Source: Adapted from U.S. Department of the Interior, Bureau of Mines, Minerals Yearbook, 1964, Washington, 1966; Limestones Cuban limestones cover a wide range of types, from the lower grades to high-grade marble. Large quantities are used in construction of roads and buildings and as raw material for producing burned lime in kilns. Burned lime is employed extensively in clarification of sugar juices; many sugar mills have their own limestone quarries and limekilns. Burned lime is also used in making mortar and plaster, treating water, and tanning leather; in the manufacture of paper, textiles, and soap; in neutralizing acid soils; and as a fertilizer. Significant quantities of good quality marble are found on the Isle of Pines and, to a lesser extent, in Oriente Province. A cutting and polishing plant located and operating at Sigua before the Revolution continued operating in the 1960s. The latest available figures, covering 1963 and 1964, indicate that substantial quantities of marble were produced in those years. Clays The nation has virtually inexhaustible supplies of clays, including most standard varieties, with the sole exception of high-grade refractory types of bauxite. Clays needed for manufacture of brick, tile, sewer pipe, flue linings, pottery, whiteware, and other ceramics are abundant. In the early 1960s over 150 brick and tile plants were in operation on the island; most of them were small and employed primitive techniques, but some of the larger plants possessed modern equipment. Overall, the combination of clay and limestone resources has made Cuba virtually self-sufficient in basic building materials. Gypsum This material, a sulfate of calcium used mainly in the building trades and in cement manufacture, is mined in Matanzas, Camagüey, and Oriente provinces. Deposits in these and other areas appear sufficient to provide for any foreseeable needs of domestic industry. Other Nonmetallic Minerals Sulfur, derived from pyrite mining, was being produced on a significant scale in the 1960s presumably for the sulfuric acid and other chemical industries. Silica sand, basic to the construction and glass industries, is somewhat scarce, but a major deposit exists on the south coast of Pinar del Río Province. Coral sand, containing calcium carbonate, is abundant along the coasts. Rock salt outcrops exist but have not been found in the right amount or location to make significant commercial exploitation possible; all domestic salt production is carried out by solar evaporation of sea water. Salt output rose significantly after the Revolution, reaching a reported 106,000 metric tons in 1965. As of 1967 the Cuban government was planning further expansion of existing facilities. Fuels The nation lacks commercial deposits of coal and does not have sufficient supplies of petroleum to provide for domestic needs. Despite extensive exploration and development efforts, production did not exceed 5 percent of domestic requirements in any year before 1970. Oil deposits in and around Jatibonico in extreme western Camagüey Province provided most of the island's domestically extracted petroleum in 1969. Small but significant supplemental supplies of petroleum were also provided by deposits at Santa María del Mar and a few lesser fields. Although domestic petroleum extraction reportedly exceeded 110,000 metric tons in 1967, this was less than 3 percent of the 5 million metric tons of petroleum products consumed in the country that year (see table 12). Considerable worldwide publicity accompanied the discovery of a serpentine-plug oilfield at Guanabo in early 1968, but its geological character indicates it was probably a relatively minor find. As early as 1961 the Cuban government was placing strong emphasis on exploratory investigation and drilling, an effort involving substantial amounts of Soviet technical assistance and equipment. Though the postrevolutionary search for oil has not proved highly productive, Soviet assistance continued at a high level through the 1960s. At the same time, the priority placed on increas Table 12. Petroleum Production in Cuba, Selected Years, *In thousands of 42-gallon barrels; 6.65 barrels are equivalent to 1 metric ton. ing domestic petroleum output has been heightened by lack of sufficient oil imports from the Soviet Union to meet rising domestic needs. As of early 1970 there had been no noticeable slackening of official Cuban efforts to expand domestic production, and no such slackening was anticipated in the immediate future. Overall prospects for substantially increased production, however, remained dim. Small amounts of natural gas have been found in connection with some oil deposits, but no major effort to exploit this type of oillinked deposit has been reported. High-pressure gas wells found near Majagua were being exploited in 1967, but there is no evidence that they can contribute significantly to solving the country's fuel problems. The same can be said of asphalt deposits found in varying quality and quantity throughout the island. In 1969 Radio Havana reported that asphaltite was being used for fuel by a powerplant in Cienfuegos, and studies have been made to see if asphalt could be substituted for petroleum in paper and textile mills; however, it is very unlikely that such substitutions can significantly reduce the country's demand for petroleum. MANUFACTURING INDUSTRIES Agriculture-Related Industry Sugar Milling and Refining Sugar production, the backbone of the economy, accounts for at least 20 percent of the gross national product (GNP). About half of this income is derived from industrial processing, primarily sugar milling and refining. In all, sugar-related activities produce roughly one-quarter of industrial income. The bulk of the sugar industry is concentrated in the mills, which pass the cane through presses to produce cane juice and crushed cane stalks or bagasse (see Glossary). A portion of the bagasse is burned to provide steam and electric power for the plant, and the cane juice is clarified by adding burned lime, applying heat, and removing the resulting precipitates. After this, boiling away most of the clear juice under vacuum precipitates sugar crystals, and these are separated from the juice by centrifuging. Blackstrap molasses, the material remaining after these processes have been completed, is used by other factories in producing cattlefeed, alcohol, and a variety of chemicals. This modern sugar milling process requires large-scale capital investment and places a great premium on achieving economies of scale through construction of very large industrial plants. On the other hand, the transportation of the heavy and bulky sugarcane is costly. Through the mid-nineteenth century the emphasis was on building small mills near the canefields, and a total of about 2,000 such mills existed in Cuba at that time. With the gradual lowering of transport costs and the increasing efficiency of large-scale production after independence, the size of the individual mills grew while their numbers shrank. The bulk of the smaller mills were in the three western provinces where most sugar was grown before independence, and the larger and more efficient units were located in Camagüey and Oriente provinces, the areas into which the sugar industry expanded during the twentieth century (see ch. 18, Agriculture). No new sugar mills have been constructed since 1929, because of government policies designed to maintain the status quo before the Revolution and because of parts, maintenance, and management problems since then. In 1959 there were 161 operating mills in the country, but by 1968 this had been reduced to 152. The total designed capacity of these 152 mills was about 7.5 million metric tons of crude sugar, but their capacity was reduced somewhat in the early 1960s during the years of lowest sugar production. After the government began emphasizing sugar in 1963 there was some recuperation, and the production of 6.2 million metric tons of sugar in 1967 clearly demonstrated a capacity of at least that amount (see ch. 18, Agriculture). As of mid-1969 there was no evidence that a capacity of 10 million metric tons per year had been approached in support of the government's 1970 sugar campaign; however, strong emphasis was placed on repairing and expanding existing mills during the 1967-69 period, and a rough estimate of between 7 million and 8 million metric tons of mill capacity for 1970 appears reasonable. Turning to by-products, the mills produce a quantity of bagasse about equal in weight to their crude sugar output. Most mills are equipped to burn the material in their power plants, a practice that has made bagasse an energy producer second only to petroleum in importance. The mills produce more of the material than they need for fuel, and this has led sugar-producing countries to develop other uses for it. Before the Revolution some ten factories of varying sizes were using bagasse to turn out pulp, fiberboard, cardboard, and paper. Of the estimated 2,600 workers in these bagasse-related industries, 1,500 were employed by one paper-producing plant. Since the Revolution the government has been searching for new ways of using bagasse, and at least one rayon plant has been converted to using it as a raw material. Blackstrap molasses, a major end-product of sugar milling, is also produced in substantial quantities. From 1959 through 1968, production averaged between 1.1 million gallons and 1.2 million |