DOCSLIB.ORG

Abstract-1627

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Abstract-1627 40 39 AR/ AR AGE AND ORIGIN OF JAROSITE MINERALIZATION AT THE HANSONBURG DISTRICT, NEW MEXICO Virgil W. Lueth1 and M. T. Heizler1 1New Mexico Bureau of Mines & Mineral Resources, Socorro, NM, 87801, [email protected] 3+ Jarosite [K2Fe6 (SO4)4(OH)12] is formed in oxidized portions of sulfide ore deposits, precipitated as a primary mineral in some thermal springs and also as result of the production of H2S from organic matter. Jarosite occurs late in the ore mineral paragenesis at the Snake Pit, Royal Flush, Mex-Tex, Portales, and Sunshine mines where it coexists with fluorite, barite and quartz. Coarsely crystalline and euhedral jarosite is occasionally included in the quartz and fluorite. Petrologic and paragenetic relationships indicate the jarosite mineralization is hypogene. Additional support for this hypothesis is seen in the paragenetic relationships displayed by the lead mineralogy. The fIrst formed lead mineral is galena (PbS) followed by anglesite (PbSO4) and fInally by cerussite (PbCO3). Mineral textures show sharp boundaries between galena and anglesite, characteristic of epitaxial overgrowth and not weathering. The cerussite is probably of secondary origin. The unusually diverse sulfate mineralogy at Hansonburg also suggests a hypogene oxidation event associated with the late stages of mineralization resulted in the formation of the complex sulfate mineral assemblage (anhydrite, antlerite, barite, beaverite, brochantite, caledonite, celestine, chalcanthite, creedite, corkite, cyanothrichite, goslarite, gypsum, jarosite, langite, linarite, plumbojarosite, serpierite, spangolite, tsumebite). Putnam (1983) modeled the mineralization at Hansonburg based on fluid inclusion compositions and determined that early sulfide mineralization was followed by a sulfate stage due to precipitation of sulfides or cooling of the mineralizing fluids. The coarse grained, euhedral jarosite also formed during this late sulfate stage of mineralization. 40Ar/39Ar geochronologic analyses were performed on hand-picked jarosite separates (confirmed by x-ray diffraction) by both CO2 laser and resistance furnace incremental heating techniques. The jarosite from the Snake Pit deposit gave well-behaved plateau age spectra and high radiogenic yields. The simple systematics provide precise ages ranging from 6.36±0.1 to 5.98±0.06 (2σ) Ma and are significant regardless of the mode of origin for the jarosite at Hansonburg. If the jarosite mineralization is hypogene, consistent with the geologic evidence, then the age represents the time of late stage sulfate mineralization at Hansonburg. Compared to other jarosite-bearing deposits such as the Copiapo jarosite deposit (40Ar/39Ar age = 5.0 ±0.3 to 4.6 ±0.06 Ma) at Webb Gap, New Mexico, the ages are similar and result from rift-related pulses of mineralization. Interpretation of the data suggests that basin dewatering and/or migration of H2S up boundary faults resulted in sulfide and sulfate (including jarosite) mineralization. Accordingly, galena-fluorite-barite mineralization probably correlates to major episodes of rift activity. If the jarosite mineralization is due to weathering, then the age represents a time of significant oxidation weathering of the Hansonburg deposits. Such a period of weathering would be due to uplift on the margins of the Oscura Mountains during the late Miocene. Keywords: jarosite, Hansonburg mining district, geochronology, argon, 40/39, pp. 18 1997 New Mexico Geological Society Annual Spring Meeting April 18, 1997, Macey Center.
