ordesa valley - Geoparque de Sobrarbe

1
Geo
route
PN
PN
ORDESA
VALLEY
TORLA-PRADERA DE ORDESACOLA DE CABALLO-GORIZ REFUGE
c Sobrarbe Geopark
Texts: The Geo-Routes PN are taken from the Geological Guide Ordesa
and Monte Perdido National Park" from the Collection of Geological
guides of the National Parks (IGME-OAPN, Roberto Rodríguez Fernández,
dir and coord.)
The texts of these Geo-routes have been developed by Alejandro
Robador Moreno, Luis Carcavilla Urquí, Josep Maria Samsó Escolá and
Ánchel Belmonte Ribas (Scientific Coordinator Sobrarbe Geopark).
Figures and illustrations, by Albert Martinez Ríus, and photographs by
Josep María Samsó Escolá, Luis Carcavilla Urquí, Alejandro Robador
Moreno and Ángel Salazar Rincón
Translation into French and English: Trades Services, S.L.
Design and layout: Pirinei, S.C.
GEOROUTE
NETWORK
CBC project Pyrenees-Monte Perdido, World Heritage (PMPPM)
of the 2007-2013 POCTEFA Program.
S
OBRARBE GEOPARK GEO-ROUTE
NETWORK
The Sobrarbe Geopark is located in the north of the province of Huesca and
coincides with the district of the same name. This area is noted for its many cultural and natural
values, most notably its spectacular geology.
Indeed, the Geo-Route network of the
Sobrarbe Geopark was created to learn about and
understand its geological heritage in greater depth.
This is a network of 30 self-guided routes that allow
visitors to access the most outstanding geological
sites in the district and understand their origin,
meaning and significance. All Geo-Route have
been designed so that they can be covered on foot
and are clearly signposted; in most cases they are
based on official short-route (PR) or long-route
(GR)except PN 1, PN 4, PN 5, PN 9, PN 10 and PN 11
that combine a stretch of road and vehicle with
trails paths. There is a brochure on each route in
order to facilitate the interpretation of each stop on
the way.
In addition, 11 of these geological routes
are located in the Ordesa and Monte Perdido
National Park, including the territory of the Geopark,
and 3 of the Geo-routes are of a cross-border
nature, allowing visitors to enjoy the geological
heritage of the Pyrenees-Monte Perdido, declared a
World Heritage Site by UNESCO.
In addition to the Geo-Route network, there
are mountain bike (MTB) routes in the Geopark,
some of which feature small information panels
along the way and there is also a brochure that
Taken together, these routes will enable visitors to enjoy the most beautiful parts of
the Sobrarbe district and also obtain further information on its long geological history
dating back over 500 million years.
T
HE SOBRARBE GEOPARK
In 2006 the Sobrarbe District was declared a Geopark and became part of the European
Geopark Network, sponsored by UNESCO. A Geopark is a district with unique geological features for
which a sustainable development strategy has been developed. Consequently, the key objective is to
preserve its natural and cultural heritage and promote development through the appropriate
management of the geological environment. There are currently 60 Geoparks in Europe and 100 in the
word. The Sobrarbe Geopark features an exceptional geological environment, with over 100 places of
geological interest that have been inventoried; many of which can be visited on the Geo-Route
network.
More info:
www. geoparquepirineos.com
1
M
AP OF THE SOBRARBE GEOPARK
GEO-ROUTE NETWORK
Gèdre
Aragnouet
Gavarnie
Bujaruelo
Víu
Torla
P.N. DE ORDESA Y
MONTE PERDIDO
Broto
Cin
ca
Viadós
Bielsa
PARQUE
NATURAL
NATURAL
DE
POSETSMALADETA
MALADETA
Escuaín
Fanlo
oA
ra
Río
A-138
Pineta
Monte
Perdido
Gistaín
Nerín
Rí
San Juan de Plan
Plan
Saravillo
Puértolas
Lafortunada
Laspuña
Fiscal
N-260
Ascaso
Escalona
Boltaña
Labuerda San
Victorián
Aínsa
San Juan de Toledo
Foradada
N-260
Campo
Bárcabo
Lecina
GEO 1 Geo-Route
PN 1
Palo
Samitier
Río E
Paúles
de Sarsa
Abizanda
A-138
PARQUE NATURAL
NATURAL
DE LA SIERRA Y
LOS CAÑONES DE
GUARA
Tierrantona
Embalse de
Mediano
Arcusa
sera
Las Bellostas
Embalse de
El Grado
Geo-Route in National Park of Ordesa and Monte Perdido
The various Sobrarbe geo-routes vary in length, difficulty, theme and duration. Consequently, almost
everyone will be able to find a route that suites them.
