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Pegmatite Deposits of Virginra

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Pegmatite Deposits of Virginra Pleaoc teturn this publication to the Virginia Geologieal Survcy whcn you havc no further uce for it. Postagc will bc rcfundcd. COMMONWEALTH OF VIRGINIA STATE COMMISSTON ON CONSERVATION AND DEVELOPMENT VIRGINIA GEOLOGICAL SURVEY ARTHUR BEVAN, State Geologist Bulletin 33 Pegmatite Deposits of Virginra BY ARTHUR A. PEGAU UNIVERSITY, VIRGINIA 1932 COMMONWEALTH, OF VTRGINIA STATE COMMISSION ON CONSERVATION AND DEVELOPMENT VIRGINIA GEOLOGICAL SURVEY ARTHUR BEVAN, State Geologist Bulletin 33 Pegmatite Deposits of Virginia BY ARTHUR A. PEGAU UNIVERSITY, VIRGINIA 1932 RICHMOND: DrvrsroN or Puncrress .r,xo pnrrnrc 1932 STATE COMMISSION ON CONSERVATION AND DEVELOPMENT Wrr,r-rarw E. Censom, Chairrnatn,, Riverton Cor-BrteN Wontnau, Vice-Chaimnoz, Richmond E. Gnrrnrrn DonsoN, Norfolk Tnouas L. Fenne& Charlottesville JuNrus P. Frsnsunm, Roanoke Len Louc, Dante Rurus G. Rosrnrs, Culpeper Rrcrrenp A. Grr-r-rau, E*ecwtive Secretary and, Treaswrer, Richmond 111 LETTER OF TRANSMITTAL ColttltoNwBALTE oF Vrncrmre Vrncrrre Gpor,ocrcer- Sunvsv ljxrvsnsrtv op VrncrNre Crrenr-o:r:rBsvrr,r-E, Ve., January 16, 1930. To the State Cornrnission on Conservation and, Dezteloprnent: GnNrlplreN: I have the honor to transmit and to recommend for publication as Bulletin 33 of the Virginia Geological Survey series of reports a manuscript and illustrations of a report on the Pegmatite Deposits of Virginia, by Dr. Arthur A. Pegau, Assistant Professor of Geology, University of Virginia, and Survey Mineralogist. This report discusses chiefly the mica and feldspar deposits of economic importance in the Piedmont region. It treats of their dis- tribution, geologic relations, origin, and value. Suggestions are given for prospecting and mining these deposits. Associated minerals of economic value are briefly discussed. This report will be of value to all interested in the mica and feld- spar resources of the State, as well as in the geology of the southern part of the Piedmont province. It should be helpful in directing pros- pecting and mining operations. Respectfully submitted, Anrsun Bevex, State Geologist.. Approved for publication: State Commission on Conservation and Development, Richmond, Virginia, January 16, 1930. E. O. FrpprN, Erecuti've Secretary. CONTENTS Pece. Abstract 1 Introduction 3 Scope of report ------- 3 Field and laboratory work -------- 3 Acknowledgments -------- 3 Location of deposits 5 Topography and drainage 6 General features 6 Amelia-Goochland district 6 Martinsville-Lynchburg district 6 "'"ilr.JT:r#'1rl-------__________-__----------------------------- i ir',t*Til'#:'11'*"i.------------------------------- --,,----------- 13 Emery ----- 10 *ir#::-------------- li Cassiterite ---j:---r-:--:---:--- 11 ' Rare-earth minerals 1l Gems and precious stones ------- li Previous geologic work ----.-- 11 Geology and petrography ---------- 15 General features 15 Wissahickon schist ------- 15 Garnetiferous mica schist 16 General character and distribution ----------- 16 Megascopic character L6 Microscopic character 16 Biotite gneiss 17 'character General and distribution --,-------- 17 Megascopic character L7 Microscopic charactei 17 Hornblende schist - General character and distribution - ------ 18 . Megascopic character 18 Microscopic character 19 Origin and age -------- 19 Quartz monzonite gneiss of the Amelia-Goochland area_'-.------,- 20 General character and distribution ----------- 20 Megascopic character 20 Microscopic character 20 vll vlt1 CoNrBNrs Pecr Chemical composition and classification _____- 2l Origin and age -------- ---___-,-________________ ____________ 22 Moneta biotite-hornblende gneiss Zz Definition 22 Character and distribution ___- ____, 22 Biotite gneiss 23 Megascopic character______, ____ _____ 23 Microscopic character 23 Chemical composition and classification ____,, 24 Hornblende g-neiss _____ Zs Character and distribution _____ ____ -______:_ 25 Megascopic character Zs Microscopic character Zs Origin and age 26 Hornblende metagabbro gneiss ___- 26 ' Character and distribution ___-____ 26 Megascopic character 26 Microscopic character 26 Origin and age _ ___-___ 2Z Hornblende-chlorite metapy.roxenite 27 Character and distribution __- ____-_ _ 27 Megascopic character 2g Microscopic character 2g Origin and age -_______, 2g Leatherwood granite 29 Character and distribution ___ ____ 29 Megascopic character _ Zg Microscopic character 29 Chemical composition and classification - 30 0rigin and age ___- 3l Diabase 31 Character and distribution --___- Megascopic character Microscopic character ----,--------------,- :i Origin and age ____- Pegmatite -_-__ 32 General features __ 32 Mode of occurrence - 32 Texture ------------ ----- Nature of contacts -- Mineral composition -------------------,------------,--------:_ ;; Weathering Structure and metamorphism -____-__ _ 42 Origin and paragenesis ___- 42 Age -------- Economic geology of individual areas____________. 