Load more

Recommended publications
  • Mineral Processing
    Mineral Processing Foundations of theory and practice of minerallurgy 1st English edition JAN DRZYMALA, C. Eng., Ph.D., D.Sc. Member of the Polish Mineral Processing Society Wroclaw University of Technology 2007 Translation: J. Drzymala, A. Swatek Reviewer: A. Luszczkiewicz Published as supplied by the author ©Copyright by Jan Drzymala, Wroclaw 2007 Computer typesetting: Danuta Szyszka Cover design: Danuta Szyszka Cover photo: Sebastian Bożek Oficyna Wydawnicza Politechniki Wrocławskiej Wybrzeze Wyspianskiego 27 50-370 Wroclaw Any part of this publication can be used in any form by any means provided that the usage is acknowledged by the citation: Drzymala, J., Mineral Processing, Foundations of theory and practice of minerallurgy, Oficyna Wydawnicza PWr., 2007, www.ig.pwr.wroc.pl/minproc ISBN 978-83-7493-362-9 Contents Introduction ....................................................................................................................9 Part I Introduction to mineral processing .....................................................................13 1. From the Big Bang to mineral processing................................................................14 1.1. The formation of matter ...................................................................................14 1.2. Elementary particles.........................................................................................16 1.3. Molecules .........................................................................................................18 1.4. Solids................................................................................................................19
    [Show full text]
  • Chemistry of Formation of Lanarkite, Pb2oso 4
    SHORT COMMUNICATIONS MINERALOGICAL MAGAZINE, DECEMBER 1982, VOL. 46, PP. 499-501 Chemistry of formation of lanarkite, Pb2OSO 4 W E have recently reported (Humphreys et al., 1980; sion which is at odds with the widespread occur- Abdul-Samad et al., 1982) the free energies of rence of the simple sulphate and the extreme rarity formation of a variety of chloride-bearing minerals of the basic salt, and with aqueous synthetic of Pb(II) and Cu(II) together with carbonate procedures for the preparation of the compound and sulphate species of the same metals includ- (Bode and Voss, 1959), which involve reaction of ing leadhillite, Pb,SO4(COa)2(OH)2, caledonite, angtesite in basic solution. PbsCu2CO3(SO4)3(OH)6, and linarite, (Pb,Cu)2 Kellog and Basu (1960) also determined AG~ for SO4(OH)2. By using suitable phase diagrams it has Pb2OSOa(s) at 298.16 K using the method of proved possible to reconstruct, in part, the chemical univariant equilibria in the system Pb-S-O. They history of the development of some complex obtained a value of -1016.4 kJ mol-1 based on secondary mineral assemblages such as those at literature values for PbO(s), PbS(s), PbSO4(s), and the Mammoth-St. Anthony mine, Tiger, Arizona, SO2(g) and another of - 1019.8 kJ mol- 1 based on and the halide and carbonate suite of the Mendip adjusted values for the above compounds. These Hills, Somerset. two results, for which the error was estimated to A celebrated locality for the three sulphate- be about 4.5 kJ mol-1, seem to be considerably bearing minerals above is the Leadhills-Wanlock- more compatible with observed associations than head district of Scotland (Wilson, 1921; Heddle, the earlier values.
