Physiographic, stratigraphic, and structural development of the Quadrilatero Ferrifero, Minas Gerais, Brazil

The Quadrilatero Ferrifero is an area of some 7,000 square kilometers in central Minas Gerais, Brazil centered about lat. 20°15' S, long. 43°30' W.  For 250 years the region has poured forth a variety of mineral riches, now totaling more than $2 billion, and future production will undoubtedly be even greater.  The main products are iron ore, manganese ore, and gold.  To assist this development, the Braziliam and American Governments in 1946 jointly undertook the first detailed geologic study of the region: this report is a synthesis of the results of work and mapping by 17 Brazilian and American geologists under this program; other reports discussing the economic geology, the metamorphic geology, and the igneous geology of the region as a whole are being prepared.