50 General statement 50 ConrBmrs lx Pece Ameliaarea-- - 50 Location and accessibility -----,-___ 50 Topography and drainage 50 Rock types 50 Pegmatites 52 General statement 52 Occurrence --. - 52 Texture 5J Mineral composition JJ Principal mines and prospects General features Pinchback property Jefferson property JO Smith property - 57 .Rutherford property 59 Other mines and prospects 59 Ponton prospect - 59 Schlegal mine ----'---- Ligon prospect _-- 60 Miller mine 60 Morefield mine 60 Goochland area 6l Location and. accessibility -------,--, -,, 61 Topography and drainage_ ol Rock types 6l General features 6l Quat tz monzonite gneiss 62 Hornblende metagabbro 62 Pegmatites ---- 62 General features 62 Occurrence -- 62 Texture 62 Nature of contacts OJ Mineral composition 63 Mines and prospects 64 General features 64 Irwin mine ---- Amber Queen mine - o5 Nicholas prospect OJ Wiltshire prospect 65 Salter prospect ---------- ___-__ 65 Saunders mine ------- 66 Childress mine - 66 Rutile deposits - -. 66 Ridgeway are:l ---. 66 Location and accessibility ---------- 66 Topography and drainage --- ----,--- 67 CoNrrNrs Rock types ------'"2; Pegmatites 68 General features 68 Occurrence --. 68 Texture _-_- -. 68 Nature of contacts 69 Mineral composition - 69 Principal mines and prospects 70 General features 70 Ridgeway mine -*------ 7L Garrett property 7t Grindstaff mine 7l Garrett spar mine 72 Garrett-Penn mine ------- 72 Oliver property .--------- 73 Phillips mine -------- tr Lovelacemine- - tr Pace mine ----------:---- tr Other mines 4' Tom Smith -ir;---------- ---------.---------------------- ;i Clifton mine -- 74 Axton area Location and accessibility ___- 74 Topography and drainage AA,a Rock types _ 74 Pegmatites t r General features tr Occurrence tJ Texture - t r Nature of contacts 76 Mineral composition _ 76 Principal mines and prospects 76 General statement to Vicama Mica Company mines ------- 76 Martin mine --* _ 77 Dalton property Z7 Tyler mine 77 Other mines and prospects ---- 77 Altavista area - 78 Location and accessibility ---,------- 78 Topography and drainage ----- /6 Rock types 78 Pegmatites *____ 79 General features 79 . Occurrence- _ Z9 Mineral composition 79 Mines and prospects Zg Coxmsrs xl Kaolin mines and prospects ------- "T; Jackson mine ------,- 79 Motley prospecr ---------- 80 Broomfield prospects 80 Feldspar and mica mines and prospects,---- 81 Farmer prospect 81 Smith mine - 8l -"'t*;T:i' "ff":";t*:. -- --------------------:-"-------"-- :; Rock types 82 Pegmatites General features 82 Occurrence 82 Texture 83 Nature of contacts 84 Mineral composition 84 Mines and prospects 85 General {eatures 85 Moneta area - -- 85 Wheatly mine ,,-,---- -----:- 85 Young mine 86 ' Hales Ford prospects ----------- 87 Nance and Woolridge prospects 87 Nichols prospect 87 Bells area - ---- 8? Bells prospects ----------- 87 Hottinger mine - 88 Patterson prospect 89 Otter Hill prospecrs Hafris prospects ------,-- 90 Forest area --. - - 90 Everett prospect 90 Radford prospect 90 'Ivy prospect 90 Chestnut Mountain area - -,,--- 91 Location and accessibility ---------- 9l Topography and drainage 9l Rock types - 91 Pegmatites 91 3ffi:i:"':111 ,_-_____- --------- - ---- --,-------.--- ?t Texture Nature of contacts 92 Mineral composition 92 Mines and prospects General features 93 xll CoNreNrs Pacr Deposits along the Rocky Mount road--------- 93 Cooper mines ------- 93 Miscellaneous mineral deposits 93 General statement 93 Other feldspar deposits 94 Location 94 Morton prospect 94 Davis prospect -,--------- 94 Emer5r dePosits --------- 94 Location -- 94 Associated rocks ------- 94 Ore bodies 95 Cassiterite deposits 95 Allanite deposits 95 Lucian Burley tract 96 Location 96 Occurrence 96 John Campbell tract 96 Location 96 Occurrence 97 Wall rock 97 Mineral composition 98 Economic geology of the minerals -- -- 101 Mica - 101 General statement 101 Characteristics - 101 Classification 101 Ijses ---- -- . t02 value ---_-- lo2 Mining methods 103 Production records Possible future sources ------------- 104 Summary of productive areas -- 105 Feldspar 106 General statement 106 Classification --- L07 Ijses ------- n7 Mining methods 108 Milling 108 Possible future sources 109 Miscellaneous minerals Quartz ----- 109 Kaolin ----- llo Emery ----- 110 Cassiterite - 110 Gem minerals 1ll Rare minerals 111 Bibliography LLz Index ------ 117 ILLUSTRATIONS Pr,ero Pacs l. Geologic map of the Amelia and Goochland areas, Amelia, Goochland, Louisa, and Powhatan counties ----- - ,- -------In pocket 2. Geologic map of the Ridgeway area, Ilenry County, Virginia, and Rockingham County, North Carolina ,-.--..------ -In pocket
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