Geo Blogging with Mark: Tiles, cork, wine and marble!

The Artemis web site diary recounts how Mark found a 'nice wee hotel' in Montemor o Novo last night....

There is a good description of the town here and an excellent set of photos on Flickr of which this is just one. Montemor o Novo, like many small towns and villages throughout the Mediterranean occupies a hilltop site. Unlike the UK where villages would normally seek low ground, Mediterranean settlements perch on the high ground. Often, as in the case of Montemor, it was for reasons of defence (there is an old castello on the hill just south of the town) but in a country where the most easily irrigated land is in the valleys, there is little point in using that land for settlement. Hence, towns and villages grew up on the hilltops as predominantly farming communities with farmed land spread out below. There are other good examples of this type of site and function in other settlements along Mark's route today.

The photo above and a 'zoom in' on Google to any of the settlements in this part of Portugal reveal a mass of striking red roofs. Almost every building is covered in terracotta tiles. One of the things which I find interesting about architecture is that buildings often reflect local geology..... thus the grey, unweathered granite houses in Aberdeen or the honey coloured, edges-softened-by-the-rain, houses in the Cotswolds, the slates on the roofs in Wales etc. Here in Portugal the red tiles are made of red clay - terra rossa -which is the predominant soil type.

From above it gives a rich colour to bare earth seen here on an aerial shot from Google along Mark's route today. Terra rossa soils tend to develop in areas which are underlain by limestone and which have a Mediterranean climate. I don't claim to fully understand the chemistry but the red is iron oxide and is the result of clay residue from weathered limestone oxidising. It is considered to be a very good soil for growing vines.

One of the other agricultural products for which this region of Portugal is particularly noted is cork. More than half of the world's cork oak forests are found in the Alentejo of Portugal and they traditionally supplied the cork for wine producers all over the world. There is ,however, an environmental 'issue' related to the current trend of replacing cork with plastic 'corks' or even screw tops! This WWF video explains .....

...and below 'harvested' cork

Along Mark's route today there were many small dams - reminders of the aridity of summer in this part of Portugal and the need to store water from the winter to permit cultivation on irrigated land in the summer. Many of the irrigated areas have the centre pivot systems which we have become familiar with all across the world....

It is worth remembering that apart from vines and tree crops such as olives, few other crops would survive the summer drought without the aid of irrigation. Where land is not irrigated, little will grow in the summer months. On the image below of Vimieiro, for example, many of the fields will have been harvested of their crop of wheat early in the summer and will now lie empty until they are sown in time for the autumn rains.

The image above and this one of Vila Boim also serve to illustrate the pattern of land tenure described earlier in this posting. In the UK we are used to a pattern of dispersed rural settlement with isolated farmhouses surrounded by their land. Here in Portugal, the farms are clustered together close to the villages with their land scattered in several plots around the surrounding countryside. It ensures that all farmers have an equal share of the range of types of land but it is much less efficient than farming contiguous plots of land.

In all of these images the terra rossa soils are very noticeable and their presence links to two other products of this part of the Alentejo. Firstly, as mentioned, terra rossa develops on limestone. The metamorphosed form of limestone is marble and this region is famous throughout the world for its high quality marble. Portugal is the second largest exporter of marble in the world (after Italy) and 85% of it comes from the

area around Estremoz, Borba and Vila Vicosa through which Mark travelled this afternoon. The Google imagery is rather low res in this area but it does give an impression of the extent of the quarries and the image below, sourced from Flickr, shows one of the Estremoz quarries in operation.

Terra rossa soils are also particularly good for vine growing and the region around Estremoz and Borba has an abundance of vineyards which produce high quality wines.