Industrial minerals and rocks
This chapter overviews the origin, exploration and exploitation of Chilean industrial minerals (IM), the main such resources being evaporites, brines and other chemical products located in the northern part of the country. Following a general introduction to the subject, the geological processes relevant to IM generation are described, followed by more detailed accounts dealing with the evaporite deposits of the northern Chile salt flats, especially the nitrate and iodine ores that have provided the most valuable IM contribution to the Chilean economy.
Chile is administratively divided into ‘Regiones’ numbered I to XII from north to south, as well as the Metropolitan Region around Santiago, and the description of mineral deposits and mines is based on these geographical subdivisions (Fig. 7.1). Chilean industrial mineral production is concentrated in northern Chile, accounting for about 3–7% of Chilean mining exports in 2004, with a value of about US$500 million.
The exploitation of industrial minerals has been closely related to Chilean economic development, with the modern mining history of the country beginning during the late nineteenth and early twentieth centuries when an outstanding income was derived from the nitrate industry. During their heyday, these resources were in high demand because of their use in the manufacture of fertilizers and gunpowder. For a brief period in the nineteenth century Chile was also an important producer of borate.
The importance of IM resources in Chile is based on their variety and quality and also the huge nature of some of the reserves. Variety is provided
Figures & Tables
This book is the first comprehensive account in English of the geology of Chile, providing a key reference work that brings together many years of research, and written mostly by Chilean authors from various universities and other centres of research excellence. The 13 chapters begin with a general overview, followed by detailed accounts of Andean tectonostratigraphy and magmatism, the amazingly active volcanism, the world class ore deposits that have proven to be so critical to the welfare of the country, and Chilean water resources. The subject then turns to geophysics with an examination of neotectonics and earthquakes, the hazardous frequency of which is a daily fact of life for the Chilean population. There are chapters on the offshore geology and oceanography of the SE Pacific Ocean, subjects that continue to attract much research not least from those seeking to understand world climatic variations, and on late Quaternary land environments, concluding with an account examining human colonization of southernmost America.
During his voyage on H.M.S. Beagle, an extended visit to Chile (1834-35) had a profound impact on Charles Darwin, especially on his understanding of volcanoes, earthquakes and tsunamis. Over more recent decades scientists have come to recognize the Chilean Andes as providing the classic example of a mountain belt produced by oceanic subduction beneath a continent, as well as some of the most dramatic scenic and climatic variations on Earth. In the final chapter, the editors offer a description of a drive from the Mediterranean landscapes of central Chile to the hyperarid Atacama Desert, a contribution designed to give visitors a chance to experience for themselves the geology and scenery of this extraordinary country.