Geology of the Western Great Smoky Mountains Tennessee
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Geology of the Western Great Smoky Mountains Tennessee GEOLOGICAL SURVEY PROFESSIONAL PAPER 349-D Geology of the Great Smoky Mountains Tennessee and North Carolina GEOLOGICAL SURVEY PROFESSIONAL PAPER 349 This volume was published in separate chapters, A D Geology of the Western Great Smoky Mountains Tennessee By ROBERT B. NEUMAN and WILLIS H. NELSON GEOLOGY OF THE GREAT SMOKY MOUNTAINS, TENNESSEE AND NORTH CAROLINA GEOLOGICAL SURVEY PROFESSIONAL PAPER 349-D Interpretation of geologic history from late Precambrian on, based on mapping in and around the western part of the Great Smoky Mountains National Park UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1965 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 CONTENTS Page Page Abstract______-------_---_-_______________ Dl Devonian System.______________________-----------_ D40 Introduction ________________________________ 2 Upper Devonian Series._________________________ 40 Location.._ ___-___-___--_--_____________ 2 Chattanooga Shale__________________________ 40 Geography._____________________________ 3 Mississippian System-___________-__-___---_---__--_- 41 Physiography _______________________ 3 Lower Mississippian Series_______________________ 41 Human geography ___________________ 3 Grainger Formation.._______________________ 41 Fieldwork_ __ __________________________ 4 Upper Mississippian Series_______________________ 42 Acknowledgments- _____------____________ 4 Greasy Cove Formation. ___________ _________ 42 Nature and extent of exposures..______________ 4 Greasy Cove and Grainger Formations, undiffer- Structural framework._______________________ 5 entiated _____________________________________ 44 Metamorphism. _ ____________________________ 5 Structural geology-_____________-_______---_-------- 45 Later Precambrian rocks.___________________ 5 Rocks beneath Great Smoky fault________----_-__ 45 Ocoee Series.-_________________________ 5 Great Smoky Group.________________ 6 Syncline north of Chilhowee Mountain. _______ 45 Elkmont Sandstone._____________ 7 Guess Creek fault._____________-_--_------_ 45 Snowbird Group.____________________ 9 Rocks between Guess Creek and Great Smoky Metcalf Phyllite_________________ 9 faults._-__________-____-___----__------- 47 Unclassified formation of Ocoee Series __ 10 Overridden rocks of the windows.____________ 47 Cades Sandstone_______________ 10 Great Smoky fault__________________-___---__-_- 51 Walden Creek Group_________________ 14 Chilhowee Mountain structural block_____---____ 55 Licklog(?) Formation_____________ 14 Miller Cove fault________ -______- __ --- 56 Wilhite Formation.______________ 14 Rocks between Miller Cove and Rabbit Creek faults. 57 Sandsuck Formation _____________ 22 Rabbit Creek fault_.._-______-__.--------------- 59 Cambrian and Cambrian (?) rocks. _____________ 23 Rocks between Rabbit Creek and Oconaluftee faults. 60 Chilhowee Group.___-__------___________ 23 Oconaluftee fault-______________________----__-- 62 Cochran Formation __________________ 23 Nichols Shale-_______________________ 25 Rocks above Oconaluftee fault___________________ 63 Nebo Quartzite-__-------____________ 26 Interpretive summary.______________________________ 63 Murray Shale._______________________ 27 Reconstruction of Ocoee basin of sedimentation ____ 63 Hesse Quartzite-____________________ 27 Sedimentation of Ocoee Series._____________--_--- 66 Helenmode Formation._______________ 28 Elkmont and Cades Sandstones.______---_-_-_ 66 Age of the Chilhowee Group __________ 29 Metcalf Phyllite---------------------------- 67 Shady Dolomite____---_---______________ 29 Wilhite Formation._____________.-_____----- 67 Rome Formation-_______________________ 32 Summary __ _ __________________----___----_- 67 Missing interval______________________________ 33 Later Paleozoic time____________________________ 68 Ordovician System..__________________________ 33 Lower Ordovician Series._________________ 33 Time of folding, metamorphism, and faulting-______ 68 Knox Group Jonesboro Limestone. 33 Surficial geology and post-Paleozoic history.___________ 69 Middle Ordovician Series__________________ 34 Valley and Ridge province.---------------------- 69 Lenoir Limestone.___________________ 35 Outliers of the Valley and Ridge province the coves__ 71 Blockhouse Shale.____________________ 35 Tuckaleechee Cove_____________-__---------- 71 Tellico Formation...__________________ 36 Cades Cove_________________-__-_------_--- 73 Chota Formation.___________________ 37 Miller Cove-- -_ _ -- -- - 73 Sevier Formation.___________________ 38 Blue Ridge province______________ ------------ 74 Bays Formation.