mountains in the Firenzuola area were created by uplift movements between
5 and 10 million years ago, which brought to the surface a sea bed which
dates back to 20 million years ago. The alluvial deposits of the basin
were thus the origin of the marly-sandstone outcrops that are often to
be seen on the flanks of the mountains in the Alto Mugello, that is, strata
of sandstone alternating with marl (also called galestro), which is limestone
mixed with clay.
The widespread and clearly evident availability of this primary material
explains the centuries-old tradition of stonemasons working with pietra
serena, commonly called "Firenzuola stone", in the mountainous
zone of the Alto Mugello. This area takes in the territory of the councils
of Firenzuola, Palazzuolo sul Senio, and Marradi.
There are outcrops of the rock all along the lines cut by water courses,
and it is clearly visible along the Santerno (Coniale), Senio (Acquadalto),
and Lamone (Fantino) valleys; in the basin of the Rio Dell'Alpe towards
the Rovigo valley; on the right-hand bank of the Torrente Sillaro between
Piancaldoli and Giugnola, where the thinness of the surface capping above
the stratified slabs makes extraction particularly convenient; in the
area to the south-west of Palazzuolo sul Senio, in the whole series of
small valleys cut by the tributaries of the Fosso di Campanara and the
Fosso dell'Aghezzola; at Valcarpine, in the small valley of Fosso di Salecchio,
to the east of Palazzuolo sul Senio; at Ca' del Gallo to the north-west
of Marradi, between Ca' del Falco and Ca' del Vento.
This activity, which has extremely ancient roots, has never been
abandoned, and indeed there are still today some 50 active quarries.
98% of the material extracted is sandstone, while the remaining 2% is
colombino or alberese (fine limestone), which comes from an approximately
2.5 metre thick layer of resedimented sandstone; the latter is harder
and more solid, and is recognisable by its darker colour, and by the presence
of right-angled fractures which divide it into almost perfectly square
Translated by Jeremy Carden
Picture by Kee-Ho Casati