Central Volcanic Province

Calatrava: Spain's central volcanic region

We drove through here and explored it on our way north to catch the ferry back to the UK in late October 2007. This is the area between Almagro, where we camped, and Moral de Calatrava.

Almagro campsite, almost deserted at the end of October, sports a windmill and a noria (water wheel)

And some evidence of volanic activity - a bomb (with Jan for scale)

The Calatrava Volcanic Province

The Calatrava Volcanic Province (CVP) is made up of strombolian and phreatomagmatic eruptions through the Cenozoic continental sediments. The region is sub-circular, centred approximately on Ciudad Real, but vents are along NW-SE trends. 

The high ground is where the harder, volcanic rocks are more resistant to erosion than the surrounding fine-grained sediments. As we didn't have too much time we headed for one particular area, around Valenzuela to see if we could find some sections in road cuttings.

A lava flow exposed in a road cut. At the base is grey basalt with joints where the rock has fractured; above this is the weathered rubbly top. This is overlain by a thinly bedded ash fall layer (below the sloping surface of the upper part of the road cut). The face of the cutting - the bit we are interested in - is about 3m high

This close up photo is about 40 cm from top to bottom. It is the upper part of the exposure in the road cut and shows (1) at the base is the weathered rubbly top of the flow. (2) This is overlain by thin layers of ash fall with reddish veyr fine graned material and greyer more lithic and pumice rich layers. There is a soil horizon over this which starts at the overhang

A little way downhill we could examine the centre of the flow more easily