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Tantalum Mineralogy, Rare-Element Granitic Pegmatites, Separation Lake

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Tantalum Mineralogy, Rare-Element Granitic Pegmatites, Separation Lake Ontario Geological Survey Open File Report 6022 Tantalum Mineralogy of Rare-Element Granitic Pegmatites from the Separation Lake Area, Northwestern Ontario 2000 ONTARIO GEOLOGICAL SURVEY Open File Report 6022 Tantalum Mineralogy of Rare-Element Granitic Pegmatites from the Separation Lake Area, Northwestern Ontario by A.G. Tindle and F.W. Breaks 2000 Parts of this publication may be quoted if credit is given. It is recommended that reference to this publication be made in the following form: Tindle, A.G. and Breaks, F.W. 2000. Tantalum mineralogy of rare-element granitic pegmatites from the Separation Lake area, northwestern Ontario; Ontario Geological Survey, Open File Report 6022, 378p. e Queen’s Printer for Ontario, 2000 e Queen’s Printer for Ontario, 2000. Open File Reports of the Ontario Geological Survey are available for viewing at the Mines Library in Sudbury, at the Mines and Minerals Information Centre in Toronto, and at the regional Mines and Minerals office whose district includes the area covered by the report (see below). Copies can be purchased at Publication Sales and the office whose district includes the area covered by the report. Al- though a particular report may not be in stock at locations other than the Publication Sales office in Sudbury, they can generally be obtained within 3 working days. All telephone, fax, mail and e-mail orders should be directed to the Publica- tion Sales office in Sudbury. Use of VISA or MasterCard ensures the fastest possible service. Cheques or money orders should be made payable to the Minister of Finance. Mines and Minerals Information Centre (MMIC) Tel: (416) 314-3800 Macdonald Block, Room M2-17 1-800-665-4480(toll free inside Ontario) 900 Bay St. Toronto, Ontario M7A 1C3 Mines Library Tel: (705) 670-5615 933 Ramsey Lake Road, Level A3 Sudbury, Ontario P3E 6B5 Publication Sales Tel: (705) 670-5691(local) 933 Ramsey Lake Rd., Level A3 1-888-415-9845(toll-free) Sudbury, Ontario P3E 6B5 Fax: (705) 670-5770 E-mail: [email protected] Regional Mines and Minerals Offices: Kenora - Suite 104, 810 Robertson St., Kenora P9N 4J2 Kirkland Lake - 10 Government Rd. E., Kirkland Lake P2N 1A8 Red Lake - Box 324, Ontario Government Building, Red Lake P0V 2M0 Sault Ste. Marie - 70 Foster Dr., Ste. 200, Sault Ste. Marie P6A 6V8 Southern Ontario - P.O. Bag Service 43, Old Troy Rd., Tweed K0K 3J0 Sudbury - Level B3, 933 Ramsey Lake Rd., Sudbury P3E 6B5 Thunder Bay - Suite B002, 435 James St. S., Thunder Bay P7E 6S7 Timmins - Ontario Government Complex, P.O. Bag 3060, Hwy. 101 East, South Porcupine P0N 1H0 Toronto - MMIC, Macdonald Block, Room M2-17, 900 Bay St., Toronto M7A 1C3 This report has not received a technical edit. Discrepancies may occur for which the Ontario Ministry of Northern Devel- opment and Mines does not assume any liability. Source referencesare included in the report and users are urged to verify critical information. Recommendations and statements of opinions expressed are those of the author or authors and are not to be construed as statements of government policy. If you wish to reproduce any of the text, tables or illustrations in this report, please write for permission to the Team Leader, Publication Services, Ministry of Northern Development and Mines, 933 Ramsey Lake Road, Level B4, Sudbury, Ontario P3E 6B5. Cette publication est disponible en anglais seulement. Parts of this report may be quoted if credit is given. It is recommended that reference be made in the following form: Tindle, A.G. and Breaks F.W. 2000. Tantalum mineralogy of rare-element granitic pegmatites from the Separation Lake area, northwestern Ontario; Ontario Geological Survey, Open File Report 6022, 378p. iii Contents Abstract .................................................................................. ix Introduction ............................................................................... 1 Experimental methods and presentation of data................................................... 2 Columbite--tantalite group minerals ............................................................ 3 Ferrotapiolite .......................................................................... 7 Ixiolite ................................................................................ 8 Strüverite ............................................................................. 9 Wodginite group minerals .................................................................... 9 Pyrochlore group minerals .................................................................... 12 Cassiterite ................................................................................ 