COAL RESOURCES OF MONTANA - MBMG - Welcome
COAL RESOURCES OF MONTANAJay A. Gunderson and John WheatonMontana Bureau of Mines and Geology, Billings, MontanaABSTRACTCoal has been a valuable source of energy and vital part of Montana’s history and economy for 200 years,providing energy for heating homes and cooking, fuel for the westward expansion of railroads, raw material forsmelting and other industrial applications, and since about the 1960s, a major source of fuel for generating electricity. Montana ranks first among the states in the size of its demonstrated reserve base, with 119 billion shorttons of coal, and sixth in production at roughly 40 million short tons per year. The most economically importantcoal resources occur in the Paleocene Fort Union Formation in the Powder River Basin, Bull Mountain Basin,and Williston Basin in eastern Montana. These account for over 95 percent of Montana’s coal resources and allof the State’s current coal production. Since the 1970s, research on Montana coal has focused almost exclusively on quantifying resource tonnages and chemical composition of Fort Union Formation coalbeds available forstrip mining.BACKGROUNDCoal has played a vital role in Montana’s historyand economic development. This brief historical viewprovides a backdrop to the discussion that follows onMontana’s coal fields. More detailed historical reviewsare provided by Morgan (1966) and Chadwick (1973).Coal-bearing formations underlie about 35 percentof Montana (fig. 1). Coal rank generally increasesfrom east to west—from lignite in the east, to subbituminous and bituminous coal further west. Thecoal-bearing formations range in age from Late Jurassic/Early Cretaceous to Tertiary (Miocene; fig. 2). Although historically, mining has been conducted in allof Montana’s coal regions, commercial mining duringthe past 50 yr has been limited to Tertiary (Fort UnionFormation) coalbeds in the Powder River Basin, BullMountain Basin, and Williston Basin (fig. 1).DiscoveryOn July 28, 1806, Captain William Clark of theCorps of Discovery observed coal in the bluffs alongthe Yellowstone River of southeastern Montana:“in the evening I passd. Straters of Coal in thebanks on either Side. those on the Stard. Bluffs wasabout 30 feet above the water and in 2 vanes from4 to 8 feet thick, in a horozontal position. the CoalContained in the Lard Bluffs is in Several vaines ofdifferent hights and thickness. this Coal or Carbon-ated wood is like that of the Missouri of an inferiorquallity.” (Moulton, 2001).Uses and DemandsHeatingIn 1807, Manuel Lisa, a French fur trader, built atrading post at the confluence of the Bighorn and Yellowstone Rivers and utilized lignite coal from nearbyoutcrops to heat buildings during the winter months(Morgan, 1966). During the homesteading era of thelate 1800s and early 1900s, coal was used as fuel forcooking and heating homes by farmers and ranchers,and local coal mines appeared across rural Montana.Coal for Metals MiningWith the advent of hardrock mining in Montanain the mid-1800s came demand for transportation andsmelting fuels. Steam, generated by coal, poweredmine equipment (steam hoists and transportation) andprovided energy to move ore from mines to smelters. Coking coal (or metallurgical coal) from three ofMontana’s coal fields was important for use in blastfurnaces for copper smelting in the late 1800s and early 1900s (Averitt, 1966). Coking ovens were built andoperated near Livingston, Great Falls, and Gardner.The demand for coking coal waned in the early 1900sdue to the development of more efficient methods ofsmelting.1
MBMG Special Publication 122: Geology of Montana, vol. 2: Special KFEET VALIERFIELDNORTH-CENTRALREGIONSidneyGreat FallsÜTERTIARYLAKE BEDSGlendiveHelenaMiles CityBULL MOUNTAINBASINLOMBARDFIELDLEGENDTRAIL CREEK LIVINGSTONFIELD STILLWATERButteLignite CoalGARFIELDREGIONGREAT FALLS - ripBillingsBozemanSubbituminous CoalBituminous CoalActive Coal MineTERTIARYLAKE BEDSFIELDELECTRICFIELDDillonRED LODGEFIELDMontana PRB OutlineHardin0County BoundaryPOWDER RIVERBASINBRIDGER SILVERTIPFIELD306090Figure 1. Map of Montana coal regions (modified from Cole and others, 1982).Basin orFieldCoalZonePeriod/Age (my)WillistonBull MountainPowder RiverRed LodgeBlackfeet ValierTertiaryLake bedsFlathead65Mid-&ontinentalSeaway StageKishenehn?WasatchFort UnionHell CreekFox HillsBearpawBlackfeet ValierNorth CentralRegressionTransgressionJudith RiverCretaceousBridgerSilver TipStillwaterTrail Creek Livingston ElectricFormationClaggettEagleTelegraph CreekRegressionTransgressionRegressionColorado GroupTransgressionKootenai144MorrisonJurassicGreat Falls LewistownLombardFigure 2. General stratigraphic position and age of coal-bearing formations.2Regression120 Miles
