DOCSLIB.ORG

White Mica Geochemistry of the Catheart Mountain Porphyry Copper Deposit, Maine -- White Mica Geochemistry of the Catheart Mountain Porphyry Copper Deposit, Maine

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
White Mica Geochemistry of the Catheart Mountain Porphyry Copper Deposit, Maine -- White Mica Geochemistry of the Catheart Mountain Porphyry Copper Deposit, Maine White Mica Geochemistry of the Catheart Mountain Porphyry Copper Deposit, Maine -- White Mica Geochemistry of the Catheart Mountain Porphyry Copper Deposit, Maine By ROBERT A. AYUSO U.S. GEOLOGICAL SURVEY BULLETIN 1803 DEPARTMENT OF THE INTERIOR DONALD PAUL HODEL, Secretary U.S. GEOLOGICAL SURVEY Dallas L. Peck, Director UNITED STATES GOVERNMENT PRINTING OFFICE: 1987 For sale by the Books and Open-File Reports Section, U.S. Geological Survey Federal Center, Box 25425, Denver, CO 80225 library of Congress Cataloging in Publication Data Ayuso, Robert A. White mica geochemistry of the Catheart Mountain porphyry copper deposit, Maine. (U.S. Geological Survey bulletin ; 1803) Bibliography: p. Supt. of Docs. no.: I 19.3:1803 1. Mica-Maine-Somerset County. 2. Porphyry-Maine-Somerset County. 3. Geochemistry-Maine-Somerset County. I. Title. II. Title: Catheart Mountain porphyry copper deposit. Ill. Series. QE75.89 no. 1803 557.3 s 87~00317 [QE391.M6] [549' .67] CONTENTS Abstract 1 Introduction 1 Analytical procedures 1 Geology 2 Summary of the petrography 3 Summary of rock bulk composition 5 Definition of white mica 7 Composition of white micas at Catheart Mountain 7 Regular variations in white mica composition 9 Discussion 9 Relation of white micas and bulk composition 9 Aluminous white micas in mineralized rocks 11 Summary 14 Acknowledgments 14 References cited 14 FIGURES 1. Location map and surface expression of hydrothermal alteration of the Catheart Mountain porphyry Cu-Mo deposit 2 2-9. Graphs showing: 2. Variation in Al203 and Cu, the wide range in Fe203 and Cu, and the variation in F and Cu in the mineralized bulk rocks at Catheart Mountain 5 3. Wide range in S as a function of Cu, the variation in Mo and Cu, and the variation in Sn and Cu in the mineralized bulk rocks at Catheart Mountain 7 4. Change in Fe+ Mg+ Mn as a function of 2-Alv 1 in the white micas from Catheart Mountain 12 5. Distribution of Na/(Na + K) and Si in the white micas from mineral­ ized rocks and unmineralized rocks from Catheart Mountain 12 6. Distribution of Al1v + Alv 1 and Si+(Mg+ Fe) in the white micas from mineralized rocks and unmineralized rocks from Catheart Mountain 12 7. Distribution of Si and Al1v + (Na + K) in the white micas from miner­ alized rocks and unmineralized rocks from Catheart Mountain 12 8. Distribution of 2Alv 1 and Mg+Ti in the white micas from mineral­ ized rocks and unmineralized rocks from Catheart Mountain 13 9. Change in Cu content of the bulk rock and the Al1v + Alv 1 in the white micas coexisting with sulfides, and the distribution of S in the bulk rock and the Al1v + Alv 1 in the white micas coexisting with sulfides 13 Contents Ill TABLES 1. Summary of hydrothermal alteration, mineralogy, and sulfide occurrence in the Catheart Mountain Cu-Mo deposit, Maine 4 2. Representative analyses of the mineralized and unmineralized rocks in the Cat­ c-~a ~ !lllliH<tal l CCO'.:t~ 3. Average compositions, standard deviations, and structural formulas of white mica in the potassic alteration zone at Catheart Mountain 8 4. Average compositions, standard deviations, and structural formulas of white mica in the quartz sericite, sericitic, and propylitic alteration zones at Catheart Mountain 10 IV Contents White Mica Geochemistry of the Catheart Mountain Porphyry Copper Deposit, Maine By Robert A. Ayuso Abstract and, thus, it is potentially a good monitor of the changing chemical environment. This paper discusses the compo­ White micas from hydrothermally altered and mineral­ sition of white mica from different hydrothermal alter­ ized zones in the Catheart Mountain Cu-Mo porphyry ation zones in the Catheart Mountain Cu-Mo deposit in deposit have regular compositional variations that are gen­ erally related to the contents of copper, total iron, and Maine (fig. 1) as a function of the copper