Depositional Settings of Texas Lignites: Dallas to San Antonio, Texas, July 4-8, 1989

42 Pages·3.694 MB·English

Depositional Settings
of Texas Lignites
Dallas to San Antonio, Texas
July 4-8, t 989
Field Trip Guidebook Tt73
Leaders:
~lterB. Ayers, Jr., John A. Breyer,
and Robert B. Finkelman, Editors
American Geophysical Union, Washington, D.C.
Copyright 1989 American Geophysical Union
2000 Florida Ave., N.W., Washington, D.C. 20009
ISBN: 0-87590-575-7
Printed in the United States of America
COVER Continuous surface miner, at right, mines lignite and loads
haul truck while a dragline, in the background, removes overburden
above Jackson Group lignite in San Miguel mine (photo by
W. B. Ayers, Jr.).
IGC FIELD TRIP T173:
DEPOSITIONAL SETTINGS OF TEXAS LIGNITES
TABLE OF CONTENTS
Introduction................................................................................................................................... 1
CitiesVisitedDuringFieldTrip 3
GeologicSettingsofLigniteintheWilcoxGroupofEast-CentralTexasandtheJacksonGroup
ofSouthTexas--W.B. Ayers, Jr. 5
EvidenceforEstuarineSedimentationinWilcox(paleogene)DepositsattheBigBrownLigniteMine--J.A.Breyer......... 17
Geology of the Jewett Lignite Mine--M.P. Palmquist 23
Geology ofSandowLigniteMine,LowerCalvertBluffFonnation, East-CentralTexas--W.B. Ayers, Jr. 26
Geology of Elgin-Butler Clay Pits--W.B. Ayers, Jr ; 31
DepositionalSettingoftheSanMiguelLigniteMine,JacksonGroup(Eocene),SouthTexas--W.B.Ayers,Jr 33
v
Editors:
Walter B. Ayers, Jr.
Bureau of Economic Geology
The University of Texas at Austin
University Station, Box X
Austin, TX 78713
John A. Breyer
Department of Geology
Texas Christian University
Fort Worth, TX 76129
Robert B. Finkelman
U.S. Geological Survey
Mail Stop 956
Reston, VA 22092
vii
IGC FIELD TRIP T173:
DEPOSITIONAL SETTINGS OF TEXAS LIGNITES
INTRODUCTION
Worldwide,coalisthemostabundantfossil-fuel (43.9milliont; 48.5 milliontons), NorthDakota(22.6
resource. Low-rankcoal(subbituminousandlignite)con milliont; 25 milliontons),Louisiana(1.8 milliont; 2.0
stitutes29percentoftheprovedrecoverablereservesl inthe milliontons), andMontana(0.2milliont; 0.2milliontons).
I
world and43percentofthosereservesinthe U.S.,which InTexas,99percentoftheminedcoalislignite(Kaiser,
containsthegreatestprovedrecoverablereselVesoflow-rank 1985),whichisusedalmostexclusivelytogenerateelec
coals(Table 1)(NCA, 1986). In 1984,26percentofthecoal tricity. In 1987,Texaspowerplantsused45.6milliont
producedintheworldwaslignite,andGennany(DR)ledall (50.3milliontons)oflignitetogenerateapproximately20
ligniteproducers(Table 1). percentofTexas'electricity. Anewmineandcompanion
Coalmakesup72percentoftheU.S. fossil-fuel powerplantareunderconstruction, andmodestgrowthof
resource; however,itaccountsforonly23percentofthe coalutilizationinTexas isprojectedthrough 1995(Landmarc,
energyconsumed(Halbouty, 1988;Tellmann, 1988). Coal 1988).