    [Show full text]
  • Hydrowoodwardite Cu2al2(SO4)(OH)8 • Nh2o. C 2001-2005 Mineral Data Publishing, Version 1
    Hydrowoodwardite Cu2Al2(SO4)(OH)8 • nH2O. c 2001-2005 Mineral Data Publishing, version 1 Crystal Data: Hexagonal. Point Group: 32/m (probable). As porous botryoidal crusts and small stalactitic aggregates. Physical Properties: Fracture: Uneven. Tenacity: Brittle upon partial dehydation. Hardness = n.d. D(meas.) = 2.33(8) D(calc.) = 2.48 Slowly and reversibly dehydrates to woodwardite. Optical Properties: Translucent. Color: Blue to pale blue. Streak: Pale blue. Luster: Vitreous. Optical Class: [Uniaxial.] n = 1.549(5)–1.565(5) ω = n.d. = n.d. Cell Data: Space Group: R3m (probable). a = 3.070(7) c = 31.9(2) Z = 3 X-ray Powder Pattern: St. Briccius mine, Germany. 10.5 (100), 5.26 (17), 3.50 (6), 2.60 (5b), 1.524 (4b), 2.46 (2b), 2.23 (2b) Chemistry: (1) SO3 15.50 SiO2 5.60 Al2O3 19.20 CuO 28.39 ZnO 0.41 Na2O 0.10 H2O 30.10 Total [99.30] (1) St. Briccius mine, Germany; by ICP-MS, SiO2 from admixed amorphous silica, H2Oby 2− 1− TGA, (SO4) , (OH) and H2O confirmed by IR, original total given as 99.3%; corresponds to • (Cu1.92Zn0.04)Σ=1.96Al2.04(SO4)1.04(OH)7.96 5.08H2O. (2) St. Christoph mine, Germany; analysis 2− not given, (CO3) from stoichiometry and presence confirmed by IR; then stated to correspond • to (Cu1.96Zn0.04)Σ=2.00(UO2)0.04Al2.00[(SO4)0.64(CO3)0.36]Σ=1.00(OH)8 nH2O. Occurrence: Rare in the oxidized portions of base metal sulfide mines. Association: Woodwardite, schulenbergite, namuwite, brianyoungite, langite, linarite, allophane, amorphous silica.
    [Show full text]
  • Ramsbeckite (Cu, Zn)15(SO4)4(OH)22 • 6H2O C 2001-2005 Mineral Data Publishing, Version 1 Crystal Data: Monoclinic, Pseudohexagonal
    Ramsbeckite (Cu, Zn)15(SO4)4(OH)22 • 6H2O c 2001-2005 Mineral Data Publishing, version 1 Crystal Data: Monoclinic, pseudohexagonal. Point Group: 2/m. Crystals are tabular with large {001}, also {210}, {110}, {100}, giving a slightly rounded rhombic outline, to 3 mm. Twinning: Observed, repeated, forming cylindrical aggregates. Physical Properties: Cleavage: On {001}, perfect. Fracture: Conchoidal. Tenacity: Brittle. Hardness = 3.5 D(meas.) = 3.39–3.41 D(calc.) = 3.37 Optical Properties: Transparent to translucent. Color: Green, blue-green. Streak: Pale green. Luster: Vitreous. Optical Class: Biaxial (–). Pleochroism: Weak; X = pale blue-green, emerald-green; Y = Z = blue-green, yellow-green. Orientation: Y = b; X ∧ c =5◦; Z ∧ a =5◦. Absorption: X > Y = Z. α = 1.624–1.669 β = 1.674–1.703 γ = 1.678–1.707 2V(meas.) = 36◦–38◦ 2V(calc.) = 38.0◦ Cell Data: Space Group: P 21/a. a = 16.088–16.110 b = 15.576–15.602 c = 7.102–7.112 β =90.0◦−90.27◦ Z=2 X-ray Powder Pattern: Bastenberg mine, Ramsbeck, Germany. 7.090 (100), 3.549 (25), 1.776 (20), 3.254 (13), 4.400 (12), 3.232 (12), 3.244 (11) Chemistry: (1) (2) (3) SO3 17.4 17.6 17.51 CuO 44.5 43.8 43.49 ZnO 15.8 18.1 22.25 H2O 19.3 [20.5] 16.75 Total 97.0 [100.0] 100.00 (1) Bastenberg mine, Ramsbeck, Germany; SO4 by photometry, CuO, ZnO by AA, H2O by gas 1− chromatography, (OH) computed for charge balance; corresponds to (Cu10.30Zn3.58)Σ=13.88 • (SO4)4.00(OH)19.76 9.84H2O.
