 and 10,000 B.P. (MARDONES & JALUT, 1983; TAILLEFER, 1985, VILAPLANA, 1983; MONTSERRAT & VILAPLANA, 1987). Palinologic analysis only de ec a cold phase in he Ta diglacial. The e is no ace o i (JALUT e a/., 1982) in Lou des (MARDONES, 1982), Ribago za (MONTSERRAT & VILAPLANA, 1987), he Tena Valley (MARTÍ-BONO, pe s. comm.) and e en in A iège, in F eychinede pea bog. Howe e , he geomo phological analysis allows us o es ablish a di e ence among se e al mo phogene ic phases a ibu ed o his pe iod by some au ho s (BRU e al., 1985; SERRANO, 1991a; MARTÍ & SERRÂT, 1990). We include he high moun ain I and II episodes in o he Ta diglacial because s udying he mo phological posi ion o he mo aines and he lichen co e , we ha e es ablished ha hey a e e y close in ime (SERRANO, 1991 a; 1991 b). Taking in o accoun palinological analysis we hypo he ically assign he i s episode o he Old D yas, be ween 15,000 and 13,000 B.P. wi h cold cha ac e is ics (DUPLESSY e a/., 1981 ; RUDDIMANN & MCINTYRE, 1981 ; JALUT & MARDONES, 1984); he second one is loca ed in he ecen D yas. The " a diglacial in e s a e" would be loca ed be ween hem (JORDA, 1985). 3.4.2. His o ic g ow h: The Li le Ice Age This phase ep esen s he las cold pulsa ion o some mo phogene ic impo ance in he high Gallego basin. I is loca ed in he Li le Ice Age, he glacial eappea ing be ween he XVI h and XlX h cen u ies. In In ie no Massi , om his o ical pape s, MARTÍNEZ DE PISÓN & ARENILLAS (1988) ha e checked he exis ence o a ongue glacie which s a ed i s e ac ion in he eigh ies o he XlX h cen u y. Some la ge and c acked ongues we e loca ed and desc ibed by scien is s and climbe s like Russel 98 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es GLACIAL EVOLUTION OF THE GALLEGO VALLEY & 03 ^4 O 5 m Fig. 10. Glacial ex ension du ing he uppe moun ain expansion phase (F.G. 6). 1, idges. 2, i e s. 3, lakes. 4, glacial ongues. 5, elic ice. 5, ock glacie s. 7, no ixed glacial on s. in 1867 and Lequeu e in 1874. LUCAS-MALLADA (1878) also s udied bo h dis anced "ices" and SCHRADER ( 1936) poin ed ou in 1898 wo glacie s in he In ie no and a hi d one in Pondiellos. The pulsa ions esponsible o he inne a cs may be ela ed o hose desc ibed by PLANDE (1947), BRUNET (1956) and BARRERÉ (1953). The claimed 99 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es PIRINEOS 138 Fig. 11 .Glacial ex ension du ing he uppe moun ain e ac ion phase (F.G. 7). 1, idges. 2, i e s. 3, lakes. 4, glacial ongues. 5, elic ice. 6, ock glacie s. 7, ancien ock glacie s. 8, no ixed glacial on s. a S abiliza ion beginning in 1905 and a maximum las pulsa ion be ween 1910 and 1915. In he s udied a ea he Li le Ice Age is cha ac e ized by he exis ence o wo pulsa ions: a i s phase ill he middle o he XlX h cen u y p oduced a maximum expansion. I is ollowed by a e ac ion ha inishes in he i s 100 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es GLACIAL EVOLUTION OF THE GALLEGO VALLEY H^ 0^ & m V Fig. 12. Glacial ex ension du ing he Li le Ice Age. 1, idges. 2, i e s. 3, lakes. 