content of the sulfur in the whole rock. Micas in unmineralized rocks whole rock. exhibit no such relationship. White mica compositions Recent investigations on the composition of white reflect primarily the control imposed by the celadonitic sub­ micas in porphyry copper deposits include studies by stitution AIIV +Aiv1=Si+ (Fe, Mg). Guilbert and Schafer (1978), Beaufort and Meunier The variation in white mica composition in the Cat­ (1983), and Parry and others (1984). Guilbert and Schafer heart Mountain porphyry may be explained by super­ (1978) and Guilbert (1980) suggested that white mica in position and overprinting of mineral assemblages by ore porphyry mineralized areas might be an aid in explora­ fluids during mineralization and during the waning stages tion. McDowell and Elders (1980) studied white micas of hydrothermal alteration. Local bulk compositional differ­ from a geothermal field, and Hendry (1981) used white ences, changing PHao and fluid compositions during miner­ alization, and superposition of mineral assemblages along mica composition to study wall-rock alteration in volcanic­ microzoned veins contributed to variation in white mica hosted copper mineralization. Gunow and others (1980) composition. However, the general relation between white studied the fluorine content of sericite in the Henderson mica composition and base-metal content in the mineral­ molybdenite deposit in Colorado. In addition, the possi­ ized rocks at Catheart Mountain suggests that identification bility that white mica composition changes as a function of of this white mica population might be useful as an indica­ proximity to mineralization has been investigated in hydro­ tor of mineralization gradients. thermally altered submarine exhalative ores (Plimer and de Carvalho, 1982), in stratiform sulfide deposits (McLeod and Stanton, 1984), and in stratabound Ba-Zn INTRODUCTION mineralization (Fortey and Beddoe-Stephens, 1982). Mineralized rocks from porphyry copper deposits represent a complex interaction of magmatic and hydro­ ANALYTICAL PROCEDURES thermal processes. Titley (1982) and Beane and Titley (1981) recently summarized the geologic complexity of Twenty-two samples from the Catheart Mountain most porphyry copper deposits and noted the variation of Cu-Mo deposit were obtained from representative drill the intensive parameters before, during, and after miner­ cores traversing the regional hydrothermally altered and alization. Thus, the observed mineral assemblage depends mineralized zones (fig. 1). Polished microprobe thin sec­ on composition of the host rock, on position of the rock tions were obtained as close as possible to single veins in with respect to the ore fluid and heat sources, and on the drill core splits analyzed for major and trace elements as intensity and efficiency of late hydrothermal alteration well as for base metals (Mo, Cu, Sn, W, and so on). An events. effort was made to obtain the thin-section samples from Mineralogic studies may be of great value in under­ areas in the drill core that clearly contained chalcopyrite standing the chemical environment during mineralization and molybdenite in close proximity to white mica. in porphyry copper systems. For example, white mica Electron microprobe analyses of white mica were occurs in the potassic, phyllic, and mineralized zones of done at the U.S. Geological Survey, Reston, Va. Initially, most porphyry copper systems (Creasey, 1959; Meyer and the micas were analyzed with an automated, three­ Remley, 1967; Lowell and Guilbert, 1970; Rose, 1970) channel electron microprobe employing a combination of Analytical Procedures chemical, emission-spectrographic, and instrumental neutron-activation analyses. A complete presentation of the bulk-rock analyses and a discussion of the bulk chemistry are in preparation. GEOLOGY The Catheart Mountain Cu-Mo deposit is in a shallowly emplaced, fine- to medium-grained pluton that intruded the southeast flank of the Boundary Mountain anticlinorium (Albee and Baudette, 1972); this pluton belongs to a group of mineralized intrusives within the Appalachian porphyry province (Hollister, 1978). The two most important rock types at Catheart Mountain are quartz monzonite and