    [Show full text]
  • Wroewolfeite Cu4(SO4)(OH)6 • 2H2O C 2001-2005 Mineral Data Publishing, Version 1 Crystal Data: Monoclinic
    Wroewolfeite Cu4(SO4)(OH)6 • 2H2O c 2001-2005 Mineral Data Publishing, version 1 Crystal Data: Monoclinic. Point Group: m. Lathlike crystals, to 1 mm. Twinning: By reflection on {001} and {100}, yielding fourlings. Physical Properties: Cleavage: Perfect on {010}, {100}, {001}. Hardness = ∼2.5 D(meas.) = 3.27(1) D(calc.) = 3.30 Optical Properties: Translucent. Color: Dark greenish blue; blue in transmitted light. Streak: Pale blue. Luster: Vitreous. Optical Class: Biaxial (–). Pleochroism: Strong; X = pale blue; Y = deep greenish blue; Z = greenish blue. Absorption: Y Z > X. α = 1.637(2) β = 1.682(2) γ = 1.694(2) 2V(meas.) = 53◦ Cell Data: Space Group: Pm. a = 6.045(1) b = 5.646(1) c = 14.337(6) β =93.39(1)◦ Z=2 X-ray Powder Pattern: Loudville mine, Massachusetts, USA. 7.152 (100), 3.581 (70), 2.628 (35), 2.004 (30), 2.431 (20), 2.379 (20), 2.278 (20) Chemistry: (1) (2) SO3 16.48 16.40 CuO 64.22 65.16 H2O [19.30] 18.44 Total [100.00] 100.00 (1) Loudville mine, Massachusetts, USA; by electron microprobe, H2O by difference; 1− with (OH) calculated for charge balance and H2O adjusted for best agreement between • measured and calculated densities, then corresponds to Cu3.94(SO4)1.00(OH)5.88 2.11H2O. • (2) Cu4(SO4)(OH)6 2H2O. Polymorphism & Series: Dimorphous with langite. Occurrence: An uncommon secondary mineral in the oxidation zone of copper-bearing hydrothermal mineral deposits; may be post-mine or formed in dumps and in slags. Association: Langite, posnjakite, serpierite, brochantite, linarite, malachite, chalcocite, covellite.
    [Show full text]
  • Journal of the Russell Society, Vol 4 No 2
    JOURNAL OF THE RUSSELL SOCIETY The journal of British Isles topographical mineralogy EDITOR: George Ryba.:k. 42 Bell Road. Sitlingbourn.:. Kent ME 10 4EB. L.K. JOURNAL MANAGER: Rex Cook. '13 Halifax Road . Nelson, Lancashire BB9 OEQ , U.K. EDITORrAL BOARD: F.B. Atkins. Oxford, U. K. R.J. King, Tewkesbury. U.K. R.E. Bevins. Cardiff, U. K. A. Livingstone, Edinburgh, U.K. R.S.W. Brai thwaite. Manchester. U.K. I.R. Plimer, Parkvill.:. Australia T.F. Bridges. Ovington. U.K. R.E. Starkey, Brom,grove, U.K S.c. Chamberlain. Syracuse. U. S.A. R.F. Symes. London, U.K. N.J. Forley. Keyworth. U.K. P.A. Williams. Kingswood. Australia R.A. Howie. Matlock. U.K. B. Young. Newcastle, U.K. Aims and Scope: The lournal publishes articles and reviews by both amateur and profe,sional mineralogists dealing with all a,pecI, of mineralogy. Contributions concerning the topographical mineralogy of the British Isles arc particularly welcome. Not~s for contributors can be found at the back of the Journal. Subscription rates: The Journal is free to members of the Russell Society. Subsc ription rates for two issues tiS. Enquiries should be made to the Journal Manager at the above address. Back copies of the Journal may also be ordered through the Journal Ma nager. Advertising: Details of advertising rates may be obtained from the Journal Manager. Published by The Russell Society. Registered charity No. 803308. Copyright The Russell Society 1993 . ISSN 0263 7839 FRONT COVER: Strontianite, Strontian mines, Highland Region, Scotland. 100 mm x 55 mm.
