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CATION DETERMINATIVE CURVES for Mg Fe Mn OLIVINES from VIBRATIONAL SPECTRA1

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Ameican Mineralooist Vol. 57, pp. 962-9850972\ CATION DETERMINATIVE CURVES FoR Mg_Fe_Mn OLIVINES FROM VIBRATIONAL SPECTRA1 RocnrnG. BunNs ANDtr'RANK E. HucerNs,Department ol Earth and Planetarg Sciences, M ass achus ett s I nstitute oI T echnolo gg, Cambridge, M assachusetts02 I Sg Agsrnegr INrnooucrrox cation systemsonly. 'Paper presented at the lgz0 Annual Meetings of the Geologioar society of America, Milwaukee, Abstr., p. 5ll-Bl?. 967 968 BUNNSAND HUGGINS Early studiesof the infrared spectraof olivines (Lehmann,Dutz' that and Koltermann,1961 ; Duke and'stephens,1964) have-shown peak maxima are compositiondependent' Duke and Stephens(1964) suggestedfrom measurementsdown to 400 cm-l that infrared spectra .orrld b. usedas determinativecurves for olivines.we have extended the spectralrange to 200 cm-1and have derived equationsof cation compositiondeterminative curves for the Mg-Fe, Fe-Mn, and Mg-Mn olivine binary solid-solutionseries, and have constructeda determi- native grid for ternary Mg-Fe-Mn olivines' ExronrlrpNter, MPruoos The chemical analyses of the minerals used in the present study are sum- and marized in Table 1. specimens 1-11 belong to the forsterite-fayalite series, the specimens 11-15 conform closely to the fa.yalite-tephroite series, while and 1' tephroite-forsterite series is represented only by specimens 15, 16' 17' (specimen19), Data are also included for roepperite (specimen 18), monticellite (specimens1-18) and willemite (specimen20). The compositionsof the olivines are plotted oo u triuogrrlar diagram for the MpSiOa Fe"SiOn, and Mn'SiO' pseudobinary components in Figure 1-. This figure demonstrates the restricted nature of olivine minerals. Most of the spectra were measured over the range 2000-200cm-' oi a Perkin- Elmer model 225 recording spectrophotometer using powdered olivine specimens that in pressed cesium iodide discs. The precision of this instrument is zuch -F preparation of certain peak maxima may be read to 0'5 cm-' unit' Sample (Burns and silicat'e minerals for irrfrared, measurements is described elsewhere Prentice. 1968:Bancroft and Bums, 196,9)' lrtg 2 5 io4 T1 tL 7 : Mn25i04 Fc25lC)4 Frq. 1. Compositions of the olivines used fOr infrared measurements. DETERMINATION OF OLIVINES FROM SPECTRA 969 Relationships between olivine composition (X) and frequency (y) of eash peak maximum in the infrared spectrum (in cm-t units) were computed by a least squares method, using the CURFIT 2 ALGOL program on file at the Oxford University Computing Laboratory, England. This progra^rn enables a series of polynomials up to degree n ta be computed, provided there are (n * 2) or more points, together with two statistical error estimates: (l) sum of squares of residuals 2(lz.t" - o",t"l') for all points of coordinates (X, r) for each poly- nomial having the form v = c(n,O)* c(n,l)X + ... * c(n,n) Y and (2) standard deviations d(n, q) for the correspondingcoefficients c(n; q). The best-fit polynomial relating peak maxima to olivine composition was taken to be that for which the ratio residual (n): residual (n * l) did not exceed2:1. Rnsur,rs The spectraof minerals with the olivine structure are remarkably similar in the region 1000-550cm-1. This is illustrated by Figure 2, in which the spectraof the olivines forsterite,fayalite, tephroite,and monticelliteare comparedwith that of willemite which doesnot have the olivine structure.Five peaksmay be distinguishedin this region, the positionsof which changewith cation content of the olivine. An additional seven or eight peaks may be recognizedin the region below 550 cm-1,the relative intensitiesand positionsof which may vary with olivine composition. The spectra of the forsterite-fayalite series (except specimen8, which containsappreciable Mn) are illustrated in Figure 3 and the positionsof the peak maxima are summarizedin Table 2. Thirteen peaks or prominent shoulderscould be identified in the spectrum of forsterite (specimen1). Most of the peaks could be traced across the forsterite-fayalite series.Such sets of peaks are here labelled bands1 to 13. All of the bands on the forsterite-fayaliteseries show a shift of peak maxima to lower frequencieswith increasingiron content.How- ever,the compositionalvariations of the individual bandsdiffer, with the result that there are alsonotable changesof relative intensity and breadthof the band envelopesacross the seriescaused by the merging and divergenceof neighboringbands. For example,bands 6 and 7 appearto divergewith increasingiron content,so that band 6, which starts as a prominentshoulder in the spectrumof specimen1 becomes a distinct peak in the spectraof specimens5 to 11. The spectraof the fayalite-tephroiteseries are illustrated in Figure 4. The sameseries of bandsfound for the fosterite-fayaliteseries