quartz-feldspar porphyry, both of which contain mineralization. Nearby mineralized plutons in northern Maine include the newly reported Mo miner­ [] Quartz-sericitic 500 1000 METERS alization at Priestly Lake (Ayuso and Shank, 1983; Ayuso, 1984) and the Cu-Mo mineralization at Deboullie (Boone, Propylitic rn 1962; Hollister, 1978). The Catheart Mountain quartz monzonite and Figure 1. Location map and surface expression of hydro­ quartz-feldspar porphyry occur within the Attean Quartz thermal alteration of the Catheart Mountain porphyry Cu­ Monzonite of Ordovician age; this occurrence has led to Mo deposit. Also shown are the drill-hole sites. the assumption that the Attean Quartz Monzonite and the rocks at Catheart Mountain are genetically related and may be of the same age. However, petrographic studies wave-length and energy-dispersive procedures. Approxi­ have indicated that rocks at Catheart Mountain are sig­ mately half of the analytical work was done using an nificantly different from those from the Attean Quartz 1 automated ARL-SEMQ nine-channel electron Monzonite, and that they constitute a distinct mappable microprobe under similar operational conditions as in the unit. first part of the study, including 15-kilovolt operating The Attean Quartz Monzonite is coarsely voltage, 0.1-microamp beam current, and data-acquisition porphyritic and intrudes volcanic and volcaniclastic rocks (McGee, 1983) and correction procedures by the Bence that unconformably overlie the Precambrian (Naylor
Load more

Recommended publications
  • Studies of Celadonite and Glauconite
    Studies of Celadonite and Glauconite GEOLOGICAL SURVEY PROFESSIONAL PAPER 614-F Studies of Celadonite and Glauconite By MARGARET D. FOSTER SHORTER CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY PROFESSIONAL PAPER 614-F A study of the compositional relations between celadonites and glauconites and an interpretation of the composition of glauconites UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1969 UNITED STATES DEPARTMENT OF THE INTERIOR WALTER J. HIGKEL, Secretary GEOLOGICAL SURVEY William T. Pecora, Director For sale by the Superintendent of Documents, U.S- Government Printing Office Washington, D.C. 20402 - Price 40 cents (paper cover) CONTENTS Page Abstract.-_ ____-____-_--__-_-___--______-__-_______ Fl Interpretation of glauconite coniposition___-___________ F13 Introduction.______________________________________ 1 Relation between trivalent iron and octahedral aluminurn____________________________________ 13 Selection of analyses and calculation of atomic ratios___ 2 The Fe+3 :Fe+2 ratio_______________________ 13 Relation between the composition of celadonites and Relation between iron and potassium____________ 14 glauconites_ _ ___________________________________ 3 Fixation of potassium___________________________ 14 High potassium celadonites and glauconites-_______ 7 Deficiency in potassium content-_________________ 14 Relation between glauconite composition and geo­ Low potassium celadonites and glauconites_________ logic age_____________________________________ 15 Relation between Si, R+2 (VI), Al(VI), and R+3 (VI)_
    [Show full text]
  • Duration of Hydrothermal Activity at Steamboat Springs, Nevada, from Ages of Spatially Associated Volcanic Rocks
    Duration of Hydrothermal Activity at Steamboat Springs, Nevada, From Ages of Spatially Associated Volcanic Rocks GEOLOGIC AiL SURVEY PROFESSIONAL PAPER 458-D Duration of Hydrothermal Activity at Steamboat Springs, Nevada, From Ages of Spatially Associated Volcanic Rocks By M. L. SILBERMAN, D. E. WHITE, T. E. C. KEITH, and R. D. DOCKTER GEOLOGY AND GEOCHEMISTRY OF THE STEAMBOAT SPRINGS AREA, NEVADA GEOLOGICAL SURVEY PROFESSIONAL PAPER 458-D UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1979 UNITED STATES DEPARTMENT OF THE INTERIOR CECIL D. ANDRUS, Secretary GEOLOGICAL SURVEY H. William Menard, Director Library of Congress Cataloging in Publication Data Main entry under title: Duration of hydrothermal activity at Steamboat Springs, Nevada, from ages of spatially associated volcanic rocks. (Geology and geochemistry of the Steamboat Springs area, Nevada) (United States. Geological Survey. Professional paper ; 45 8-D) Bibliography: p. D13-D14. 1. Geothermal resources-Nevada-Steamboat Springs. 2. Geology- Nevada Steamboat Springs. 3. Potassium-argon dating. I. Silberman, Miles L. II. Series. III. Series: United States. Geological Survey. Professional paper ; 45 8-D. QE75.P9no. 458-D [GB1199.7.N3] 557.3'08s [553] 79-16870 For sale by the Superintendent of Documents, U.S. Government Printing Office Washington, D.C. 20402 Stock Number 024-001-03215-5 CONTENTS Page Abstract __________ _______.._____________ Dl Potassium-argon ages Continued Introduction ______________________________________________ 1 Rhyolite domes______________________
