SOBRARBEGEOPARK SPACE

GEOPARK INTERPRETATION CENTRE

aínsa

1Geo route

GEO-

ROUTE

NETWORK

c Sobrarbe Geopark

Texts: Luis Carcavilla Urquí (IGME) and Ánchel Belmonte Ribas

(Scientific Coordinator Sobrarbe Geopark).

Figures and illustrations: Albert Martínez Rius

Photographs: Luis Carcavilla Urquí

Translation into French and English: Trades Servicios, S.L.

Design and layout: Pirinei, S.C.

CBC project Pyrenees-Monte Perdido, World Heritage (PMPPM)

of the 2007-2013 POCTEFA Program.

1

Taken together, these routes will enable visitors to enjoy the most beautiful parts ofthe Sobrarbe district and also obtain further information on its long geological historydating back over 500 million years.

SOBRARBE GEOPARK GEO-ROUTE

NETWORK

THE SOBRARBE GEOPARK

The Sobrarbe Geopark is located in the north of the province of Huesca andcoincides with the district of the same name. This area is noted for its many cultural and naturalvalues, most notably its spectacular geology.

In 2006 the Sobrarbe District was declared a Geopark and became part of the EuropeanGeopark Network, sponsored by UNESCO. A Geopark is a district with unique geological features forwhich a sustainable development strategy has been developed. Consequently, the key objective is topreserve its natural and cultural heritage and promote development through the appropriatemanagement of the geological environment. There are currently 60 Geoparks in Europe and 100 in theword. The Sobrarbe Geopark features an exceptional geological environment, with over 100 places ofgeological interest that have been inventoried; many of which can be visited on the Geo-Routenetwork.

More info: www. geoparquepirineos.com

Indeed, the Geo-Route network of theSobrarbe Geopark was created to learn about andunderstand its geological heritage in greater depth.This is a network of 30 self-guided routes that allowvisitors to access the most outstanding geologicalsites in the district and understand their origin,meaning and significance. All Geo-Route havebeen designed so that they can be covered on footand are clearly signposted; in most cases they arebased on official short-route (PR) or long-route(GR)except PN 1, PN 4, PN 5, PN 9, PN 10 and PN 11that combine a stretch of road and vehicle withtrails paths. There is a brochure on each route inorder to facilitate the interpretation of each stop onthe way.

In addition, 11 of these geological routesare located in the Ordesa and Monte PerdidoNational Park, including the territory of the Geopark,and 3 of the Geo-routes are of a cross-bordernature, allowing visitors to enjoy the geologicalheritage of the Pyrenees-Monte Perdido, declared aWorld Heritage Site by UNESCO.

In addition to the Geo-Route network, thereare mountain bike (MTB) routes in the Geopark,some of which feature small information panelsalong the way and there is also a brochure that

MAP OF THE SOBRARBE GEOPARK

GEO-ROUTE NETWORK

The various Sobrarbe geo-routes vary in length, difficulty, theme and duration. Consequently, almosteveryone will be able to find a route that suites them.

Geo-Route Geo-Route in National Park of Ordesa and Monte PerdidoGEO 1 PN 1

TorlaBielsa

Fanlo Gistaín

Plan

Lafortunada

Escuaín

SanVictorián

San Juan de Toledo

Foradada

Tierrantona

Boltaña

Laspuña

Puértolas

Ascaso

Escalona

Aínsa

Arcusa

Paúles de Sarsa

Lecina

Bárcabo

PaloSamitier

Abizanda

Broto

Fiscal

Las Bellostas

Nerín

Campo

Víu

2

Gavarnie

GèdreAragnouet

PinetaBujaruelo

MontePerdido

Río

Ara

Río Cinca

Embalse deMediano

Embalse de El Grado

Río

Ese

ra

PP.N. DE ORDESA.N. DE ORDESA YYMONTE PERDIDOMONTE PERDIDO

PPARQUE NAARQUE NATURALTURALDE LADE LA SIERRASIERRA YY

LOS CAÑONES DELOS CAÑONES DEGUARAGUARA

PPARQUEARQUENANATURALTURAL

DEDEPOSETS-POSETS-

MALADETMALADETAA

Viadós

San Juan de Plan

Labuerda

A-1

38

N-260

A-1

38

N-260

Saravillo

Geopark Interpretation Centre

Aínsa: a town between two rivers. Urban geology

Geology: A bird's eye view

Inside the canyon

Breath-taking landscapes of water and rock

Sobrarbe at your feet

Crossing the Jánovas Gully

Iron Age Elements

Whims of water for lonely mountaineersA lake among the oldest rocks inSobrarbe

The hidden lake

A road with tradition

A privileged vantagepoint

Secrets of the Guara Mountains

Geology for the Saint

A passage between two worlds

Water inside the Earth

The Jewel of Cotiella

Treasures of the Posets-Maladeta Nature Park

Ordesa Valley

Mount Perdido

The Roland Gap

Cutas Viewpoints

La Larri

Balcon de Pineta

Añisclo Canyon (lower part)