    [Show full text]
  • Antlerite Cu3(SO4)(OH)4 C 2001-2005 Mineral Data Publishing, Version 1
    Antlerite Cu3(SO4)(OH)4 c 2001-2005 Mineral Data Publishing, version 1 Crystal Data: Orthorhombic. Point Group: 2/m 2/m 2/m. Crystals are thick tabular {010}, equant or short prismatic [001], with dominant {110}, another twenty-odd forms, to 2 cm; commonly fibrous and in cross-fiber veinlets, feltlike, granular or powdery lumps and aggregates. Physical Properties: Cleavage: {010}, perfect; {100}, poor. Tenacity: Brittle. Hardness = 3.5 D(meas.) = 3.88 D(calc.) = 3.93 Optical Properties: Translucent. Color: Emerald-green, blackish green, pale green. Streak: Pale green. Luster: Vitreous. Optical Class: Biaxial (+). Pleochroism: X = yellow-green; Y = blue-green; Z = green. Orientation: X = b; Y = a; Z = c. Dispersion: r< v,very strong. α = 1.726 β = 1.738 γ = 1.789 2V(meas.) = 53◦ Cell Data: Space Group: P nam. a = 8.244(2) b = 11.987(3) c = 6.043(1) Z = 4 X-ray Powder Pattern: Synthetic. (ICDD 7-407). 4.86 (100), 2.566 (85), 3.60 (75), 2.683 (75), 6.01 (25), 5.40 (25), 2.503 (25) Chemistry: (1) (2) SO3 22.32 22.57 CuO 66.34 67.27 H2O 10.52 10.16 insol. 0.88 Total 100.06 100.00 (1) Chuquicamata, Chile; average of two analyses. (2) Cu3(SO4)(OH)4. Occurrence: Uncommon, typically formed in the oxidized zone of copper deposits under highly acid conditions, especially in arid regions. Association: Brochantite, atacamite, chalcanthite, kr¨ohnkite,natrochalcite, linarite, gypsum. Distribution: In the USA, in Arizona, from the Antler mine, near Yucca Station, Mohave Co., large crystals at several mines in Bisbee, Cochise Co., from the Grandview mine, Grand Canyon, Coconino Co., in Copper Basin, between Skull Valley and Prescott, and at Jerome, Yavapai Co.; from the Blanchard mine, near Bingham, Hansonburg district, Socorro Co., New Mexico; in the Darwin district, Inyo Co., California; from the Northern Light mine, near Black Mountain, Mountain View district, Mineral Co.
    [Show full text]
  • Minerals Found in Michigan Listed by County
    Michigan Minerals Listed by Mineral Name Based on MI DEQ GSD Bulletin 6 “Mineralogy of Michigan” Actinolite, Dickinson, Gogebic, Gratiot, and Anthonyite, Houghton County Marquette counties Anthophyllite, Dickinson, and Marquette counties Aegirinaugite, Marquette County Antigorite, Dickinson, and Marquette counties Aegirine, Marquette County Apatite, Baraga, Dickinson, Houghton, Iron, Albite, Dickinson, Gratiot, Houghton, Keweenaw, Kalkaska, Keweenaw, Marquette, and Monroe and Marquette counties counties Algodonite, Baraga, Houghton, Keweenaw, and Aphrosiderite, Gogebic, Iron, and Marquette Ontonagon counties counties Allanite, Gogebic, Iron, and Marquette counties Apophyllite, Houghton, and Keweenaw counties Almandite, Dickinson, Keweenaw, and Marquette Aragonite, Gogebic, Iron, Jackson, Marquette, and counties Monroe counties Alunite, Iron County Arsenopyrite, Marquette, and Menominee counties Analcite, Houghton, Keweenaw, and Ontonagon counties Atacamite, Houghton, Keweenaw, and Ontonagon counties Anatase, Gratiot, Houghton, Keweenaw, Marquette, and Ontonagon counties Augite, Dickinson, Genesee, Gratiot, Houghton, Iron, Keweenaw, Marquette, and Ontonagon counties Andalusite, Iron, and Marquette counties Awarurite, Marquette County Andesine, Keweenaw County Axinite, Gogebic, and Marquette counties Andradite, Dickinson County Azurite, Dickinson, Keweenaw, Marquette, and Anglesite, Marquette County Ontonagon counties Anhydrite, Bay, Berrien, Gratiot, Houghton, Babingtonite, Keweenaw County Isabella, Kalamazoo, Kent, Keweenaw, Macomb, Manistee,
    [Show full text]
  • Posnjakite: ~[Cu4(OH)6(H20)O] Octahedral Sheets in Its Structure