    [Show full text]
  • Experimental Data for High-Temperature Decomposition of Natural Celadonite from Banded Iron Formation
    Chin. J. Geochem. (2015) 34(4):507–514 DOI 10.1007/s11631-015-0066-2 ORIGINAL ARTICLE Experimental data for high-temperature decomposition of natural celadonite from banded iron formation 1 1 1 K. A. Savko • S. M. Piliugin • N. S. Bazikov Received: 5 March 2015 / Revised: 1 May 2015 / Accepted: 6 July 2015 / Published online: 17 July 2015 Ó Science Press, Institute of Geochemistry, CAS and Springer-Verlag Berlin Heidelberg 2015 Abstract Three experiments were set up to evaluate (KMA), Russia. Subalkaline BIF contains widespread conditions for the high-temperature decomposition of riebeckite, aegirine, celadonite, tetraferribiotite, and Al- celadonite from a banded iron formation in an alumina-free free chlorite instead of grunerite, stilpnomelane, minneso- system and identify its decomposition products. It was taite, and greenalite, which are the usual minerals in BIF estimated that at 650 and 750 °C, with a NiNiO buffer and elsewhere. At the KMA iron deposits, BIF with alkali pressure of 3 kbar, celadonite completely decomposes and amphibole were metamorphosed at 370–520 °C and 2–3 the decomposition products were tetraferribiotite, mag- kbar (Savko and Poskryakova 2003). netite and quartz. Under more oxidizing conditions (he- In the KMA, BIF green mica, which is responsible in matite-magnetite buffer instead of NiNiO), ferrous composition to the celadonite with the formula KFe3?(Mg, 2? potassium feldspar sanidine forms instead of magnetite. Fe ) = [Si4O10](OH)2, is quite abundant (Savko and During the celadonite decomposition in oxidizing condi- Poskryakova 2003). Celadonite forms emerald-green scales tions more magnesian and aluminous tetraferribiotite, sizing from a few tenths to 1.5–2 mm, composing up to along with ferrous sanidine, are formed than at reducing 30 %–40 % modal.
    [Show full text]
  • Factors Responsible for Crystal Chemical Variations in The
    American Mineralogist, Volume 95, pages 348–361, 2010 Factors responsible for crystal-chemical variations in the solid solutions from illite to aluminoceladonite and from glauconite to celadonite VICTOR A. DRITS ,1 BELL A B. ZV I A GIN A ,1 DOUGL A S K. MCCA RTY,2,* A N D ALFRE D L. SA LYN 1 1Geological Institute of the Russian Academy of Science, Pyzhevsky per. 7, 119017 Moscow, Russia 2Chevron ETC, 3901 Briarpark, Houston, Texas 77063, U.S.A. AB STR A CT Several finely dispersed low-temperature dioctahedral micas and micaceous minerals that form solid solutions from (Mg,Fe)-free illite to aluminoceladonite via Mg-rich illite, and from Fe3+-rich glauconite to celadonite have been studied by X-ray diffraction and chemical analysis. The samples have 1M and 1Md structures. The transitions from illite to aluminoceladonite and from glauconite to celadonite are accompanied by a consistent decrease in the mica structural-unit thickness (2:1 layer + interlayer) or csinβ. In the first sample series csinβ decreases from 10.024 to 9.898 Å, and in the second from 10.002 to 9.961 Å. To reveal the basic factors responsible for these regularities, struc- tural modeling was carried out to deduce atomic coordinates for 1M dioctahedral mica based on the unit-cell parameters and cation composition. For each sample series, the relationships among csinβ, maximum and mean thicknesses of octahedral and tetrahedral sheets and of the 2:1 layer, interlayer distance, and variations of the tetrahedral rotation angle, α, and the degree of basal surface corruga- tion, ∆Z, have been analyzed in detail.