2
Nº
1
2
3
GEO-ROUTE
Geopark Interpretation Centre
Aínsa: a town between two rivers.
Urban geology
Geology: A bird's eye view
4
Inside the canyon
5
Breath-taking landscapes of water
and rock
6
Sobrarbe at your feet
7
Crossing the Jánovas Gully
8
Iron Age Elements
9
10
Whims of water for lonely mountaineers
A lake among the oldest rocks in
Sobrarbe
11
The hidden lake
12
13
14
A road with tradition
A privileged vantagepoint
Secrets of the Guara Mountains
15
Geology for the Saint
16
A passage between two worlds
17
Water inside the Earth
18
The Jewel of Cotiella
19
Treasures of the Posets-Maladeta
Nature Park
Nº
GEO-ROUTE IN NATIONAL PARK OF ORDESA AND
MONTE PERDIDO
TRAVEL
DIFFICULTY
DURATION
THEME*
Geopark area
-
1 hour
All
Aínsa
Low
Short
RTF
Samitier castle and
hermitages
Low
Medium
TF
Congosto de Entremón
Medium
Short
TR
Vero River canyon
viewpoints
Low
Medium
RF
Ascaso- Nabaín
Medium
Medium
TF
Near Jánovas
Medium
Short
TR
Viu-Fragén-Broto
Low
Short
GR
Ordiso Valley
MediumHigh
Long
GKR
Lake Pinara and Puerto Viejo
Low
Medium
GR
Lake Bernatuara
Medium
Long
RGT
Bujaruelo Pass
Medium
Medium
RGT
Fiscal-GradatielloPeña Canciás
High
Long
RT
Las Bellostas-Sta. Marina
Low
Long
FRT
Low
Short
RT
Medium
Long
RFT
Low
Medium
KR
Low
Short
GR
Medium
Long
GR
Espelunga de San Victorián
Collado del Santo
Badaín-Chorro de Fornos
Basa de la Mora
(Ibón de Plan)
Viadós-Ibones de Millars
TRAVEL
DIFFICULTY
DURATION
THEME*
PN1 Ordesa Valley
Torla-Cola de CaballoGóriz Shelter
LowMedium**
Medium
RGF
PN2 Mount Perdido
Góriz Shelter-Mount Perdido
High
Long
TRKGF
PN3 The Roland Gap
Góriz Shelter - Roland Gap
High
Long
TRKGF
PN4 Cutas Viewpoints
Torla-Viewpoints-Nerín
Low**
Medium
KRGFT
Low**
Medium
RGT
High
Long
FTG
Medium
Long
RGT
PN5 La Larri
PN6 Balcon de Pineta
Bielsa-La Larri Valley
Pineta-Balcón de Pineta
PN7 Añisclo Canyon (lower part)
San Urbez-Fuen Blanca
PN8 Añisclo Canyon (upper part)
Fuen Blanca-Añisclo Pass
High
Long
RGTF
Escalona-Puyarruego
Low**
Medium
RTK
Tella, Revilla-Escuaín
Low**
Medium
TK
Broto -BujarueloOtal Valley
Low**
Medium
GTK
PN9 Circuit Añisclo Canyon
PN10 Escuaín Valley
PN11 Otal Valley
* Theme: T- Tectonics; F- Fossils;K- Karst; R- Rocks; E- Stratigraphy; G- Glaciarism
** Combining vehicle and hiking
3
G EOLOGICAL HISTORY OF THE
The geological history of the Sobrarbe Geopark goes back over 500 million
years. Many geological events that have affected the current landscape and relief took
place over that vast period of time. The geological history of Sobrarbe can be divided into 6
different episodes, each of which includes significant moments that led to today's geological
landscape.