Gunderson and Wheaton: Coal Resources of MontanaTranscontinental RailroadsThe railroads headed west through Montana toconnect major Midwestern cities to the Pacific coastduring the 1880s. To encourage expansion into thewestern states, the Federal government enticed railroads to expand service by granting them land andmineral rights in every odd-numbered, 640-acre section within 10 mi on each side of the track (U.S. Government, 1862). Coal was preferred over wood as fuelfor steam locomotives because it has higher energycontent per unit volume. In response to the demand forcoal, many small mining operations opened to supplythe railroad. By the 1950s, diesel engine locomotivesreplaced steam engines and the early era of robust coalmining in Montana came to a close (fig. 3).Thermal Electric GenerationThe coal industry in Montana was rejuvenated inthe 1970s when the Clean Air Act of 1970 was enacted,allowing the U.S. Environmental Protection Agency tolimit sulfur-dioxide emissions and other air pollutantsthat threatened public health. Rather than incurringthe expense of retrofitting coal-fired power plants withemission controls to accommodate high-sulfur easternU.S. coal, companies sought western U.S. coal withlower sulfur content. As a consequence, the PowderRiver Basin (PRB) emerged as one of the primarycoal-producing regions in the United States. Demandfor low-sulfur eastern Montana coal, along with useof dedicated coal trains, or “unit trains,” marked thebeginning of the modern coal era in Montana.The anticipated growth in coal production and usewas outlined in a major 1975 study that listed potential for up to 52 new electrical generating plants inthe northern Great Plains, with 9 located in Montana(NGPRP, 1975). Of the 9 anticipated sites in Montana,only 4 were constructed and are located at Colstrip,Montana. The same report presented three development scenarios projecting growth in Montana coalproduction from 7.1 million short tons (MST) per yearin 1971 to between 58 and 393 MST per year by 2000.Even the lowest projection was never realized; instead,Montana’s coal production has remained level at about30 to 40 MST per year since the late 1970s (fig. 3).Coal Mining in MontanaCurrent MiningMontana currently produces about 35 to 40 MSTper year of coal from five strip mines and one underground mine (table 1, fig. 3). Nearly all coal currentlymined is used for electrical generation, with smallamounts used for home heating. Roughly 25 percentof the coal produced in Montana is used locally togenerate electrical power; the remaining 75 percent isshipped overseas and to coal-fired power plants in theMidwest.MONTANA COAL PRODUCTION50Powder River Basin45MILLION SHORT TONS40Other Coal FieldsTotal (UndiīerenƟated)3530252015EPA Clean Air ActDiesel Locomotives1050YEARFigure 3. Montana coal production (1880–2018). Data source: Montana Department of Labor and Industry; Milici, 1997.3
MBMG Special Publication 122: Geology of Montana, vol. 2: Special Topics7DEOH &RDO SURGXFWLRQ IURP PRGHUQ PLQHV LQ 0RQWDQD 0LQH 1DPH HDUV RI 3URGXFWLRQ DQG 6WDWXV EVDORND DFWLYH &RDO 3URGXFWLRQ LQ PLOOLRQV RI VKRUW WRQV &RDOEHG 1DPH 5RVHEXG 0F.D\ 5RVHEXG 0F.D\ 'HFNHU DFWLYH QGHUVRQ 'LHW] 'LHW] 5RVHEXG 6SULQJ &UHHN DFWLYH QGHUVRQ 'LHW] 'LHW] 6LJQDO 3HDN DFWLYH 0DPPRWK 5HKGHU 3XVW 6DYDJH DFWLYH 7RWDO YHUDJH RI WKH PRVW UHFHQW \HDUV RI SURGXFWLRQ Note. 'DWD 6RXUFH 0RQWDQD 'HSDUWPHQW RI /DERU DQG ,QGXVWU\ Future MiningTwo conditions are putting downward pressureon current coal markets in the United States. First, arenewed focus on coal’s environmental impact (concerns about climate change due to CO2 emissions;changes in local hydrologic balance; and restoration ofthe soils and surface usage) has resulted in decreasedusage. Aging coal-fired power plants are being shutdown rather than retrofitted with additional emissionscontrol equipment. Second, increased natural gasproduction from unconventional resources is replacingcoal for a larger portion of electrical power generation.Although coal will continue to be an important part ofthe U.S.’s energy portfolio, the U.S. Energy Information