Añisclo Canyon (upper part)

Circuit Añisclo Canyon

Escuaín Valley

Otal Valley

Geopark area

Aínsa

Samitier castle and hermitages

Congosto de Entremón

Vero River canyon viewpoints

Ascaso- Nabaín

Near Jánovas

Viu-Fragén-Broto

Ordiso Valley

Lake Pinara and Puerto Viejo

Lake Bernatuara

Bujaruelo Pass

Fiscal-Gradatiello-Peña Canciás

Las Bellostas-Sta. Marina

Espelunga de San Victorián

Collado del Santo

Badaín-Chorro de FornosBasa de la Mora (Ibón de Plan)

Viadós-Ibones de Millars

Torla-Cola de Caballo-Góriz Shelter

Góriz Shelter-Mount Perdido

Góriz Shelter - Roland Gap

Torla-Viewpoints-Nerín

Bielsa-La Larri Valley

Pineta-Balcón de Pineta

San Urbez-Fuen Blanca

Fuen Blanca-Añisclo Pass

Escalona-Puyarruego

Tella, Revilla-Escuaín

Broto -Bujaruelo-Otal Valley

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* Theme: T- Tectonics; F- Fossils;K- Karst; R- Rocks; E- Stratigraphy; G- Glaciarism** Combining vehicle and hiking

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Nº TRAVEL DIFFICULTY DURATION THEME*

Nº GEO-ROUTE TRAVEL DIFFICULTY DURATION THEME*

PN1

PN2

PN3

PN4

PN5

PN6

PN7

PN8

PN9

PN10

PN11

GEO-ROUTE IN NATIONAL PARK OF ORDESA ANDMONTE PERDIDO

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GEOLOGICAL HISTORY OF THE SOBRARBE GEOPARK

1THE REMOTEST PAST

2TROPICAL MARINE SEDIMENTATION

3THE FORMATION OF THE PYRENEES

(between 500 and 250 million years ago)

(between 250 and 50 million years ago)

(between 50 and 40 million years ago)

The geological history of the Sobrarbe Geopark goes back over 500 millionyears. Many geological events that have affected the current landscape and relief tookplace over that vast period of time. The geological history of Sobrarbe can be divided into 6different episodes, each of which includes significant moments that led to today's geologicallandscape.

Over a long period of the Palaeozoic, the land nowoccupied by Sobrarbe was a seabed where silt, mud, clay andsand accumulated. Today these sediments have become theshale, sandstone, limestone and quartzite that form the northernmountains and valleys of the District. These rocks were intenselyaltered by the Variscan orogeny: an episode of intense tectonicactivity that affected much of Europe and resulted in a hugemountain range. Numerous folds and faults attest to this pasttogether with granite that was also formed in that era.

The giant mountain range formed in the previous stage washeavily eroded and almost disappeared. Once erosion has almost

swept away the mountain range, the resulting flat land wascovered by a shallow tropical sea. Coral reefs appeared and the

calcareous mud we see today in the shape of limestone, dolomiteand marl, containing abundant marine fossils, accumulated. Thesea fluctuated several times and there were many time when its

depth increased and decreased; however, it practically coveredthe area throughout this episode.

The marine sedimentation process continued during this episode, butunder very different conditions to previous episodes. The sea, whichseparated what is today the Iberian Peninsula from the rest of Europe,gradually dried up. About 45 million years ago, as this sea becamenarrower and sedimentation occurred on the seabed, thousands ofmetres below the surface, on land, the Pyrenees began to develop. I

Folds in Palaeozoic rocks

Fossils of marine organisms in the

Cretaceous limestone

Typical landscape of turbidites outcrops

In Sobrarbe we can find exceptional examples of turbidites, rocks formed in that sea as itaccumulated huge amounts of sediments resulting from the development of the mountain range,while the mountains continued to develop.

PALAEOZOIC542 m.a. 488 m.a. 443 m.a. 416 m.a. 359 m.a. 299 m.a. 251 m.a.