are remarkably uniform acrossthe fayalite-tephroite series.The peak maxima data summarizedin Table 3 show that the compositional 'D6 +d€do6rNddo tsccqooNhEo ON 6dEdo<+NtdF 6ccqooooqF NO r.oN90 66dEq@Fd! rl cEqEiNboFll N+Ntl N. !dd!6HFv .l ll 6ECEdEo+6ll ..Fdao MddEO@FFE -t I 6cEFilhooFtq) d{mHt e€€EdobbE 6EEENFooqla dd@ol N9F €NNOOEON qeNooco odEd6e@ild .l aE6tro@do4t9 6{eol do Egodoo .l I E@Noool9 .6s660 Ei6 .l c60 lo o6doo d666io .l Chodoolo do OoF q@imoolo dih o Eio6oo = dd---- o hoEE@o oo o r@ro6o bb$io do+ o qso@ooro o .: ,t o do< .t sooq$oro oE. E:3' d@N60N .t e _9? o Eoooooro oa ..:. o 6; o io@itso@ 6@iH@i o J- rl o cooFoo NE: sii@ * 35 o o- oooooo !HAJ ;c: e NNoo06a6a@a o o N No o o o o ! ! .4iHOOCOdd!oObcd-i @H<hhEZAZO?hEEOF DETERMINATION OF OLIVINES FROM SPECTRA 97I Tanr,n 1, coNr. 1. Forsterite; Webster, North Carolina; analysts: J. Carpenter, D. G. W. Smith (microprobe). 2. Chrysolite; Jan Mayan Island, Arctic Ocean (Berkeley 12489); analyst: D. G. W. Smith (microprobe). 3. Chrysolite; Skaergaard intrusion, East Greenland (Oxford 45Zi); analyst: D. G. W. Smith (microprobe). 4. Hyalosiderite; Skaergaard intrusion, East Greenland (Oxford 5107); analyst: D. G. W. Smith (microprobe). 5. Eyalosiderite; Skaergaard intrusion, East Greenland (Oxford 5111); analyst: D. G. W. Smith (microprobe). 6. Hyalosiderite; Skaergaard intrusion, East Greenland (Oxford 4077); analyst: J. V. Srnith (1966). 7. Hyalosiderite; Lydenburg, Transvaal, South Africa (Cambridge 54087); analyst: D. G. W. Smitb (miooprobe). 8. Hortonolite; location unknown (Berkeley 12494); analyst: D. G. W. Smith (microprobe). 9. Ferrohortonolite; Skaergaard intrusion, East Greenland (Oxford 5181); analyst: D. G. W. Smith (microprobe). 10. Ferrohorionolite; Skaergaard intmsion, East Greenland (Oxford 4147); analyst: D. G. W'. Smith (microprobe). 11. Fayalite; Rockport, Massachusetts (USNM R9517); analyst: D. G. W. Smith (microprobe). 12. Knebelite; Schysshyttan,Sweden (Berkeley l%lll); analyst: D. C. Harris (microprobe). 13. Knebelite; Dannemora, Sweden; analyst: G. E. Brown, personal communi- . cation (microprobe). 14. Manganknebelite; Broken llill, Australia; analyst: D. C. Harris (micro- probe). 15. Tephroite; Clark's Peninsula, Wilkes Land, Antarctica; Mason (1959). 16. Picrotephroite; Sterling, New Jersey, U.S.A. (Ilarva.rd 105490); analyst: Hurlbut (1961). 17. Picrotephroite; Franklin, New Jersey, U.S.A. (Harvard 85551); analyst: Hurlbut (1961). 18. Roepperite; Franklin, New Jersey, U,S.A. (Harvard Bauer Collection); analyst: D. C. Harris (microprobe). 19. Monticellite; Crestmore, California, U.S.A. (BM 1960, 334); ana.lyst: Moehlman and Gonyer (1934). 20. Willemite; Belgium (Oxford Museum); unanalysed. variations of all bands for the fayalite-tephroiteseries are smaller than those for the forsterite-fayaliteseries (Table 2). In the forsterite-tephroiteseries the poor representationof speci- menshaving compositionsbetween 10 and 50 percentMnzSiO+ makes it difficult to correlatebands unambiguouslyacross the seriesat low frequencies.This region of the infrared spectrais illustrated in Fig- ure 5 and the peak maximadata are summarizedin Table 3. The spec- 972 BURNS AND HUGGINS mg2sl04 (rl, to25l04 (*||] z = t123l04 I (rlt, a 2 a C.tla!lOa (/19) ln25l O4 (*20) ,lrrrrl looo aoo 600 aoo 200 Gn'r Frc. 2. Comparative infrared spectra of willemite and the olivines forsterite, faYaliLe, tephroite, aud monticellite. DETERMINATION OF OLIVINES FROM SPECTRA 973 -T--r--l-,-Trooo 90() 80() 400 300 #4 *6 #7 o E o : E c E lrl'l l'lrl rooo 90() 800 6()() 50() 4()(, 3()() cm-l Fra. 3. rnfrared spectra of Mg-Fe olivines of the forsterite-fayalite series. 974 BURNS AND HUGGINS 60() 500 400 300 20() #lt #.12 o I c o lb t E UI tr o L F 9N !! cc oo !! lrlrlLlrl 600 500 40(, 300 2oo cm-l Frc. 4. Infrared spectra of Fe-Mn olivinee of the faya,lite-tephroite series. DETERMINATION OF OLIVINES FRCIM SPECTRA w5 Table 2. Peak naxima in the infrareil spectra ol olivines of the f,orsterite - fayalite series Specinen No. L23 4567 891011 Banal 1 982 9 84 980 967 913 968 965 961 958 950 945 2 954 951 945 935 940 939 935 927 926 919 9r4 3 885 885 885 882 882 880 881 874 877 A76 472 838 838 836 834 835 834 833 830 830 a29 427 505 604 597 588 588 585 583 573 57r 568 558 5 s s 510 513 508 5r0 510 506 506 504 496 A90 49L 492 487 482 482 450 472 I 469 s 465 ssss s 408 s s 9 4r5 413 406 394 396 392 390 377 377 366 356 10 399s s s 1I Jt6 3t5 S t2 352 350 348 349 334 338 327 304 I3 294 294 288 284 282 28o s 266 s s 253 :es a proninent shoulder or tra appear to conform with trends in the forsterite-fayalite and fayalite-tephroite series, as most bands (in the forsterite-tephroite series) move to lower frequencies with increasing manganese content' Table 3, Peak mdina in the infrared sPectra
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  • Petrographic Investigation of Smithing Slag of the Hellenistic to Byzantine City of Sagalassos (SW-Turkey)K

