Energy Resources Program
Thursday, March 19, 2015
USGS Publication: Professional Paper 1708
Fossil fuels from the Appalachian basin region have been major contributors to the Nation’s energy supplies over much of the last three centuries. Appalachian coal and petroleum resources are still available in sufficient quantities to contribute significantly to fulfilling the Nation’s energy needs. Although both conventional oil and gas continue to be produced in the Appalachian basin, most new wells in the region are drilled in shale reservoirs to produce natural gas...
Friday, December 19, 2014
USGS Publication: SIR 2014-5196
Standards for the public disclosure of mineral resources and reserves do not require the use of any specific methodology when it comes to estimating the reliability of the resources. Unbeknownst to most intended recipients of resource appraisals, such freedom commonly results in subjective opinions or estimations based on suboptimal approaches, such as use of distance...
Tuesday, May 28, 2013
Outside Publication: International Journal of Coal Geology In spite of its large endowment of coal resources, recent studies have indicated that United States coal production is destined to reach a maximum and begin an irreversible decline sometime during the middle of the current century. However, studies and assessments illustrating coal reserve data essential for making accurate forecasts of United States coal production have not been compiled on a national basis.
Monday, April 22, 2013
USGS Publication: Scientific Investigations Map 3240The Ucross-Arvada area is part of the Powder River Basin, a large, north-trending structural depression between the Black Hills on the east and the Bighorn Mountains on the west. Almost all of the study area is within Sheridan and Johnson Counties, Wyoming.
Tuesday, April 02, 2013
USGS Publication: Open-File Report 2012–1205
This map sheet with accompanying Geographic Information System (GIS) project is an update of the existing U.S. Geological Survey (USGS) Conterminous U.S. Coal Fields map. This update was compiled using data primarily from the USGS National Coal Resource Assessment (NCRA) and information from other published maps.
Tuesday, February 26, 2013
USGS Publication: Data Series 713
This report by the USGS of the Powder River Basin (PRB) of Montana and Wyoming is part of the U.S. Coal Resources and Reserves Assessment Project. Essential to that project was the creation of a comprehensive drill hole database that was used for coal bed correlation and for coal resource and reserve assessments in the PRB. This drill hole database was assembled using data from the USGS National Coal Resources Data System, several other Federal and State agencies, and selected mining companies.
USGS Publication: Fact Sheet 2012–3143
Using a geology-based assessment methodology, the U.S. Geological Survey estimated in-place resources of 1.07 trillion short tons of coal in the Powder River Basin, Wyoming and Montana. Of that total, with a maximum stripping ratio of 10:1, recoverable coal was 162 billion tons.
See Press Release for listing of all related publications.
USGS Publication: Open-File Report 2012–1113
The purpose of this report is to summarize geology, coal resources, and coal reserves in the Montana Powder River Basin assessment area in southeastern Montana. This report represents the fourth assessment area within the Powder River Basin to be evaluated in the continuing USGS. See Press Release for listing of all related publications.
Press Release & Related Publications
The Powder River Basin of Wyoming and Montana contains about 162 billion short tons (BST) of recoverable coal from a total of 1.07 trillion short tons of in-place resources according to a new USGS assessment. This assessment also estimates that 25 BST of those resources are currently economical.
The coal industry in the United States has undergone fundamental changes over the past several years that have resulted in a reduction in the number of operating coal mines, the merging or consolidation of numerous coal companies, and a drastic decrease in coal production. Since 2008, when a record of more than 1.17 billion short tons of coal were produced in the U.S., annual coal production volumes have dropped precipitously. In 2016, approximately 739 million short tons of coal were produced, according to figures released by the Energy Information Agency (EIA) and Mine Safety and Health Administration (MSHA). This represents nearly a 37 percent reduction in annual production from the nation’s coal mines. Despite this reduction in the number of operating coal mines and the corresponding drop in annual production, the EIA projects that coal will continue to provide fuel to generate approximately 30 percent of the electricity used in the U.S. The generation of electricity accounts for the consumption of approximately 92.5 percent of coal mined in the U.S. The use of coal to produce coke for steel making, as well as other industrial, commercial, and institutional uses, accounts for the remainder of U.S. coal consumption.
There are numerous coal beds, of varying thickness, extent, and quality, in coal fields and basins spread throughout the U. S. - these compose the total coal resources of the nation. However, not all of the total coal resources can be extracted. The portion of the total coal resources that may be able to be extracted are defined as recoverable coal resources. Recoverable coal resources are calculated by subtracting coal resources lost due to previous mining activities, exposure to weathering along outcrops, geological conditions, environmental, land use, or societal restrictions, and mining technology limitations from the total coal resources.
