Geology and Mineral Resources of Paraguay A Reconnaissance

98 GEOLOGY AND MINERAL RESOURCES OF PARAGUAYthe low-grade lateritic iron ores that cover the surfacein much of central Paraguay, as concretions of ironcarbonate in some of the clay deposits, and in variousother forms. The only treatment needed to produceexcellent mineral pigments from such materials consistsof washing, roasting under carefully controlled conditions,grinding, and grading as to color. The resultantpigments should be equal in most respects to importedproducts.The suggestion that Paraguay could produce muchof its own paint is not original; DeMersay (1860) inhis description of the red soils of the Misiones, nearEncarnacion, Trinidad, and other towns along the AltoParana*, says that the early Jesuits used local materialsin decorating their churches and colleges. He saysthat "clay veins" in the soils yielded red ochre, whichwas calcined, ground, washed, and mixed with amucilage made from the juice of a local cactus (Cactusperumanus). He adds that yellow and white paintswere made in the same way as the red ones.A small pigment industry would require only afew hundred dollars worth of washing, grinding, androasting equipment. Technical knowledge can beeasily gained by experiment and from the literature, or,perhaps better, by sending a technician to Brazilwhere there is a well-developed though primitivepigment industry. Except for the initial machinery,no raw materials would need to be imported in orderto produce pigments regularly.Production of pigments alone would save manydollars of foreign exchange annually. The saving couldbe increased several fold if finished paints, instead ofpigment, were produced. Locally produced tung,linseed, and castor oils could be easily and economicallytreated to produce excellent vehicles for paints. Ifthese oils were used, a fair share of the country'spaint requirements could be met with no importsother than turpentine, small amounts of dryer, andcontainers for the final product. High-grade modernpaints would, of couse, also require the importation ofwhite lead, lithopone, and other ingredients. As notedabove, glass containers could be produced locally,saving additional amounts of foreign exchange.PORTLAND CEMENTThe portland cement plant at Vallemi has alreadydemonstrated that it is technologically possible to producegood portland cement in Paraguay. Large reservesof raw material and fuel are available locally.Except for machinery parts and balls for grinding, theonly materials that must be imported are a few tonsof gypsum per year and paper bags for sacking thefinished product. Paper bags could be replaced bylocally made cotton bags or wooden kegs if that shouldseem desirable to conserve a little additional foreignexchange.As this is the only large-scale mineral industry nowin Paraguay, except for brick and tile, and as it iscapable of producing all of the vitally needed cement,it would appear advisable for the Government to useall possible means to encourage and maintain regularproduction and to place the venture on a sound financialfooting. This is even more desirable if the Vallemiplant is capable of producing an exportable surplus ofcement over Paraguay's requirements.POTTERY AND CLAY PRODUCTSParaguay contains abundant deposits of clay suitablefor most grades of pottery, earthenware, and manyother products, yet it still imports a large proportionof its needs of finished goods. Many of these needscould be produced locally with adequate modern machineryand careful technical control throughout themanufacturing process. Probably the initial investmentwould be relatively large, but continuing imports ofraw materials would be small and would be confinedessentially to coloring materials and to ground feldsparfor glazes. As suggested in the paragraph on glassmaking,there is a strong probability that requirementsof feldspar can be met locally when more is known aboutthe bodies of granitic rock near the Rio Apa and elsewherein the country.TALC AND PYROPHYLLITETalc, which is used as a filler in insecticides, soaps,paints, and many other products, is imported in comparativelysmall, but nevertheless important, quantity.One deposit of talc is known near San Miguel and wasbeing actively explored in 1952; other deposits willdoubtless be found. As described above, there is alsoat least one very large deposit of pyrophyllite, whichis adaptable to most of the same uses as talc, north ofCaapucu.It is doubtful that the local material is of sufficientlyhigh grade to be used in preparation of toiletries, butit should certainly be able to compete successfully withimported talc for most commercial purposes. Moreover,if a cheap local source of talc were available, thedemand for it would probably increase.WATER RESOURCESWater is unquestionably the most valuable single resourcein Paraguay. There are possibilities of developinghydroelectric power at the Sal to del Guaira on theRio Parana and at smaller falls on several major tributariesof that stream. Were it not that all the potentialsources of water power are so remote from centers ofpopulation, such possibilities doubtless would have beenrealized long ago. In addition to this potential use, wa-