Overall, Italy is not very favored for underground resources; a mining country has never been, but today its conditions of inferiority, compared, not only to the large, better-endowed extra-European states, but also to most of the European ones, derive essentially from two causes: on the one hand, from the shortage of some products, of which the need and consumption have grown dramatically in recent times (fossil fuels, oil, iron, copper, etc.), on the other hand by the scarcity and dissemination of many mineral deposits, which today make them economically not very convenient the use, instead often practiced with profit in the past, when all the industries had a more limited range.
The mines and quarries have given employment, in recent years, to just 110,000 people, and have provided an income not exceeding 1.1-1.2 billion. Large mining centers do not exist: in the Alps the mining districts are scattered and small in size; in the peninsula the most important district is in one of the most geologically ancient parts, the so-called Tuscan Metalliferous Chain with Elbe; it has a parallel in that of south-west Sardinia (Iglesiente). A noteworthy place also belongs to Sicily for sulfur, the Apuan Alps for marbles.
Among the products of real mines, the first place in terms of value goes to sulfur, which is found here and there throughout the Sub-Apennines, in a characteristic Miocene formation, which is called gypsum – sulfur formation, but, as has just been said, it gives rise to exploitation above all in Sicily (sulfur in the province of Agrigento and Caltanissetta) and secondarily in Romagna. Italian production, which culminated in the period 1899-1905 and was then at the forefront of the whole globe, declined in the face of competition from the United States, which today produce approximately three times the Italian one. This is around 2-2.3 million tons of ore, equal to 325-350,000 tons. yearly of crude sulfur; for some years it has been constantly and significantly increasing again. For the conditions under which the extraction takes place, see. Sicily.
For the production of iron, the most important center is still the island of Elba; then come the mines of Val d’Aosta (Cogne), Val Camonica and neighboring regions, and Sardinia (Iglesiente, Nurra); among the latter some, activated during the world war, are now inactive; in fact, attempts are made to save, as far as possible, the modest Italian reserves (perhaps just 150 million tons of ore, according to very approximate calculations). The production of the ore, which was about 560,000 tons. per year in the last five years before the war, it approached 1 million during the war (994,000 tons in 1917), then fell; since 1925 it has recovered and in 1929-30 it reached 700,000 tons again. This figure does not include iron pyrites, which are widely extracted (for an almost equal quantity) above all in the Tuscan Metalliferous Chain. Production declined in 1931-32. For lead and zinc minerals, Italy comes third in Europe, but far behind Spain and Prussia; production reaches 200-280,000 tons per year, three quarters from Iglesiente (also the Tuscan Metalliferous Chain; Agordino mine, etc.). Associated with lead minerals (especially galena) is silver (about 15,000 kg. Extracted annually). The extraction of bauxite is in progress, which dates, it can be said, from 1920 (90,000 tons in 1926; 192,000 in 1929 and 161,000 in 1930; in 1931 there was a sharp decrease, presumably temporary) from which the aluminum (mines in Abruzzo and Istria),
Italy has the primacy in the world for the production of mercury, supplied by the mines of M. Amiata (Tuscany) and Idria (Gorizia) (220-240,000 tons of ore per year equal to 2000 tons of metallic mercury) and it has some iron manganese mines (Sardinia) and antimony (Tuscany); on the other hand, it produces very modest quantities of copper (about 15,000 tons; increasing since 1928: Tuscany, Ligurian Alps) in comparison with the ever increasing needs. More serious is the lack of fossil fuels, an indispensable element for large modern industry. Apart from the very small production of anthracite and actual litanthrac, a certain quantity of fuel is extracted in Istria which in terms of carbon content is close to litantrax and has the denomination of Liburnian coal .(200-220,000 tons per year). On the other hand, lignite abounds, which in the war period was actively extracted, but today, when the most urgent needs ceased, it is used only in the richest and most accessible deposits (Upper Valdarno, surroundings of Spoleto, Iglesiente, Valdagno in the Vicentino); the annual quantity tends to decrease (from 600-700,000 to 300-400,000 tons). Some peat bogs are also abandoned, the most abundant remaining active (about ten, which give a product of 7-8000 tons).