Cambrian Ordovician Silurian Devonian Carboniferous Permian Tria

EPISODES: 1

5

SOBRARBE GEOPARK

4THE SOBRARBE DELTAS

5THE ICE AGES

6 TODAY

(between 40 and 25 million years ago)

(last 2,5 million years)

Once the mountain range and its foothills had formed,erosion began to transform it. The river valleys widened and

the present river network began to be formed. On severaloccasions during the Quaternary, mainly over the last two

and a half million years, various cold spells occurred,covering the mountains with snow and ice. The last major

ice age reached its peak about 65,000 years ago. Hugeglaciers covered the valleys and mountains and shaped the

landscape, effectively eroding some places andaccumulating sediment in others. The landscape of the

entire northern section of the District was shaped by thoseancient glaciers.

Today, erosion processes are slowly and graduallywearing away the mountain range. This erosion occurs in

many ways: through the action of rivers, erosion on theslopes, karst dissolution, etc. The landscape that we see

today is only an instant in a long evolutionary processthat is on-going, but now with the participation of man

who is changing the environment like no other livingbeing is capable.

The formation of the mountain range caused thegradual disappearance of the sea, which was becomingshallower and elongated. About 40 million years ago, asystem of deltas marked the transition between the area thathad emerged and later stages of this marine gulf. Althoughthis period was relatively short, huge amounts of sedimentaccumulated, which can be found today in the southern partof the District converted into marl, limestone and sandstone.Once the sea had retreated definitely from Sobrarbe, therelentless effects of erosion became all the more intense ifpossible. About 25 million years ago, active and dynamictorrents accumulated huge amounts of gravel that, over time,became conglomerates, such as those that form the bulk ofPeña Canciás.

Glaciers like the ones we see today in the Alps covered

the Pyrenees at that time

Río Cinca, agente modelador actual

Conglomerates: rocks formed from rounded

fragments of other rocks

MESOZOIC CENOZOIC 199 m.a. 145 m.a. 65 m.a. 23 m.a. 2,5 m.a.

Tria Jurassic Cretaceous Palaeogene Neogene Quaternary

2 3 4 5 6

EPISODES REPRESENTED IN THE GEO-

ROUTES

Episode 1: Variscan orogeny - Episode 2: Tropical marine sedimentation - Episode 3: The formation of thePyrenees - Episode 4: The Sobrarbe deltas- Episode 5: The ice age - Episode 6: Today

Nº GEO-ROUTE EPISODES

Ordesa Valley

Mount Perdido

The Roland Gap

Cutas Viewpoints

La Larri

Balcon de Pineta

Añisclo Canyon (lower part)

Añisclo Canyon (upper part)

Circuit Añisclo Canyon

Escuaín Valley

Otal Valley

PN1

PN2

PN3

PN4

PN5

PN6

PN7

PN8

PN9

PN10

PN11

2 5 6

2 3 5 6

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Nº GEO-ROUTE EPISODES

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Geopark Interpretation Centre

Aínsa: a town between two rivers.Urban geology

Geology: A bird's eye view

Inside the canyon

Breath-taking landscapes of water and rock

Sobrarbe at your feet

Crossing the Jánovas Gully

Iron Age Elements

Whims of water for lonely mountaineers

A lake among the oldest rocks in Sobrarbe

The hidden lake

A road with tradition

A privileged vantagepoint

Secrets of the Guara Mountains

Geology for the Saint

A passage between two worlds

Water inside the Earth

The Jewel of Cotiella

Treasures of the Posets-Maladeta Nature Park

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3 6

2 3 6

2 3 6

2 4 6

3 6

3 6

5 6

5 6

1 5

1 2 5 6

1 2 5

4 6

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2 3

2 3

2 6

2 5 6

1 5 6

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Geo route

SOBRARBE

GEOPARK SPACE

One of the castle's towers, inthe heart of the old quarters of Aínsa,houses the Sobrarbe Geoparkinterpretation and visitor centre, knownas the Geopark Space. It containsextensive information on the geologyof the district in the shape of panels,maps, models, rock collections, videosand interactive displays, which canhelp plan visits and routes. TheGeopark Space takes up four floors of

the Castle's tower and describes thegeological history of the District.

The vertical architecture of thetower symbolizes the geologic timeline,from the remote Palaeozoic on theground floor to the present day on thethird floor. Therefore, as visitors walk upthe stairs, they will discover the 500 millionyears of the Earth's history recorded inthat the rocks of Sobrarbe.