Administration (EIA) projects flat coal productionand consumption for the next several decades (EIA,2019). The future of coal may well depend on newtechnologies for utilization—technologies that aremore efficient, cost-effective, and environmentallyfriendly than those used today.Environmental ImpactsCoal mining falls under the jurisdiction of Stateand Federal bonding and reclamation rules (MontanaCode Annotated, 2017; SMCRA, 1977). Reclamationrules require mining companies to restore land (hydrology, topography, soils, and vegetation) that hasbeen disturbed by mining activities to original condition and use. Impacts to and recovery of the hydrogeologic system is discussed in detail in Meredith andothers (2020). Climate change, soils, air quality, andland use fall outside the purview of the Montana Bureau of Mines and Geology (MBMG), and the reader47RWDO &XPXODWLYH &RDO 3URGXFWLRQ PLOOLRQV RI VKRUW WRQV %LJ 6N\ FORVHG 5RVHEXG DFWLYH ² &RDO 3URGXFWLRQ \U YHUDJHPLOOLRQV RI VKRUW WRQV is referred to the Montana Department of Environmental Quality, Coal and Uranium Program.OVERVIEW OF COAL IN MONTANACoal FormationCoal is a combustible sedimentary rock composedof organic material [primarily carbon (C), hydrogen(H), and oxygen (O)] derived from the decay of plantmatter, plus variable amounts of moisture, volatiles,other elements such as sulfur and nitrogen, and inorganic material (mineral matter). The relative amountsof organic constituents (particularly percent carbon)determine coal rank, an important measure of coalquality that is directly related to heating value or energy content (fig. 3 and table 4 in Averitt, 1975). Coalheating value is generally expressed in British thermalunits per pound (Btu/lb). Inorganic material withincoalbeds comes from the occasional influx of clasticsediment into the coal-forming swamp or basin. Thismaterial—termed “ash”—can be dispersed within coalor occur as thin, definable layers, called partings.Coal forms in wetlands (e.g., swamps, bogs, mires,floodplains, and lagoons) where the accumulation ofdecaying plant material, or peat, exceeds the rate ofbacterial decay and oxidation of the plant debris. Aspeat is buried and compacted, heat and pressure driveoff volatiles and moisture, to form lignite (low rank)coal. Continued metamorphism transforms low rankcoal into higher rank coal (lignite to subbituminousto bituminous to anthracite). It may take as much as100 ft of plant material to form a 5-ft-thick bed ofbituminous coal. Because heat and pressure increase
Gunderson and Wheaton: Coal Resources of Montanawith depth, and since older coalbeds tend to have been generally higher in low-lying peat mires where fineburied more deeply than younger coalbeds, there is agrained sediments can accumulate more easily than ingeneral relationship between age and coal rank; olderraised swamps.coalbeds tend to be higher rank than younger coalbeds.Coal QualityCoal Depositional EnvironmentsThe term “coal” encompasses a wide range ofCoal-forming environments exist in both coastalrocks with a wide range of properties and composition.(marginal marine) and terrestrial (non-marine) settings Some coal constituents are harmful to the environment(fig. 4). Both types of depositional environments were (e.g., mercury and oxides of sulfur and nitrogen); othactive in Montana’s past, a consequence of the Jurasers may require special equipment and/or equipmentsic and Cretaceous seas that periodically flooded andmaintenance for combustion (e.g., sodium). The pridrained the mid-continental region of North Americamary indicator for the quality of coal as a fuel is rank,(fig. 2).or heating value. Thus, determination of coal quality—After the Jurassic seas withdrew from North Amer- or coal chemistry—is important because it impactscoal utility and value, emissions, waste products, andica, rivers and lakes formed on the broad low-lyingequipment design and efficiency (e.g., turbines, boilfloodplain that remained. These floodplain wetlandsers). Coal quality can be assessed via chemical andbecame sites for peat accumulations that eventuallypetrographic analyses.formed the terrestrial coalbeds of the Late Jurassic/Early Cretaceous Morrison Formation. During theChemistryLate Cretaceous, several cycles of marine transgresThere are two common analytical tests performedsions and regressions led to frequent flooding ofon coal samples to determine coal quality: proximatecoastal swamps