NATURAL ZEOLITE DEPOSITS—AN IMPORTANT AND WIDELY-DISTRIBUTED INDUSTRIAL MINERAL RESOURCE IN CUBA

Zeolites are crystalline, hydrated aluminosilicates that are commonly used for ion exchange, to reduce soil nutrient leaching and boost the effectiveness of fertilizers, as an animal feed additive, as a cement additive or replacement, as filler in a variety of products, and in pharmaceuticals, among other uses. Although found in a variety of rock types, economic deposits are best developed in altered vitric, acidic to intermediate tuffs and in volcaniclastic sedimentary rocks.

Cuba produced an estimated 44,500 metric tons of zeolites in 2014 and exported about 10 percent to Europe and Latin America. Most production is for domestic purposes, although efforts are being made to expand exports. Zeolites are one of a handful of mineral commodities exported from Cuba.

Deposits are found throughout Cuba, with the major deposits found in central and eastern Cuba. These deposits are associated what are described in the literature as the Cretaceous and Paleogene volcanic arcs. The deposits are described as being hosted by back-arc sequences of tuffaceous rocks or found in axial zones of the Paleogene arc in the central parts of Cub. In all cases, the zeolite deposits are largely composed of clinoptilolite-heulandite and (or) mordenite, although other zeolite minerals are occasionally present.

Publically available data concerning the locations, geology, mineralogy, grade and tonnage of the zeolite deposits in Cuba are scarce, although the explored and reported zeolite resources are on the order of 300 Mt. Principal clinoptilolite-heulandite deposits include the Upper Cretaceous Tasajeras and Piojillo deposits in the Villa Clara Province, and Cretaceous San Andrés and Paleocene–Eocene Caimanes deposits in Holguín Province. Principal mordenite deposits include Paleocene-Eocene Palmarito de Cauto deposit in Santiago de Cuba and the Eocene Bueycito deposit in the Granma Province.