    [Show full text]
  • List of Abbreviations
    List of Abbreviations Ab albite Cbz chabazite Fa fayalite Acm acmite Cc chalcocite Fac ferroactinolite Act actinolite Ccl chrysocolla Fcp ferrocarpholite Adr andradite Ccn cancrinite Fed ferroedenite Agt aegirine-augite Ccp chalcopyrite Flt fluorite Ak akermanite Cel celadonite Fo forsterite Alm almandine Cen clinoenstatite Fpa ferropargasite Aln allanite Cfs clinoferrosilite Fs ferrosilite ( ortho) Als aluminosilicate Chl chlorite Fst fassite Am amphibole Chn chondrodite Fts ferrotscher- An anorthite Chr chromite makite And andalusite Chu clinohumite Gbs gibbsite Anh anhydrite Cld chloritoid Ged gedrite Ank ankerite Cls celestite Gh gehlenite Anl analcite Cp carpholite Gln glaucophane Ann annite Cpx Ca clinopyroxene Glt glauconite Ant anatase Crd cordierite Gn galena Ap apatite ern carnegieite Gp gypsum Apo apophyllite Crn corundum Gr graphite Apy arsenopyrite Crs cristroballite Grs grossular Arf arfvedsonite Cs coesite Grt garnet Arg aragonite Cst cassiterite Gru grunerite Atg antigorite Ctl chrysotile Gt goethite Ath anthophyllite Cum cummingtonite Hbl hornblende Aug augite Cv covellite He hercynite Ax axinite Czo clinozoisite Hd hedenbergite Bhm boehmite Dg diginite Hem hematite Bn bornite Di diopside Hl halite Brc brucite Dia diamond Hs hastingsite Brk brookite Dol dolomite Hu humite Brl beryl Drv dravite Hul heulandite Brt barite Dsp diaspore Hyn haiiyne Bst bustamite Eck eckermannite Ill illite Bt biotite Ed edenite Ilm ilmenite Cal calcite Elb elbaite Jd jadeite Cam Ca clinoamphi- En enstatite ( ortho) Jh johannsenite bole Ep epidote
    [Show full text]
  • Minerals of Rockbridge County, Virginia
    VOL. 40 FEBRUARYJMAY 1994 NO. 1 &2 MINERALS OF ROCKBRIDGE COUNTY, VIRGINIA D. Allen Penick, Jr. INTRODUCTION RockbridgeCountyhas agreatdiversityofrocksandminerals.Rocks withinthecountyrangeingeologic agehmPmxnbrianthroughDevonian (01desttoyoungest)covexingatimespanofatleast 1OOOmilIion years. The county liesmostlywithintheVdeyandRiagePhysi~hich~~ 1). Thisprovinceis underlainbysedimentaryrochcomposedof dolostone, limestone, sandstone, andshale. TheexlMlceastempartofRockbridge County is withintheBlueRidge PhysiowhicPro. This areaisrepre sentedbyallthreemajorrocktypes: sedirnentary,igneous, andmetarnorphic. Theseinclu&Qlostone,qdta,inta~s~neandshale,granite, pmdiorite, andunakite. Ingeneral, theol&strocksarefoundin theeastem portion with youngerrocks outcropping in the westernpart of thecounty o%w2). Mininghasplaydan~tpaainthehistoryofRockbridgeCounty. Indians probably were thefirstco1lectorsof localqu~andquartzitefrom which they shapedprojectilepoints. Important deposits of ironore were mined in the 1800s near the towns of Buena Vista, Goshen, Vesuvius, and in Amoldvalley. Other early minesin thecounty -&manganese, waver- tine-marl, tin, niter (saltpeter), lithographiclimestone, silicasand, andcave orryx Thecounty has been prospected for barite, gibbsite (alumina), gold, silver, limonik(ocher),beryl, Ghalerite (zinc), andilmeniteandmtile(tita- nium), but no production has beenreported for t.Quarriesare still producing dolostone.lirnestone, andquartzitefor constructionaggregate andshale forbrickmanufacture. This report describes 102mineralsandnativeelements
    [Show full text]
  • Supplementary Table 1