productionisoneofthelargestindustriesinthe U.S., where Becauseoflowheatingvalue,transportationcosts, and
coalisusedprimarilytogenerateelectricity. In1987,electric the tendencyforspontaneouscombustion,ligniteusuallyis
utilitiesused78percentofthedomesticproductiontogenerate nottransportedfar; mine-mouthelectric-generatingplantsare
57percentoftheelectricityusedintheU.S. (Landmarc, 1988; locatedintheligniteoutcropbelt. Largeresources, which
Tellmann, 1988). Othercoalmarketsincludegeneralindus exceed21.2billiont(23.4billiontons) innear-surface(less
try,steelmanufacturing, andexportation. than61 m [200ft] deep)deposits,makeligniteacost-effec
Ofthe814.3milliont(897.9milliontons)ofcoalmined tivefuel forpowergenerationinTexas(Kaiserandothers,
intheU.S.in 1986,approximately8percentwaslignite ~.980). Additionally,Texasligniteisanattractivefuelbecause
(Friedmanetal., 1987; Zaburunov, 1988). Inthe U.S., ofitsproximitytomajorutilityandindustrialmarkets.
ligniteoccursintheFortUnionRegion(NorthDakota, Thisfieldtripwillfocusonthedifferentdepositional
Montana,andSouthDakota),the GulfCoastRegion(Texas, settingsoflignitedepositsintheTertiary(paleogene)Wilcox
Louisiana,Arkansas, Mississippi,andAlabama), Colorado, andJacksonGroupsinTexas(seeFigure 1). Thosedepo
andAlaska. In 1986,themajorproducingstateswereTexas sitionalsettingswereintetpretedfrom regionalsubsurfaceand
TABLE 1 RankingsofCountriesbyProvedRecoverableReselVesofLow-RankCoal
(SubbituminousandLignite)andby 1984ProductionofLignite(NCA, 1986)
ProvedRecoverableReselVesl 1984LigniteProduction2
1. U.S. 1. Gennany(DR) 9. Bulgaria
2. U.S.S.R. 2. U.S.S.R. 10. Greece
3. Australia 3. Gennany(FR) 11. Romania
4. Gennany(FR) 4. Czechoslovakia 12. Turkey
5. Yugoslavia 5. Yugoslavia 13. Spain
6. Gennany(DR) 6. U.S. 14. Hungary
7. Poland 7. Poland 15. Canada
8. Australia
IProvedrecoverablereservesarethoserecoverableunderexistingeconomicconditionswithexistingtechnology; proved
recoverablereselVesinthecountrieslistedrangefrom 83.7billiontonsofcoalequivalent(t.c.e.) to 3.6billiont.c.e(one
t.c.e.=27.8xlQ6Btu/metricton). T.e.e. areusedhereforcomparisonofinternationalreserves; inthesecondcolumnofthis
tableandthroughouttheremainderoftheguidebook,coalreservesandproductionwillbereportedinmetrictons(t)andshort
tons (tons).
2Productioninthecountrieslistedrangedfrom 299.8milliont(330.6milliontons)to9.9milliont(10.9milliontons). Ten
othercountriesproducedlignitein1984.
T173: 1
localoutcropstudies. Thefield tripwillalsoinvolvedis GulfCoastregion,alignite-burningpowerplant,anda
cussionsofcoalqualitytrends,organicandinorganicgeo lignite-burningaluminumsmeltingplantorabrickandtile
chemistry,petrography,andenvironmentalconcerns manufacturingplantthatuseslignitetofirearotarykilnto
associatedwithlignitemining. Wewilltouropen-pitlignite calcineclay.
minesthatillustratethedifferentminingtechniquesusedinthe
Scale
o 20 60 100 mi
I I I I STOP 1
I I I Big BrONn
o 40 80 120 km
Jewett
STOP
2
79
N
6
Bryan/
SandON
College Station FIGURE 1 RoadLog.
Austin 95 STOP 4
Day1:Dallas,orientation.
Elgin -Butler
Day2:Stop I--BigBrownLigniteMine
andPowerPlant; Stop2--Jewett
LigniteMine;Evening:Bryan!
CollegeStation.
Day3:Stop3--SandowLigniteMineand
San Antonio
AluminumPlant;Stop4--Elgin
ButlerOayPitsandBrickPlant;
Evening: Austin.
Day4:BureauofEconomicGeology;
TheUniversityofTexasatAustin;
Evening: SanAntonio.
Day5:Stop5--SanMiguelLigniteMine;
Evening: Washington, D.C.
REFERENCES
Friedman, S.A., R.W. Jones, C.G. Treworgy, and C.J. Landmarc,Theoutlookforutilitycoalmarkets,11,no.2,
Smith,Developmentsincoalin 1986,Am.Assoc.Pet. pp.6-7, 30, 1988.