The lack of hard coal to be used for industrial uses has been tried to remedy with the exploitation of hydraulic energy, of which Italy is very well supplied. Numerous recent studies have ascertained the quantity available and have led to the execution of huge works to regulate its distribution. In 1898 the installed power of hydroelectric plants per motive power did not reach 100,000 kilowatts, while today it exceeds 3½ million kilowatts. About three quarters of the plants in Piedmont, Lombardy, Veneto and Venice Tridentina, that is, in Alpine Italy, which has more abundant rivers of water and a more regular regime, concur for about three quarters; the largest plant is that of Cardano sull’Isarco (182,000 kW. of installed power); another eight plants exceed 50,000 kW. Lazio (plants on the Aniene), Umbria (Nera and Velino), Abruzzo (Pescara), Calabria (Ampollino and Neto) follow in importance. Other large plants are under construction.
Despite the numerous and diligent researches carried out in recent years, the production of oil is very scarce; the pockets used today are found almost only at the foot of the last Apennine offshoots degrading towards the Po Valley, in the provinces of Parma and Piacenza at different depths; small quantities come from the province of Frosinone (San Giovanni Incarico); elsewhere the tastings have not so far given the desired result. The quantity, from less than 5500 tons. in 1926, it rose to around 8,000 in 1930, a minimal percentage of the total quantity required by national needs. To a somewhat greater extent, asphalt, bitumen and similar products are obtained, which are also used today for the preparation of lubricating oils, etc .; oil shales are widespread in the peninsular and Sicilian Sub-Apennines (around Ragusa: asphalt), but not everywhere they appear profitable; indeed, in recent years, production (220-320,000 tons) tends to decrease.
Other products, which have some importance in Italy, are graphite (Cuneo, Carrara: 6-7000 tons per year); alumite (Tolfa near Civitavecchia: 825 tons in 1930); rock salt (almost only in Sicily: 60-70,000 tons per year). The production of sea salt is richer (500-650,000 tons per year), which is obtained from six or seven active salt pans (Cagliari, the most important for production; Margherita di Savoia, in Puglia; Pirano; Cervia; Comacchio; Tarquinia; Trapani; Syracuse); to it is added the spring salt (Saline di Volterra).
Among the products of the quarries, first of all are the marbles, which indeed, compared in value, have the absolute first place among the products of the Italian subsoil, due to the high value of the statuary white marble of the Apuan Alps, which gave rise to a thriving marble industry; Carrara, which is its center, is indeed the Italian city that has the largest percentage of the population devoted to occupations connected with the extraction of minerals. White marbles also come from Val Venosta (Lasa) and Novarese; colored marbles from many Alpine areas and some from the Apennines and Antiappennines. There are also numerous and varied construction or cutting stones: granites, porphyries, syenites, diorites from the Alps, slates in Lavagna (Riviera di Levante), sandstones in Tuscany, travertine in Lazio, volcanic tuffs, peperini, etc., also in the Lazio and Campania, limestone stones of considerable value in Puglia (tuff, Lecce stone); and then alabaster (Volterra), plaster; also talc, pumice, etc.
Another richness of the subsoil, of which Italy is well provided, is finally offered by mineral springs, now at high temperatures (thermal) especially in the domain of active or inactive volcanic systems (Abano near Padua, Agnano, Ischia, etc. ), more often at ordinary temperature. Among these, some are widely known for their therapeutic qualities and have therefore given birth to thriving health resorts (Roncegno, Levico, Recoaro, Peio, S. Pellegrino, Salsomaggiore, Montecatini, Porretta, Tivoli, Telese, Fiuggi, Termini Imerese and many others) ; in some sources the extraction of salts is also carried out (in addition to the source salt, also sulphates, carbonates, etc.). A separate place belongs to the boraciferous fumaroles of Tuscany (Cecina and Cornia basins: Larderello, Serrazzano and Castiglione) which are constant water vapor emissions at very high temperatures (120 ° -190 °) and high pressure (up to 4 atmospheres); they have long been used for the extraction of boric acid, other boric salts and also ammonium carbonate, etc., but more recently they have allowed a much more important application, since, due to the constancy of the jet and the constant temperature, they are conveniently used to operate thermoelectric plants. These are essentially the first industrial uses of heat belonging to the inner layers of the Earth. but more recently they have allowed a much more important application, since, due to the constancy of the jet and the constancy of the temperature, they are conveniently used to operate thermoelectric plants. These are essentially the first industrial uses of heat belonging to the inner layers of the Earth. but more recently they have allowed a much more important application, since, due to the constancy of the jet and the constancy of the temperature, they are conveniently used to operate thermoelectric plants. These are essentially the first industrial uses of heat belonging to the inner layers of the Earth.