The Geological Knowledge of the Iron Quadrangle Evolved from a Cartographic Approach

Abstract

The Iron Quadrangle is one of the world’s largest mineral province, covering an area of approximately 6.500 km2 in
the central-southeastern state of Minas Gerais. Once the mapping is an effi cient form of communication of geological
concepts, this paper seeks to outline from graphic representations of the nineteenth century the evolution of geological
knowledge of the region. The Englishman John Mawe was the fi rst foreigner to obtain permission and visited, in 1810, gold and diamonds mines. The map he produced restricted to the location of these districts and therefore, precedes the
representations of the understanding of the geology. The German Wilhelm Ludwig von Eschwege outlined the region’s
orographic system and proposed a stratigraphic ordering of its terrain. He also produced the fi rst graphic representations
of the geology of Brazilian southeastern. In their works, published between 1818 and 1832, it clearly in the graphic
representations the evolution of his understanding on geology of the region .The fi rst half of the nineteenth century is
also characterized by geological observations made by foreign naturalists, mainly by Peter Claussen and Aimé Pissis,
and the geologist and mining engineer Virgil von Helmreichen. In addition to detailing the formations, they produced
not only the fi rst sketches and geological maps of the Iron Quadrangle region but also the fi rst representations of folded
structures. We conclude that the graphic representations analyzed reveal more than geological features, they are the product of a historical circumstance, and so are images of both the state of the art as the geology geological mapping itself.