COMMONWEALTH OF VIRGINIA DEPARTMENT OF CONSERVATION AND ECONOMIC DEVELOPMENT DIVISION OF MINERAL RESOURCES GEOLOGY AND MINERAL RESOURCES OF FREDERICK COUNTY Charles Butts and Raymond S. Edmundson BULLETIN 80 VIRGINIA DIVISION OF MINERAL RESOURCES James L. Calver Commissioner ol Mineral Resources and State Geologisl CHARLOTTESVI LLE, VI RGINIA | 966 COMMONWEALTH OF VIRGINIA DEPARTMENT OF CONSERVATION AND ECONOMIC DEVELOPMENT DIVISION OF MINERAL RESOURCES GEOLOGY AND MINERAL RESOURCES OF FREDERICK COUNTY Charles Butts and "'"Raymond S. Edmundson BULLETIN 80 VIRGINIA DIVISION OF MINERAL RESOURCES James L. Calver Commissioner of Mineral Resources and State Geologist CHARLOTTESVILLE, VIRGINIA I 966 Couuorwnlr-trr or VnctNrl Dnp,llruBxt oF PuRctrAsEs eto Suppr-v Rrcrrruorqo 1966 DEPARTMENT OF CONSERVATION AND ECONOMIC DEVELOPMENT Richmond, Virginia MenvrN M. Surrronr,ltNo, Director A. S. Recrrat, J*., Executiue Assistant BOARD Canr,rsr,e H. HunrBr,srNe, Williamsburg, Chairman ANonnw A. Fenr,ov, Danville, Vice-Chairman Joe P. Gn Ls, Roanoke Ar,r,eN M. HBvwenp, Newport News Cr,euor A. Ju,ssue, Jn., Charlottesville Genraxo E. Moss, Chase City Ennu,sr L. Surrrr, Grundy JorrN S. TrronxroN, Culpeper Ancrrrr L. WENnrcH, Hopewell CONTENTS Pecr Abstract 1 qrannage . 5 5 6 9 .'..'....',....'..',.',......''..'.'..'...'.'..'....,....-'.....'..'.......'.....'.'.....'..'.''..'.-.'.',.. l ? 12 o1 2r 24 26 28 Lincolnshire formation ,o r{unourgEdinburg rormatlonformation --. ... ... ....... ......... ......... .. .................. 30 Oranda formation ................. Zz Yartinsbr,rrg formation gs Oswego -formation g6 Juniata formation gB Silurian System ................ r.rr"jroraJor-;i"; ...... ............................... ...................................................... ..... .. .. ;3 Clinton fotr"uii;; -- - " " 4l McKenzie forrrradon ................. $:l.#+A'fi;ffi" - 11 vyrls Lireex lormatlon 46 Tonolow-ay formation 4g ....'. ...'.''.',''.'....'..'..'.. ...' .. '..''''.. 5i Coeymans- ( ?_) limestone 6? Neq Scotland limestone i4 Oriska.ny sa-ndstone 58 Onond.aga formation 61 Hamilton formation 64 Chemu.ng fo-rmation 68 Hampshire formation T0 Missilsippian Pocono (?) formation 71 Structure - yf..rl.lg; !!;tl"- N;;;h iir""l.i"rvrvu'ra'r a'uand associatedassuuraf,eq. slrucrures...........,tr,r"t,r;;; ...... ..... Mt. Pleasant .... 'r?76 syncline -. .':: - " - 86 Great ri ,r M-ountain.. : ^---^- {orth anticli-norium . .. ..... ...'..... ...................................... ............ ;i S.leepy Creek Mountain (Meadow nru".fry ,y".ti;; . .. ;i Cacapon Mountain anticlinorium ............... .................................................... ...... ............ ir6 v Peop Geologic history ............................... 94 Mineral resources 96 Industrial limestones and dolomites 96 High-calcium limestone 96 Impure limestone 97 High-magnesium dolomite 100 Crushed and broken stone...................... 100 Quarries and mines 105 108 CIay, shale, and related rnaterials............ 108 109 Iron ore 113 116 Apoendix I: Discussion of lower Middle Ordovician limestones in Shenandoah '^ Valley, Virginia, by Charles Butts.................... ...... 125 Appendix II: List of fossil names.................... .................... 131 Index 139 vl ILLUSTRAT]ONS Pr-"c,Tn P.ecB G.eologic I map olFrederick County, Virginia ....... ..........In pocket t. lvrap ot structural elements in Frederick County, and generalized struc- ture sections of Little North Mountain................ ........In pocket Frcunr 1. Index map showing_lorarion of Frederick County 2 2. lL- u..s. tttghway Il across a part of r\ortnJ,t"y Nloun(aln......... the valley belt to Great 2 6 View of Great Noith M|""i"i" ....... ........................... 7 4. View of the even crest of Little North Mountain... 5. X;y+i"iiii;;'^fi"d Jr unop petricoar G"p .:..... I 6. unnxry sltrceous lamrnae tn the upper part of the Conococheague Iimestone 7. Mudcracks 'zo t" tt co"l.o"h;;il;"New i.;;;;;i;, ......"..... ....................... ............. .... Sharp boujrdary "between the Market ;A ii;;;l;;hir" ti-"ri|"", ig 9. 10. Bedding in Martinsburg shale cut by ... .. gs 11. uswego "l"""ug;....................... -conglome.rate Z7 12. Cross-bedded Juniata sandstone Short Mountain underlain by steeply dipping Tuscarora ,u"art""" .. ....... 40 r+. Fall,Run,.o.ccupying a narrnw chinneliir tfre Keefer.."Jrt"""--,................ iS 15. Small antrcline in the Bloomsburg red beds......"...... 45 16. ChertyNew Scotland limestone aid typical cufoia*.h"ii fl";;................... SS 17. View along _the strike of the.Oriskany'sandstone.- 5g iB. Calcareous facies of the Oriskany with several beds oi q";;_;;;bi" 19. Weathered cherty limestone beneath the Oriskany ,unart"""............................ OO 20. 21. Spheroidal,w.eathering in the Hamilton formation.. 66 22. lhrck-bedded sandstone near the top of the Hamilton formation.............. 66 23. Shale .and very fine-grained, thinibedded sanJstone of the Si;lfi"; 2+. Sqrall anticlin" il ;h; i;;;; ;; ;i ih; B;uiii", io.-"tion ........ .... .. .. 73 25. Minor folding in the New Market and Lincolnshire 1imestones........................ iZ 26. Sllurlan sandstone in Fawcett cap showing faulted contact with the Martinstrurg shale and the Marcellus sha1e.....i................ 7+ 27. TABLES P.q,cn 1. Stratigraphic,nomenclarure used iri this report and in adjacent Morgan (or). and Berkeley counties, West Virginia - . ..................................... l4 2" uhemrcal.composition of the New Market limestone at selected bcalities J- Ana.lyses ol i-m_pure limestones at selected localities in Frederick countv 101 t. Analyses of dolomite at selected localities in Frederick County... .. tO+ Physical.test da-ta,at two selected localities in Frederick Cr""tv....................... iOS 6" Potential use erf clay materials from Frederick County............ ... ... 110 vl1 GEOLOGY AND MII\ERAL RESOURCES OF FREDERICK COUNTY By Crrenr,rs Burrsl AND RAyMoNo S. EonruNosox2 ABSTRACT Frederick County occupieS about 433 square miles in northern Virginia and lies wholly within the Valley and Ridge province of the Appalachian Highlands. Southeast of Little North Mountain is a broad lowland, a segment of Shenandoah Valley, which is underlain by Cambrian and Ordovician limestone and shale. The northwestern part of the counfy is characterized by northeastward-trending ridges, some of large size, and intervening valleys. Here the exposed srrara, ranging in age from Late Ordovician to Early Mississippian, consist mainly of sandstone and shale with minor amounts of limestone. The aggregate thickness of the sedimentary sequence is estimated at 22,000 feet. The present attitude of the rocks is related to Iate paleozoic orogeny. In the eastern part of the county the symmetry of the folds in response to the compressive forces from the east is shown by the oversteepened and locally overturned east limbs of synclines and west limbs of dnticlines, and by the easterly dip of the thrust faults that cut some of the major folds. To the northwest faults are less common, and the folds are more open and less overturned. Minor folding, faulting and cleavage are well displayed in a few exposures of incompetent soft shales and thin-bedded Iimestones and sandstones. In the past, manganese ore and iron ore have been mined in Frederick county. Mineral resources of economic importance which are being produced and processed at the present time include limestone and dolomite, silica sand, and clay and shale. INTRODUCTION LocerroN arNo Srze or.Anee Frederick county covers an area of about 433 square miles in the northern part of Virginia (Figure 1). virginia counties bordering tg+0. -tOeceased.2Department of Geology, University of Virginia, Charlottesville. VrnerNre Drvrsror or MrNBner. Rrsouncps Frederick are Clarke on the east and Warren and Shenandoah on the south. Adjoining West Virginia counties are Berkeley and Morgan on the northeast and Hampshire and Hardy on the northwest. The maxi- mum length of the county, measured from Cacapon Mountain southward to U. S. Highway 11 at Cedar Creek, is 32 miles. The base map (Plate 1) used in this report is a composite of parts of the Capon Bridge, Gerrardstown, Middletown, Winchester and Wardensville topographic sheets of the U. S. Geological Survey. Winchester, the county seat, is located near the intersection of latitude 39' 10' N. and longitude 78' lU w. Figure l. Index map showing location of Frederick County. PneseNr INvosrrceuoN This report, prepared primarily for the residents of Frederick County, includes a discussion of the general geology, stratigraphR geologic struc- ture, aQd mineral resources. The geologic history that gave rise to the present land forms and the origin of the rocks and minerals are discussed briefly. The results of other investigations, including published maps and reports, have been drawn upon freely in preparing this report. The geologic map (Plate 1) shows the distribution of the various rock types (formations) and geologic structure. The use of this map, structure sections, and the accompanying descriptions in the text should give a better understanding of the natural resources and serve as a basis for more detailed exploration and testing. Orrrnn INvosucerroNs Roberts (1942) speaks of William Barton Rogers as being so closely identified with the foundations of geology in Virginia, his adopted State, Gnor,ocv or Fnroonrcx CouNrv 3 that he overshadows all other students during the period from 1835 to 1880. Butts refers specifically