    Supplementary Table 1. Compositional groups, typical sample numbers and location with their bulk compositional, mineralogical and petrographic characteristics at different metamorphic grades. Sample #s, Mineral assemblage, Compositio N/E Traverse, Texture Metamorphic Bulk Chemical mode nal GPS and grade Characteristics and Group coordinates other comments mineral chemistry Ms-Chl-Qtz-Ilm-Mag-Gr ± Kfs ± Pl Mode: (Qtz 35-42%, Ms 30 - 33%, Chl 25 - 30%, Pl 5-7%). #1/00, E, Lithology: Chlorite quartz phyllite (minor white 27 o11.268, mica), white mica quartz phyllite (minor chlorite) /88 o38.581 Two compositional and chlorite bearing quartzite. Millimeter to centimeter groups (one richer in scale banding into M- Al 2O3 ~25 wt.%, Muscovite: domain (mica + chlorite Chlorite Normal #187/01, another ~20 Wt.%). rich), grain size 2 - 20 m 187/3, Rocks richer in Paragonite 5%, Pyrophyllite 19%, Celadonite 12%, and Q - domain (quartz - 187/3/ CHAKRA Al 2O3 are relatively Fe-celadonite 13%. feldspar rich), grain size 10 , N, GPS not less ferruginous (see - 50 µm. known Fig 3). Chlorite: XMg (Mg/(Mg+Fe(tot)) = 0.37 - 0.41. Plagioclase: XAn = 0.03 #ID/00,E, Ms-Chl-Qtz-Bt - Pl ± Ilm ± Tur ± Gr 27 o11.268, /88 o38.581 Chl - Qtz - Ms - Ilm -Gr - Tur - Bt - Pl #2/00, E, Two subgroups - 27 o11.465, high Al, low Fe (18 o /88 38.650 - 24 wt% Al 2O3, - Mode: (Qtz 35-42%, Ms 30 - 33%, Bt 15 - 18%, Chl 4.5-5 wt% Fe 2O3) 10 - 12%, Pl 5-7%). Pervasive foliation defined #3/00, E, and low Al, high Fe by biotite, white mica, o 27 11.465, (14.5 - 17 wt% chlorite and occasional o /88 38.692 Al 2O3, 6.0 - 8.0 wt% Muscovite: ilmenite (S 2) almost parallel Fe 2O3).
    [Show full text]
  • Glauconite and Celadonite" Two Separate Mineral Species
    MINERALOGICAL MAGAZINE, SEPTEMBER I978, VOL. 42, PP. 373-82 Glauconite and celadonite" two separate mineral species H. A. BUCKLEY, J. C. BEVAN, K. M. BROWN, AND L. R. JOHNSON Department of Mineralogy, British Museum (Natural History), Cromwell Road, London SW7 58D AND V. C. FARMER The Macaulay Institute for Soil Research, Craigiebuckler, Aberdeen AB9 2QJ SU M M A RY. Analyseso f glauconites and celadonites from records the analyses of both minerals using X-ray continental sedimentary rocks and sea-floor basalts using diffraction (XRD), infra-red spectrometry (IR), X-ray diffraction, electron probe microanalysis, infra-red electron probe microanalysis (EPMA), and X-ray spectroscopy, and X-ray fluorescence spectroscopy are fluorescence (XRF). Modern XRD and IR tech- reported. The minerals are shown to be distinct species; each an isomorphous replacement series, glauconite hav- niques analyse a relatiyely large sample compared ing an average half unit cell of Ko.85(Fe3+, A13+)x.34 with EPMA; they do, however, distinguish and (Mg 2+, Fe2+)o.66(Si3.76Alo.z4)Olo(OH)2 whereas cela- identify most of the minerals present. Since the donite approaches the ideal half unit cell of K(Fe 3+, areas of individual analysis by EPMA approach I A13+)(Mg2+, Fe2+)Si4Oxo(OH)2. Considerable Fe 3+- pm in diameter, most impurities can be avoided by AIvl interchangeability occurs in the octahedral layer in using this technique. The external morphology of both minerals and considerable substitution of alum- selected samples was determined using a Cam- inium in the tetrahedral layer of glauconites results in the bridge Instruments' 6oo Stereoscan.