1GEOPARK INTERPRETATION CENTRE

aínsa

9

The Geopark Space is located in the south-east tower of the Castle of Aínsa.To reach the centre, head towards the old quarters of Aínsa, either on footfrom the lower part of the town or by car from the car park at the top. Once

in Castillo Square, follow the signs.

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iSTARTING POINT:

The Geopark Space is theGeopark's interpretation centre. It bringstogether all the information needed tobecome familiar with this district andunderstand how it was formed and why itwas declared a Geopark in 2006. But theGeopark Space is more than that: it isintended to be a springboard that willencourage visitors to discover the geologySobrarbe on their own, using theinformation available and the existinginfrastructure. In addition, the Centreguides are very familiar with the district, soplease do not hesitate to ask them, as theycan propose routes or places to visit basedon your needs and interests.

The Space consists of four floorsbrimming with information in the shape ofpanels, models, interactive displays andvideos. This "path through the Geopark

Space" you are now holding can help youlink all this information and relate it to thepanels installed at the roadsides and to theGeopark's 29 Geo-Routes. Indeed, thisbooklet aims to encourage visitors not tolinger here, but to leave the GeoparkSpace to visit some of the amazing placesof geological interest in the District.

Fig. 1. Southeast tower of Aínsa Castle, where the Geopark Space is located

2

1

0

3FLOORTHE ICE AGE

FLOOR

THE PYRENEES RISEFROM THE SEA

FLOOR

SOBRARBE BEFORE HE PYRENEES

FLOOR

THE WORLD OFGEOPARKS

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Fig. 2. Geopark Space items

GROUND FLOOR

THE WORLD OF GEOPARKS

Room 1, which is also the reception area, is known as "The World of Geoparks".First, let us focus on a back-lit panel entitled "The geological heritage of

Sobrarbe". Much of the panel's information is dedicated to explaining what a Geopark is;a denomination granted by the European Geoparks Network and UNESCO. The bottomsection of the panel includes seven photographs depicting the most unique aspects of thegeology of the Geopark. In other words, what makes Sobrarbe a land of exceptionalgeological value. The geological heritage of this district makes it an internationallandmark. More specifically, the panel highlights seven themes: mining heritage, stunninglandscapes, fossils, submarine sedimentary rocks, karst phenomena, tectonics andglaciation. The information provided in the following rooms will refer to these issues andto others that are equally unique. In addition, we shall be able to witness magnificentexamples of them on the Geopark's Geo-route Network.

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We can now pay attention to themap-model located in the centre of theroom. It is a seemingly complicated map, inwhich geologists display the various rocks inthe Geopark and their age. The first thingyou notice is that there are 32 differentgeological units, each with a differentcolour and code. These will be described ingreater detail in the following rooms, but atthe moment we only have to note thatthese types of rocks were formed in threetime periods. The first period is called thePalaeozoic, meaning "ancient l ife". Itcorresponds to the oldest rocks in theGeopark. On the model, they arerepresented in green, brown and orange,but always in subdued tones. Look at themap and see where they appear; you willonly see them in the northern section.

Other types of rock, as you will seein the map legend, were formed in theMesozoic. This era is also known as the "ageof reptiles" or "dinosaurs" because theseanimals dominated life on land during thatperiod. The rocks that were formed at thistime are coloured pastel green and blue.Try to find them on the map and you will seethey occupy an elongated strip from eastto west in the top section of the Geopark.

Finally, the Cenozoic rocks, whichare the most recent, are coloured in severalshades of yellow and orange. If youobserve the map, you will see that they arethe most abundant and occupy the entiresouthern section of the Geopark.

stop1

Fig. 3. Ground floor of the Geopark Space

An interesting idea that can beextracted from the map is that Sobrarbefeatures a wide variety of geologic units andthat they are organized according to a simplelay-out: ancient Palaeozoic rocks in the north,Mesozoic rocks along the south of the former,and Cenozoic rocks in southern and centralpart of the District, as these are the mostwidespread. Later, we shall see what kinds ofrocks are typical of each of these sectors, howthey were formed and why this particular lay-out arose in greater detail. However, to giveyou an idea, the first floor of this centre isdedicated to Palaeozoic rocks, the second toMesozoic and Cenozoic rocks, and the third tothe geological processes that have shapedthem. Therefore, as you make you way up thestairs, you will be travelling in geological time"up" from the distant past to the present.

If you need more information, stop to have amore detailed look at the panels, butremember that you still have another threefloors full of content. Before going on to visitthe rest of the Centre, take note of thefollowing idea that summarizes theinformation contained on this floor: theSobrarbe Geopark contains a rich and variedgeological heritage as a result of its lengthygeological history recorded in the rocks thatformed in this area, covering more than 500million years. Geological heritage andgeodiversity are two of the hallmarks of thisterritory.

