Abstract

The La Vieja coal mine is in the village of El Empalizado, on the northwestern border of the municipality of Zipaquirá with the municipality of Pacho (department of Cundinamarca, Colombia), 55 kilometers north of Bogota; 25 kilometers on the road from Zipaquirá to Pacho.

The area covered by this report is approximately 25 square kilometers, within which 176 hectares were studied in detail, 92 of them belonging to Marco T. Fernandez.

The coal seams of the La Vieja mine are in the lower part of the Guaduas Formation, which corresponds to Maastrichtian Zone A (Van der Hammen, 1957).

The structure of the deposit is a monocline with regional strike N 25 E and a dip of 45-60º to the SE. This monocline corresponds to the western flank of the Río Frío syncline and, in turn, to the eastern flank of the La Vieja anticline (mentioned for the first time).

The coal is bright, of the "atrito-vitrain" type, bituminous, coking: easily about 70%, low sulfur content; its calorific value is from 6000 to 8000 calories/gram.

The coal thickness in the various currently mineable seams (5) ranges from 0.65 to 1.85 meters. Total coal reserves at the La Vieja mine are approximately 3.4 million tonnes, of which 1.8% are proven reserves, 3.5% are probable reserves, and the remainder, 94.7%, are possible reserves.

The status of the mine is described. Finally, certain conclusions and several recommendations are given.