GEORGIA STATE DIVISION OF CONSERVATION DEPARTMENT OF MINES, MINING AND GEOLOGY GARLAND PEYTON, Director THE GEOLOGICAL SURVEY Bulletin Number 53 TALC DEPOSITS OF MURRAY COUNTY, GEORGIA By A. S. FURCRON Assistant State Geologist and KEFTON H. TEAGUE Associate Geologist Tennessee Valley Authority MINERALOGY OF TALC DEPOSITS By JAMES L. CALVER Associate Geologist Tennessee Valley Authority Published in Cooper~tion with the Tennessee Valley Authority ATLANTA 1 9 4 7 ..... Southwestern end of the Cohutta Mountains in Georgia, looking east from a point at the western edge of Chatsworth; Fort Mountain on left; Cohutta Mountain on right. Talc ia mined from a aeries of deposita which occur along the western aide of these mountains. LETTER OF TRANSMITTAL Department of Mines, Mining and Geology Atlanta,· April 3, 1947 To His Excellency, M. E. Thompson, Governor Commissioner Ex-Officio, State Division of Conservation Sir: I have the honor to submit herewith Georgia Geological Survey Bul­ letin No. 53, "Talc Deposits of Murray County, Georgia," by Dr. A. S. Furcron, Assistant State Geologist, Kefton H. Teague, and Dr. James L. Calver, Associate Geologists of the Tennessee Valley Authority. This -.:eport has been prepared and published in cooperation with the Tennes­ see Valley Authority. This bulletin is a detailed report upon a long established mineral industry. It presents a complete review of structural, stratigraphic and petrologic problems of the districts which are involved in the economics of the talc. Detailed mine maps have been correlated with surface and subsurface structure. The results of this work indicate that our talc de­ posits are the most extensive in the Southeastern states. The report offers numerous suggestions on improvement of mining methods which would lead to increased production; also it shows that many prospects of the district may be developed into mines. A geologic map is submitted which shows distribution of Fort Mountain gneiss which contains the talc deposits. It is believed that this map will prove quite helpful to those who may prospect for new deposits in the future. It is desired, too, to point out the value of cooperation such as the Tennessee Valley Authority has contributed in this instance. Undoubtedly it would not have been practicable for this department of the State Government to have undertaken this project alone. The cooperation of the Regional Products Research Division, Commerce Department, Tennessee Valley Authority, has provided the technical personnel con­ sidered necessary to supplement our own staff in condu~ting a special field project and the publication of this report, thus enabling us to pre­ sent a publication which, in itself, is in this instance an accomplishment which would not ordinarily have been considered a part of our regular routine. Very respectfully yours, GARLAND PEYTON Director. v CONTENTS ABSTRACT --------------------------------------------------------------------------- 1 FIELD WORK AND ACKNOWLEDGMENTS-------------------- 2 PREVIOUS GEOLOGIC WORK----------------------------------- -------- 3 INTR 0 D U CTI 0 N ---------------------------- ·--------------------------. __________ 3 Location and Accessibility ------------------------------------------------ 3 Physiography --·--------------------------------------------- ____________________ 4 STRATIGRAPHY AND PETROLOGY INTR 0 D U C TI 0 N ------------------------------------------------------------------ 5 PRE-CAMBRIAN ROCKS ---------------------------------------------------- 6 Cohutta Schist ------------------------------------------------------------------- 6 Dis tri b uti on -------------------------------------------------------------------- 6 Lithologic Character ------------------------------------------------------ 7 Origin and Geologic Age ---------------------------------------------- 7 Fort Mountain Gneiss -------------------------------------------------------- 9' Distri b uti on ____ : _____________________________________________________ :_________ 9' Lithologic Character ---· -------------------------------------------------- 1 0· Relation to Cohutta Schist -------------------------------------------- 11 Origin and Geologic Age -------·------------------~------------------- 12 Cor bin Granite -----------------------·-------------------------------------------- 12 D istrib uti on ______________________________ -------------------------------------- 12· Lithologic Character ---------------------------------------------------- 13 Relation to Enclosing Rocks -----·---------- ________________________ 13 Origin and Geologic Age ------------------------------------------------ 14 Micro cline Dikes ------------------------------------------------------------ 14 Distribution ------------------------------------------------ __ ___ __________ 14 Lithologic Character --------------------------··----------------------- 14 Origin and Geologic Age -------------------------------------------- 16 PALE 0 Z 0 IC R 0 C KS ------------------------------------------------------------ 16 Ocoee Series -----------··---------------------------------------------------------- 16 Definition and Interpretation -------------------------------------- 16 Distribution _______ ------------------------------------------------------------- 18 Lithologic Character ------------------------------------------------------ 18 Origin and Geologic Age --------------------------------------------- 19 Wilhite Slate ____________________ -------------------------------------------------- 21 Rome Forrna ti on -------------------------------------------- ____________________ 2 2 D istri b uti on ____________________ ------------------------------------------------ 2 2 Lithologic Character --------------------------------------~------------- 2 2 Geologic Age ---· ________________________________ ------------------------------ 2 2 Conasauga Formation _____ ---------------------------------------------- ____ 2 3 · Distribution -------------------------------------------------------------------- 2 3 Lithologic Character ____ ---------~------------------------------ ·--------- 23 Geologic Age _____________________________ -------~----------------------- __ ____ 2 3 Knox Do lomite ___________________ -------------------------------··--------------· _ 23 Distribution ___ c____________________________________________________________ ____ 2 3 Lithologic Character __________ ~--------------------- ---------------------- 2 4 Geologic Age ---------------------------------~-------- ---- ---------------- 24· STRUCTURE ---------- -------------------------------------- ------------------------ 24 VII MET A MORPHISM ---------------------------------------------------------------- 2 5 TALC DEPOSITS GENERAL PROPER'TIES OF TALC -----------"------------------------ 27 WORLD DISTRIBUTION OF TALC ------------------------------------ 28 'TALC DEPOSITS OF MURRAY COUNTY ------------------------ 30 · Distribution of Deposits ---------------------------------------------------- 3 0 VariE:ltie.S of Talc in Murray County -------------------------------- 30 Uses -------------------------------------------------------------------------------------- 3 2 Chemical Analyses ----------------------------------------------------------- 34 Pro d u ction -------------------------------------------------------------------------- 3 5 Structural Features of the Talc Deposits ------------------------ 37 Mineralogy of Talc Deposits ----------------------""-"------~----------- 38 Crayon Talc ---------------------------------------~-----~-~------------------- 40 White- Grinding Talc -------------------"--~"----------"----------------- 40 Dark Grinding Talc ------------------------------------------------------ 41 Genesis of Murray County Talc Deposits ________________________ 41 Description of Mines and Prospects ___ :____________________________ 44 Georgia Mine ----------------------------~-"'--"---------------------------- 44 South ern Mine -------------------"-----------------------~-------------------- 4 5 Cohutta Mine ---------------------------------------------------------------- 48 Fort Mountain Mine ------------------------------------------------------ 4 9 Other Mines and Prospects ---------------------"-------------------- 51 Pickering Mine ---------------------~"---------------------"-------------- 51 Rock Creek Road Prospect --"-------------------------------- 52. Chicken Creek Mine -------------------------------------------------- 52 Old C'oh utta Mine ------------------------------------------------------ 52 Bramlet Mine and Prospect -------------·------------------------ 53 Fields Prospect ------------------"--------------------------------------- 54 ~~~1o~~!~o:~e ~:--~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ ~ Latch Prospect -------------------------------"---------------------------- 55 Mill Creek Prospect -------------------------------------------------- 56 Warren Earnest Prospect ------------------------------- 56 Mining -----·--------------------------------------~----------------------------------- 57 Milling ----------------"--------------------------------------------------------------- 59 Future of the Industry -----------------------~------------------------------- 6~ Other Mineral Resources -------------------------------------------------- 6 !I Gold ----------------------------------------------- ----------------~--------------- 6 !:1 Lead and Silver -------------------------------------------------------------- 6 9 FeIds par -------------------------------------------------------------------------