Geol. Bull., 71, no. lOB, pp. 364-373, 1987. NeA,Internationalcoal: Natl. CoalAssoc.,pp.1-1 to1-19,
Halbouty,M.T.,Theroleofenergyinthereindustrialization 1986.
ofAmerica, Geol. Soc. Am. Newsletter, 6, no. 10, Tellmann,J.R.,Themarketchallengesfacingcoal,
pp. 293-296., 1988. Landllnarc,11,no. 2,pp.4-5,20, 1988.
Kaiser,W.R.,Texaslignite--statusandoutlookto2000,UT Zabunmov,S.A.,QualitycontrolandTexaslignite,Coal
Austin,Bur. Econ. Geol. Min. Res. Circ. 76, 17pp., Mining, 25, pp. 34-37, 1988.
1985.
Kaiser, W.R., W.B. Ayers, Jr., and L.W. LaBrie, Lignite
resources inTexas, UTAustin, Bur. Econ. Geol., RI104,
52 pp., 1980.
T173: 2
CITIES VISITED DURING FIELD TRIP
DALLAS AUSTIN
Dallas,oneofthemostcosmopolitancitiesintheU.S., Austin,locatedontheedgeoftheBalconesEscaIpment
wasestablishedin1841 byJohnNeelyBryan,aTennessee andastridetheColoradoRiver,isconsideredtobeTexas'
lawyerwhobuiltalogcabintradingpostontheeastbankof mostattractivecity. In1838,JakeHarrellcampedonthe
theTrinityRiver. Bythemid-1870's,Dallashadbecomea northbankoftheColoradoRiverandwassoonjoinedbya
thrivingbusinesstownandmarketcenterwithanurban handfulofothersettlers. Inthefallof1838,thepresident
qualityunmatchedanywhereonthefrontier. Itsgrowth electoftheRepublicofTexas,MirabeauLamar,recom
resultedprimarilyfromimmigrationsofskilledandcultured mendedHarrell'ssettlement,thencalledWaterloo,asthesite
groupsofFrench,Gennan,Swiss,English, andother forTexas'pennanentcapital. Itwasapprovedin 1839and
Europeans. Inlessthan150years,Dallasdevelopedintoa constnlctionbegan. Thefirstcapitolwasaone-story,framed,
modem,dynamiccityofalmostonemillionpeople,secondin whitewashedbuilding,enclosedbyaneight-footstockadeto
sizeinTexasandseventhinthenation. protectthecitizensfromIndianattack.
DallasisthelargestbankingcenterintheSouthwest;a In1841FrancefonnallyrecognizedtheRepublicofTexas
leaderinwholesalebusiness;secondinthenationfor andsentanambassadortoAustin. Theambassadorsoonleft
insurancecompanyhomeoffices;oneofthenation'stopthree townafteradisputewithhisneighborovermaraudingpigs.
fashionmarkets;thelargestcottontradingcenterinthenation; Theincidentbecameknownas"ThePigWar."
amongthetopfiveconventionsites;amajorcenterforoil In1883theUniversityofTexas(UT)fonnallyopenedfor
industryactivity;and,ofcourse,thelocationforthepopular classes. Thatsameyear,constructionbeganonanewcapitol,
TVshow"Dallas." TheDallas-FortWorthInternational whichwasmadeofTexasgraniteandpatternedafterthe
Airportisthefourthbusiestintheworld. nationalcapitol;theTexascapitolisactuallysevenfeettaller.
OnNovember22, 1963,PresidentJohnF. Kennedywas Growthofthecityhasbeensteadybutslowenoughto
assassinatedinDallas. Thistragicevent,whichcapturedthe retainmuchofitssmall-townchann. Austincurrentlyhas
attentionoftheworld,hasdrawnvisitorsworldwidetothe about485,000people. UT,oneofthecountry'smosthighly
sitetolearnmoreaboutaneventthatmadeaprofound regardedinstitutesofhigherlearning,isnowthelargest
impressiononpeopleofmanynations. universityinTexas,withmorethan50,000students. The
campusalsoincludestheLyndonBainesJohnsonLibrary,
containingmorethan31 millionpapersfromPresident
DRYAN/COLLEGE STAnON Johnson's era.
