Available knowledge concerning the origin and geologic structure of mexico is still incomplete. Each day scientific discoveries, advances in mapping, and new techniques of exploration offer more information toward the development of tour understanding. Nevertheless, it is still difficult to achieve a complete description of the geologic character of the territory of the nation, as well as to work out functional models to explain the origin of its geologic structure. Along with the development of geologic studies that science has made in mexico, there have been a few attempts to formulate general works covering the many aspects of geology that the country presents. Nevertheless, one must recognize that the lack of information about certain periods in the geological history of the national territory, and the numerous unexplored areas, have constituted some principal obstacles toward achieving a finished work of this type.
Inreviewing past information, it is worth indicating that in 1896 a somewhat unsettled entitled A Sketch of the Geology of Mexico formulated by Jose Guadalupe Aguilera and Ezequiel Ordonez of the Geologic Institute of Mexico, a descriptive work that constituted an important complement to and summary for the Geologic Map of Mexico, which had benn published earlier. Nevertheless, it was not until 1949 that V. Garfias and T.C. Chapin published the work entitled Geology of Mexico, in during the geological history of the republic are included.
A more recent work is The Geology of Mexico, whose author was Ing. Manuel Alvarez, Jr., and which the Faculty of Engineering of UNAM printed as notes