and lagoons lying landward of theshoreline. Thus, Late Cretaceous coalbeds in Montana and ultimate analyses. Proximate analyses are relatedto burning characteristics and used to determine heatare primarily marginal marine in origin. Final regression of the sea at the end of the Cretaceous once again ing value (Btu/lb), moisture content, volatile matter,fixed carbon, and percent ash. Ultimate analyses proleft a newly exposed land surface that was drainedvide information about the major organic elementalby a large-scale fluvial system(s) flowing northwardcomposition of coal in terms of carbon, hydrogen,into the retreating Cannonball Sea during the Tertiarysulfur, oxygen, and nitrogen. Guidelines for sample(Flores, 1992). Interfluvial wetlands such as mires,collection and analytical methods are given by Golilakes, and bogs accumulated an immense amount ofghtly and Simon (1989) and Speight (2005).peat, resulting in Tertiary coal deposits that are theCoal-quality data from Montana have been gathlargest in the State.ered and reported since the early 1900s. Early mappersThe type of depositional environment—marginof the U.S. Geological Survey (USGS) and the U.S.al marine or terrestrial—can lead to very differentBureau of Mines (USBM) collected samples at minecoalbed distributions, geometries, and composition.Coalbeds that form in coastal wetlands tend to be thin, locations and reported results in reconnaissance mapping publications. These data were compiled by Fieldlaterally continuous, elongate parallel to the paleoner and others (1932) and Gilmour and Dahl (1967).shoreline, and occur in sequences of mixed marineA large amount of quality data were gathered onand non-marine rocks (fig. 4). Terrestrial coal-formingcoalsamples from drillhole cores and from activeenvironments are typically fluvial and lacustrine in origin and include interfluvial mires, swamps, and other mines during the joint USGS and MBMG exploratory drilling program of the 1960s, 1970s, and 1980s.localized wetlands. Coalbeds formed in fluvial enviResults of proximate and ultimate analyses were pubronments are lenticular and discontinuous; they oftenlished along with drillhole stratigraphic data in severalmerge and split over relatively short distances.USGS reports: for example, Affolter and Hatch (1980)Coal quality, or chemistry, is also influenced byand Tewalt and others (1989). Other coal-quality datadepositional environment (Fort Union Coal Assessare found in many of the coal publications cited in thisment Team, 1999). For example, sulfur content tendsreview, such as Matson and others (1973).to be higher in marginal marine coal than terrestrialcoal. Ash content from the influx of clastic material is5
MBMG Special Publication 122: Geology of Montana, vol. 2: Special Topics dĞƌƌĞƐƚƌŝĂůWĞĂƚ ǁĂŵƉ ĞĂ ŽĂůƚWĞĂDĂƌŝŶĞ ƐĞĚŝŵĞŶƚƐŶƚƐŝŵĞĚĞƐŝŶĞ DĂƌ%WĞĂƚWĞĂƚ ǁĂŵƉ dĞƌƌĞƐƚWĞĂƚ ǁĂŵƉƌŝĂů ĞĂDĂƌŝŶĞŶƚƐĚŝŵĞ ƐĞĚŝŵĞŶƚƐ ƐĞƌŝŶĞͲDĂEŽŶ&ZŝǀĞƌ ƐLJƐƚĞŵWĞĂƚWĞĂƚ ǁĂŵƉ ŽĂů ůĂLJ ĂŶĚ ŝůƚ ŽĂů ŚĂŶŶĞů ĂŶĚƐƚŽŶĞŚĂŶŶĞů ĂŶĚƐƚŽŶĞFigure 4. Simplified sketches of coal-forming environments in marginal marine (coastal) and terrestrial (fluvial) settings. (A) Marginalmarine setting (regression). (B) Marginal marine setting (transgression). (C) Fluvial setting.Some data are publicly available from the USGScoal quality (COALQUAL) database (Palmer and others, 2015) and from the National Coal Quality Inventory (NaCQI) database (Hatch and others, 2006).PetrographyAt the microscopic level, coal is made up of organic particles called macerals (e.g., liptinite, vitrinite,inertinite), similar to the way an igneous rock is madeup of minerals. The petrographic approach to the studyof coal composition employs the idea that coal macerals have distinct physical and chemical properties thatcontrol the overall composition and behavior of coal(Stach and others, 1982). Few petrographic studieshave been conducted on Montana coalbeds; one example is a study by Sholes and Daniel (1992) on theKnobloch coalbed.6Sulfur ContentThe modern mining surge in Montana was the direct result of a national concern with acid rain duringthe early 1970s. Burning coal releases sulfur in theform of SO2 that can react with water and oxygen inthe atmosphere to form sulfuric acid (H2SO4), whichcan then be incorporated into rain water. The need tomitigate acidic rain led to demand for the low-sulfur( 1 percent sulfur) coal found in the Powder RiverBasin (PRB) of Montana and Wyoming. Nationally,sulfur content in coal ranges from about 0.5 to 5.0percent (Chou, 2012). Sulfur content in Tertiary coalof eastern Montana is typically less than 1.0 percent.In coal, sulfur is present primarily in mineral formsuch as pyrite (FeS2) and associated sulfide minerals,secondarily as organic sulfur, and lastly in sulfate or