____________________ 38 Tellico Formation and Blockhouse Shale, Post-Paleozoic history-._________-______---_----_ 75 undiff erentiated ___________________ 39 References cited-______________________---_--------- 76 Correlation of Middle Ordovician Series. 40 Index._.._..-._..._._._.____-_____-_------_------_ 79 IV CONTENTS ILLUSTRATIONS [Plates are in pocket] PLATE 1. Shaded relief map of the western part of the Great Smoky Mountains showing physiographic subdivisions. 2. Geologic map, sections, and inset map of the western Great Smoky Mountains and vicinity. 3. Geologic map of the Kinzel Springs quadrangle. 4. Structure sections of the Kinzel Springs quadrangle. 5. Geologic map and structure sections near Walker Hollow. 6. Structure contour map of the Great Smoky fault surface. Page FIGURE 1. Index map___---_-__-_-________-_--_-__--_-_----_--___-______--__-______________ D2 2. Map showing generalized geology and biotite isograd_________________________________ 6 3. Cades Sandstone_______________________________________________________________ 11 4. Wilhite Formation_______________-______--______----______-_-__________-_________ 16 5. Sedimentary structures in fine-grained rocks interbedded with conglomerate of the Wilhite Formation_____________________________________________________________________ 18 6. Columnar section of Shady Dolomite.___--_-__--------__-_-___---_______-__-____-__ 30 7. Correlation of Middle Ordovician rocks__---___--------____-------_________-__-_____ 40 8. Block diagram showing geologic interpretation at the northeast end of Mississippian outcrop belts, Kinzel Springs quadrangle._-_-_-_--_-_-___---_______-----________-___----_ 46 9. View of Little River Gap________-_-____---____------__-_-_-----_________-_-_--__- 47 10. Geologic map of rocks beneath Great Smoky fault in Tuckaleechee Cove window-------- 49 11. Geologic sketch of Cedar Bluff_______-_-_______-__------_-_______________________ 50 12. Geologic section of High Top______________________________________________________ 50 13. View of Cades Cove_______-.___ ______--__-_--___.._--_____-____-_____-_________. 52 14. Structural features.__-___---_______-____-_____-_----_--____--_-__________________ 53 15. Geologic sections showing alternative projections of rocks overridden by the Great Smoky fault.__------___-_-_----___-__-_-----__----_-------------_--_---___--________ 54 16. Geologic sketch of folds in the Wilhite Formation..__________________________________ 57 17. Section showing idealized relations between arched surface of Great Smoky fault and cleavage __--______-_----_______-____________----_____--__---__________________ 58 18. Restored section showing relative positions inferred for the major units of the Ocoee Series and related rocks and the positions of faults that dismembered them _________________ 65 19. Map of parent materials of soils in the southeastern quarter of the Kinzel Springs quad rangle. _______________________________________________________________________ 72 TABLES Page TABLE 1. Temperature and precipitation at Gatlinburg, Tenn___-_-_________-_-____. D4 2. Correlation of formations of the Chilhowee Group in Tennessee and Virginia- 24 GEOLOGY OF THE GREAT SMOKY MOUNTAINS, TENNESSEE AND NORTH CAROLINA GEOLOGY OF THE WESTERN GREAT SMOKY MOUNTAINS, TENNESSEE By ROBERT B. NEUMAN and WILLIS H. NELSON ABSTRACT suck Formation, the uppermost formation of the Walden Creek Rocks of the Great Smoky Mountains, a part of the Blue Group of the Ocoee Series; the contact between the Cochran Ridge province, have been thrust northwestward over younger and the Sandsuck appears to be conformable in this area. more easily eroded rocks of the Valley and Ridge province along Southeast of the Chilhowee Mountain sequence, the upper the Great Smoky fault. plate of the Great Smoky fault is cut into three principal The overridden rocks in a nearly homoclinal sequence north blocks by thrust faults that obscure original relations of the west of the fault are also exposed in windows eroded through Ocoee Series. Folds and faults in all three blocks are complex. its upper plate farther southeast. The homoclinal sequence Metamorphism has altered most of the fine-grained rocks to consists of Lower Ordovician to Mississippian rocks. The slates and phyllites, and biotite appears in the southeastern Mississippiau rocks, about 1.500 feet thick, are limestone, shale, part of the area. and sandstone of the Greasy Cove Formation and siltstone, The northwesternmost of these three blocks contains parts of sandstone, and conglomerate of the Grainger Formation. The the Walden Creek Group, the Wilhite Formation for the most Chattanooga Shale represents the uppermost part of the De part, and possibly a small part of the Licklog Formation. The