Coal Resources of the Springfield Coal Bed in Western Kentucky

Historically, the Springfield (Western Kentucky No. 9) coal bed has been the leading source of production in the Western Kentucky Coal Field. The Springfield coal is known for its lateral continuity in terms of both thickness and coal quality. It is estimated to have the largest original and remaining resource in the Western Kentucky Coal Field (Greb and others, 1992)

Available Coal Resoures of the Handshoe 7.5–Minute Quadrangle, Knott County, Kentucky

Coal resources available for mining have been estimated for the Handshoe Quadrangle within the Hazard Coal Reserve District of the Eastern Kentucky Coal Field. Twelve coal beds within the quadrangle are potentially mineable and comprise the basis of these resource estimates. Seven of these beds have been commercially developed, but only four have produced more than 1 million tons: the Tiptop, Hazard No. 8, Hazard No. 4, and Upper Elkhorn No. 3. A computerized Geographic Information System was used to calculate estimates of original, mined-out, and remaining resources, restrictions to mining, and available resources

Coal Resources of the Upper Elkhorn No. 3A Coal (Lower Bed) in Eastern Kentucky

This map is one of a series that shows the regional characteristics of the Upper Elkhorn No. 3 coal zone. The maps were prepared as part of the U.S. Geological Survey\u27s National Coal Assessment Program, which compiles regional maps and databases that provide a comprehensive assessment of the most important coal beds in the nation. The Upper Elkhorn No. 3 coal zone has been one of the leading producers in the state of Kentucky and, in some areas, is of very high quality. Bed stratigraphy within the Upper Elkhorn No. 3 zone and coal thickness of the No. 3A coal are described in KGS Map and Chart Series 7 (series 12). The map shows mined-out areas and thickness characteristics of remaining coal. Figure 1 shows point-data locations, and Figure 2 shows tonnage calculations for the Upper Elkhorn No. 3A coal (also known as the Kellioka or B seam south of the Pine Mountain Fault)

Available Coal Resources of the Salyersville South 7.5-Minute Quadrangle, Magoffin County, Kentucky

Coal resources available for mining have been estimated for the Salyersville South Quadrangle, which is located in the Licking River Coal Reserve District of the Eastern Kentucky Coal Field. Nine coal beds within the quadrangle are potentially mineable and constitute the basis of these resource estimates. Seven of these beds have been commercially developed, but only five have produced more than 1 million tons: from youngest to oldest, the Skyline A, Lower Broas, Lower Peach Orchard, Middle Peach Orchard, and Upper Peach Orchard. A computerized Geographic Information System was used to calculate estimates of original, mined-out, and remaining resources, as well as restrictions to mining and available resources

Coal Resources of the Upper Elkhorn No. 3B Coal (Upper Bed) in Eastern Kentucky

This chart is one of a series that shows the regional characteristics of the Upper Elkhorn No. 3 coal zone. The maps and charts were prepared as part of the U.S. Geological Survey\u27s National Coal Assessment Program, which compiles regional maps and databases that provide a comprehensive assessment of the most important coal beds in the nation. The Upper Elkhorn No. 3 coal zone has been one of the leading producers in the state of Kentucky and, in some areas, is of very high quality. Bed stratigraphy within the Upper Elkhorn No. 3 zone and thickness of the No. 3A coal are described in KGS Map and Chart Series 7-8 (series 12). This chart shows original total coal thickness (Fig. 1), mined-out areas (Fig. 2), mining facies (Fig. 3), and resource calculations (Fig. 4) for the Upper Elkhorn No. 3B coal (also know as the Darby or C seam south of the Pine Mountain Overthrust Fault). The coal-thickness map is not a traditional isopach map, because the mineable bed is not composed of the same benches in all areas (Fig. 3). Discontinuities, delineated by facies boundaries on the map, indicate abrupt changes in thickness caused by splitting; discontinuities also occur between areas where entirely different beds in the Upper Elkhorn No. 3 zone are favored for mining

