EXPLORATION AND COAL RESOURCES OF MÉXICO

The geological history of México shows that there has been three events that were suitable for the development and formation of coal beds. The first event happened during the time span from the Upper Triassic to Middle Jurassic Epochs (200 - 170 Ma); the second event of favorable geologic conditions took place at the end of the Late Cretaceous Epoch during the Maestrichtian age (75-65 Ma); and the last third event happened during the Eocene Epoch, Lutetian - Bartonian Age (50 - 40 Ma).

The Triassic - Jurassic event is represented by the coals of Northwest México in the State of Sonora, and the coals present in the South of México in the State of Oaxaca.

The Maestrichtian age event is represented by the higher tonnage coals of the Sabinas and Fuentes - Río Escondido sub-basins in the State of Coahuila; the coals of Ojinaga and San Pedro Corralitos of the Chihuahua State; and the coals of Cabullona in the state of Sonora.

Eocene Epoch coals and lignites are present in the Colombia - San Ignacio region of Coahuila State.

The Mexican coals that have been more explored and developed, because of their economic potential, are the Maestrichtian coals in the Coahuila State. Most of the coals in the sub-basins of Sabinas and Monclova are metallurgical, whereas the coals from the Fuentes - Río Escondido basins are steam coals (long flame type); the latter ones are being used by the utility company (Federal Commission of Electricity, CFE) to generate electricity in their plants of Nava, Coahuila.

Total annual production of steam and metallurgical coal of the State of Coahuila, is approximately 15.4 million metric tons. Six million is metallurgical coal and 9.4 is steam coal used locally to generate electricity.

The Triassic - Jurassic coals from Sonora and the Oaxacan Mixteca are mostly bituminous but range up to semi-antracitic or anthracitic. All the coal beds are badly deformed by several tectonic events that avoids any type of economic explotation; some of them have also been affected by igneous intrusions, in Central Sonora, that formed graphite beds that are presently being mined successfully for this commodity.