    Petrographic Investigation of Smithing Slag of the Hellenistic to Byzantine City of Sagalassos (SW-Turkey)K

    American Mineralogist, Volume 101, pages 1072–1083, 2016 Petrographic investigation of smithing slag of the Hellenistic to Byzantine city of Sagalassos (SW-Turkey)k KIM EEKELERS1,*, PATRICK DEGRYSE1, AND PHILIPPE MUCHEZ1 1Earth and Environmental Science, Katholieke Universiteit Leuven, Celestijnenlaan 200E, 3001 Heverlee, Belgium ABSTRACT The frequent occurrence of iron slag in excavation layers of the Hellenistic to Byzantine city of Sagalassos (SW Turkey), indicates continuous iron working from the 1st to 7th century A.D. The slag samples are identified as smithing hearth bottoms and are found in dump fills, building foundations, and road constructions. Although several smelting sites are present in the 1800 km2 large territory of the city, the chemical signature of the smelting slag does not correspond to the characteristics of the smithing slag found in the city itself. The smithing slag does offer insight in the smithing techniques applied, which in turn provides information about the objects produced and production chain or “chaîne opératoire” followed for iron production in Sagalassos. Textural and mineralogical analyses reveal two main smithing techniques that were applied throughout the 1st to 7th century A.D. The most commonly applied smithing technique is used for the production of simple bulk materials, like hammers or anvils. Microscopic textures in the slag show mainly mechanical deformation at relatively high temperatures. The second, more sophisticated smithing technique shows the blacksmith treated the iron at different temperatures. The presence of high-lime contents indicates the use of a flux and/ or a protective agent against oxidation. This technique was applied to make more complex objects or objects with cutting edges.
  • Crystal Structure and Some Thermodynamic Properties of Ca7mgsi4o16-Bredigite