1
THE REMOTEST PAST
(between 500 and 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 northern
mountains and valleys of the District. These rocks were intensely
altered by the Variscan orogeny: an episode of intense tectonic
activity that affected much of Europe and resulted in a huge
mountain range. Numerous folds and faults attest to this past
together with granite that was also formed in that era.
Folds in Palaeozoic rocks
2
TROPICAL MARINE SEDIMENTATION
(between 250 and 50 million years ago)
The giant mountain range formed in the previous stage was
heavily eroded and almost disappeared. Once erosion has almost
swept away the mountain range, the resulting flat land was
covered by a shallow tropical sea. Coral reefs appeared and the
calcareous mud we see today in the shape of limestone, dolomite
and marl, containing abundant marine fossils, accumulated. The
sea fluctuated several times and there were many time when its
depth increased and decreased; however, it practically covered
the area throughout this episode.
3
Typical landscape of turbidites outcrops
Fossils of marine organisms in the
Cretaceous limestone
THE FORMATION OF THE PYRENEES
(between 50 and 40 million years ago)
The marine sedimentation process continued during this episode, but
under very different conditions to previous episodes. The sea, which
separated what is today the Iberian Peninsula from the rest of Europe,
gradually dried up. About 45 million years ago, as this sea became
narrower and sedimentation occurred on the seabed, thousands of
metres below the surface, on land, the Pyrenees began to develop. I
In Sobrarbe we can find exceptional examples of turbidites, rocks formed in that sea as it
accumulated huge amounts of sediments resulting from the development of the mountain range,
while the mountains continued to develop.
PALAEOZOIC
542 m.a.
Cambrian
EPISODES:
4
488 m.a.
Ordovician
443 m.a.
416 m.a.
Silurian
359 m.a.
Devonian
1
299 m.a.
Carboniferous
251 m.a.
Permian
SOBRARBE GEOPARK
4
THE SOBRARBE DELTAS
Conglomerates: rocks formed from rounded
fragments of other rocks
(between 40 and 25 million years ago)
The formation of the mountain range caused the
gradual disappearance of the sea, which was becoming
shallower and elongated. About 40 million years ago, a
system of deltas marked the transition between the area that
had emerged and later stages of this marine gulf. Although
this period was relatively short, huge amounts of sediment
accumulated, which can be found today in the southern part
of the District converted into marl, limestone and sandstone.
Once the sea had retreated definitely from Sobrarbe, the
relentless effects of erosion became all the more intense if
possible. About 25 million years ago, active and dynamic
torrents accumulated huge amounts of gravel that, over time,
became conglomerates, such as those that form the bulk of
Peña Canciás.
5
THE ICE AGES
(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 several
occasions 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. Huge
glaciers covered the valleys and mountains and shaped the
landscape, effectively eroding some places and
accumulating sediment in others. The landscape of the
entire northern section of the District was shaped by those
ancient glaciers.
6
Glaciers like the ones we see today in the Alps covered
the Pyrenees at that time
TODAY
Today, erosion processes are slowly and gradually
wearing away the mountain range. This erosion occurs in
many ways: through the action of rivers, erosion on the
slopes, karst dissolution, etc. The landscape that we see
today is only an instant in a long evolutionary process
that is on-going, but now with the participation of man
who is changing the environment like no other living
being is capable.
Río Cinca, agente modelador actual
MESOZOIC
CENOZOIC
199 m.a.
Tria
145 m.a.
Jurassic
2
65 m.a.
23 m.a.
Cretaceous
Palaeogene
3
4
2,5 m.a.