4, 5, elic ice. 6, ock glacie s. 7, Flowing deb is. ilacial ongue. decade o he XX h cen u y. The glacie e ac ion up o I s p esen s a e began a he beginning o his cen u y. I ma ks he end o his phase. I mus be poin ed ou , inally, he absence o Holocene pulsa ions, al hough hey a e p esen in mos o he empe a e moun ains in he wo ld (LE ROY LADURIE, 1967; GROVE, 1977; ROTHLISBERGER e al., 1980; ZIMBUHL & 101 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es PIRINEOS 138 HoLZHAUSER, 1988). This subjec cons i u es a di e ence be ween he Pan icosa moun ains and he Alpine ones. 4. Conclusions Clima ic e olu ion, al i ude and exposu e ha e con olled he glacial dynamics in he s udy a ea. These ac o s, oge he wi h he mo phos uc u al one, explain he di e ences o Pleis ocene and Holocene glacial ea u es and dynamics. The uppe a eas a e domina ed by e osion ea u es, wi h well-de eloped ci ques and oughs. He e, ice accumula ion was he mos impo an ac o and he glacial his o y is mo e complex. Lowlands a e also domina ed by e osion ea u es, bu deposi ional ones a e e y equen . He e, he con luence o ongues caused ice masses o enla ge, and e osion and deposi ion land p ms a e well pe o med by Gallego ough, as well as la e al and on al mo aines complexes. In he high Gállego'basin i e main glacial phases ha e occu ed: The p e- maximal (F.G. 0), Pieniglacial, Finipleis ocene e ac ion, Ta diglacial and Li le Ice Age. Such main phases a e di ided in o di e en episodes o dynamic and clima ic cha ac e spaced a he bo om o he oughs and slopes: Th ee main episodes du ing he Pieniglacial (F.G. 1, 2 and 3), wi h o he ea u es sca e ed in he Gallego ough walls; h ee mo e episodes du ing he Finipleis ocene e ac ion, one clima ic e en (F.G. 5) and wo dynamic ones (F.G. 4 and 5'); wo mo phogene ic phases om he Ta diglacial (F.G. 6 and 7); and se e al small ones du ing he Li le Ice Age (F.G. 8) pulsa ions. All o hem, oge he wi h he p esen glacie s and elic ice, a e he Pleis ocene and Holocene his o y o glacial ea u es in he Tena Valley and Ribe a de Bies*cas. Re e ences ALONSO, P., MARTÍNEZ DE PISÓN, E. & NICOLÁS, P. (1983): Los glacia es españoles ac uales. Policopiado. ANDRIEU, V., HuBSCHMAN, J., JALUT, G. & HERAIL, G. (1988): Ch onologie de la déglacia ion des Py énées ançaises. Dynamique de sedimen a ion e con enu poilinique des paléolacs: applica ion à la in e p é a ion du e ai glaciai e. Bull. ass. F ançaise pou l'é ude du Qua e nai e, 2-3: 55-67. BARRERÉ, P. (1952): Le elie des massi s g ani iques de Neou ielle, Cau e e s e Pan icosa. Re ue Géog aphique des Py énées e du Sud Ques , 2: 69-98. BARRERÉ, P. (1953): Equilib e glaciai e ac ual e qua e nai e dans l'Oues des Py énées Cen ales. Re ue Géog aphique des Py énées e du Sud Ques , 2: 116-134. BARRERÉ, P. (1963): La pé iode glaciai e dans l'Oues des Py énées cen ales ancoespagnoles. Bull. Soc. Géol. de F ance, 5(7): 516-525. BARRERÉ, P. (1966): La mo phologie qua e nai e dans la égion de Biescas e de Sabiñánigo (Hau A agón). Bull. Ass. F . E ude du Qua e nai e, 2: 129-138. BARRERÉ, P. (1975):Te ases e glacis d'é osion en oches end es dans les mon agnes du Hau A agon. E udes Géog aphiques, 1: 29-43. 102 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es GLACIAL EVOLUTION OF THE GALLEGO VALLEY BRU, J., GÓMEZ ORTÍZ, A., SERRÂT, D., VENTURA, J. & VILAPLANA, J. M. (1985): Sín esis de la dinámica glacia cua e na ia en la e ien e me idional del Pi ineo ca alán. Ac as de la P ime a Reunión del Cua e na io Ibé ico, GETC-GTEPQ, Lisboa, ol. 1: 165-184. BRUNET, R. (1956): Un example de la eg ession des glacie s py énéennes. Pi ineos,39- 42:261-264. CASAS, J. M. & FONTBOTÉ, J. M. (1945): El alle de Tena. Rasgos isiog á icos y economía egional. Pi ineos, 2: 37-107. CHUECA, J. (1989): Ca ac e ís icas de los glacia es ocosos del á ea me idional del ba oli o de Pan icosa (Pi ineo Oscense)". Geog