    [Show full text]
  • MUSCOVITE Which Grades Into “Sericite” at Depth (Klein, 1939)
    1939). 4. Arcadian mine (Klein, 1939). 5. Kearsarge lode: Generally found with “adularia,” MUSCOVITE which grades into “sericite” at depth (Klein, 1939). KAl2AlSi3O10(OH)2 6. Wolverine mine, Kearsarge: Variety “sericite” A widespread and abundant mica. It occurs in (Morris, 1983). 7. Quincy mine: Dark green, igneous rocks (granites and granitic pegmatites), waxy, barrel-shaped pseudohexagonal crystals up metamorphic rocks (slates, phyllites, mica schists, to 1 cm (pseudomorphous after chlorite?) occurred and micaceous gneisses), sediments and in a large pocket of calcite crystals associated with sedimentary rocks (chiefly sands and some native copper on the 7th level, approximately 100 sandstones), wall rocks of various ore deposits, and meters NE from the Number 2 Shaft. as a replacement of various primary silicates Iron County: Iron River district: As the 2M1 (plagioclase, andalusite, etc.) as the variety type in oxidized iron formation (Bailey and Tyler, “sericite.” 1960). Muscovite is widespread in the Portage Lake Keweenaw County: 1. Central mine: “Sericite” Volcanics of the Keweenaw (often referred to as forms tan, velvety coatings on calcite. 2. “sericite”) in a variety of parageneses (Livnat, Northeast of Gay: In Jacobsville Sandstone in 1983). While the varietal name “sericite” has been section 16, T56N, R30W; contains 1.5 to 4% used for any fine-grained muscovite, it is best Cr2O3 and ~1% V2O3 (L. L. Babcock, personal applied to secondary fine-grained muscovite that communication). 3. Dan’s Point, section 27, has replaced other pre-existing silicates by low- T59N, R27W: A very fine-grained vanadian temperature potassium metasomatism. “Phengite” muscovite occurs with calcite in veinlets less than 1 defines a series of potassium micas with mm thick on the faces of bleached joints in a silty compositions intermediate between muscovite and Keweenawan sandstone.
    [Show full text]
  • Gems and Placers—A Genetic Relationship Par Excellence
    Article Gems and Placers—A Genetic Relationship Par Excellence Dill Harald G. Mineralogical Department, Gottfried-Wilhelm-Leibniz University, Welfengarten 1, D-30167 Hannover, Germany; [email protected] Received: 30 August 2018; Accepted: 15 October 2018; Published: 19 October 2018 Abstract: Gemstones form in metamorphic, magmatic, and sedimentary rocks. In sedimentary units, these minerals were emplaced by organic and inorganic chemical processes and also found in clastic deposits as a result of weathering, erosion, transport, and deposition leading to what is called the formation of placer deposits. Of the approximately 150 gemstones, roughly 40 can be recovered from placer deposits for a profit after having passed through the “natural processing plant” encompassing the aforementioned stages in an aquatic and aeolian regime. It is mainly the group of heavy minerals that plays the major part among the placer-type gemstones (almandine, apatite, (chrome) diopside, (chrome) tourmaline, chrysoberyl, demantoid, diamond, enstatite, hessonite, hiddenite, kornerupine, kunzite, kyanite, peridote, pyrope, rhodolite, spessartine, (chrome) titanite, spinel, ruby, sapphire, padparaja, tanzanite, zoisite, topaz, tsavorite, and zircon). Silica and beryl, both light minerals by definition (minerals with a density less than 2.8–2.9 g/cm3, minerals with a density greater than this are called heavy minerals, also sometimes abbreviated to “heavies”. This technical term has no connotation as to the presence or absence of heavy metals), can also appear in some placers and won for a profit (agate, amethyst, citrine, emerald, quartz, rose quartz, smoky quartz, morganite, and aquamarine, beryl). This is also true for the fossilized tree resin, which has a density similar to the light minerals.