Fig. 4. The Sobrarbe Geopark is noted for its rich and varied geological heritage, but also for the opportunities it offers visitors to enjoy that heritage. This is

undoubtedly a geologically privileged land. Zierracils Viewpoint in the Ordesa and Monte Perdido National Park.

AÍNSA CASTLE

The Geopark Spaceoccupies one of the towers of theoutstanding Aínsa Castle, which wasdeclared a Historic-Artistic Monument in1965. Today, beside the old town and thecollegiate church, has the denomination ofCultural Interest, according to the Law ofthe Aragonese Cultural Heritage. It is amilitary construction built in two phases. Thetwo towers were built during the first phase,in the late eleventh century.

At a later stage, in the mid-sixteenth century, King Felipe II (and I ofAragon) built the walled fortress we seetoday, enclosing the two towers. Thepurpose was to protect Aínsa from possibleattacks by the French, during the period ofreligious unrest that existed throughoutEurope at the time and that led tocontinuous clashes between Protestantsand Catholics.

!!

FIRST FLOOR.

SOBRARBE BEFORE THE PYRENEES

The Pyrenees are a mountain range that, as explained on the next floor, began

to form about 50 million years ago. But if the geological history of Sobrarbe

goes back 500 million years, what was this region like before the formation of the

Pyrenees? That distant past is explained in this room, which corresponds to the period

known as the Palaeozoic, which lasted until about 250 million years ago.

Over a long

period of the Palaeozoic, the

land now occupied by

Sobrarbe was a seabed where

silt, mud, clay and sand

accumulated.

Today these

sediments have become the

shale, sandstone, limestone

and quartzite that form the

mountains and valleys in the

north of the District. These

rocks were intensely altered by

the Variscan orogeny: an episode of intense tectonic activity that began to affect much of

Europe about 370 million years ago.

During the 80 million years it lasted, it gave rise to a huge mountain range, which

was patiently eroded away, the extent of which we can now deduce due to the remnants of

its geological foundations. The granitic rocks, folds and faults are the remains of those

ancient Palaeozoic mountains.

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On accessing this floor, there is apanel titled "The oldest rocks of Sobrarbe"on the right. If you look at the centralsection you will see a map that representswhere these ancient rocks are found. As wehad seen in the map-model on the ground

floor, we shall only find them in the north ofthe district as part of some of the mosticonic peaks, such as Viñemal (3,289 m)and Posets (3,369 m), two of the range'sgiants (Fig. 5).

Fig. 5. Marble outcrops on Viñemal (3,289 m) that forms the backbone of this great peak,

seen from the area near Ordiso, on Geo-Route 9.

stop2

542 m.a. 488 m.a. 443 m.a. 416 m.a. 416 m.a

PALAEOZOIC

Slate, quartzite, marble, sandstone and clay

Marine sedimentation

Cambrian Ordovician Silurian Devonian

15

Fig. 6. The spectacular landscapes of the Posets-Maladeta Nature Park are formed on Palaeozoic rocks, and can be viewed from Geo-Route 19.

The rocks that form thesemountains are mainly slate, quartzite,marble, limestone and granite. If you wouldlike to see Sobrarbe landscapes carved inrocks formed in the Palaeozoic, we suggestseveral options. The north-western corner ofthe Geopark features the Ordiso andViñemal formations.

This is an out-of-the-way area, onlyaccessible on foot and requires a several-hour hike. Therefore, it is ideal if you want toavoid crowds. Geo-Route 9 runs throughthis somewhat remote but beautiful areawhere we will mainly find limestone formedduring the Palaeozoic era.

OTHER GEOPARK FACILITIES

The Geopark Space ishoused in one of the three towers ofAínsa Castle. The north-east towerhouses the Tourist Office and otherGeopark units, such as the GeoVisionRoom (projection room) and thetechnical office, which includes alibrary. Both are available for visitors onrequest.

!!

416 m.a 359 m.a. 299 m.a.

PALAEOZOIC

Limestone Limestone, shale, coal Granite

Sedimentation in a tropical sea Formation of paleozoic mountain range

Devonian Carboniferous

A more comfortable option is to visitthe Bielsa tunnel area, to the north of Parzán,right on the border with France. This is on Geo-Route 10, which is shorter than the previousone, where we see mostly see slate andquartzite.

