Historical review of and current progress in coal-resource estimation in the United States

摘要

Nine estimates of the coal resources of the United States have been published in the past 71 years. Although many details of these estimates differ markedly, the 1913, 1922, and 1974 estimates are surprisingly similar. Some differences are due to increased geologic data, others reflect changes in terminology, definitions, criteria, guidelines, and methodologies used for estimating coal resources and reserves during the last 100 years. Because of the increased data and changes, many of the early estimates are not particularly useful in modern resource assessments.