Reserves are the portion of the recoverable coal resources that can be extracted economically at a time of classification. The portion of recoverable coal resources that can be defined as reserves will vary over time, based on fluctuations in mining costs and the market value of the coal.
In energy assessments, it is important to estimate not only the total coal resources, but to inventory the recoverable coal resources and coal reserves as well. Estimating the available coal resources and reserves provides a more accurate appraisal of how much of the total U.S. coal resources are realistically available for extraction in the future.
There is often confusion in the use of the terms coal “resources” and “reserves”. The two terms are often used interchangeably, but there are significant differences in their definitions. The terms are defined, from USGS Circular 891, as follows:
Coal resources – include in-place tonnage estimates that are determined by summing the volumes for identified and undiscovered coal deposits, utilizing a specified minimum thickness.
Coal reserves – are a subset of coal resources that are classified as economically extractable at the time of classification, after considering environmental, legal, and technological constraints. The facilities for extraction do not need to be in place or operative at the time of classification.
In order to be classified as economically extractable, the current market value of the extracted coal must be greater than the total cost to extract it.
The task of the U.S. Coal Resources and Reserves Assessment Project is to conduct a systematic determination of recoverable coal resources and reserves, on a regional basis for all major coal provinces in the United States. This differentiates the current coal assessment project from previous generations of coal assessment projects, in which typically only total coal resources were calculated.
The Project is focused on defining coal resources and reserves in the Northern Great Plains and Rocky Mountain Coal Provinces, with an emphasis on determining coal resources and reserves on Federal lands. The first U.S. coal basin to be evaluated was the Powder River Basin (PRB) in Wyoming and Montana, because it has been the most productive coal basin in the United States over the past 25 years. The results of the PRB assessment were published in Professional Paper 1809 in 2015.
Currently, assessment studies in three separate areas of the Greater Green River Basin are in progress – Little Snake River coal field and Red Desert area (WY), Yampa coal field (CO), and Rock Springs Uplift coal field (WY). The Greater Green River Basin was prioritized for assessment because it contains vast land areas controlled by the Federal government, large portions of the basin have not been formally assessed for coal resources, and previously proprietary drill hole data have become available for use in geologic modeling and economic evaluations.
Areas under consideration for assessment are the Raton Basin and Piceance Basin in the Rocky Mountain Province and the Williston Basin in the Northern Great Plains Province. Also under consideration, in order to assess remaining thermal coal supplies that may be available for extraction for electrical generation, are the Illinois Basin, Northern Appalachian Basin, and Gulf Coast/Texas lignite region.
As part of the USGS Energy Resources Program, the U.S. Coal Resources and Reserves Assessment Project research efforts yield state-of-the art, digitally-based assessments that detail the quantity, quality, location, and accessibility of the Nation’s coal resources and reserves.
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The Greater Green River Basin (GGRB) is a large, irregularly shaped, intermontane desert basin in the Rocky Mountain coal region. The basin is located in southwestern and south-central Wyoming and northwestern Colorado. The GGRB contains several coal fields of economic importance. There are several active coal mines in the basin, utilizing both surface and underground mining methods. The structural geology is relatively complex, with intra-basin anticlinal features dividing the GGRB into several sub-basins. The coal beds in the GGRB were deposited in fluvial/deltaic and lacustrine paleoenvironments and are Late Cretaceous, Paleocene, and Eocene in Age.[+]
Because of its areal extent, the Greater Green River Basin has been divided into three separate assessments – Little Snake River coal field and Red Desert area (WY), Yampa coal field (CO), and Rock Springs Uplift coal field (WY). The Greater Green River Basin was prioritized for assessment because it contains vast land areas controlled by the Federal government, large portions of the basin have not been formally assessed for coal resources, and previously proprietary drill hole data have become available for use in geologic modeling and economic evaluations.
The coal resources and reserves assessment of the GGRB is part of the current generation of U.S. coal assessments that not only define the total coal resources, but also systematically determine the available coal resources and reserves for a region or basin. The determination of available coal resources show what coal may be available for extraction after environmental, land use, and technological restrictions are applied to the total coal resources. The determination of reserves from the available coal resources shows what coal is currently available to be economically extracted, based on market conditions and projected mining costs. Determining available coal resources and reserves are important factors to be considered in the development of a national energy policy and for providing energy security for the United States.
