Giant trilobites and biotite nodules in Portugal

Peter Perkins (UK) The generally accepted reason for the fame of Arouca is Princess Mafalda, born 1195, who was responsible for the convent becoming Cistercian. Here is an interesting story – she was beatified in 1793. However, I won’t go into that now, but it is well worth investigating. For this article, there are other reasons for its fame, at least among geologists. Arouca is 38km to the south east of Oporto, in northern Portugal, and gives its name to one of two geoparks in Portugal. In Arouca Geopark (Fig. 1), which has an area of 330km2 (just a little smaller than the Isle of Wight), there are two quite remarkable geological features, one palaeontological and the other concerning igneous petrology. Fig. 1. Map of Arouca Geopark. A geopark is an area of significant size that has a particular geological heritage, with a certain number of sites of special importance – scientific quality, rarity, aesthetic appeal and educational value. It must also have a sustainable strategy for development to be accepted as a member of the worldwide network of geoparks. There are 42 in Europe, in 16 countries. The other Portuguese Geopark is Naturtejo, through which the River Tagus flows. There are nine geoparks in the British Isles, for example, NW Highlands (Scotland), Copper Coast (Ireland), Fforest Fawr (Wales) and the English Riviera. The website,, gives website addresses for all. The geology of Portugal is very complex. There are no strata younger than Triassic, except for Holocene deposits in … Read More

To access this post, you must purchase Annual subscription, 12 Month Subscription or Monthly subscription.