aphicalia, 26: 61-74. DuPLESSY, J. C. e al (1981): Deglacial wa ming o he no heas e n a lan ic ocean: co ela ion wi h he paleoclima ic clima ic e olu ion o he Eu opean con inen . Palaeogeog . Palaeoclima . Palaeoecology, 34: 121-144. EQUIP DE GEOMORFOLOGIA( 1980): Ca álogo de los glacia es de la Península Ibé ica. No es de Geog a ía Física, 3: 35-55. FONTBOTÉ, J. M. (1948): La ibe a de Biescas. Pi ineos, 7: 39-91. GARCÍA-RUIZ, J. M. (1989): Mapa geomo ológico E. 1: 50.000. Salien (M. T. N. 145). Geo o ma Ediciones, 29 p. + 1 mapa, Log oño. GARCÍA-RUIZ, J. M. & PUIGDEFÁBREGAS, J. (1982): Fo mas de e osión en el lysch eoceno su pi enaico. Cuade nos de In es igación Geog á ica, 8: 85-1 28. GÓMEZ ORTÍZ, A. ( 1987): Con ibució geomo ologica a l'es udi deis espais sup a o es als pi enencs. Génesi, o gani zació i dinámica deis modela s glacial y pe iglacials de la Ce danya i l'Ai U gell. Ins . ca og a ic de Ca aluña, 161 p., Ba celona. GROVE, J. M. ( 1977): The glacial his o y o he Holocene. P og ess in Physical Geog aphy, 3(1): 2-53. HERAIL, G., HUBSCHMAN, J. & JALUT, G. (1987): Qua e na y glacia ion in he F ench Py enees. Qua e na y Science Re iew, 5: 397-402. HETU, B. &GANGLOFF, P. (1989): Dépo s glaciai es du Pleis ocene in é ieu su le piémon no d des Py énées A lan iques. Z. Geomo ph. N. F., 33(4): 385-403. HUBSCHMAN, J. (1984): Glaciai e ancien e glaciai e ecen . Analyse compa ée de l'al é a ion des mo aines e minales no dpy énéennés. Colloque Mon agnes- Piémon s. Re ue Géog aphique des Py énées e du Sud Oues : 313-332. JALUT, G. & MARDONES, M. (1982): Rappo s en e l'é olu ion clima ique e la dynamique glaciai e en A iège e su le piémon de Lou des depuis en i on 50.000 B. P. jusqu'à 10.000 B. P. Colloque de Géomo phologie, Mon agnes e Piemon s, Uni . Toulouse Le Mi ail, 10 p. JALUT, G., DELIBRIAS, G., DAGNAC, J., MARDONES, M. & BOUHOURS, M. ( 1982): A palaeoecologial app oach o he las 21.000 yea s in he Py enees: he pea bog o F eychenede (al . 1.350 m., A iège, Sou h F ance). Palaeogeg aphy. Palaeoclima ology, Palaeoecology, 40: 321-359. JALUT, G. & MARDONES, M. (1984): E olu ion clima ique e dynamique glaciai e en A iège e su le piémon de Lou des dépuis en i on 50.000 jusqu'à 10.000 B. P. Mon agnes e Piemon s, Re ue Géog aphique des Py énées e du Sud Oues , 55: 298-312. JoRDA, M. (1985): Le D yas ecen : une c ise mo phoclima ique majeu e dans les Alpes F ançaises du Sud. S udia Geomo phologica Ca pa o-Balcanica, 18 p. LE ROY LADURIE, E. (1967): His oi e du clima depuis l'an mil. Flamma ion, 366 p., Pa is. MALLADA, L. (1878): Desc ipción ísica y geológica de la p o incia de Huesca. Mem. Com. Mapa Geol. España, . XV. Mad id. XV+439 p. MARDONES, M. (1982): Le Pleis ocene supé ieu e L'Holocéne du piémon de Lou des: Le gisemen de Biscaye (Hau es Py enees). E ude Palynologique, sédimen ologique e géomo phologique, A06 p., Jou ouse. MARDONES, M. & JALUT. G. (1983): Le Tou biè e de Biscaye (Al . 409 m.). App oche paleoécologique des 45.000 de niè es années. Pollen e spo es, 25(2): 163-212. MARTÍ BONO, C. (1977): Al os alles de los íos A agón y Gallego. Guía de Excu siones I y II. 2.- Reunion Nacional G upo T abajo Cua e na io. T abajos Neógeno Cau e na io, 6: 337-348. 