U.S. DEPARTMENT OF THE INTERIOR U.S. GEOLOGICAL SURVEY COAL MAP OF SOUTH AMERICA By Jean N. Weaver and Gordon H. Wood, Jr. Pamphlet to accompany COAL INVESTIGATIONS MAP C-145 CONTENTS Summary 1 Introduction 1 Background 1 Methods 1 Definitions and Criteria Used in this Report 2 Sedimentary Basins 2 Coal Basins, Fields, and Occurrences 2 Age 2 Rank 2 Rank classes and rank groups of coal 3 Peat 3 Coal and Peat Deposits 3 Age of South American Coal Deposits 3 Mississippian Coal 4 Pennsylvanian, Pennsylvanian and Permian, and Permian Coal Triassic Coal 4 Jurassic Coal 4 Cretaceous Coal 4 Tertiary Coal 4 Peat - 4 Explanation of Selected Columns in the Tabular Data for each Country Internal Administrative Area (Internal Adm. Area) 4 Map Number 5 Coal Field, Occurrence/Mine Name 5 Operator 5 Mine Type 5 Recovery Activity 5 Number of beds 5 Coal Quality Parameters 5 Summary 5 Acknowledgments 5 Selected References 6 South American Counterparts 12 TABLES Coal Mines and Occurrences in Argentina 16 Coal Mines and Occurrences in Bolivia 19 Coal Mines and Occurrences in Brazil 21 Coal Mines and Occurrences in Chile 27 Coal Mines and Occurrences in Colombia 29 Coal Mines and Occurrences in Ecuador 31 Coal Mines and Occurrences in Guyana 32 Coal Mines and Occurrences in Paraguay 33 Coal Mines and Occurrences in Peru 34 Coal Mines and Occurrences in Suriname 39 Coal Mines and Occurrences in Uruguay 40 Coal Mines and Occurrences in Venezuela 41 Contents III SUMMARY result of library research and it did not include updated infor­ mation from scientists and others in the coal-bearing coun­ All nine countries that were visited in South America tries of South America. During the Fall of 1991, the senior contain coal deposits. Some coal deposits are more econom­ author (Weaver) visited Uruguay, Argentina, Chile, Peru, ical to exploit than others, but all have been or could be Ecuador, Colombia, Venezuela, Brazil, and Bolivia. The developed to some extent for local use. Export of Venezue­ purpose of the nine-country visit was twofold: (1) to discuss lan and Colombian coal will probably increase in the near with geologists and other authorities in each country the future. Deforestation is an environmental concern in many quantity, quality, and distribution of known coal resources parts of South America. For this reason, coal as an alterna­ and the status of coal recovery and utilization and (2) to tive energy source could be developed. If and when this hap­ inform them of the current role of coal research in the U.S. pens, opportunities could be present for the United States Geological Survey. Paraguay was not visited because of time and foreign companies to invest in and (or) cooperatively constraints. Guyana and Suriname were visited in the spring conduct coal exploration, development, mining, and utiliza­ of 1993. tion programs in South America. INTRODUCTION METHODS This report was prepared to provide (1) a map of the coal The geologic and mining engineering literature on the fields and occurrences of coal in South America; (2) written coal fields and coal occurrences of South America range documentation and references of the coal deposits identified from modern formal published reports to letters and other on the coal map; and (3) data regarding the quality of the coal informal documents that date back as far as the late 1700's. in each deposit. Because of the great range in age of reports and in the exper­ The authors hope this report, which we believe to be the tise of their authors, the quality of the reports ranges from most complete compilation of published data on coal for the poor to excellent. Some reports state without further infor­ continent, will provide coal resource information to help mation that coal was exposed in a river bed, canyon wall, or guide exploration, development, mining, industrial and on a hillside. Other reports provide much data, which may or domestic use, export and import of coal, and aid in land-use may not include precise locations, age designations of coal planning throughout South America. On first examination, beds, ranks of coal, chemical analyses, stratigraphy, thick­ our research seems to substantiate a common belief that coal nesses of overburden, thicknesses of coal beds, mine maps resources of South America are small. However, the data and cross sections, petrographic descriptions of coal, and gathered for this report indicate that this belief may be erro­ postulated depositional environments of coal. Only a few neous. Such an error is easily understood because much, if reports include enough data to be considered as adequately not most, of South America's coal-bearing rocks are con­ describing an individual mine, group of mines, or a coal cealed from view by (1) thick jungle and associated soils, (2) field. Consequently, the authors adopted the following meth­ younger volcanic rocks, (3) non-coal-bearing Tertiary and ods and guidelines for assessing South American coal Quaternary valley fill adjacent to mountain ranges, and (4) resources. complex structural features within nearly inaccessible high 1. No attempt was made to estimate the coal resources mountain ranges. These factors have made it exceedingly (recoverable coal) of the individual mines, occurrences, and difficult for geologists and explorers, who have mostly worked without the aid of adequate maps, to find and evalu­ coal fields of South America. ate the coal potential of South America. 