InadditiontohousingtheStateCapitolandbeingacenter
In1865WilliamJoelBryan,onlandinheritedfromhis forhighereducation,Austinisalsoacenterforhigh-tech
uncle,StephenF.Austin,laidoutandsUlVeyedatownsiteof industry. Numerouscomputerandmicroelectronicscom
640acresalongarailroadrouteinBrazosCounty. The paniesnowcallAustinhome.
townsitewasnamedBryaninhishonor. In1891 Bryanwas
incorporatedasacity. Twentyyearsearlier,theTexasState
Legislaturehadestablishednearbythestate'sfirstpublic BUREAU OF ECONOMIC GEOLOGY,
institutionofhigherlearning,theAgriculturalandMechanical THE UNIVERSITY OF TEXAS AT AUSTIN
CollegeofTexas(since 1963knownasTexasA&M
University). Thecollegeopeneditsdoorstostudentsin 1876. TheBureauofEconomicGeology(BEG)isaresearch
TheCityofCollegeStationwasincorporatedin'1938. unitofTheUniversityofTexasatAustinandfunctions asthe
Withtime,BryanandCollegeStationmergedintoasingle stategeologicalswveyofTexas. LocatedintheBalcones
metropolitanarea. TodayBryanhasalmost60,000residents ResearchCenter,a2o-minutedrivenorthofthemainuni
andCollegeStationalmost53,000;morethan39,000students versitycampus,BEGoccupiesthreebuildings,including
areregisteredatTexasA&M. aResearchandAdministrationbuilding,MineralStudies
Duringthe 1970'sandearly 1980's,A&M wasdescribed Laboratory,corelayoutfacilities, andacorerepository. BEG
asthefastestgrowingpublicinstitutionofhigherlearningin isstaffedbymorethan60scientists,75professionalsupport
thenation. Itboaststhenation'slargestenrollment(morethan staff,and30half-timestudentassistants.
9,000students)inengineering. A&M'sCollegeofGeo WhencreatedbytheBoardofRegentsin1909,BEGwas
scienceshasabout600students. 'Thereareapproximately mandatedtocollectanddistributeinfonnationconcerilingthe
2,700facultymembersattheuniversity. TheTexasA&M resourcesofTexasandtoassistthoseinterestedindeveloping
UniversitySystemmaintainsanoperatingbudgetof$750 theseresources. Inkeepingwiththesegoals,BEGstaffstudy
millionandaresearchbudgetof$176million,bothamongthe StateresourcesandpublishtheirfindingsinBEGreports,
largestinthenation. maps,andcrosssections;morethan 1.5millionreportsand
T173: 3
mapshavebeendistributed. BEGstaffalsorespondto In1718aFranciscanmission,SanAntoniodeValero,
thousandsofrequestsforinfonnationfromindividuals, nowknownastheAlamo,andapresidio,orfort, wereestab
industry,andfromgovernmentagencies,andtheysupport lished. By1731LaVillita,asettlementmadeupofthefami
otherstateagenciesbyreviewingdocumentssuchasenviron liesofSpanishsoldiers,wasbegunnearby. SanAntoniode
mentalimpactstatementsandminepennitapplications. Bexar,thefirstcivilsettlementinTexas,wasalsoestablished
Toaccomplishitsmissionsofbasicandappliedresearch in1731.
andtheacquisitionanddisseminationofinfonnation,BEG SanAntoniowasoncethecapitaloftheSpanishprovince
hasongoingstudiesinenergyandmineralresources,envi ofTexas.HeretheSpaniardsexpendedtheirgreatesteffortin
ronmentalandcoastalstudies,geologicmapping,hydrology, missionaryworkwithnativeIndians. FourmissionsinSan
geochemistry,andbasinanalysis. Fundingforthesestudies Antonioarestillbeingused.
isfromtheTexasLegislature,theUniversityBoardof In1836theAlamobecamethefocusofTexasliberty
Regents,StateandFederalagencies,privatefoundations, whenasmallbandofdefendersfoughttothedeathagainst
andindustrialassociates. attackingMexicantroops,whosenumbers.havebeenesti
ResearchsupportatBEGisprovidedbyahighlytrained matedat2,000to5,000. Amongthemenwhodiedatthe
professionalstaffthatincludescartographers,computer AlamowereAmericanfolkheroesDavyCrockett,JimBowie,
scientists,andeditors. Facilitiesandequipmentsupporting andWtlliamTravis.
