From I Brent de l'Art/ Proloco Trichiana
The Brent de l'Art are a natural conformation, very similar to a canyon, due to thousands of years of erosion by water, which has brought to light layers of rock formed millions of years ago.
This erosion is due to the debris that the water carries into these narrow valleys. Stones and plants overwhelmed by the flood of water, once they enter the canyon, create eddies, hit the walls, digging into the rock and then flow downstream. The flow of water in narrow valleys like that of the Brent is also characterized by the significantly amplified noise of flowing water, which does not happen in normal, more open valleys.
It is assumed that the most important natural excavation work lasted from 10,000 to 15,000 years, coinciding with the thaw following the end of the Wurmian Glaciation which ended 9,000 – 10,000 years before Christ and continues, although in a much weaker manner, today again.
It is not uncommon to find many rough stones of an almost spherical shape in the narrowest bends and bends of the river. These are the stones that swirl in circles on the walls of the Brent, modeling the rock like an expert sculptor.
The typical red color of the Brent is due to the presence of the Cretaceous "Scaglia Rossa", a rock formed during the Upper Cretaceous, i.e. 90-65 million years ago. It is composed of carbonate mud deposits mixed with planktonic foraminiferal fossil shells (marine invertebrates) which make it an easily erodible material, even if it has good vertical stability. This rocky conformation forms the walls of the Brent de l'Art, revealing its calcareous-marly layers generally brick-red in colour, due to the presence of iron oxides, and more whitish layers due to secondary discolouration, both interspersed with further layers of red and grey-green clays. These particular geological characteristics account for the majesty and beauty of the Brent de l'Art, a place that allows an exceptional leap in time, to millions and millions of years ago.