One of the best parts of the district tosee Palaeozoic rocks, whether metamorphicor granite, is the Posets-Maladeta Nature Park,the western half of which is in the district ofSobrarbe. One of the Nature Park's visitorcentres is in the town of San Juan de Plan,where an interesting exhibition describes notonly the origin of the Palaeozoic rocks that

form its substrate, but also the effect of theglaciers during the Quaternary and the richand varied flora and wildlife. Geo-Route 16covers one of the most interesting areas of theNature Park. At the Visitor Centre of San Juande Plan, they will be able to recommendother excursions that are longer or shorteraccording to your interests.

The main idea behind the visit to thisroom is that, before the Pyrenees wereformed, many geological events took placein Sobrarbe that we can deduce studyingPalaeozoic rocks.

Fiig. 7. The granitic rocks found in the northern part of the Geopark were also formed in the Palaeozoic and can also be visited on Geo-Route 19.

The Sobrarbe Geopark has aninventory that identifies and describes over 100

sites of geological interest; 4 of these aremuseums and/or interpretation centres, such

as the one we are in now. It is unusual for adistrict the size of Sobrarbe to have on such an

exceptional geological heritage, especiallytaking into account that 70% of them are very

or exceptional unique, landmarks at aregional, national or international level. If we

add the existence of the many geologyinterpretation facilities, it is not surprising thatthis district was declared a Geopark in 2006.

!!LIST OF SITES OF GEOLOGICAL

INTEREST IN THE SOBRARBE

GEOPARK

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SECOND FLOOR

THE PYRENEES RISE FROM THE SEA

This floor includes descriptions of some of the events leading to the formation

of the Pyrenees; a process that lasted many millions of years in the Mesozoic and early

Cenozoic. Three distinct episodes or stages can be identified throughout this process.

Once erosion nearly wiped out themountains that had formed in thePalaeozoic, as we saw on the ground floor,the resulting almost flat land was covered bya shallow tropical sea. Coral reefs appearedand the calcareous mud we see today in theshape of limestone, dolomite and marl,containing abundant marine fossils,accumulated. The sea changed over time,but practically covered the area throughoutthis episode that lasted almost 200 millionyears separating the current IberianPeninsula from France.

Later, in the Cenozoic, the marinesedimentation process continued butunder very different conditions from thosethat had existed previously. The sea,which separated what is today theIberian Peninsula from the rest ofEurope, gradually dried up. About 45million years ago, as this sea becamenarrower and sedimentation occurredon the seabed hundreds and eventhousands of metres below the surface,on land, the Pyrenees began todevelop. You can see a picture thatrepresents this in the panel entitled "Fromthe Pyrenees to the Himalayas andbeyond". In Sobrarbe we can findexceptional examples of turbidites, rocksformed in that sea as it accumulated hugeamounts of sediments resulting from thedevelopment of the mountain range, while

the mountains continued to develop. There isa diagram that explains this on the paneltitled "The marine realm of the Eocene basinof Aínsa", located on one of the tables withrock samples.

Fig 8. Second floor of the Geopark Space

PROTECTED

AREAS IN THE SOBRARBE

GEOPARK

The Sobrarbe Geopark encompasses

several protected areas. The Ordesa and

Monte Perdido National Park, declared a

national park in 1918, is located to the north-

west and is certainly one of the most unique

enclaves in the Pyrenees. The National Park is

part of the transboundary property Pyrenees-

Monte Perdido, declared World Heritage by

UNESCOAlso in the Geopark is much of the Biosphere

Reserve "Ordesa-Viñamala"; 20 rock art sites declared

World Heritage are located.The Posets-Maladeta Nature

Park is in the north-east section; part lies within the

boundaries of the Geopark and another part in the

district of Ribagorza. A similar case is that of the Sierra

y Cañones de Guara Nature Park, in the south of the

Geopark and shared by two districts. In addition, the

Geopark features several glaciers, which were

declared Natural Monuments in 1990 for their

protection.

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Finally, the formation of themountain range caused the gradualdisappearance of the sea, which wasbecoming shallower. About 43 million yearsago, a system of deltas marked thetransition between the area that hademerged and later stages of the marinegulf. Although this period was relatively short(3 million years), huge amounts of sedimentaccumulated, which can be found today inthe southern part of the District in the shapeof marl, limestone and sandstone. You cansee more about how this happened in thepanel entitled "the disappearance of theSobrarbe Sea", also located on one of thetables with rock samples.

Once the sea had retreateddefinitely from Sobrarbe, the relentlesseffects of erosion began. About 25 millionyears ago, active and dynamic torrentsaccumulated huge amounts of gravel that,over time, became conglomerates, such asthose that form the bulk of Peña Canciás.