Gunderson and Wheaton: Coal Resources of Montanaelemental forms. The sulfur originates from two predominant sources: parent plant material and sulfatein seawater that floods coastal peat swamps (Chou,2012). Most freshwater streams and rivers are lowin sulfate concentrations, and contribute little sulfurto coal. Generally, low-sulfur coal such as that in thePRB and Williston Basin was deposited in freshwater,fluvial systems.Resource AssessmentsThe quantity of coal in Montana has been estimated several times, and these estimates vary dependingon the data available and the economics of foreseeable demands. Estimates are described as resourcesand reserves, which have different, yet very specificmeanings. Coal resources include tonnage estimates ofidentified and hypothetical resources for coal zones ofa minimum thickness and within certain depth limits(commonly 0–2,000 ft deep). Coal reserves, a subsetof coal resources, are considered economically producible at the time of classification. A review of theseand other terms related to coal tonnage estimates isprovided by Wood and others (1983) and Pierce andDennen (2009). The reader should be aware that manyauthors (past and present) use criteria similar to Woodand others (1983), but with their own modifications.For coal tonnage estimates cited in this paper, we retain the original authors’ use of the terms resource andreserve.Total identified coal resources in Montana wereestimated in 1975 to be 291.6 billion short tons (BST;Averitt, 1975). This includes all bituminous coal morethan 14 in thick and all subbituminous coal and lignite beds more than 30 in thick to a depth of 3,000 ft.The EIA (2018) currently estimates the demonstrated reserve base for Montana to be 118.6 BST, with74.4 BST deemed to be recoverable (38.5 BST surface-minable and 35.9 BST underground-minable).Early Estimates of Total ResourcesCoal tonnage estimates were a critical componentof early 1900s mapping and formed the foundation forsome of the first statewide coal resource and reserveestimates for Montana. Combo and others (1949)summarized coal in Montana by county, rank, reliability category, and thickness. Their estimate of 222 BSTof coal included 2.4 BST of bituminous, 132.1 BSTof subbituminous, and 87.5 BST of lignite coal. Theyspecified reliability categories of measured and indicated, inferred, and unclassified as to thickness basedon distance from the drillhole or outcrop, and depthsup to 2,000 ft.Strippable Deposits and ReservesBeginning in the 1960s, attention shifted to identifying and quantifying coal reserves rather than totalresources, with greater emphasis on strippable deposits in eastern Montana (i.e., coalbeds in the Fort UnionFormation). Averitt (1965) provided an estimate ofwhat he termed strippable resources of 5.1 BST forseveral fields with thick coalbeds located near existinginfrastructure in eastern Montana. During the next 5yr, several reports quickly increased strippable reserveestimates to nearly 25 BST based on additional mapping and drillhole information (e.g., Ayler and others,1969; Matson, 1969).In a comprehensive report on eastern Montanastrippable coal, Matson and others (1973) provided detailed coalbed and overburden thickness maps, lithologic data, and coal-quality data for 32 individual coaldeposits in the PRB. Their compilation of coal deposits in the Montana portion of the PRB gave an indicated strippable coal reserve (as they defined the term) of32 BST based on coal thickness, overburden thickness,and a 2- to 3-mi radius around data points. Matson(1975) later included several more strippable depositsin the Williston Basin, Bull Mountain Basin, and onIndian lands in the PRB to get a total of 42.6 BST ofstrippable coal reserves (as he defined the term).In 1975, the USBM published a report summarizing the strippable and underground coal reserve baseof the United States by state and county (Hamiltonand others, 1975). This report estimated Montana’sdemonstrated reserve base to be 108.4 BST: 65.8 BSTunderground and 42.6 BST strippable.Availability and RecoverabilityThe proportion of coal resources that are recoverable from undisturbed deposits varies from less than40 percent in some underground mines to more than90 percent at some surface mines. The USGS alsorecognized that better resource and reserve estimatescould be obtained by considering and excluding certain land-use and technological restrictions such ascemeteries, roads, other infrastructure, alluvial valleys,etc.—issues that could significantly reduce the amountof coal considered to be recoverable (Fort Union CoalAssessment Team, 1999; Luppens and others, 2009).Thus, new coal tonnage estimates by the USGS andstate geological surveys were needed to place more7