2. Data presented for individual coal occurrences were Reports on the geology, mining, and paleobotany-pale- derived from the credited coal company or geological sur­ ontology of coal and coal-bearing rocks in South America vey (s) or mining companies of the country. helped us classify coal fields and coal occurrences as to their 3. The coal map is comprehensive and shows most of the age, rank, depth of burial, number of beds, and sulfur and ash known coal fields and reported occurrences. This is in con­ content. A list of selected references by nation is included, trast to most published maps which show only "major" coal and a section has been included which lists the most perti­ fields and occurrences. The map also shows areas that may nent references used in this study. In addition, data was be underlain by coal and where the geology suggests that obtained from written and oral communications with foreign coal could be present. coal authorities during the visits to each country. Information on the size of coal fields and coal occur­ rences in South America is summarized on the map. The BACKGROUND map clearly shows that many occurrences can be grouped into fields because such occurrences have a common geo­ This study was started by the late Gordon H. Wood, Jr. logic history. Each coal field or coal occurrence shown on The original compilation, completed before his death, was a the map is identified by a serial number that is unique within each country. In the tables for each country, each coal COAL BASINS, FIELDS, AND OCCURRENCES deposit is further identified by a name, or where there is no name, that fact is indicated. Each deposit listing also has Coal basins can be coincident with sedimentary basins. supporting data gathered from the literature or from cooper­ In many cases, however, coal basins are part of larger sedi­ ating specialists from the South American countries. mentary basins. Because of local and regional tectonic dis­ turbances, some coal basins have been deformed. Coal fields and coal basins can be areally coincident; DEFINITIONS AND CRITERIA however, coal fields are commonly smaller than coal basins and their boundaries are commonly geographically and eco­ USED IN THIS REPORT nomically defined. Coal occurrences usually are reports of coal of undeter­ Identified coal-in-place. Known coal occurrence. Loca­ mined extent. Occurrences may range from organic material tion, rank, quantity, quality, and depth of burial are known or such as coalified wood in otherwise non-coal-bearing rocks, are estimated from specific geologic evidence. Identified coal to preliminary indications of economically valuable coal may be at any depth of burial, but it will not be more than 3 deposits. mi (4.8 km) from the point where a coal thickness is measured (Wood and others, 1983). The areas on the map marked by symbols and colors for rank designation and geologic age, AGE respectively, are known coal occurrences. Hypothetical coal-in-place. Coal which probably exists The geologic ages of the coal-bearing rocks of each coal at depth, is more than 3 mi (4.8 km) from points of thickness field and occurrence are reported in the tables for each coun­ measurement, is believed to be similar to known coal occur­ try and are shown on the map. Colors represent ages of the rences that surround points of measurement, and is a logical coal-bearing rocks. Geologic age assignments follow those extension of known coal (identified coal-in-place). On the accepted by the U.S. Geological Survey. The Periods are map these areas appear as pink areas surrounding areas of abbreviated in the tables as follows: Carboniferous = Carb., known coal occurrence. Mississippian = Miss., Pennsylvanian = Penn., Permian = Speculative coal-in-place. Undiscovered coal that is Perm., Triassic = Tri., Jurassic = Jur., Cretaceous = Cret., postulated to exist in (1) geologic settings suitable for the Tertiary = Tert., and Quaternary = Quat. Age assignments formation of peat from swamp deposits and the formation of straddling period boundaries are shown, for example, as peat to coal, or (2) areas where coal beds are hidden in the Perm./Carb. Where the coal is mostly of one age, that period subsurface because of burial by younger sedimentary or vol­ is placed first as Perm./Carb.