Fig. 9. Anticlinal de Boltaña, exemple des énormes plis créés lors de la formation de la chaîne des Pyrénées, et que l'on peut contempler depuis les Géo-

Routes 6 et 7.

Many of the rocks found in Sobrarbewere formed under the sea and containfossils. If you would like to see some of thefossils found in Sobrarbe, we recommend you visitthe Palaeontological Museum of Sobrarbe inLamata, just 20 kilometres from Aínsa in the directionof Barbastro. Among various specimens, you can seeone of the most complete jaws found to date inEurope of an Eocene crocodile from about 40 millionyears ago. Admission to the museum costs 2 andyou must book in advance by calling 649 683 498 orsend an email to: museolamata@yahoo.es.

A FOSSIL MUSEUM IN SOBRARBE

Jaws of the so-called "Sobrarbe crocodile" at the Sobrarbe

Palaeontological Museum , in the town of Lamata.

!!

251 m.a. 199 m.a. 145 m.a. 145 m.a. 65 m.a.

Tria Jurassic Cretaceous Palaeogene

MESOZOIC

Sandstone, limestone, clay and gypsum Limestone and marl

Erosion of Palaeozoic mountains Sedimentation in a tropical sea

As already mentioned, most Sobrarberocks were formed during the Mesozoic andearly Cenozoic. Consequently, many of theroutes cross landscapes formed on rocks thatoriginated in these geological eras.

Several panels in this room arededicated to explaining how the lithosphericplates move. It is precisely these movements thatform mountain ranges like the Pyrenees and thatgenerate faults and folds in the rocks. Sobrarbehas spectacular examples, such as the BoltañaAnticline (Fig.xx), ten kilometres from this Centreand crossed by Geo-Routes 6 and 7, which youcan glimpse from the window on the top floor.

Many of the most popular geologicalformations in Sobrarbe are based on rocks from

the Mesozoic and Cenozoic, such as MontePerdido (Geo-Routes PN 2), Peña Montañesa(Geo-Routes 15 and 16), Peña Canciás (thesummit of which can be reached following Geo-Route 13), the Cotiella massif (on Geo-Routes 17and 18) and the Guara Mountains (on Geo-Routes 5 and 14).

The main idea taught on this floor isthat the Pyrenees were formed as a resultenormous forces generated by the movementof tectonic plates.

The sediments that accumulated onthe seabed for 50 million years folded andresulted in the mountains that became thePyrenees.

Fig. 10. The hermitages of Samitier (Geo-Route 3) provide a magnificent view of the portion of the District formed in the Mesozoic and Cenozoic.

145 m.a. 65 m.a. 23 m.a. 2,5 m.a. Actualidad

Cretaceous Palaeogene Neogene Quaternary

MESOZOIC CENOZOIC

Sedimentation in FORMATION OF Sedimentation Final withdrawal of the sea and a tropical sea THE PYRENEES in deltas the erosion of the mountains

Limestone,sandstone and marl

Limestone, sands-tone, clay, turbidite

Sandstone andconglomerates

Fluvial depositsand glaciers

Fig. 11. The spectacular scenery surrounding Plan Lake (or Basa de la Mora) also formed on rocks formed in the Mesozoic and Cenozoic.

Ica Ages

If there is one process that hasshaped the Pyrenean relief, it is glacial action.On several occasions during the Quaternary,mainly over the last two million years, variouscold spells occurred, covering the mountainswith snow and ice. The last major ice agereached its peak about 64,000 years ago.Huge glaciers covered the valleys andmountains and shaped the landscape,effectively eroding some places andaccumulating sediment in others. Themountain lakes, waterfalls, flat-bottomedvalleys and glacial cirques are proof of thisglacial activity. Today, only small glacierssurvive in Sobrarbe and are found at altitudesabove three thousand metres. The mostimportant is the glacier on Monte Perdido,located on the north side of the peak. Accessto the base requires a three-hour hike fromthe Bielsa Parador (State Hotel). In addition,Geo-Routes 8, 9, 10, 11, 12, 18, 19 , PN 1, PN 4,PN 5, PN 6, PN 8 and PN 11 lead throughcertain emblematic areas where one can seethe effects of glaciers.

Today, erosion processes are slowlyand gradually wearing away the mountainrange. This erosion occurs in many ways:through the action of rivers, erosion on theslopes, karst dissolution, etc. The landscapethat we see today is only an instant in a longevolutionary process that is on-going. Thepanels found on this floor will help youunderstand this landscape transformation

process which, in addition to erosion, alsoinvolved sedimentation.

