STATE OF TENNESSEE DEPARTMENT OF ENVIRONMENT AND CONSERVATION DIVISION OF GEOLOGY BULLETIN 58, PART II Geologic Map of East Tennessee With Explanatory Text Compiled by JOHN RODGERS Geologist, U. S. Geological Survey with the Collaboration of Geologists of the Tennessee Division of Geology Tennessee Valley Authority and United States Geological Survey Prepared under the Joint Auspices of the United States Geological Survey and the Tennessee Division of Geology Nashville, Tennessee 1953 Reprinted 1993 STATE OF TENNESSEE FRANK G. CLEMENT, Governor DEPARTMENT OF CONSERVATION Jim McCORD, Commissioner DIVISION OF GEOLOGY W. D. HARDEMAN, State Geologist 1993 STATE OF TENNESSEE Ned McWherter Governor DEPARTMENT OF ENVIRONMENT AND CONSERVATION J. W. Luna Commissioner DIVISION OF GEOLOGY Edward T. Luther State Geologist CONTENTS Page Abstract…………………………………………………...…………………………………………………1 Introduction ………………………………………………………...……………………………………… 3 Area covered by present map…………………………………………………………………...…………. 3 Compilation of the map ……………………………………………………………………………………. 3 Map units…………………………………………………………………………………………………… 6 Acknowledgments……………………………………………………………………………………….…. 8 Physical geography …...........…………………………………………………………........................…… 11 Regional setting .........................…............…………………………………………………….…. 11 Unaka Mountains .............................................……………………………………………….….. 11 Valley of East Tennessee ........................................………………………………………………. 14 Cumberland Plateau ..............................……………………………………………………….…. 16 Erosion surfaces ................................................………………………………………………….. 17 Description of rock units .............................................……………………………………………….…… 21 Pre-Cambrian crystalline complex …………………………………...............................…….….. 21 Mount Rogers volcanic group ….......................................…………………………………..…… 23 Ocoee series ....................................................………………………………………………….… 24 Name, subdivision .........................................……………………………………………. 24 Northeast of Pigeon River ……………………………………………………………..… 24 Southwest of Pigeon River, foothill belt……………………………………………….… 28 Southwest of Pigeon River, mountain belt…………………………………………..…… 31 General remarks………………………………………………………………………...… 33 Unicoi formation and Cochran conglomerate…………………………………………………...… 34 Hampton formation and Nichols shale………………………………………………………..…… 38 Erwin formation and equivalent rocks…………………………………………………………..… 39 Shady dolomite……………………………………………………………………………….….… 42 Rome formation……………………………………………………………………………….…… 43 Conasauga shale or Conasauga group…………………………………………………………...… 47 Name, contacts………………………………………………………………………….… 47 Northwestern phase: Conasauga shale………………………………………………….… 48 Central phase: Pumpkin Valley to Maynardville formations…………………………..… 49 Southeastern phase: Honaker dolomite, Nolichucky shale, and Maynardville limestone………………………………………………………………... 51 Knox dolomite or Knox group…………………………………………………………………….. 53 Name, subdivision………………………………………………………………………… 53 Northwestern phase: dominantly dolomite……………………………………………….. 55 Southeastern phase: dominantly limestone……………………………………………….. 61 Lower and middle parts of Chickamauga limestone and equivalent rocks………………………... 64 Present status of the stratigraphy of the Chickamauga limestone………………………… 64 Belt between the Saltville fault and the Knoxville and Rocky Valley faults (northwest part of Red Belt of Safford)…………………………………………. 68 Belt between the Knoxville and Rocky Valley faults and the Chestuee and Dumplin Valley faults (main Red Belt of Safford)………………………………...72 Belts southeast of the Chestuee and Dumplin Valley faults and of the Saltville fault northeast of Morristown (Gray Belt of Safford and lesser belts to southeast and southwest)……………………………………………….. 76 iii Page Belts between the Saltville fault and the Whiteoak Mountain and Hunter Valley faults (middle belts)…………………………………………………... 82 Belts northwest of the Whiteoak Mountain and Hunter Valley faults (northwestern belts)…………………………………………………………………… 87 Correlation beyond East Tennessee……………………………………………………… 90 Synthesis…………………………………………………………………………………. 92 Upper part of Chickamauga limestone and equivalent rocks…………………………………….. 94 Juniata formation and Sequatchie formation……………………………………………………... 97 Silurian and Lower Devonian rocks……………………………………………………………… 98 Chattanooga shale and other Devonian and basal Mississippian shale…………………………... 104 Grainger formation and Fort Payne chert………………………………………………………… 106 Newman limestone……………………………………………………………………………….. 108 Pennington formation…………………………………………………………………………….. 110 Pennsylvanian rocks……………………………………………………………………………… 113 Paleozoic intrusive rocks…………………………………………………………………………. 