Coal Resources of the Lower Elkhorn Coal Bed in Eastern Kentucky

This chart is one of a series that shows the regional characteristics of the Lower Elkhorn coal. The maps were prepared as part of the U.S. Geological Survey\u27s Natural Coal Assessment Program, which compiles regional maps and databases that provide a comprehensive assessment of the most important coal beds in the nation. The Lower Elkhorn coal is one of the leading producers in the state of Kentucky and has, in some areas, a reputation as an excellent metallurgical-grade coal. It is known locally as the Pond Creek, Imboden, Path Fork, Blue Gem, Straight Creek, Bruin or Vires coal bed. This chart describes the distribution of data used for the coal assessment, generalized mined-out areas in relation to coal thickness, geologic structure of the bed, and coal-resource estimates

Coal Availability in Western Kentucky

Fourteen quadrangles in five separate areas of the Western Kentucky Coal Field were studied to determine what factors affect the availability of coal for mining. Each study area consisted of at least two adjacent 7.5-minute quadrangles in order to account for the geologic variability across broad distances in western Kentucky, and determine how this variability affects availability. Areas both north and south of the Rough Creek Fault System were selected to measure the effect of different geologic, structural, and overburden settings on coal availability. The study emphasized the coals occurring stratigraphically between the Springfield and the Baker. About 90 percent of western Kentucky coal resources is associated with only six beds, and one bed, the Springfield (W. Ky. No. 9), constitutes 25 percent of the entire estimate. Seventy percent of the resource is greater than 56 in. thick. Most mining in the Western Kentucky Coal Field is currently by underground methods; only 25 percent is by surface mining. A geographic information system (GIS) was used to estimate tonnages. Point data were obtained from over 5,000 drill-hole and geophysical-log descriptions, and included coal thickness, parting thickness, elevation, and stratigraphic position. Outcrops were digitized from U.S. Geological Survey (USGS) 7.5-minute geologic quadrangle maps, and land-use restrictions from USGS 7.5-minute topographic quadrangle maps. Mined-out areas were obtained from the Kentucky Department of Mines and Minerals, and locations of oil and gas wells from the Kentucky Geological Survey. A digital elevation model was obtained from the U.S. Geological Survey. Land-use restrictions can apply to both surface and deep mining. Technological restrictions in this study generally apply only to deep mining, and include barriers around existing mines, mining within 40 vertical feet of a seam, active oil and gas wells, coal too thin for current underground mining methods (less than 28 in.), and small mine blocks. Many technological restrictions in western Kentucky could be overcome if the relatively low profit margins in the region increased. Tonnage estimates for each bed are reported by categories of coal thickness, overburden thickness, and reliability of the estimate. Thickness categories used in this study are 14 to 28 in., 28 to 42 in., and greater than 42. in. Overburden categories are surface-mineable, deep-mineable, and too deep to mine with current technology. Reliability categories, based on distance from coal-thickness measurements, are measured (within % mi of a data point), indicated (between % and % mi), inferred (between % and 3 mi), and hypothetical (beyond 3 mi). Total original resources for the assessed coals in the 14 studied quadrangles are estimated at 5.55 billion tons (BT). Almost half this total is accounted for by the Springfield coal, and nearly a quarter by the Baker. About 77 percent of the coal is considered deep-mineable. A total of 1.084 BT, or 20 percent of he original resource, has been mined out or lost to mining. Thus, 4 BT, or 80 percent of original resources, remain. The average amount of restricted coal is 26 percent of original resources, and 88 percent of this restricted amount is by technological factors. The most important technological restriction was coal too thin to mine. Small interburden thickness between two mineable seams is a key factor in some areas; other locally important factors are mine barriers and small mine blocks. The average availability of coal in the 14 studied quadrangles is 54 percent. The results by quadrangle range from 9 to 91 percent, which confirms the necessity of studying larger areas. Deep-mineable coal between 28 and 42 in. thick and surface-mineable coal between 14 and 28 in. thick is considered available, but uneconomic. The uneconomic resources account for 14 percent of the original resource, leaving 40 percent of the coal that is both available and economic

