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Geology

The Pigelleto Nature Reserve is in the south of Monte Amiata and extends over a wide territory in the region of Tuscany. It is between P.gio Zoccolino in the North and M. Civitella in the South (fig. 1). In figure 2 you can see that in the highest part of the area there is a lack of vegetation whereas the Pigelleto is covered by Santa Fiora and Pietraforte near the Tyrranean Sea. Montains here allochthous and irregular.
The rocks that emerge are made of limestone and loam rock. The mountain is devided into two blocks and on the highest areas you will find sandstone of the Pietraforte kind, covered by grey loam rock.

fig 1 = topographic map
F.o. 129 IGM 1:100.000

Th main mountains and a small group of mountaind on the Eastern side of the Pigelleto include characteristic hills made of limestone with tower-like profile. They are P.gio Roccaccia(m 884), P.gio Pampagliano(m. 969) and P.gio Roccone(m 913). When clay comes in contact with the water bearing limestone, big blocks of this limestone slips to the valley creating large and charateristic niches creating a gab between one block and seperated by rivers of debris. The montain sides are characterised by the pecular concave-convex like form. In the valley there are plains often occupied by water stagnations. The soil of the Pigelleto Reserve has been changing for years even if there is a wide range of vegetation. At west Santa Fiora valley it is possible to find solphur mines and other minerals such as cinnabar, marcasite, pyrite, antimonite, millerite, quarzt, calcite and dawsonite. In the South there is the anti-appeninines stratum which the Siele river. It is also rich in ore deposits. Today the mines have been abbandoned and are a memory of a past.

fig 2 = geological map
pb = clayey rock with limestone (Late Cretaceous) sf= Santa Fiora calyey -limestone rocks (Early Cretaceous - Palaeocene)
pf= Pietraforte calyey - sandstone rocks (Early Cretaceous)