    Zeitschrift fUr Kristallographie 149, 249~257 (1979) ([I by Akademische Verlagsgesellschaft 1979 Posnjakite: ~[Cu4(OH)6(H20)O] octahedral sheets in its structure M. Mellini and S. Merlino Istituto di Mineralogia e Petrografia and C.N.R., Centro di Studio per la Geologia StrutturaIe e Dinamica dell' Appennino, Pisa, Italy Received: November 27, 1978 Abstract. The crystal structure of posnjakite '(space group Pa, a = 10.578, b = 6.345, c = 7.863 A, {3= 117.98°) was determined by direct methods and refined to a final R value of 0.05. The structure is characterized by corrugated sheets of distorted copper octahedra with crystal chemical formula ~[CuiOHMH20)O). Sulphate groups are connected to one side of the octahedral sheet by corner sharing. The resultant composite octahedral- tetrahedral layers are connected to each other by hydrogen bonds. The crystal chemical formula ofposnjakite is CU4(S04)(OH)6' H20 with two such units in the unit cell. The relations ofposnjakite with other copper sulphate hydrates are noted and discussed. Introduction Posnjakite was first found in an ore quartz vein of the Nura-Taldinsk tungsten deposit in central Kazachstan by Komkov and Nefedov (1967) who, on the basis of microchemical tests and the supposed paramorphism of the mineral after langite, proposed the chemical formula CU4(S04)(OH)6 . H20; they determined the following unit cell parameters: a = 9.80(5),b = 6.32(5), c = 7.85(5) A, {3= 107(1)° (space group not stated). Posnjakite in association with langite was also found at Borovec (Czechoslovakia) and studied by Miskovsky (1975), who also synthesized it, and by Sekanina (1975) who, on the basis of careful goniometric measures, asserted "that (1) posnjakite crystals are limited by their own faces and they are not paramorphs after langite, (2) that they are tabular on (lOl) and (3) that (231) ist the twin plane".
    [Show full text]
  • And Associated Lead Fluoride Minerals from the Grand Reef Mine, Graham County, Arizona
    CALCIOARAVAIPAITE A NEW MINERAL 1'.01411II1 ••••• AND ASSOCIATED LEAD FLUORIDE MINERALS FROM THE GRAND REEF MINE, GRAHAM COUNTY, ARIZONA Anthony R. Kampf Mineralogy Section Natural History Museum of Los Angeles County 900 Exposition Blvd. Los Angeles, California 90007 Eugene E. Foord United States Geological Survey Box 25046, Denver Federal Center, MS 905 Lakewood, Colorado 80225 The Grand Ree] mine in southeastern Arizona, best known to collectors for superb crystals of linarite, is also the type locality for a unique suite of lead fluoride minerals. Crandreeiite, pseudograndretiflte, laurelite, aravaipaite, and artroeite have been found nowhere else; added to this group is calcioaravaipaite, described here for the first time. INTRODUCTION The Grand Reef mine is situated in Laurel Canyon, about 6 km In 1969 a bench was blasted near the top of the reef just south of northeast of Klondyke, in the Aravaipa mining district of Graham a vertical stope known as the "glory hole." Most of the mine's well- County, Arizona. Jones (1980) provided an overview of the history, crystallized oxidized minerals, predominantly sulfates, have been geology and mineralogy of the deposit. The mineralogy was recovered from this area. The fine linarite crystals up to 5 em in treated in greater detail in a thesis by Besse (1981). The mine length for which the mine. is most famous were found here. This is exploits a small epithermallead-copper-silver deposit hosted by a also the source of six new lead fluoride minerals (Table I). The first silicified breccia. The breccia is highly resistant to weathering and four, grandreefite, pseudograndreefite, laurelite and aravaipaite, forms a precipitous cliff known as the "reef," from which the name were discovered on a single specimen (LACMNH 25414) recov- of the mine is derived.