In 2009, the USGS completed the first digital National Coal Resource Assessment (NCRA) of in-place coal resources. The current generation of U.S. coal assessments will not only be a refinement of the coal resources, but also the systematic determination of the regional coal reserve base in all the major coal provinces in the U.S. The reserve base provides not only estimates of coal resources that are... [+]
currently economic (reserves), but what may become economic with current technologies (recoverable resources), which is important from a national energy security and policy standpoint. The first U.S. coal basin to be evaluated in this new assessment phase is the Powder River Basin, WY (PRB). The PRB is the single most important coal basin in the U.S. production-wise, supplying over 42 percent of the total coal produced in the U.S. in 2012.
USGS Professional Paper 1809, Coal Geology and Assessment of Coal Resources and Reserves in the Powder River Basin, Wyoming and Montana, was published in 2015. It is the compilation of four USGS Open File Reports into a single publication, covering four different assessment areas in the PRB. Professional Paper 1809 provides an overview of the geology and reports the original resources for the entire PRB, as well as the available coal resources and reserves.
The NCRA project was a multi-year effort by the U.S. Geological Survey (USGS) Energy Resources Program to identify, characterize, and assess the coal resources that will supply a major part of the Nation’s energy needs during the next few decades. The purpose of the NCRA was to (1) digitally assess selected coal beds and zones that will be the most important in the next few decades, (2) create publicly available... [+]
stratigraphic, geochemical, and geographic information system (GIS) databases to answer a variety of questions to government, industry and public decision makers, and (3) provide interpretive geologic and geochemical information for the primary coal resources of the Nation.
The NCRA study was a five-region project designed to provide a geologic assessment of the top-producing coal beds and coal zones in the United States. The five regions include:
(1) Northern and Central Appalachian Basin
(2) Gulf Coast
(3) Illinois Basin
(4) Colorado Plateau
(5) Northern Rocky Mountains and Great Plains
The NCRA was a cooperative effort between the USGS and a number of State geological surveys in these coal-bearing regions. A study of coal resources on Federal lands was also conducted.
The USGS coal resource assessments have produced coal resource maps and descriptions, or models, that identify and characterize the coal beds and coal zones that will provide the bulk of the U.S. production for the next several decades. The assessments are designed to provide geoscientists, policy makers, planners, and the general public with concise geologic information on the quantity and quality of the remaining coal resources. Official ERP coal assessment methodologies are currently available within this website.
NCRA geochemical databases will provide accurate and comprehensive information to aid in the prediction of potential emissions from the combustion of coal from of those coal beds and coal zones. In addition, NCRA data can directly aid in the delineation of areas with potential for coal-bed methane production, mine flooding, surface subsidence, and acid mine drainage.
The USGS Energy Resources Program researches and provides studies on the quantity, quality, and location of the Nation’s coal resources and has world class research facilities investigating coal petrology and coal quality. These studies address coal extraction, utilization and disposal issues, human health and environmental impact issues, and identify suitable resources for the Nation’s electric power generation.
The U.S. Geological Survey Energy Resources Program has developed coal databases to monitor the location, quantity, and physical and chemical characteristics of U.S. coal and coal-related deposits.
Coal fields of the conterminous United States—National Coal Resource Assessment updated version (contains downloadable GIS and metadata files):
USGS Open-File Report 2012–1205
Drill hole data for coal beds in the Powder River Basin, Montana and Wyoming:
USGS Data Series 713
Coal database for Cook Inlet and North Slope, Alaska:
USGS Digital Data Series 599
Shallow Coal Exploration Drill-Hole Data—Alabama, Georgia, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, South Carolina, Tennessee, and Texas:
USGS Open-File Report 2011-1262
Vitrinite reflectance variations in Paleocene-Eocene coals of the Powder River, Williston, Hanna, Bighorn, and Bull Mountain basins, U.S.A. [extended abstract]:
Abstract [.pdf] [5.91 MB] l Associated Data [.xlsx] [1.65 MB]
USGS Frequently Asked Questions (FAQ) Pertaining to "Coal"
NCRDS State Cooperators
ASTM Committee D05 on Coal and Coke
U.S. Department of Energy Clean Coal Initiative
U.S. Energy Information Administration
International Committee for Coal & Organic Petrology (ICCP)
The Society for Organic Petrology (TSOP)
Page Last Modified: Friday, October 13, 2017