Neogene
5
Quaternary
6
5
E
PISODES REPRESENTED IN THE GEOROUTES
Nº
GEO-ROUTE
EPISODES
PN1
Ordesa Valley
2
PN2
Mount Perdido
2
PN3
The Roland Gap
PN4
Cutas Viewpoints
PN5
La Larri
PN6
Balcon de Pineta
2
PN7
Añisclo Canyon (lower part)
2
PN8
Añisclo Canyon (upper part)
2
PN9
Circuit Añisclo Canyon
3
6
PN10
Escuaín Valley
3
6
PN11
Otal Valley
5
6
3
5
6
2
3
5
6
2
3
5
6
3
5
3
5
6
5
6
1
1
3
3
5
5
6
Episode 1: Variscan orogeny - Episode 2: Tropical marine sedimentation - Episode 3: The formation of the
Pyrenees - Episode 4: The Sobrarbe deltas- Episode 5: The ice age - Episode 6: Today
Nº
GEO-ROUTE
1
Geopark Interpretation Centre
2
Aínsa: a town between two rivers.
Urban geology
3
Geology: A bird's eye view
4
5
EPISODES
1
2
3
4
5
6
3
6
2
3
6
Inside the canyon
2
3
6
Breath-taking landscapes of water
and rock
2
4
6
Sobrarbe at your feet
3
6
7
Crossing the Jánovas Gully
3
6
8
Iron Age Elements
5
6
9
Whims of water for lonely mountaineers
5
6
10
A lake among the oldest rocks in Sobrarbe
1
11
The hidden lake
1
2
5
12
A road with tradition
1
2
5
13
A privileged vantagepoint
14
Secrets of the Guara Mountains
2
15
Geology for the Saint
2
3
A passage between two worlds
2
3
6
16
17
18
19
4
Water inside the Earth
2
1
6
6
6
2
The Jewel of Cotiella
Treasures of the Posets-Maladeta
Nature Park
5
6
5
6
5
6
7
8
Geo
rute
PN
PN
1
ORDESA
VALLEY
TORLA-PRADERA DE ORDESACOLA DE CABALLO-GORIZ REFUGE
This is without doubt the most
popular route in the National Park; essential
in order to understand the spectacular
Ordesa
Valley
and
its
waterfalls.
Achievable for everyone as far as the Cola
de Caballo (Horsetail Waterfall).
This is the one route that every
visitor that comes to Ordesa should
experience. It runs along the floor of the
Ordesa Valley, visiting the countless
waterfalls and enables visitors to imagine
what this valley was like 50,000 years ago
when it was completely covered in ice.
Arripas cascade. Photo Archive Sobrarbe County. Nacho Pardinilla
9
LEGÉNDE
N
250 m
i
1
Parking
Home Geo-Route
Tour Geo-Route
Walking Tour
Number of stop
6
2
5
i
1
7
3
4
i
1
LA GEO-ROUTE PN1
PN This is clearly the most popular route in the Ordesa and Mount Perdido
National Park. Most visitors do this route on foot as it provides magnificent
views of the legendary Tozal del Mallo and Gallinera cliffs and of the Estrecho, Soaso
and Cola de Caballo waterfalls.
The route is clear and perfectly signposted and features information panels
explaining botanical, ecological and environmental details. From the Cola de Caballo
waterfall, the route becomes a little more difficult as it makes its way up to the Góriz
refuge. This is an Alpine section and not suitable for all visitors. The last section of the
route provides stunning views of the head of the Ordesa Valley.
In summer, due to the number of visitors, the route starts in Torla. There are
coach services to the Pradera car park, which is the starting point of the route described.
Ordesa Valley is one of the valleys that best preserves its glacial morphology in
the Pyrenees. However, this is not the only attraction of the route because we will be able
to see the layout of sedimentary rocks and view many fossil remains.
Stop 1: Breathtaking view of the Ordesa Valley from Torla. A spectacular
fold in the foreground.
Stop 5: The
beautiful Cola
de Caballo
(Horsetail
Waterfall) at the
end of Ordesa
Valley.
Stop 3: Unique rudist fossil outcrop and
interpretation.
Stop 2: Observation of the main stratigraphic
units in the area.
Fig. 1. Route Scheme
11
stop
1
STARTING POINT IN TORLA
Breathtaking view of the Ordesa Valley from Torla. A spectacular fold in the
foreground.
WHAT WE CAN SEE
- Séries de roches sédimentaires stratifiées
- Il s'agissait de sédiments déposés au fond de la mer
From the Ordesa Walk, to the north,
flanked by Tozal del Cebollar, we can
contemplate a magnificent view of the north
face of the Ordesa Valley. Below the summit of
Mondaruego, we can see the layout of the rocks
forming horizontal bands of various colours and
aspects. These layers correspond to the main
stratigraphic units: Estrecho Limestone (K2),
Marboré Sandstone (K3) and Salarons and
Gallinera Limestone (T1 and T2).
The almost horizontal layout of the
rocks happened by chance, as they are
part of the Mount Perdido overthrust and,
as we can see in the geological section in
the figure, the Mount Perdido Parador and
Puente de los Navarros rest on Gallinera
Limestone, rocks that we shall also see at
the top of the north face of Ordesa.
Fig. 2: View from Torla
towards Ordesa Valley. The
horizontal layout of the
various layers of sedimentary
rocks can be seen in the
background. They can be
distinguished by their
different colours,
corresponding to the
Cretaceous and Tertiary
formations. A spectacular
fold in the Tertiary limestone
that is overlapping the
turbidites of the Hecho group
(T7) can be seen in the
foreground (Tozal del
Cebollar, left of the image).
In the background, at the
bottom of Peña
Mondarruego, we can see
the overthrust placing
material from the Cretaceous
(K2) above Tertiary (T1)
material; i.e. older material
on top of younger layers.
12
stop
2
PRADERA DE ORDESA
Observation of the main stratigraphic units in the area.
WHAT WE CAN SEE
- Meadows in Ordesa Valley: Gallinero, Tozal del Mallo
- Strata of sedimentary rocks
Key point in a visit to Ordesa Valley
and the place where the park warden's
office and a bar-restaurant is located.
Several routes start at this point and run
through the main valley or one of the side
valleys, such as Carriata and Cotatuero.
cross the Meadow (Pradera) heading east
and follow the signs to Cola de Caballo.
After a few minutes, we shall come to the
Lana de Cotatuero meadows, located on
a debris cone of the torrent of the same
name.
The spectacular Tozal del Mallo or
the Gallinero Cliffs can be seen from the
car park. These large limestone cliffs are
precisely the elements that most attract the
attention of visitors.
The Cotatuero waterfall, with a 150
metre drop, can be found at the top of this
valley. The fir forest in the valley is also
famous. It stands on large scree slopes at
the foot of the Gallinero cliffs. This cliff gives
its name to the "Gallinera Limestone"
geological formation.
To start this route, we have to
Fig. 3: View of the southern face of Ordesa Valley with the main stratigraphic formations. The lower formations are from the late Cretaceous and those
from the Tertiary can be seen at the top. Unit T6 is discordant above the T1 and T2 materials.
13
stop
3
ARRIPAS AND EL ESTRECHO WATERFALLS
Unique rudist fossil outcrop and interpretation.
WHAT WE CAN SEE
- A step in the river that forms a waterfall
- It corresponds to a limestone layer with rudist fossils
Continuing along the track we shall
soon come to the vantage point and the
source of the Arripas waterfall. From here,
there are several spectacular waterfalls
flowing down the rocky outcrop that form
the "Estrecho Limestone" and which take
their name from this geographic feature.
This
limestone
is
noted
for
containing rudist fossils, which were a type
of bivalve that became extinct on the
border between the Cretaceous and
Tertiary eras. This is one of the few places in
the National Park where these fossils can be
found. To see them, you must look closely
on one side of the track near the turn-off to
the Estrecho Waterfall.
Beyond
the
higher
Estrecho
vantage points, located next to the main
track, the route runs through a spectacular
beech forest. Along the forest track there
are several signs showing the way to the
said vantage points overlooking the
waterfalls. The track then passes through a
flatter area, which corresponds to the
transition between the "Estrecho Limestone"
and the "Marboré Sandstone".
This transition zone is less resistant
to erosion and gives rise to "fajas" (narrow
paths, often overhanging the valley), such
as the Canarellos path, which links with the
main valley track in the area.
Fig. 4 The beautiful Estrecho waterfall in contrast with the limestone of
the same name.
14
Fig. 5: Example of an
outcrop with rudist fossils.
The image on the right
highlights the fossils,
which are usually vertical
and cut lengthwise or in
perpendicular sections,
such as the lower circular
shape. The small figure
recreates the general
aspect of a rudist with its
two valves; the larger one
is conical and the smaller
one acts as a lid.
stop
4
GRADAS DE SOASO
WHAT WE CAN SEE
- A succession of waterfalls
- Steps resulting from horizontal rock strata.
Fig. 6: Gradas de Soaso: small linked waterfalls that fall from layer to layer down the "Marboré Sandstone".
15
Fig. 7: Waterfalls are formed by the
alternation of hard rocks that resist
erosion and softer rocks that are easily
eroded.
As we leave the wooded area, we
shall start to cross meadows. This will take
us to Gradas de Soaso, a series of linked
waterfalls that drop, layer by layer, over
the "Marboré Sandstone", formed by thick
and compact layers of sandstone.
These rocks feature abundant
fossils in this section. These fossils, unlike
those
in
the
Estrecho
Limestone,
correspond to the remains of oysters and
unicellular organisms (foraminifera), known
as orbitoids.
Gradas de Soaso.
Photo Archive Sobrarbe County. Nacho Pardinilla.
Fig. 8 Detail of the small and abundant fossils, known as orbitoids, in the
Marboré Sandstone, that were typical in the late Cretaceous.
16
Fig. 9: Aspect of orbitoids cut in half. In order to see the small
chambers, a magnifying glass is required.
Fig. 10 :View of the valley from an area near the access to Góriz. Part of the
Soaso cirque, with its U-shaped glacier morphology, can be seen in the
foreground and, in the background, the Estrecho area where the typical Ushaped glacial landscape has been altered through the action of the river,
resulting in a V shape.
The valley has a clear U profile
(more or less flat and wide floor and steep
slopes). This is typical of glacial valleys,
although, downstream the valley seems to
have been affected by subsequent fluvial
erosion that has created a V profile, as in
the Estrecho area.
Therefore, the valley presents two
sections with clearly different profiles:
although the ice covered the entire valley,
the glacial morphology has survived better
at the top of the valley. The slopes are very
irregular due to slope screes, which alter
and mask the many remains of glacial
moraines.
Fig. 11: This sequence displays what can be seen in this area. Firstly, the ice
of the glacier created a U-shaped valley with moraines at the bottom and
sides. When the ice retreated, the materials in the moraines mixed with the
screes on the slopes. Finally the erosive action of the river changed the
valley.
17
stop
5
COLA DE CABALLO (HORSETAIL WATERFALL)
The beautiful Cola de Caballo (Horsetail Waterfall) at the end of Ordesa
Valley.
WHAT WE CAN SEE
- A spectacular waterfall that widens as it falls from the source.
- The waterfall is caused by a karst spring.
Fig. 12: The Cola de Caballo is one of the most emblematic places in the National Park. It is located at the bottom of the Ordesa Valley.
Its source is a groundwater spring located above the waterfall.
18
After climbing to the Gradas
Waterfalls, the route reaches the floor of
Soaso Valley, which has a very clear Ushaped profile that is typical of glacial valleys.
We shall then reach the Cola de Caballo
waterfall, one of the emblematic places in
the National Park.
The waterfall flows from the highest
point of the "Marboré Sandstone", which is
easily identifiable by its ochre colour. The water
that flows through the ravine comes from a
karst spring located a few hundred metres
further up. Therefore, there is no "real" river that
feeds the waterfall; the water we see here
comes from the uppers reaches of the Mount
Perdido massif, where it filters into the subsoil.
After a few kilometres under the ground, it
comes to the surface creating a spring and the
beautiful waterfall we can see.
Fig. 13: Recreation of what the Soaso Cirque must have looked like 65,000 years ago. The glacier descended from Mount Perdido forming a great
icefall that overcame the most resistant rocks (Gallinera Limestone, T2).
19
stop
6
TRACK OVER THE CLAVIJAS DE SOASO TO GORIZ
WHAT WE CAN SEE
- Various types of rocks
- Limestone and sandstone from the Palaeocene and Eocene
From this point, there are two ways to
reach the Goriz refuge: a shortcut over the
Clavijas de Soaso, suitable for mountaineers,
and a longer but easier path that will enable
us to enjoy the limestone formations of
Salarons and Gallinera (T1, T2 and T3).
After crossing some screes, the track
traces a curve and becomes a very narrow
path. We shall reach a meadow growing on
easily eroded rocks that form some of the
Fig. 14: Detail of fossils of small black nummulites.
typical narrow paths ("fajas") in this valley,
where we can observe the nummulites that
are typical of the small shelter found at the
side of the path.
Later, the rocks will change and, on
the last slopes, we shall find large white layers
of microconglomerates made of quartz
pebbles. Among these, we can also find
limestones and carbonated sandstone with
alveolinas.
Fig. 15:Aspect of the white layers that consist of sandstone and gravel
with quartz pebbles forming crossed layers. This is a type of rock that
almost entirely consists of quartz, called quartzite.
Fig. 16: Reconstruction of nummulites and
alveolinas, displaying their internal
structure divided into several sections.
20
stop
7
GORIZ REFUGE
WHAT WE CAN SEE
- Strange nodules in the limestone
- Fossils of marine sponges
Before reaching the refuge, we will
notice some grey limestone rocks along the
way with strange ochre-coloured shapes
measuring several centimetres long.
Fig. 17: Grey limestone with abundant round and hollow silex nodules that
correspond to fossil sponges. These sponges had a skeleton of siliceous
spicules, which makes them stand out on the calcareous, water soluble
rocks.
Fig. 18: Drawing of a
sponge before it became
a fossil and where it is
cut into the sections we
can see.
These are nodules, composed of
silex, which is a variety of microcrystalline
quartz that resists the dissolution that
affects the rest of the limestone, making
them stand out. Despite their irregular
appearance, we can see that some of
them have a hole in the centre if we look
carefully. These are nodules formed from
fossils of siliceous sponges that lived in a
tropical sea about 50 million years ago.
Several mountain routes start at this
point. Two of them are described in this
guide: the route up Mount Perdido and one
that visits the Brèche de Roland and Mount
Taillon. In any case, the views of the Mount
Perdido massif from the vicinity of Góriz are
spectacular. We recommend a walk
around the area, where it is also easy to
find interesting karst elements, especially
sinkholes, limestone paths and catch
basins.
Fig. 19: View of Ordesa Valley from the head of the valley towards the southwest as it is today and a reconstruction of its probable appearance when it
was covered by a glacier.
21
!
SIR CHARLES LYELL: AN ILLUSTRIOUS VISITOR.
Sir Charles Lyell was one of the most
influential scientists in the development of
modern geological concepts during the early
nineteenth century and an excellent
communicator of those concepts in his major work
"Principles of Geology"; which was published in
1830. In this work, Lyell developed and extensively
documented the principle known as
"uniformitarianism", already outlined by Hutton,
which states that "Geological remains from the
distant past can, and should, be explained by
reference to geological processes now in
operation". This proposition allows us to interpret
the formation of rocks and various geological
phenomena recorded in rocks by comparing
them with the processes that we can see in
operation today on Earth.
One of the main problems facing researchers in
the early nineteenth century was to find
mechanisms that had pushed sedimentary rocks
that had settled on the sea floor to the tops of mountain ranges. Lyell devoted much effort
to this problem by studying variations in sea level linked to volcanic eruptions, which were
the main tectonic force visible for geologists of the time. This line of research led him to visit
most active volcanic areas in Europe, including the Garrotxa volcanoes in the Eastern
Pyrenees. During this trip Lyell made ??an excursion through the Mount Perdido massif on 22
and 23 August, 1830, arriving from the Gavarnie area and accompanied by Captain
Samuel Cook and local guides. His travel diary for this trip contains several drawings made
from the Góriz area, where he spent the night, in which his great capacity for geological
analysis is patent.
Fig. 20: Drawing of the Góriz fold from
Sir Charles Lyell's travel diary. In the
drawing we can read the following from
left to right: - A. limest. with flint - limest.
A - grass (repeated 3 times) - clay
slate - limest.
22
Soaso Cirque.
Photo Archive Sobrarbe County. Nacho Pardinilla
!
PYRENEES-MONTE PERDIDO,
A TERRITORY BORDER WORLD HERITAGE
In 1997, UNESCO added the
Pyrenees-Monte Perdido site to its World
Heritage List in recognition of its natural
and cultural importance. The site covers
a cross-border area and includes the
Gèdre, Gavarnie and Aragnouet valleys
in France and the district of Sobrarbe in
Spain.
This remarkable mountainous landscape
straddles the border between France
and Spain. At its centre lies the limestone
massif of Monte Perdido. The PyreneesMonte Perdido World Heritage Site
extends across 31,189 hectares and
includes the municipalities of Torla, Fanlo,
Tella-Sin, Puértolas, Bielsa and Broto in
Sobrarbe on the Spanish side and the
Gèdre, Gavarnie and Aragnouet valleys
in the Hautes-Pyrénées Department on
the French side. The entire Ordesa and
Monte Perdido National Park in Spain lies
within the listed site, while in France the
area is also protected by the Pyrenees
National Park.
Cultural and natural heritage
Monte Perdido from Mountain Sesa
Photo Archive Sobrarbe County. Nacho Pardinilla
Gavarnie Cirque.
Photo Archive Sobrarbe County. Nacho Pardinilla
The Pyrenees-Monte Perdido is home to deep canyons and cirques with spectacular
walls: three canyons and a gorge on the southern side in Spain (Ordesa, Añisclo, Pineta and
Escuaín) and four large glacial cirques on the northern side in France, which is steeper
(Gavarnie, Estaubé, Troumouse and Baroude).
The karstic, glacial and valley landscapes contrast with the almost flat-topped peaks and the
underground waters that have formed extensive galleries, chasms and grottoes.
This single site thus harbours outstanding cultural and natural aspects: The geological
and biological characteristics of the site make it an extremely interesting place for science and
conservation, as it includes numerous endemic species of flora and fauna.
It is an outstanding cultural landscape that combines the beauty of a matchless
natural setting with a socio-economic structure that dates far back into the past and illustrates
ways of life typical of mountainous areas that are disappearing in Europe.
People have developed their way of life, their relationship with the environment and
their bonds with others in this area since prehistoric times. In the Middle Ages, an unusual form
of economic and social organisation came into being. In both Spain and France, the families,
towns, villages, valleys and regions on each side of the Pyrenean chain managed to conquer
the 'impassable wall' of the mountains and so were able to engage in trade, make business
agreements and forge alliances and cultural ties based on peace and a sense of fellow-feeling.
The landscapes we see today are the result of the legacy left to us by our forebears, who
worked hard to keep alive a basic system of farming and animal husbandry that would ensure the
survival of generations to come and their traditions, rituals, festivals, music and legends.
www.pirineosmonteperdido.es
Brèche de Roland
Photo Archive Sobrarbe County. Pierre Meyer
ORDESA VALLEY
TORLA - GORIZ REFUGE
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> PRACTICAL INFORMATION
ROUTE: Torla - Pradera de Ordesa - Cola de Caballo - Goriz Refuge
TYPE OF ROUTE: linear (return along the same route).
DIFFICULTY LEVEL: Elemental
DURATION: 3 hours to the Cola de Caballo waterfall and another 1.5 to the Góriz refuge.
DISTANCE: 15,5 km to the Cola de Caballo waterfall and 21 km to the Góriz refuge.
GRADIENT: 450 to the Cola de Caballo Waterfall and 950 to Góriz.
i
STARTING POINT: Torla
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
COMMENTS
This Geo-Route runs through the Ordesa y Monte Perdido National Park, part of the transboundary
site Pyrenees-Monte Perdido, declared World Heritage by UNESCO.
At certain times of year it is restricted access by private vehicle to "La Pradera de Ordesa", having an
alternative bus service.Information Point of the National Park in Torla. Tel: 974486472
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
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PROFILE GEO-ROUTE
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1GEO-ROUTE
PN
of Sobrarbe
www.geoparquepirineos.com