Stone books preserving signs of life
The “Paiva library” is located over the Mourinha stream (a tributary of Paiva), where there are quartzite strata that are exposed and verticalized in such way that it justifies its designation, in a clear analogy to the book spines arranged in a bookcase. This quartzite outcrops, from the Arenigian age (Inferior Ordovician), were the result of the sand deposition, at about 480 million years ago (Ordovician Period), in the shallow banks of the Gondwana paleocontinent, at latitudes very close to the South Pole. The vertical strata present here are related to the continental collision that originated the Pangaea and the formation of the Variscan chain. This compressive process caused the immersion of wide areas, leading to the verticalization of these strata that were horizontally deposited.