Furthermore, as soon as you reach the thirdfloor, you will notice the large windows thatprovide magnificent views of the surroundingareas.

In fact, you will be able to see someof the Geopark's sites of geological interestGeopark from them. Consequently, thewindow situated above the panel entitled"How long will the Pyrenees last?" provides aview, on a clear day, of two emblematic sitesin the Geopark: the Boltaña Anticline and theMonte Perdido Massif (Fig. 12). The former canalso be seen from the viewpoint located inBoltaña Castle and on Geo-Routes 6 and 7.The first even reaches the Nabaín summit, alsovisible from this window (Fig.xx). There areseveral National Park routes if you wish to visitthe Monte Perdido Massif: PN 1, PN 2, PN 3, PN4 and PN 6.

Fig. 13. The Monte Perdido glacier, the most important in Sobrarbe and one of the largest on the southern side of the Pyrenees, measuring about 80

hectares.

Fig.12. View from one of the windows on the third floor.

THIRD FLOOR

THE ICE AGE

This floor describes the geological processes that took place once the Pyrenees

had been formed. They are the processes that have generated the relief that we

see today, many of which are still on-going, proving that the Pyrenean landscape is dynamic

and continues to evolve.

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On the other hand, the windows onthe staircase leading to this floor offerspectacular views of Peña Montañesa,where Geo-Routes 15 and 16 offer some oftheir most unique features.

On the other hand, the karstmodelling also displays exceptional levelsof development in Sobrarbe; its origin isexplained in the panel entitled "Karst: whenwater dissolves the rock". There are over 800known cavities in this district, some of whichare several kilometres long.

We must mention two of the mostimportant systems in the world due to thegradient between the entrance and exit,which exceeds one thousand metres, suchas the Fuentes de Escuaín system and theArañonera System. Sobrarbe also have thehighest cavity in all Europe, the Punta delas Olas, whose mouth is above threethousand metre line. In addition, Sobrarbeis also home to most of the few ice cavesthat still exist on the Spanish side of thePyrenees.

The most famous is Casteret, in theOrdesa and Monte Perdido National Park.Visit ing these caves requires specificpotholing skil ls and the appropriateequipment. It is much easier to see theeffects of karst formation on the surface,such as sinkholes and springs. Some of themost spectacular examples are found inOrdiso Valley (Geo-Route 9), in the CotiellaMountains (Geo-Route 18), and the Ordesaand Monte Perdido National Park (Geo-Routes PN 7 and PN 10.

Finally, the importance of rivers in Sobrarbeis also worth mentioning. A panel entitled"Waterways: between erosion andsedimentation" explains how rivers work inSobrarbe. Precisely, the two major rivers inthe district, the Ara and the Cinca, join here,in Aínsa, as can be seen in Geo-Route 2.

Having described theessential features of the Geopark'sgeology, only one thing is left to do: go outinto the field and obtain first-handknowledge of the district's geologicalheritage. With this in view, the Geopark has13 roadside panels, 30 Geo-Routes forhiking, 13 mountain bike routes withgeological information, the Parzán miningcircuit, the Sorrosal railway and othercentres and museums.

Something for all ages and for allseasons. In addition, there are elevengeological routes in the Ordesa and MontePerdido National Park.

If you have any questions, pleasevisit the reception desk in this Centre whereour staff will be happy to advise you onroutes and viewpoints.

DISCOVER THEGEOLOGICAL HERITAGE OF !!

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SOBRARBE GEOPARK SPACE

GEOPARK INTERPRETATION CENTRE

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> PRACTICAL INFORMATION

ROUTE: Sobrarbe Geopark Space

TYPE OF ROUTE: inside the Geopark Space.

DURATION: 30 -60 minutes

STARTING POINT: Sobrarbe Geopark Space South-east tower of Aínsa Castle.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> COMMENTS

i

1GEO-ROUTEwww.geoparquepirineos.comof Sobrarbeof Sobrarbe

- From July 1 to August 31:

9:30 to 2 p.m. and 4:30 p.m. to 7:30 p.m. (Wednesday to Sunday)

- Easter:

9:30 to 2 p.m. and 4:30 p.m. to 7:30 p.m. (Monday to Sunday)

Tel. 974 500 614E-mail: info@geoparquepirineos.com

- Rest of the year: See Regional Tourism Office.

North-east tower of the Castle of Aínsa

Telephone: 974 500 512.

Free access.

The Space is open all year round as follows: