As with many geology workshops there is usually a field trip to the surrounding area. This sounds like a
good jolly – but actually I think it is where a lot of the networking goes on
while sitting on the bus and also for me I learn more in the field than sitting
listening to people talk in a lecture room.
The first day we set off very early and drove up to the
Pyrenees to see the glacial morphology. We had perfect weather and the views
were spectacular. It would have been great to do some hiking – hopefully next
time! We also saw a series of moraines further down the valleys showing the
extent of the glaciers during previous glacials. The big mystery is that there
is no evidence of the last glacial....? Was it too dry?
Spectacular views of large U-shaped valleys in Ordesa National Park
An explanation of the geology and geomorphology
The second day we headed in to the Iberian Range, to karst
country. We spent the day around the Monastery of Piedra, now a hotel, but
previously owned by a wealthy family. This region is surrounded by limestone
and the river waters are so concentrated with carbonate that they are
precipitating limestone as they go over water falls (like stalagmites and
stalagtites in caves). These tufa deposits are growing rapidly at almost 10 cm
per year... so the waterfalls are actively managed in the park to make sure
they don’t grow too big... or start to cause flooding.... It was very cool and
lush in the park, an oasis compared to the surrounding dry and hot karst
plateau.
One of the many water falls in the Monastery de Piedra park
The largest waterfall which you walk down behind
The fish ponds in the limestone gorge
On the final day we went west into the “Badlands”. I will
have to look up the origin of this name – but it is basically very soft
sediment that is eroding rapidly. There is a cap of hard mudstone on the top of
the sediments which has protected some of the sediment below to form mesas and
pillars. But we were here to look at the fluvial erosion and deposition during
the Holocene (the last 12,000 yrs). It is amazing that people live here and
grow crops as it is a highly changeable landscape. Of course it is usually very
dry... but there was rain the night before so there was a very muddy river
flowing and we couldn’t get up close to the sections we had hoped to get to
see.
One of the almost eroded mesas...
Eroding Holocene fluvial muds...
Three different landscapes and geological/geomorphological
processes. Some associated with cold periods and others with warm and others
probably a combination of both – as unfortunately the dating is not well
constrained. A few weird features that are also still hard to explain and more
work to do. It is clear that Spain has a diverse landscape. I look forward to
coming back and exploring some more.