MBMG Special Publication 122: Geology of Montana, vol. 2: Special Topicsemphasis on “available” and “recoverable” coal.In 1995, the USGS began the U.S. National CoalResources Assessment (NCRA) project, in cooperationwith state geological surveys, to conduct systematic,geology-based, regional assessments of the Nation’sremaining recoverable coal resources for significantcoalbeds in major coal provinces and regions (Pierceand Dennen, 2009).The Powder River Basin was the first of fourNorthern Rocky Mountains and Great Plains coalregions to be assessed in the NCRA program. Coalavailability studies were produced for significantindividual coalbeds (Fort Union Assessment Team,1999), first over specific 7.5-minute quadrangles in theMontana PRB (e.g., Gruber, 1990; Wilde and Sandau,2004), and then for the entire Montana portion ofthe PRB (Haacke and others, 2013). These local andregional studies formed the underpinnings for a complete reassessment of coal reserves in the Montana–Wyoming PRB (Luppens and others, 2015). Of theestimated 1,162 BST of original coal resources in thePRB, only 25 BST—or about 2 percent—are deemedto be reserves. These results demonstrate the impact ofvarious technical constraints, land-use restrictions, andmining economics on computing coal reserves.DESCRIPTION OF MONTANA COAL FIELDSMany studies and reports that describe and inventory coal in Montana have been generated. Territorialgeologists, railroad geologists, and USGS workersbegan mapping coal ahead of the westward expansionof the railroad during the late 1800s and early 1900s.Working solely from surface information, they described and mapped Montana’s coal-bearing regionsand specific coal fields or deposits. One example oforiginal mapping is by Woolsey and others (1917),who describe the Bull Mountains Coal Field. Another example is work published by Baker (1929), whomapped the northward extension of the Sheridan CoalField in Wyoming into Montana. These early publications provide reconnaissance geologic maps and township-by-township, or in some cases section-by-section,descriptions of near-surface coal deposits in Montana.An excellent compilation of these early inventoriesis provided by Combo and others (1949). They included descriptive field summaries, a list of references forthe early 1900s publications, and estimates of totalcoal reserves (as they defined the term) for Montana.Other statewide summaries are given by Bateman8(1966) and Cole and others (1982). Matson (1975)provides a summary of field mapping completed onstrippable coal deposits in eastern Montana. A particularly useful publication by Pinchock (1975) givesa location map and references for coal field studiescompleted prior to the mid-1970s. Rather than cite allof the early studies in this review, we refer the readerto Combo and others (1949) and Pinchock (1975).We present here a brief summary of Montana’scoal regions and individual coal fields (fig. 1), organized by the three major periods of coal formation inMontana: the Late Jurassic/Early Cretaceous, LateCretaceous, and Tertiary. Table 2 provides basic characteristics of each field or region for comparison. Allcoal-quality information in table 2 and in the text thatfollows is reported on an “as-received” basis unlessstated otherwise.Late Jurassic/Early Cretaceous (Morrison Formation)Following the last of the Jurassic marine regressions ( 155 Ma), fine-grained distal sediments of theMorrison Formation were deposited on the emergingsurface of marine sediments during Late Jurassic andEarly Cretaceous. The coal-bearing upper part of theMorrison Formation, considered to be Early Cretaceous (Engelhardt, 1999; Vuke, 2000), includes mudstones, siltstones, and fine-grained sandstones formedin a mixed fluvial-lacustrine environment (Harris,1966, 