CI 3:77 C 2 North Carolina Department of Conservation and Development Robert L. Stallings, Jr., Director Division of Mineral Resources Jasper L. Stuckey, State Geologist Bulletin 77 Anthophyllite Asbestos in North Carolina by Stephen G. Conrad, William F. Wilson, Eldon P. Allen Division of Mineral Resources and Thomas J. Wright North Carolina State Minerals Research Laboratory Raleigh 1963 North Carolina Department of Conservation and Development Robert L. Stallings, Jr., Director Division of Mineral Resources Jasper L. Stuckey, State Geologist Bulletin 77 Anthophyllite Asbestos in North Carolina by Stephen G. Conrad, William F. Wilson, Eldon P. Allen Division of Mineral Resources and Thomas J. Wright North Carolina State Minerals Research Laboratory Raleigh 1963 MEMBERS OF THE BOARD OF CONSERVATION AND DEVELOPMENT Hargrove Bowles, Jr., Chairman Greensboro Dr. Mott P. Blair, Vice Chairman Siler City John M. Akers Gastonia Robert E. Bryan , Goldsboro Mrs. B. F. Bullard Raleigh Daniel D. Cameron Wilmington Mrs. Fred Y. Campbell Waynesville Dr. John Dees Burgaw William P. Elliott, Sr. Marion E. Hervey Evans, Jr. Laurinburg E. R. Evans Ahoskie Andrew Gennett Asheville Luther W. Gurkin, Jr. Plymouth Woody R. Hampton Sylva Charles E. Hayworth High Point Gordon C. Hunter Roxboro Roger P. Kavanagh, Jr. __ Greensboro R. Walker Martin Raleigh Carl G. McCraw Charlotte Lorimer W. Midgett Elizabeth City Ernest E. Parker, Jr. Southport R. A. Pool Clinton Eric W. Rodgers Scotland Neck Robert W. Scott Haw River James A. Singleton, Jr. __ Red Springs J. Bernard Stein Fayetteville Paul H. Thompson Fayetteville Charles B. Wade, Jr. Winston-Salem ll LETTER OF TRANSMITTAL Raleigh, North Carolina September 25, 1963 To His Excellency, HONORABLE TERRY SANFORD Governor of North Carolina Sir: I have the honor to submit herewith manuscript for publication as Bulletin 77, "Anthophyllite Asbestos in North Carolina", by Stephen G. Conrad, William F. Wilson, Eldon P. Allen and Thomas J. Wright. This report contains the results of a detailed investigation of geology and mineral dressing characteristics of the anthophyllite asbestos de- posits in North Carolina and should be of value to those interested in the economic development of these deposits. Respectfully submitted, Robert L. Stallings, Jr. Director CONTENTS Page Abstract 1 Introduction 1 Location and distribution 1 Purpose of . investigation . 1 Previous work 3 Present investigation 3 Acknowledgments 4 Geography 4 Climate 4 Topography 4 Accessibility 5 Regional geology 5 Rock types 5 Structure and metamorphism 6 Peridotites and related ultramafic rocks 7 Distribution 7 Character and relations 7 Petrography 8 Dunite 8 Saxonite (harzburgite) 8 Pyroxenite 9 Enstatolite 9 Websterite 9 Soapstone 10 Alteration of peridotite 10 Serpentinization 10 Steatitization 11 Amphibolization 12 Chloritization 12 Origin 12 Age 13 Asbestos deposits 14 Mineralogy and geologic occurrence 14 Crysotile 14 Amphibole asbestos 14 Tremolite 14 Actinolite 15 Crocidolite 15 Amosite 15 Anthophyllite 15 Uses 15 Character and classification of North Carolina deposits 17 General statement 17 Cross-fiber veins 17 Slip-fiber veins 17 Mass-fiber deposits 17 Peripheral zones 18 Anthophyllite-enstatite bodies 18 Origin of anthophyllite asbestos 19 History of mining and production 20 Mining methods 21 Reserves 21 Description of mines and prospects 21 Spruce Pine area 21 Avery County 21 Burleson mine 21 Frank mine 22 Other prospects 22 Page Mitchell County 22 J. H. Pannell prospect 22 Soapstone Branch prospect 22 Other prospects 24 Yancey County 24 Blue Rock mine 24 Newdale mine ' 25 J. C. Woody mine 26 Sam Grindstaff mine 26 Gas Thomas prospect 27 C. W. Allen prospect 27 Other prospects 27 Lake Toxaway area 27 Transylvania County 29 Kilpatrick mine 29 Oakland mine 29 Walnut Cove Creek mine 30 Miller mine 30 Jennings No. 1 mine 31 Socrates prospect 32 Other prospects 32 Jackson County 32 Asbestos mine 32 Rattlesnake prospect 34 Brockton mine 35 Bad Creek prospect 35 Jennings No. 2 mine 36 Round Mountain mine 36 Coldsides Mountain mine 36 Harris prospect 37 Glenville-Norton area 37 Bryson-Manus mines 37 Henderson mine 40 Alders mine 40 Holden mine 40 Other mines and prospects 40 Macon County 40 Higdon mine 40 Peterman mine 42 Commissioner Creek prospect 42 Caldwell County 42 Johns River mine 42 Evaluation and Beneficiation 45 Introduction 45 Dry processing 45 Sample 1855A 45 Sample 1855B 45 Sample 1856 45 Sample 1857A 45 Sample 1857B 45 Sample 1858 49 Sample 1859 49 Sample 1872A 49 Sample 1872B 49 Comparison of the plus 28 mesh fiber products 49 Acid leaching and wet processing 50 Conclusions 50 References cited 60 ILLUSTRATIONS Page Figure 1. Geographic distribution of ultramafic bodies in western North Carolina 2 2. Properties