researchandreportpreparationincludeanin-houseVAX InadditiontotheinfluenceoftheSpanishandAnglo
11nSOcomputerwithanetworkofmorethan100tenninals Saxons,Gennanimmigrantshavemadetheirpresencefeltin
anddirectaccesstoallUTcampuscomputers,andaMineral SanAntonio. AfterthebattleoftheAlamotheareawas
StudiesLaboratorythatincludesstableisotopeandcoallabor abandoneduntilthe1840's,whenGennanimmigrants
atoriesandamodemarmyofanalyticalinsnuments,including resettledinSanAntonio. Foratimestteetsignsappearedin
anICP,SEM,electronmicroprobe,x-raydiffractometer,and Spanish,English,andGennan.
asedimentanalyzer. TodaySanAntonio,withitsoldSpanishflavor, multi
CentraltoresearchatBEGisthecorerepository,a1 culturedpopulation,andmanyparksandplazas,isoneofthe
hectare(2.5-acre)buildingwithmorethan 160linearkm mostpicturesqueofAmericancities. Someinner-eityareas
(100mi)ofshelves. Ithousesmorethan 100,000cuttings havebeenrestored,includingLaVillita,thecity'soldestresi
and4,000coresfromTexasandadjacentstatesthatwere dentialsection;theRiverwalk,withitsshopsandrestaurants;
acquiredthroughdonations. BEGcoresandsamplescanbe andMarketSquare,featuringaMexicanMaricet(EIMercado).
examinedinwell-equippedcore-layoutfacilities,whichare TheRiverwalkfollowsthepathoftheSanAntonioRiver
heavilyusedbybothindustryandacademicgeologists. asitmeandersitswaythroughthedowntownbusiness
district,twentyfeetbelowstreetlevel. Linedwithlush,
tropicalvegetation,thisdeep-greenwaterwayisthecenterof
SAN ANTONIO itsowncommunity. Whilestrollingalongthecobblestone
paths,youcanfmd anarrayofEuropean-stylesidewalkcafes,
SanAntonioisthethirdlargestcityinTexas,reachinga specialtyboutiques,nightclubs,andrestaurantsthatserve
populationofmorethan920,000peoplein1987. Thecity internationalfoods. NearbyisthereconstructedLaVillita,
occupiesanareaof309squaremilesatthejunctureofthe withlocalartistssellingwaresanddemonstratingcraftsin
GulfCoastalPlainandtheTexasHillCountry. restoredhistoricstonehouses.
T173: 4
GEOLOGIC SETTINGS OF LIGNITE IN THE WILCOX GROUP
OF EAST-CENTRAL TEXAS AND THE JACKSON GROUP
OF SOUTH TEXAS
W. B. Ayers, Jr.
BureauofEconomicGeology,TIleUniversityofTexasatAustin
INTRODUCTION resourcesand39percentofthedeep-basinresources, andthe
Yeguahosts7percentofthenear-surfaceresourcesandno
LignitehasbeenminedinTexasformorethanacentury. appreciabledeep-basinresources. Anindividuallignitemine
Intheearly1900's,productionwasprimarilyfrom vertical typicallycommandsaresourceblockof50to500milliontons
shaftandslopemines,andthelignitewasusedforsteam oflignitethatiscontainedinoneortwoseamsaveraging 1.5
generationinstationaryboilersatcottongins,compresses, to4.5m(5 to 15ft) thick. Inunusualcases,twoormore
andothersteam-drivenplants. Annualproductioninthefirst seamsmaymergetofonn aseammorethan6.1 m(20ft)
halfofthecenturypeakedat1.3millionmetrictons(t)(1.5 thick;attheotherextreme,riderseamsasthinas36cm
millionshorttons[tons])inthemid-1920's. Withthedis (14in)arealsomined(Kaiser, 1985). In1987,88percent
coveryofinexpensiveoilandgasandthedevelopmentofthe oftheannualproductionwasfrom theWilcoxGroup,which
internalcombustionengine,ligniteproductiondeclined, has 10lignitemines, and 12percentwasfrom2minesinthe
reachingalowoflessthan 18,144t(20,000tons)in 1950. JacksonGroup. TherearenoactiveYeguamines.