Coal Resources of the Fire Clay Coal Zone in Eastern Kentucky

This chart is one of a series that shows the regional characteristics of the Fire Clay coal zone. The maps and charts were prepared as part of the U.S. Geological Survey\u27s National Coal Assessment Program, which compiles regional maps and databases that provide a comprehensive assessment of the most important coal beds in the nation. Within this coal zone, the Fire Clay coal is the most economically important bed and is one of the leading producers in the state of Kentucky. The Fire Clay coal contains a flint-clay parting that is believed to be of volcanic origin. The widespread occurrence of this parting aids in correlation, and therefore the Fire Clay coal is a key marker bed in the region. This chart describes the distribution of data used for the coal assessment, generalized mined-out areas in relation to coal thickness, geologic structure of the bed, and coal-resource estimates. Coal thickness for the Fire Clay and Fire Clay rider beds is presented in Kentucky Geological Survey Map and Chart Series 5 (series 12)

Geology of the Fire Clay Coal in Part of the Eastern Kentucky Coal Field

Coal beds mined in Kentucky often are not laterally continuous in thickness, quality, or roof condition. Regional and local variation is common. Because thickness, quality, and roof conditions are the result of geologic processes that were active when the coal was deposited as a peat swamp, a better understanding of the relationships between geology and major coal resources can aid in identifying geologic trends, which can be extrapolated beyond areas of present mining. The focus of this study is on the Fire Clay (Hazard No. 4) coal, one of the leading producers in the Eastern Kentucky Coal Field with 20 million short tons of annual production. More than 3,800 thickness measurements, highwall and outcrop descriptions, borehole and geophysical-log descriptions, and proximate analyses from 97 localities were used in conjunction with previous palynologic and petrographic studies to investigate the geology of the Fire Clay coal in a 15-quadrangle area of the Eastern Kentucky Coal Field. The Fire Clay coal is commonly separated into two distinct layers or benches by a flint-clay and shale parting called the “jackrock parting” by miners. Maps of coal benches above and below the parting show that the lower bench is limited in extent and variable in thickness. In contrast, the coal above the jackrock parting occurs across most of the study area and is characterized by rectangular patterns of coal thickness. Multiple coal benches resulted from the accumulation of multiple peat deposits, each with different characteristics. The lower bench of the coal was deposited when a peat accumulated above an irregular topographic surface. Because the peat was being deposited at or below the water table, it was often flooded by sediment from lateral sources, resulting in moderate to locally high ash yields. This peat was drowned and then covered by volcanic ash, which formed the flint clay in the jackrock parting. The upper coal bench accumulated above the ash deposit, after irregularities in the topography had been filled. The relatively flat surface allowed the swamps to spread outward and dome upward above the water table in some areas. Doming of the peat resulted in areas of coal with generally low ash yields and sulfur contents. Sharp, angular changes in the upper coal bench are inferred to represent subtle fault influence on upper peat accumulation. The upper peat was buried by a series of river channels, which were bounded by levees, flood plains, and elongate bays. Several of the rivers eroded through the Fire Clay peats, forming cutouts in the coal. These cutouts often follow orientations similar to the angular trends of coal thinning, suggesting a relationship that can be extended beyond the present limits of mining. Also, additional peat swamps accumulated above the levees and flood plains bounding the channels. Along the thinning margins of these deposits, the peats came near or merged with the top of the Fire Clay coal, resulting in local areas of increased coal thickness. Rider coal benches exhibit high to moderate sulfur contents and ash yields, so that although they may increase coal thickness, total coal quality generally decreases where riders combine with the Fire Clay coal

Available Resources of the Fire Clay Coal in Part of the Eastern Kentucky Coal Field

Available resources for the Fire Clay coal were calculated for a 15-quadrangle area in the Eastern Kentucky Coal Field. Original coal resources were estimated to be 1.8 billion tons (BT). Coal mined or lost in mining was estimated at 449 million tons (MT), leaving 1.3 BT of remaining Fire Clay resources in the study area. Of the remaining resources, 400 MT is restricted from mining, primarily because the coal is less than 28 in. thick, normally considered too thin to mine underground using present technology. The total coal available for mining in the study area is 911 MT, or 52 percent of the original resource. Of the 911 MT, 14.9 percent is thicker than 42 in., and only 6.1 percent is accessible by surface-mining methods. The largest block of available coal is in the Leatherwood quadrangle, is less than 42 in. thick, and mostly occurs below drainage