Geological Sketch of Mexico: Geological Itineraries. Part 2

Abstract

This issue actually constitutes the second edition of the Sketch of a Geological Map of the Mexican Republic, at a scale of 1:3,000,000; it consists of the explanatory text and the corrected version of the map. The first version of this map (reproduced in De Cserna, 1990, Plate 1), which was published in 1889—a year after the Geological Commission began operating—was created somewhat hastily, as it needed to be presented at the Paris World’s Fair held that year, by Antonio del Castillo. In the December 25, 1888 edition of the Diario Oficial, Article 2 stated: “The duties of the National Geological Institute are: I. - To create and publish the geological and mining maps of the Mexican Republic along with their corresponding reports” (Ordóñez, 1946). For this reason, Del Castillo intended to write an explanation of that map, but he died in 1895 before he could do so. Nevertheless, the map was revised between 1891 and 1893 and published at a scale of 1:10,000,000. José G. Aguilera, who succeeded Del Castillo as head of the Institute, undertook the revision of the original map and the preparation of its accompanying text, which was divided into three parts and preceded by a biographical summary of Antonio del Castillo and a prologue outlining the background of the Institute’s creation and the sources of information used for both the original sketch and the revised edition.

In the second part, “Synopsis of Mexican Geology” (pp. 187–250), by Aguilera, a review is given of the chronostratigraphic units mapped in the outline, divided into systems (from the Triassic to the Quaternary), plus a unit of “Primitive and Metamorphic Rocks” and another of “Iractive Rocks,” which also includes intrusive rocks. This part contains the plate from the aforementioned “Geological Map of the Republic.” In accordance with his systematic approach, Aguilera describes each system in the following sequence, using his own words: (1) nature of the rocks; (2) geographic distribution; (3) position in the Mexican stratigraphic series; (4) dislocations; (5) main eruptions; (6) mineral deposits; (7) main industrial applications of its rocks; and (8) a concise exposition of the physical conditions of the country over the course of geological times, which amounts to an essay on the continental evolution of our territory.

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Abstract from:

Gómez-Caballero, J. A. (2005). Historia e índice comentado del Boletín del Instituto de Geología de la UNAM. Boletín de la Sociedad Geológica Mexicana: Volumen Conmemorativo del Centenario Aspectos históricos de la Geología Mexicana, 57I(2), 149-85. http://dx.doi.org/10.18268/BSGM2005v57n2a3