Saturday, June 21, 2014

Field trips in Aragon, Spain

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. 

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