Posted by: Rose | March 27, 2009

Portage

Whitewater kayaking is my passion; the sea kayaking is a very pleasant sideline for when there isn’t any water in the rivers. I don’t tend to look at rocks too much when I’m on rivers, other than to note the rock type and smile at any pretties along the way. This is usually because I’m either:

  1. Too terrified to care;
  2. Travelling at high speed with a modicum of control;
  3. Upside down/swimming and conversing with the fishies.

I was lucky enough to go to northern Portugal over New Year and was really stunned by the hospitality and beauty of this small corner of Europe.

The photo below shows Chris paddling the ‘Portage’ on the Paiva Gorge. This river reminded me a lot of Scotland in autumn, except that the trees lining the steep banks were Eucalyptus, Portugal’s cash crop.

Paiva Gorge, Portugal. Photo by Mark Rainsley.

Paiva Gorge, Portugal. Photo by Mark Rainsley.

The Paiva travels through a granite gorge where the rapids form as the water flows over and around large boulders. There were a couple of occasions were we had to get out and carry our boats around rapids that were too dangerous to run. I was surprised to note that both dodgy rapids were caused by a change in rock type, to meta-sediments. The heat from the granite has altered the sediments that it has intruded into. This is called contact metamorphism where the heat and pressure forms new minerals and changes the physical properties of the rocks that it influences, the so called  ‘country rock’.

Contact metamorphism also resulted in my portaging a rapid, slipping and dropping my kayak on my foot. Ow! And it was only when I returned home that I realised I’d missed an opportunity to go and see the Giant Woodlice at Arouca.

Paiva Gorge, Portugal

Paiva Gorge, Portugal

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Responses

  1. I’m desperate to see the Giant Woodlice, but the link isn’t working for me…..

    Andrea.

    ps, I’m really enjoying the blog btw.

  2. Trilobites are probably my favourite fossile. I didn’t realise they got quite that large.

  3. […] generated from the granite and the movement of hot fluids through fractures and fissures in the country rock  is the root cause of Cornwall being a historically important mining location for tin […]


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