The Pesciola Basin: Historical Landscape and Morphology

The shape of the Pesciola Basin in Sticciano is asymmetric and irregular. Along its course, it exhibits three right tributaries varying in length from 1.8 km to 3.3 km, while the left orographic side is marked by six small ditches, each only a few hundred meters long. This fact underscores another: the erosive action of the Pesciola waters on its left bank, causing it to migrate beneath the southern orographic ridge, thereby contributing to the strong asymmetry of its basin.

If we examine the cadastral maps from 1820 of the entire Pesciola Basin, formed by the Sticciano and Aliano branches, which depict the parcel division of the territory, we can observe how the entire area ascending from the Tresanti bridge up the hillside where the eponymous village with its church stands is characterized by a very wide parcel mesh, distinct from that present on the Pesciola plain. Here, the parcels take the form of long and narrow rectangles, parallel and orthogonal to the watercourse.

What does this difference imply? Primarily, it reflects their original use, namely pasture and fallow land, which in turn was linked to the typical lithology of this area characterized by the almost total presence of marine clays. These clays, in turn, harken back to the recent geological history of this region over the last three million years, during which the presence of a deep sea led to the deposition of silts, sands, and clays on its floor. Following the retreat of the marine waters during the Pleistocene (the last million years), these sediments were eroded by atmospheric agents, resulting in the distinctive, rounded shape that has made the Tuscan hills famous worldwide.

The “panchina” and the “cornice,” both located at the panoramic viewpoint of Chinigiano, offer a striking and excellent example of a landscape dominated almost entirely by clays.