1968; Walker, 1974).Coalbeds deposited in the Early Cretaceous Morrison Formation occur in the Great Falls–Lewistownfield and the Lombard field. Although continental,nearshore, and lacustrine deposition continued in theEarly Cretaceous, no other Lower Cretaceous coalbedshave been recorded in Montana.Great Falls–Lewistown FieldCoalbeds in the Great Falls–Lewistown field occurwithin the upper part of the 180- to 200-ft-thick Jurassic–Cretaceous Morrison Formation along the northslopes of the Little Belt and Snowy Mountains incentral Montana (fig. 1). The primary coal zone variesin thickness from 3 to 18 ft with coalbeds in 2 to 3benches averaging 4 to 5 ft thick each, separated by 1to 10-in-thick shale partings.Coal in the Great Falls–Lewistown field is bituminous with heating values ranging from 8,700 to12,900 Btu/lb and averaging 10,200 Btu/lb. Sulfurcontent varies from 1.7 to 4 percent and ash content
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MBMG Special Publication 122: Geology of Montana, vol. 2: Special Topicsranges from 8 to 30 percent. Generally, there is lowerash content and higher sulfur content in coal from theLewistown portion of the field. Silverman and Harris(1967) estimated reserves (as they defined the term) tobe 822 MST.Workable coal thicknesses are concentrated inseveral separa
coal, many small mining operations opened to supply the railroad. By the 1950s, diesel engine locomotives replaced steam engines and the early era of robust coal mining in Montana came to a close (fi g. 3). Thermal Electric Generation The coal industry in Montana was rejuvenated
Our main source of coal comes from a coal mine near Butler, Missouri. A stock pile of coal for unexpected emergencies is maintained at Blue Valley. A 90-day supply of coal consists of 45,000 tons of coal. Coal Feeders Feeding coal from the bunkers to the pulverizers is the purpose of the coal feeders. The pulverizers grind the coal into a fine .
as.edu / n e Resources -Coal 1 Based on -The Coal Resource by World Coal Institute 2005.-The Coal Resource Base, Chapter 2 of Producing Liquid Fuels from Coal by J.T. Bartis, F. Camm and D.S. Ortiz. Published by RAND 2008. ISBN: 978--8330-4511-9. -The Role of Coal in Energy Growth and CO2 Emissions, Chapter 2 of The Future of Coal, an Interdisciplinary MIT Study, 2007.
IEA Clean Coal Centre – New regulatory trends: effect on coal-fired power plant and coal demand 4 . Abstract . This review presents the recent regulatory trends, practices and developments, in major coal producing and consuming countries, which are affecting and may influence future demand for coal and coal-fired power generation.
The Lower Kittanning coal bed assessment only includes maps showing its areal extent and geochemical parameters and a history of the mining of the coal bed. Pittsburgh Coal Bed The results of the Pittsburgh coal bed assessment (North-ern and Central Appalachian Basin Coal Regions Assessment Team, 2001; Tewalt, Ruppert, Bragg, Carlton, and others,Author: Michael H. Trippi, Leslie F. Ruppert, Robert C. Milici, Scott A. Kinney
MONTANA NONPROFIT ASSOCIATION, INC A Montana Nonprofit Public Benefit Corporation BYLAWS ARTICLE I NAME 1.01 Name. The name of this Corporation shall be Montana Nonprofit Association, Inc. The business of the Corporation may also be conducted as Montana Nonprofit Association or Mo
Coal is comprised of organic and inorganic (mineral) assemblages. . do we understand coal? (CCT, advanced applications) ORGANIC PETROLOGY FINDS RELEVANCE IN GEOLOGY, METALLURGY, CHEMICAL ENGINEERING, COAL SUSTAINABILITY ACROSS THE COAL VALUE-CHAIN . LIGHT WEIGHT COMPOSITE MATERIALS Underground coal gasification Many additional uses: Paper .
Coal deposits are mined by cutting a network of 'roads' into the coal seam & leaving behind 'pillars' of coal to support the roof of the mine. These pillars can be up to 40% of the total coal in the seam - although this coal can sometimes be recovered at a later stage by 'retreat mining'.The roof is then allowed to collapse and the mine is
AS and A level specifications in business must encourage students to: develop an enthusiasm for studying business gain an holistic understanding of business in a range of contexts develop a critical understanding of organisations and their ability to meet society’s needs and wants understand that business behaviour can be studied from a range of perspectives generate enterprising and .