114 Unconsolidated mantle…………………………………………………………………………… 114 Residuum………………………………………………………………………………… 115 Locally transported mantle………………………………………………………………. 117 River alluvium…………………………………………………………………………… 118 Minor constituents of the mantle………………………………………………………… 119 Age…………………………………………………………………………………….… 120 Larger structural features………………………………………………………………………………….. 122 Unconformities and facies changes………………………………………………………………. 122 Folds and faults of the Cumberland Plateau and the Plateau front……………………………….. 126 Pine Mountain and Jacksboro faults……………………………………………………... 126 Sequatchie anticline, Emory River line, and related features……………………………. 127 Features along the Cumberland Plateau front……………………………………………. 128 Belt of dominant faulting…………………………………………………………………………. 130 Faults of the Kingston family……………………………………………………………. 130 Faults of the Whiteoak Mountain family………………………………………………… 131 Faults of the Saltville family…………………………………………………………….. 132 Belt of dominant folding…………………………………………………………………………. 134 Pulaski fault block………………………………………………………………………………... 136 Thrust sheets of the Unaka Mountains…………………………………………………………… 139 Folded thrust sheets of northeast Tennessee…………………………………………….. 139 Folded thrust sheets of the French Broad area…………………………………………... 143 Faulted thrust sheets of the Great Smoky Mountains……………………………………. 145 Source materials and outstanding future projects…………………………………………………………. 149 Plate 1, Briceville..……………………………………………………………………………….. 149 Plate 2, Maynardville…………………………………………………………………………….. 149 Plate 3, Morristown………………………………………………………………………………. 150 Plate 4, Greeneville………………………………………………………………………………. 151 Plate 5, Roan Mountain…………………………………………………………………………... 151 Plate 6, Cranberry………………………………………………………………………………… 152 Plate 7, Kingston………………………………………………………………………………….. 152 Plate 8, Loudon…………………………………………………………………………………… 153 Plate 9, Knoxville………………………………………………………………………………… 153 Plate 10, Mount Guyot……………………………………………………………………………. 154 Plate 11, Asheville………………………………………………………………………………... 154 Plate 12, Chattanooga……………………………………………………………………………. 155 iv Page Plate 13, Cleveland………………………………………………………………………..155 Plate 14, Murphy………………………………………………………………………….156 List of outstanding projects for future geologic mapping in East Tennessee……………………………………………………………………………….156 References cited………………………………………………………………………………………….…163 v ILLUSTRATIONS PLATES Page 1-14. Geologic map of East Tennessee…………………………….…see Map Container or Folio 15. Geologic cross sections maps of East Tennessee………………see Map Container or Folio FIGURE 1. Index map to plates of Geologic map of East Tennessee……………………………….….4 2. The north face of the Great Smoky Mountains as viewed from Fighting Creek Gap………………………………………………………………….……………....19 3. Facies relationships in the Conasauga group and equivalent rocks in East Tennessee and southwest Virginia………………………………………………………....46 4. Facies relationships In Middle and Upper Ordovician rocks near the 84th meridian in East Tennessee………………………………………….…....see end of text 5. Main structural features of East Tennessee……………………………………see end of text 6. Index map of source materials used in compiling Geologic map of East Tennessee…………………………………………………………………………....148 7. Index map of projects for future geologic mapping in East Tennessee………………..…157 TABLES TABLE Page 1. Sequences of units used in published folios for the Ocoee series and Immediately overlying rocks……………………………………………………….……...25 2. Subdivisions of the Ocoee series used on present map……………………………………26 3. Formations of the Chilhowee group……………………………………………………….35 4. Formations of the Conasauga group (central phase)………………………………………50 5. Subdivisions of the Knox group used on present map…………………………………….56 6. Subdivisions of Silurian and Lower Devonian rocks used on present map……………….99 vi Geologic Map of East Tennessee With Explanatory Text ABSTRACT A new geologic map of the Unaka Mountains and the Valley of East Tennessee, compiled from all available sources, is presented herewith. The accompanying text describes the rock units shown on the map. The oldest rocks present form a pre-Cambrian crystalline complex, part of the southwest end of the Blue Ridge welt of such rocks. These igneous and metamorphic rocks were already crystalline before the end of pre-Cambrian time, but they were again deformed, with the production of thrust faults and accompanying mylonite zones, at the time of deformation of the overlying Paleozoic rocks. Above this basement complex lies the immensely thick Ocoee series (perhaps 5 miles thick), composed of detrital rocks of graywacke type; these were deposited after the formation of the crystalline complex and may be of late pre-Cambrian age or possibly younger. Overlying the Ocoee series is a sequence of somewhat better sorted detrital