15 Commodity importance of oxide minerals in rare--element pegmatites................................ 16 Grades and tonnages of tantalum deposits....................................................... 17 Exploration for tantalum mineral--bearing pegmatite deposits........................................ 18 Potassium feldspar chemistry .............................................................. 18 Muscovite chemistry .................................................................... 18 Summary ................................................................................. 19 Acknowledgments .......................................................................... 20 References ................................................................................ 21 Metric Conversion Table ..................................................................... 378 FIGURES 1. Number of analyses versus Ta2O5 ....................................................... 24 2. Columbite--tantalite group distribution map................................................ 25 3. Wodginite group distribution map........................................................ 26 4. Ferrotapiolite group distribution map..................................................... 27 5. Pyrochlore group distribution map....................................................... 28 6. Ixiolite distribution map ................................................................ 29 7. Strüverite distribution map .............................................................. 30 8. Cassiterite distribution map ............................................................. 31 9. Columbite--tantalite quadrilateral........................................................ 32 10. Columbite--tantalite quadrilateral........................................................ 33 11. Columbite--tantalite quadrilateral........................................................ 34 12. Columbite--tantalite quadrilateral........................................................ 35 13. Columbite--tantalite quadrilateral........................................................ 36 14. Nb versus Ta (apfu) for the entire columbite--tantalite and ixiolite dataset......................... 37 15. Fe+Mn versus Nb+Ta (apfu) for the strüverite dataset........................................ 38 16. (a) Wodginite quadrilateral for the entire Separation Lake dataset.............................. 39 (b) Fe3+ versus W (apfu) for most of the Separation Rapids wodginite group dataset............... 39 17. Mn/(Mn+Fe) versus Ta2O5 wt % for all wodginite group data................................. 40 v 18. The three main subgroups of the pyrochlore group.......................................... 41 19. Ti/total B site versus Sb/total A site for pyrochlore group minerals............................. 42 20. Fe+Mn versus Nb+Ta (apfu) for all cassiterite data.......................................... 43 PHOTOS 1. Backscattered electron images of columbite--tantalite exhibiting primary zonation.................. 44 2. Backscattered electron images of columbite--tantalite exhibiting secondary zonation................ 45 3. Backscattered electron images of columbite--tantalite exhibiting complex features................. 46 4. Backscattered electron images of ferrotapiolite and associated minerals.......................... 47 5. Backscattered electron images of ixiolite, strüverite and microlite--ferrotapiolite................... 48 6. Backscattered electron images of wodginite group minerals................................... 49 7. Backscattered electron and X--ray images of wodginite group minerals........................... 50 8. Backscattered electron and X--ray images of wodginite group minerals.......................... 51 9. Backscattered electron and X--ray images of tungsteniferous wodginite.......................... 52 10. Backscattered electron images of pyrochlore group minerals................................... 53 11. Backscattered electron and X--ray images of pyrochlore group minerals.......................... 54 12. Backscattered electron and X--ray images of cassiterite....................................... 55 13. Backscattered electron and X--ray images of cassiterite....................................... 56 14. Backscattered electron and X--ray images of cassiterite....................................... 57 TABLES 1. Means, ranges and standard deviations for all tantalum--bearing species......................... 58 2. Tantalum--bearing mineral associations................................................... 59 3. Summary of columbite--tantalite data..................................................... 60 4. Summary of ferrotapiolite data.......................................................... 61 5. Summary of wodginite group data....................................................... 62 6. Summary of pyrochlore group
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