Inthe 1970's,increaseddemandforelectricity,coupled Onthebasisofregionalaverages,thehighestquality
withincreasedoilandgasprices,focusedattentiononlignite Texaslignite,Wilcoxlignite,averages32percentmoisture,
as animportantsourceofenergy,triggeringamajorepisode 15percentash, 1percentsulfur,and3,555kcal/kg(6,400
ofexplorationandexploitation. Texasligniteproductionhas Btu/lb),asreceived(Kaiseretal., 1980). Yegualigniteis
increasedsteadilyfromlessthan2.3milliont(2.5million intennediateandJacksonligniteispoorestquality,thelatter
tons)in 1970to45.6milliont(50.3milliontons)in 1987 having35percentmoisture,24percentash, 1.5percent
(RailroadCommissionofTexas,unpublisheddata, 1988), sulfur,and2,666kcal/kg(4,800Btu/lb). Heatingvalueof
makingTexastheleadingproducerofligniteandoneofthe Texaslignitevariesinverselywithashcontent,havinga
top 10coal-producingstates. correlationcoefficientof-0.98(Tewalt, 1986). Organic
Today, 12ligniteminessupplyfuelto9powerplantsthat sulfur,whichmakesupabout70percentofthetotalsulfurin
generateapproximately20percentofTexas'electricity Texaslignite,isalsohighestinJacksonlignites(1.3percent)
(Kaiser, 1985). ModemligniteminesinTexasarelarge andlowestinWilcoxlignites(0.60percent)(Tewalt, 1986).
surfaceminesthatprovidelignitetofuelmine-mouthpower StratigraphicvariationsinthesulfurcontentofTexaslignite
plants. Themostcommonmethodofsurfaceminingis seamshavebeenattributedtodepositionalsetting.
draglinesidecasting,butothermethods,suchascompact
bucket-wheelexcavatorandcross-pitspreader,arebeing
introducedtomeetchangingoruniqueminingconditions. DEPOSITIONAL SETTING
DepositionalsettingsofTexaslignitesareinferredfrom
RESOURCES AND QUALITY relationshipsbetweenthedepositionalframeworkfacies, as
delineatedonlithofaciesmaps,andtheoccurrenceoflignite,
InTexas,economicligniteseamsoccurinthelower shownonisoplethmaps. Theframework facies, orskeletons
TertiaryWilcoxGroup,YeguaFonnation,andJackson ofdepositionalsystems,arecomposedofthecoarsestgrained
Group, whichcropoutinthecoastalplain(Figures 1and2). terrigenousclasticsedimentsandweredepositedbythehigh
Texasligniteresourcesarereportedbydepthasnearsurface estenergytransportprocessesactingwithinthesystem(e.g.,
(6to 61 m [20to200ftl) ordeepbasin(61 to 610m [200to channel-fillsandinafluvialsystem). Frameworkfacies are
2,000ftl). Near-surface resources inseams0.9m(3 ft) or delineatedbyconventionalnet-sandandpercent-sandmaps,
thickerare21.2billiont(23.4billiontons)(Kaiseretal., aswellasbymaximum-sand(singlethickestsand)andmajor
1980). Deep-basinresourcesinseamsthickerthan1.5m(5 sandmaps(sandsgreaterthan 12m[40ftl thick)(Kaiseret
ft) are46.2billiont(50.9billiontons)(Kaiseretal., 1980; al., 1978; AyersandLewis, 1985).
AyersandLewis, 1985;KaiserandJackson,inprep.) The Ligniteisacomponentofthenonfnuneworksedimentary
WilcoxGroupcontains71percentofthenear-surfacere facies, whicharethosedepositedmarginaltotheframework
sourcesand61 percentofthedeep-basinresourcesinTexas. faciesbylow-energyphysicalprocessesorbybiological
TheJacksonGroupcontains22percentofthenear-surface processes. Withinafluvialsystem,forexample,floodbasin
T173: 5