    [Show full text]
  • Diamond Dan's Mineral Names Dictionary
    A Dictionary of Mineral Names By Darryl Powell Mineral Names What do they mean? Who created them? What can I learn from them? This mineral diction‐ ary is unique because it is illustrated, both with mineral drawings as well as pictures of people and places after which some minerals are named. The people pictured on this page have all made a con‐ tribution to what is formally called “mineral nomenclature.” Keep reading and you will discover who they are and what they did. In 1995, Diamond Dan Publications pub‐ lished its first full book, “A Mineral Collector’s Guide to Common Mineral Names: Their Ori‐ gins & Meanings.” Now it is twenty years later. What you will discover in this issue and in the March issue is a re‐ vised and improved version of this book. This Mineral Names Dictionary contains mineral names that the average mineral collector will encounter while collecting minerals, attending shows and visiting museum displays. In addition to the most common min‐ eral names, there are some unofficial names which you will still find on labels. Each mineral name has a story to tell or a lesson to teach. If you wanted to take the time, each name could become a topic to study. Armalcolite, for example, could quickly be‐ come a study of a mineral, first discovered on the moon, and brought back to earth by the astronauts Armstrong, Aldrin and Collins (do you see parts of their names in this mineral name?) This could lead you to a study of American astronauts landing on the moon, what it took to get there and what we discovered by landing on the moon.
    [Show full text]
  • Journal of the Russell Society, Vol 8 No. 2
    JOURNAL OF THE RUSSELL SOCIETY The journal of British Isles topographical mineralogy EDITOR: Norman Moles, School of the Environment, University of Brighton, Cockcroft Building, Lewes Road, Brighton, BN2 4GJ. JOURNAL MANAGER: Stand in:: Jim Robinson, 21 Woodside Park Drive, Horsforth, Leeds LS18 4TG. EDITORIAL BOARD: RE. Bevins, Cardiff, u.K. RJ. King, Tewkesbury, u.K. RS.W. Braithwaite, Manchester, u.K. I.R Plimer, Parkville, Australia T.E. Bridges, Ovington, UK RE. Starkey, Bromsgrove, U.K. NJ Elton, St Austell, U.K. RF. Symes, Sidmouth, U.K. N.J. Fortey, Keyworth, U.K. P.A. Williams, Kingswood, Australia RA. Howie, Matlock, UK Aims and Scope: The Journal publishes refereed articles by both amateur and professional mineralogists dealing with all aspects of mineralogy relating to the British Isles. Contributions are welcome from both members and non-members of the Russell Society. Notes for contributors can be found at the back of this issue, or obtained from the editor. Subscription rates: The Journal is free to members of the Russell Society. Subscription rate for non-members is £15 for two issues. Enquiries should be made to the Journal Manager at the above address. Back numbers of the Journal may also be ordered through the Journal Manager. The Russell Society, named after the eminent amateur mineralogist Sir Arthur Russell (1878-1964), is a society of amateur and professional mineralogists which encourages the study, recording and conservation of mineralogical sites and material. For information about membership, write to the Membership Secretary, Mr Dave Ferris, 6 Middleton Road, Ringwood, Hampshire, BH241RN. Typography and Design by: Jim Robinson, 21 Woodside Park Drive, Horsforth, Leeds, LS18 4TG Printed by: St.
    [Show full text]