La Carta delle Pietre Ornamentali della Regione Toscana: esempio di utilizzo applicativo del Continuum geologico regionale

Giovanni Massa (*), Sergio Mancini (*), Laila Giannetti (*), Debora Graziosi (*), Andrea Rindinella (*), Altair Pirro (*), Elia Pasqua (*), Giulia Verdiani (*), Guido Lavorini (**), Francesco Manetti (***) & Massimo Perna (***)
(*) Centro di GeoTecnologie, Università degli Studi di Siena, San Giovanni Valdarno (AR). (**) Direzione Generale delle Politiche Territoriali e Ambientali, Sistema Informativo Territoriale ed Ambientale, Regione Toscana, Firenze. (***) Consorzio LaMMA, Sesto Fiorentino (FI).

Tuscany Region Ornamental Stones Map. Tuscany Region Ornamental Stones Map, scale 1:10.000, identifies the land outcrops of stone materials (marbles, granites, slate), highlighting the quarried varieties and their commodity production geological formations, the location of active and inactive quarries and quarry landfills. Each ornamental stone appears in the legend by a code of two letters and with its trade name that immediately identifies with the experts. For example: Pietra Serena, Giallo Siena. The 71 maps of the ornamental stones collected at the moment are attached to this project. The guide for the identification of the outcrops under excavation in the past and currently in place has been provided by the Tuscany Region document called the "PRAER" (Mining Activities of the Regional Plan for Recovery of Excavated Areas and Reuse of Recoverable Waste, approved by resolution of the Regional Council n. 27 of 27 February 2007). Similarly to the document PRAER, must be remarked that a geological formation rarely present ornamental characteristics and physical-chemical and mechanical properties that make it commercially interesting in all its territorial extension. More likely, those areas must be identified, where unique ornamentation and mineralogical characteristics support that material as a variety of merchandise. For example, all the "Macigno" formation could be considered a "resource", but in fact the conditions to get out of this rock a "Pietra Serena" exploited as ornamental stone are limited. Different materials in the ornamental stones legend were grouped according to a genetic and lithological criterion. Two major lithological classes were identified which include almost all of the ornamental stones outcropping in Tuscany: sandstones and limestones (in the case of sedimentary rocks); metasandstones metalimestones and (in the case of metamorphic rocks). Exceptions are: sulphate represented solely by the rocks "alabaster chalk", cultivated in the provinces of Pisa and Siena are characterized by a complex genesis. A group apart of magmatic origin include the "Elba Granite" and two types of volcanic materials and ophiolitic breccias associated with the Ligurian tectonic units.

ornamental stones, Tuscany