Abstract

The author of the present work has tried to know each one of the mineral deposits personally, and has obtained l data for each on potentiality, quality, and others. On those that have not been able to be studied personally, the author has given credit to works published by distinguished national and foreign geologists. However, it cannot be said that this is a compendium of every one of the mineral deposits of this department due to many inconveniences like inaccessibility to the deposits, the impossibility of exploration in jungle zones, and others. Some of them perhaps can be ignored for a long time, or they will be discovered soon and studied conveniently by other authors.

In the beginning, it was believed that Tolima would be a great emporium of minerals that would increase the economic situation of the country above its current conditions as this area has a great variety of rocks whose mutual relations could give rise to useful minerals with formations from the Precambrian to the Quaternary. Thus, we can see that a large part of its territory is formed by the Central Cordillera of the Andes where the orogeny was very active, and CN already finds large nuclei of intrusive and extrusive metamorphic igneous rocks and their natural sequence of seams and deposits. The other part of this territory is made up of flat land known widely as the Llanos del Tolima, where sedimentary rocks influence almost all floors from the Triassic to the most recent outcrop.

Also, part of the territory of the department corresponds to the Eastern Cordillera range of sedimentary rocks with a small porphyry intrusion to the south.

It is logical to expect a good number of mineral deposits in this area formed by limestones, lydites, sandstones, clays, and more varieties resulting from their mutual combination. However, unfortunately, both in this part of the plains and in the mountains, the deposits do not have the magnitude and concentration desired by all the people interested in these issues of vital importance to the country.

The author has had the opportunity to visit and work three years in this section, as a field engineer from August 1, 1946, to April 31, 1947, engineer director from July 1, 1948, to date, in the National Laboratory of mining development of Ibagué. For most of the deposits studied here, except for some deposits of gypsum, gold, silver, and oil, are hardly important as reserves for the future when the scarcity of minerals in the world comes to put a flattering price on the small mineral formations studied here.

It would be very important that the country possessed the aerophotographic plan of the territory so that institutions like the National Laboratory of Mining Development of Ibagué, adequately distributed, could study all the known mineral reserves in each one of the geographic zones. A modest contribution to this ideal is the objective of the present work.

I want to express my gratitude to each of the employees of the National Mining Development Laboratory of Ibagué, whose valuable collaboration has made this study feasible. Especially to my dear colleague and fellow engineer Bernardo Taborda A. and to Mr. Jaime Rincón Pérez and Mr. Luis Cruz, draftsman-topographer, and field assistant, respectively.

Also, to the distinguished professors of the National Faculty of Mines, Dr. Gerardo Botero A., and Hernán Garcés G., who in written consultations or visits to Tolima, have provided me with data and analysis of great value for the elaboration of this work. Arturo Giraldo and Clodomiro Martinez, who, from the Direction of the Technical Section of Mines of the Ministry of Mines and Petroleum, have helped me efficiently resolve many administrative problems related to this dependence, which results in gaining time to devote to fieldwork. I would also like to thank Dr. Carlos Cardona Molina, former director of the Ibagué Laboratory, for the collaboration and encouragement always given to the undersigned.