103 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es PIRINEOS 138 MARTÍ BONO, C. (1978): Aspec os geomo ológicos del Al o A agón Occiden al. Es u- dios Geog á icos, 39: 473-494. MARTÍ BONO, C, SÉRRAT, D. & GONZALEZ, M. C. (1977): Los enómenos glacia es en la e ien e me idional de los Pi ineos. V Coloquio de Geog a ía, pp. 68-73, G anada. MARTÍ, M. & SERRÂT, D. (1990): Los glacia es ocosos del Pi ineo ca alán: p ime os esul ados. / Reunión Nacional de Geomo ologia, pp. 191-202, Te uel. MARTÍNEZ DE PISÓN, E. (1989): Mo ología glacia del alle de Benasque (Pi ineo A ago- nés). E a, 19-20: 51-64. MARTÍNEZ DE PisoN, E.& ARENILLAS, M.(1988): Los Glacia es ac uales del Pi ineo Español. In La nie e en el Pi ineo Español, M. O. P. U., 29-98, Mad id. MARTÍNEZ DE PISÓN, E., ARENILLAS, M. & MARTÍNEZ, R. (1991): El es ado de los glacia es españoles en 1991. E a, én p ensa. MENÉNDEZ AMOR, J. & MARTÍ BONO, C. (1973): Los sedimen os lascus es de Búbal. Pi ineos, 107: 45-47. MONTSERRAT, J. & VILAPLANA, J. M., (1987): The Paleoclíma ic eco ds o he Uppe Pleis ocene and Holocene in he Llause Valley (Cen al Sou he n Py enees). P/ / jeos, 129: 107-113. PANZER, W. (1948): El desa ollo de los alles y el clima de la época cua e na ia en el NE de España. Es . Geog ., 30: 79-130. PENCK, A. (1885): La pé iode glaciai e dans les Py énées. Bull. Soc. His . Na u elle de Toulouse, 19: 105-200. PLANDE, E. (1947): La nie e y los glacia es en el Pi ineo. Pi ineos, 5: 167-182. ROTHLISBERGER, P., HAAS, P., HOLZBAUSER, H., KELLER, W., BIRCHER, W. & RENNER, F. (1980): Holocene clima ic luc ua ions adio ca bon da ing o ossil soils ( Ah) and woods om mo aines and glacie s in he Alps. Geog aphica Hel e ica, 35(5):25-52. RUDDIMANN, W. F. & MCYNTIRE, A. (1981): The No h A lan ic Ocean du ing he las déglacia ion. Palaeogeog . Palaeoclima . Palaeoecology, 35: 145-214. SCHRADER (1836): Su l'é endue des glacie s des Py énées 1894. Py énées, 201-221. SERRANO, E. ( 1989): Las apo aciones más ecien es sob e las glaciaciones cua e na ias de los Pi ineos. E ía, 18: 74-77. SERRANO, E. (1991 ) a): E olución pos glacia de lade as en la al a mon aña del macizo de Pan icosa. In UGARTE y CEARRETA (eds.), The la e Qua e na y in he wes e n Py enean egion. Uni e sidad del Pais Vasco, 411-424, Vi o ia. SERRANO, E. (1991 b): Geomo ologia glacia de las mon añas y alles de Pan icosa y la Ribe a de Biescas (Pi ineo a agonés). Tesis doc o al (inédi a), Uni e sidad Au ó- noma de Mad id, 940 p. SERRANO, E. &. AGUDO, C. (1988): La deglaciación del ci co de los Ibones Azules. Es udio glaciomo ológico. Cua e na io y Geomo ologia, 2 (1-4): 115-123. SERRANO, E. & RUBIO, V. (1989): El glacia ocoso ac i o de las A gualas (Pi ineo a agonés). E a, 19-20: 195-198. SOLÉ SABARIS, L. (1942): La Canal de Be dún. Es udios Geog á icos, 6: 271-318. TAILLEFER, F. (1968): Le neoglaciai e Py énéen. Melanges O. TuHppe, 134-138. TAILLEFER, F. (1985): Idées ac uelles su le glacia ion des Py énées des l'A iège. Re ue Géog aphique des Py énées e du Sud Ques , '56(3). 323-338. VIDAL Box, C. (1933): No as sob e glacioogia pi enaica. Bol. R. Soc. Esp. His . Na , 33: 273-285. VILAPLANA, J. M. (1983): Qua e na y glacial geology o Al a Ribago za Basin (Cen al Sou he n Py ennes). Ac a Geológica Hispánica, 18(3): 207-213. VILAPLANA, J. M. (1985): Les ases glacials del Qua e na i supe io en el sec o no d-oes del Pi ineu Ando a. Re . In . Geol., 41: 67-82. ZuMBÜHL, H. J. & HoLZHAUSER, H. (1988): Glacie s des Alpes du Pe i âge glaciai e. Les Alpes, Club Alpin Suisse, 322 p.. Be na. 104 (c) Consejo Supe io de In es igaciones Cien í icas Licencia C ea i e Commons 3.0 España (by-nc) h p://pi ineos. e is as.csic.es