of asbestos fibers 16 3. Map showing location of asbestos mines in Yancey County, North Carolina 23 4. Map showing location of asbestos mines in the Brush Creek area, Yancey County, North Carolina 28 5. Map showing location of asbestos mines in the Sapphire Valley area, North Carolina 33 6. Map showing location of asbestos mines in Chattooga Ridge area, Jackson County, North Carolina 38 7. Map showing location of asbestos mines in the Glenville-Norton area 39 8. Map showing location of peridotites in Ellijay Creek area, Macon County 41 9. Map showing location of Johns River asbestos prospect, Caldwell County, North Carolina 43 10. Flowsheet for treatment of asbestos ore 46 11. Flowsheet for low grade, short-fiber ore 50 Table 1. Distribution and composition of products from dry process 47 2. Distribution and composition of products from dry process 47 3. Distribution and composition of products from dry process 48 4. Properties of plus 28 mesh aspirated fiber 48 5. Cleaning re-treatment of aspirated fiber 1857A Screen analysis of + 28 mesh fiber 1858 49 6. Comparison of chemical and mineralogical content of talc and anthophyllite concentrates 49 Plate 1. Photomicrographs of typical anthophyllite asbestos ores and related rocks 53 2. Photomicrographs of typical anthophyllite asbestos ores and related rocks 55 3. Photomicrographs of typical anthophyllite asbestos ores and related rocks 57 4. Geology of the Newdale asbestos mine, Yancey County, North Carolina in pocket 5. Geologic cross-sections of the Newdale asbestos mine, Yancey County, North Carolina in pocket 6. Geology of the Blue Rock asbestos mine, Yancey County, North Carolina in pocket 7. Photographs of typical ore samples; and contact relationships at the Newdale and Blue Rock mines, Yancey County, North Carolina 59 Vll Anthophyllite Asbestos in North Carolina by Stephen G. Conrad, William F. Wilson and Eldon P. Allen ABSTRACT Asbestos deposits in North Carolina are associated with a group of basic magnesian rocks com- monly referred to as peridotites. These rocks range from dunite to soapstone in composition, and are part of a discontinuous belt of ultramafic igneous rocks that traverse the eastern part of North America from east-central Alabama to western Newfoundland. In North Carolina the peridotite belt lies chiefly west of the Blue Ridge in the mountainous section of the State. However, a few isolated bodies occur in the Piedmont section of Burke, Caldwell, Polk, Wilkes and Wake counties. Although various types and quantities of asbestiform minerals can be found in practically all of the individual peridotite bodies throughout the area, the most important commercial deposits occur as anthophyllite asbestos associated with altered bodies in the Toxaway area of Jackson and Transylvania counties and in the Spruce Pine area of Yancey and Avery counties. Based on the arrangement of the fibers in respect to the wall rock and to each other, three types of anthophyllite asbestos ore are recognized. These types are referred to as cross-fiber veins, slip-fiber veins and mass-fiber deposits. Cross-and slip-fiber veins are the most common and are present to some extent in ultramafic bodies that range in composition from relatively unaltered dunite to soapstone. The mass-fiber deposits are divided into peripheral zones associated with partly to thoroughly altered bodies, and small, oval shaped bodies composed mostly of anthophyllite and enstatite. Past production from North Carolina has been mostly from mass-fiber deposits of the peripheral zone type. However, mass-fiber deposits of the anthophyllite-enstatite variety appear to have consider- able potential. The North Carolina State Minerals Research Laboratory determined the physical and chemical properties of nine selected ores and investigated methods of separating the major mineral components by dry and wet benefication processes. INTRODUCTION Location and Distribution highly altered bodies in the Lake Toxaway area of Jackson and Transylvania counties and in the The asbestos deposits in North Carolina are Spruce Pine area of Yancey and Avery counties. associated with a group of basic magnesian rocks, The accompanying map (Figure 1) of a portion commonly referred to as peridotites. These per- of western North Carolina shows the distribution idotites are part of a discontinuous belt that tra- of the main belt of peridotites and related ultra- verses the eastern part of North America from mafic rocks. Owing to the fact that most of the east-central Alabama to western Newfoundland, peridotites are lenticular or oval masses, usually a distance of more than 2,000 miles. In North less than 300 or 400 feet in length, it was neces- Carolina the peridotite belt lies chiefly west of the sary to exaggerate their dimensions