    [Show full text]
  • Nomenclature of the Micas
    Mineralogical Magazine, April 1999, Vol. 63(2), pp. 267-279 Nomenclature of the micas M. RIEDER (CHAIRMAN) Department of Geochemistry, Mineralogy and Mineral Resources, Charles University, Albertov 6, 12843 Praha 2, Czech Republic G. CAVAZZINI Dipartimento di Mineralogia e Petrologia, Universith di Padova, Corso Garibaldi, 37, 1-35122 Padova, Italy Yu. S. D'YAKONOV VSEGEI, Srednii pr., 74, 199 026 Sankt-Peterburg, Russia W. m. FRANK-KAMENETSKII* G. GOTTARDIt S. GUGGENHEIM Department of Geological Sciences, University of Illinois at Chicago, 845 West Taylor St., Chicago, IL 60607-7059, USA P. V. KOVAL' Institut geokhimii SO AN Rossii, ul. Favorskogo la, Irkutsk - 33, Russia 664 033 G. MOLLER Institut fiir Mineralogie und Mineralische Rohstoffe, Technische Universit/it Clausthal, Postfach 1253, D-38670 Clausthal-Zellerfeld, Germany A. M, R. NEIVA Departamento de Ci6ncias da Terra, Universidade de Coimbra, Apartado 3014, 3049 Coimbra CODEX, Portugal E. W. RADOSLOVICH$ J.-L. ROBERT Centre de Recherche sur la Synth6se et la Chimie des Min6raux, C.N.R.S., 1A, Rue de la F6rollerie, 45071 Od6ans CEDEX 2, France F. P. SASSI Dipartimento di Mineralogia e Petrologia, Universit~t di Padova, Corso Garibaldi, 37, 1-35122 Padova, Italy H. TAKEDA Chiba Institute of Technology, 2-17-1 Tsudanuma, Narashino City, Chiba 275, Japan Z. WEISS Central Analytical Laboratory, Technical University of Mining and Metallurgy, T/'. 17.1istopadu, 708 33 Ostrava- Poruba, Czech Republic AND D. R. WONESw * Russia; died 1994 t Italy; died 1988 * Australia; resigned 1986 wUSA; died 1984 1999 The Mineralogical Society M. RIEDER ETAL. ABSTRACT I I End-members and species defined with permissible ranges of composition are presented for the true micas, the brittle micas, and the interlayer-deficient micas.
    [Show full text]
  • Distinguishing Features and Identification Criteria for K
    minerals Article Distinguishing Features and Identification Criteria for K-Dioctahedral 1M Micas (Illite-Aluminoceladonite and Illite-Glauconite-Celadonite Series) from Middle-Infrared Spectroscopy Data Bella B. Zviagina 1, Victor A. Drits 1 and Olga V. Dorzhieva 2,* 1 Geological Institute, Russian Academy of Science (GIN RAS), 7 Pyzhevsky per., 119017 Moscow, Russia; [email protected] (B.B.Z.); [email protected] (V.A.D.) 2 Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry, Russian Academy of Science (IGEM RAS), 119017 Moscow, Russia * Correspondence: [email protected] Received: 12 December 2019; Accepted: 5 February 2020; Published: 11 February 2020 Abstract: A representative collection of K-dioctahedral 1M micas ranging in composition from (Mg, Fe)-poor illites to aluminoceladonites through Mg-rich illites (Fe-poor varieties) and from Fe-bearing, Mg-rich illites to celadonites through Fe-illites, Al-glauconites and glauconites (Fe-bearing varieties) was studied by Fourier-transform infrared (FTIR) spectroscopy in the middle-infrared region. Analysis and comparison of the relationships between the band positions and cation compositions of Fe-poor and Fe-bearing K-dioctahedral micas provided a generalized set of FTIR identification criteria that include the band positions and profiles in the regions of Si–O bending, Si–O stretching, and OH-stretching vibrations. FTIR data allow unambiguous identification of illites, aluminoceladonites, and celadonites, as well as distinction between Fe-illites and illites proper, as well as between Al-glauconites and glauconites. Specifically, a sharp maximum from the AlOHMg stretching vibration 1 1 at ~3600 cm− , the presence of a MgOHMg stretching vibration at 3583–3585 cm− , as well as 1 characteristic band positions in the Si–O bending (435–439, 468–472 and 509–520 cm− ) and stretching 1 regions (985–1012 and 1090–1112 cm− ) are clearly indicative of aluminoceladonite.
    [Show full text]