Geologic Map of the Great Smoky Mountains National Park Region ... ?· Geologic Map of the Great Smoky…

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  • U.S. Department of the InteriorU.S. Geological Survey

    Prepared in cooperation with the National Park Service

    Geologic Map of the Great Smoky Mountains National Park Region, Tennessee and North Carolina

    By Scott Southworth, Art Schultz, John N. Aleinikoff, and Arthur J. Merschat

    Pamphlet to accompany

    Scientific Investigations Map 2997Supersedes USGS Open-File Reports 03381, 20041410, and 20051225

    2012

  • U.S. Department of the InteriorKEN SALAZAR, Secretary

    U.S. Geological SurveyMarcia K. McNutt, Director

    U.S. Geological Survey, Reston, Virginia: 2012

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    Suggested citation:Southworth, Scott, Schultz, Art, Aleinikoff, J.N., and Merschat, A.J., 2012, Geologic map of the Great Smoky Moun-tains National Park region, Tennessee and North Carolina: U.S. Geological Survey Scientific Investigations Map 2997, one sheet, scale 1:100,000, and 54-p. pamphlet. (Supersedes USGS Open-File Reports 03381, 20041410, and 20051225.)

    ISBN 978-1-4113-2403-9

    Cover: Looking northeast toward Mount Le Conte, Tenn., from Clingmans Dome, Tenn.-N.C.

    http://www.usgs.govhttp://www.usgs.gov/pubprodhttp://store.usgs.gov

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    Contents

    Introduction ....................................................................................................................................................1Previous Investigations.................................................................................................................................1Methodology ...................................................................................................................................................3

    Field Mapping .......................................................................................................................................3Digitization and Base Map ..................................................................................................................3

    General Geologic Setting and Physiography ...........................................................................................3Introduction............................................................................................................................................3Central Blue Ridge Province ..............................................................................................................3Highlands of the Western Blue Ridge Province ..............................................................................3Foothills of the Western Blue Ridge Province .................................................................................4

    Northern Foothills ........................................................................................................................4Central Foothills............................................................................................................................5Southern Foothills ........................................................................................................................5

    Tennessee Valley of the Valley and Ridge Province .......................................................................5Rocks of the Central Blue Ridge Province .................................................................................................5Rocks of the Highlands of the Western Blue Ridge Province ................................................................5

    Mesoproterozoic Basement Complex ...............................................................................................5Paragneisses ................................................................................................................................7

    Ultramafic Rocks .................................................................................................................8Amphibolite ..........................................................................................................................9Hornblende-Biotite Gneiss ..............................................................................................10

    Orthogneisses.............................................................................................................................10Migmatitic Biotite Gneiss ...............................................................................................10Spring Creek Metagranitoid ...........................................................................................10Metamonzogranite ..........................................................................................................11Mylonitic Monzogranite ..................................................................................................11Megacrystic Metagranite ..............................................................................................11Metagranodiorite .............................................................................................................11Biotitic Porphyritic Metagranitoid ................................................................................11

    Neoproterozoic Ocoee Supergroup ................................................................................................12Introduction.................................................................................................................................12Snowbird Group .........................................................................................................................12

    Introduction .......................................................................................................................12Wading Branch Formation ..............................................................................................12Longarm Quartzite ............................................................................................................12Roaring Fork Sandstone ..................................................................................................12Pigeon Siltstone ................................................................................................................13Metcalf Phyllite .................................................................................................................13Rich Butt Sandstone .........................................................................................................13

    Great Smoky Group ...................................................................................................................14Introduction .......................................................................................................................14Elkmont Sandstone ...........................................................................................................14

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    Thunderhead Sandstone .................................................................................................14Cades Sandstone ..............................................................................................................15Anakeesta Formation .......................................................................................................15Copperhill Formation .......................................................................................................16Wehutty Formation ..........................................................................................................17Grassy Branch Formation ................................................................................................17Ammons Formation ...........................................................................................................17Dean Formation .................................................................................................................17

    Rocks of the Murphy Belt .........................................................................................................17Tusquitee Quartzite and Nantahala Formation ............................................................17

    Intrusive Rocks ....................................................................................................................................18Metadiorite, Metadiabase, and Altered Rocks .....................................................................18Pegmatite ....................................................................................................................................18Trondhjemite ...............................................................................................................................19Vein Quartz .................................................................................................................................19

    Rocks of the Foothills of the Western Blue Ridge Province .................................................................19Neoproterozoic Walden Creek Group .............................................................................................19

    Introduction................................................................................