PRELIMINARY GEOGRAPHIC INFORMATION SYSTEM COAL QUALITY DATABASE OF ACTIVE MINES IN VENEZUELA

The U.S. Geological Survey (USGS), in partnership with the Instituto Nacional de Geología y Minería of Venezuela, analyzed 14 coal samples from active mines in Estados Tachira and Merida, western Venezuela, as part of the USGS World Coal Quality Inventory (WoCQI) project. Coal quality data for the samples are spatially georeferenced and integrated into a preliminary geographic information system (GIS) database which includes data layers containing information on coal basins, geology, hydrology, topography, land use, transportation, and utilities. Venezuelan geology is represented in the GIS through a comprehensive digital geologic map compiled from 1:500,000 scale paper geologic maps and integrated with a similar-scale, previously published digital geologic map of the southern Venezuelan Guayana Shield. Coal quality data including major, minor, and trace element concentrations, and geologic, cultural, and technologic supplemental GIS data layers are being compiled in CD-ROM format with corresponding data from other South American coal-producing nations.

The 14 coal samples were collected from surface and underground mines developed in coal intervals of the Tertiary (Upper Paleocene-Middle Miocene) Los Cuervos, Carbonera, and Palmar Formations of the Andean Cordillera. Preliminary analytical results indicate that, on an as-received basis, the samples have a low average ash yield of 5.71 weight percent, ranging from 0.91 to 16.85 weight percent ash, and a moderate average sulfur content of 1.78 weight percent, with a range of 0.27 to 6.21 weight percent sulfur. Gross calorific values range from 10,734 to 15,321 British thermal units per pound (Btu/lb) (5,968 to 8,518 kcal/kg) on an as-received basis, and average 13,289 Btu/lb (7,379 kcal/kg). The coal samples have an apparent rank of subbituminous (one sample) to bituminous following the American Society of Testing and Materials D388 classification.