    Crystal Structure and Some Thermodynamic Properties of Ca7mgsi4o16-Bredigite

    crystals Article Crystal Structure and Some Thermodynamic Properties of Ca7MgSi4O16-Bredigite Xinjian Bao 1,2 , Mingyue He 3, Zhigang Zhang 4 and Xi Liu 1,2,* 1 Key Laboratory of Orogenic Belts and Crustal Evolution, Ministry of Education of China, Beijing 100871, China; [email protected] 2 School of Earth and Space Sciences, Peking University, Beijing 100871, China 3 School of Gemmology, China University of Geosciences (Beijing), Beijing 100083, China; [email protected] 4 Key Laboratory of Earth and Planetary Physics, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; [email protected] * Correspondence: [email protected] Abstract: Bredigite with the composition Ca7MgSi4O16 (Ca7MgSi4O16-Bre) has been synthesized by a solid-state reaction method at 1.2 GPa and 1373 K for 7 days, and its structure has been determined by single-crystal X-ray diffraction data. Following a relevant genealogy analysis in the literature, we have refined the structure into two space groups, Pnnm and Pnn2, and found that Ca7MgSi4O16-Bre belongs to the space group Pnnm, which can be essentially derived from the space group Pnn2 via an atomic coordinate transformation (with an average deviation of 0.039 Å only). Furthermore, some thermodynamic properties of the Ca7MgSi4O16-Bre have been obtained in this study. Using first-principles simulations based on density functional theory, the isothermal bulk modulus has been determined as 90.6(4) GPa with a pressure derivative of 5.7(1). Using density functional perturbation technique, the phonon dispersions and vibrational density of the states (VDoS) have been calculated.
  • Synthesis of Monticellite–Forsterite and Merwinite–Forsterite

    Synthesis of Monticellite–Forsterite and Merwinite–Forsterite

    Originally published as: Remmert, P., Heinrich, W., Wunder, B., Morales, L. F., Wirth, R., Rhede, D., Abart, R. (2018): Synthesis of monticellite–forsterite and merwinite–forsterite symplectites in the CaO–MgO–SiO2 model system: influence of temperature and water content on microstructure evolution. ‐ Contributions to Mineralogy and Petrology, 173. DOI: http://doi.org/10.1007/s00410‐017‐1429‐y Contributions to Mineralogy and Petrology (2018) 173:5 https://doi.org/10.1007/s00410-017-1429-y ORIGINAL PAPER Synthesis of monticellite–forsterite and merwinite–forsterite symplectites in the CaO–MgO–SiO2 model system: influence of temperature and water content on microstructure evolution P. Remmert1 · W. Heinrich1 · B. Wunder1 · L. Morales1 · R. Wirth1 · D. Rhede1 · R. Abart2 Received: 17 September 2017 / Accepted: 28 November 2017 © The Author(s) 2017. This article is an open access publication Abstract Homogeneous single crystals of synthetic monticellite with the composition Ca0.88Mg1.12SiO4 (Mtc I) were annealed in a ◦ piston-cylinder apparatus at temperatures between 1000 and 1200 C , pressures of 1.0–1.4 GPa, for run durations from 10 min to 24 h and applying bulk water contents ranging from 0.0 to 0.5 wt% of the total charge. At these conditions, Mtc I breaks down to a fine-grained, symplectic intergrowth. Thereby, two types of symplectites are produced: a first symplectite type (Sy I) is represented by an aggregate of rod-shaped forsterite immersed in a matrix of monticellite with end-member composition (Mtc II), and a second symplectite type (Sy II) takes the form of a lamellar merwinite–forsterite intergrowth.
  • The Mineralogical Magazine

    The Mineralogical Magazine

    THE MINERALOGICAL MAGAZINE AND JOUI~NAL OF THE MINERALOGICAL SOCIETY No. 214 September, 1951 Vol. XXIX The zoned contact-skarns of the Broadford area, Skye: a study of boron-fluorine metasomatism in dolomites. (With Plates XVIII-XXIV.) By C. E. TILLEY, Ph.D., F.R.S. Department of Mineralogy and Petrology, University of Cambridge. [Read in part June 24, 1948.] CONTENTS 1. Review of the progressive 5. Paragenesis of the skarn zones 644 metamorphism in the aureole 6. Productsoflimemetasomatism 652 of the Beinn an Dubhaich granite ............ 621 7. Contrasts of lime and iron- magnesia metasoma~ism in the 2. The skarn zones ...... 624 skarn successions ...... 658 3. Skarn successions associated 8. Comparison with the skarn with chert nodules ('sponge zones of other regions ...... 659 forms') ............ 632 Tables of mineral and rock analyses ......... 661 4. Mineralogy of the skarn zones 634 References ......... 663 1. REVIEW OF THE PROGRESSIVE METAMORPHISM IN THE AUREOLE OF THE BEIN~ AN DUBI~AIC~ GRA~IT~. N a preliminary note on the dolomite contaet-skarns of the Broadford I area, Skye (Tilley, 1948, a), a brief account was given of the constitu- tion and environment of these multizoned assemblages at the contact of the Durness limestone succession with the Tertiary Beinn an Dubhaich granite. 1 No detailed survey of the numerous parageneses was then attempted, and it is the purpose of the present paper to fill this gap and to discuss the genetic problems of these skarn assemblages. 1 The history of the discovery of these sk~rns and the exploratory work carried out during the 1939-45 war on some of the magnetite ore prospects has been indi- cated in the paper to which reference is now made.