 | | Journal (article/letter/editorial) | | Geology and Geophysics, University of Utah, Salt Lake City, UT 84112, USA 2 Department of Geological Sciences...Benson Mine District, Adirondack Mountains, New York and the Manitouwadge Massive Sulfide District, Ontario...euhedral grains and tendency to be intergrown with spinel. Rutile is readily distinguished from h6gbomite...performed infrared analyses on a h6gbomite from Liganga, Tanzania, and found no water. Thus the inconsistency...Enstatite-tremolite-chlorite skarns, Mautia Hill Tanzania, Tanganyika Woodford and Wilson (1976) S ap |  | | Journal (article/letter/editorial) | | closest-packed polysomatic mineral composed of spinel, T2M4O8, and nolanitelike, TM4O7(OH), modules where...characterize different stacking variants. Högbomite from a spinel-phlogopite schist at Corundum Creek (South Australia)...T8M20O38(OH)2 is composed of an alternation of spinel (S) and nolanite-like (N) blocks stacked in the...NSSNS. Högbomite from a Fe-Ti deposit at Liganga (Tanzania) with composition Mg13.5Fe5.6(Zn,Mn,Ni)0.2...explained in terms of two different modules, a spinel (S) and a nolanite (N) module (Gatehouse and Grey |  | NISHIMIYA, Yuki, TSUNOGAE, Toshiaki, SANTOSH, M., DUBESSY, Jean, CHETTY, T.R.K. (2009) Prograde and retrograde högbomites in sapphirine + quartz bearing Mg-Al rock from the Palghat-Cauvery Suture Zone, southern India. Journal of Mineralogical and Petrological Sciences, 104 (5) 319-323 doi:10.2465/jmps.090613 | Journal (article/letter/editorial) | | mm) högbomite occurs mantled by sapphirine and spinel with or without rutile, and the entire assemblage...pfu, respectively), occurs in the matrix around spinel and/or sapphirine. The texture suggests retrograde...magnesian and aluminous minerals such as sapphirine, spinel, kornerupine, and högbomite that are useful for...Sweden, is a complex Fe Mg Al oxide related to the spinel group. It has been reported as accessory phases...högbomite rimming spinel from many localities appears to suggest its formation by a spinel consuming reaction |  | | Journal (article/letter/editorial) | | as accessory phases in a metasomatically altered spinel-calcite-marble from the contact with the Bergell...relationships indicate a stepwise alteration of spinel to 1) hoegbomite or corundum + magnetite, 2) margarite...margarite and 3) chlorite. Replacement of spinel by hoegbomite can be described by the substitution 1...composition of pre-existing spinel. During the first two steps of spinel alteration, calcite was replaced...minerals and hoegbomite during replacement of the spinel-calcite-marble indicates that the metamorphic fluid |  | | Journal (article/letter/editorial) | | e exchange thermometry), are spinel-sapphirine-biotite-gedrite, spinel-corundum-sapphirine-cordierite...of primary spinel and rutile and/or ilmenite according to the generalised reaction: spinel + ilmenite/rutile...and HzO-contents. The partitioning of Zn between spinel and h6gbomite is not uniform and is considered...upon prevailing fo2 and aH2o. KEYWORDS: h6gbomite, spinel, secondary formation, oxidation, sapphifine-bearing...ROGALANO-VESTAGDER 6 ,~STFOLD SECTOR 7 WEST[R~ ONE~SS REGION SNARESUND 58.30,V/~q"~"I N FLOSTAOYA / 0 |  | | Report (issue) | | each country having a major vanadium deposit or district --------------------5. By World Bank economic...resources of vanadium cannot be distinguished. District totals are given for other deposits, for instance...number of records to the vanadium resources of a district or of an area was not done with the same detail...Kingdom. No geologic definition of a deposit (or district) is used for compiling records for this report...AUSTRALIA B Jull• .....•~·· , ·', . yob''"' I TANZANIA ,\••"'•• ,. ) j'-· -' . 'r '; ... "'- ' D |  | | Journal (article/letter/editorial) | | phlogopite-bearing diopsidite, phlogopite-humite-diopside-spinel marble, sillimanitegarnet quartzite and syn-tectonic...HoÈgbomite is a complex Fe-Mg-Al-Ti oxide related to the spinel group. Up to relatively recent, it was regarded...island (Razakamanana, 1990) and subsequently in spinel-hibonite-bearing rocks from HoÈgbomite in migmatitic...geobarothermometric pairs (cordierite-garnet, cordierite-spinel, orthopyroxeneclinopyroxene, enstatite-sapphirine...the presence of a primary assemblage formed by spinel-sapphirine-orthopyroxene-cordierite-biotite-corundum-gedrite |  | | Journal (article/letter/editorial) | | TITANIFEROUS MAGMA& 211 A. The most ancientrocksin this region which belongto the Grenville series (sedimentarymaterial...Adirondack District. Explanation: 1. Area underlain by gabbroic anorthositic rocks. 2. Sanford Lake depositsß3...havinga gabbroiccharacter, (d) titaniferousoresof Lake Sanfordtype. B. II. The rocksthat were derivedfrom...discussedin the precedingsection. The secondset, Sanford Lake type associatedwith the ancientsaturatedintrusion...connectionsin the compositionof ores comingfrom the same region are not merechance(22 analyses);theyconfirmthe |  | | Journal (article/letter/editorial) | | Vol. 69(6), pp. 937±949 Ti-free hÎgbomite in spinel- and sapphirine-bearing Mg-Al rock from the Palghat-Cauvery...TR AC T We report a new type of hoÈgbomite in a spinel- and sapphirine-bearing silica-deficient Mg-Al...enclosed within or along grain boundaries of greenish spinel. It is compositionally very unique due to the lack...reaction took place at retrograde stage ( <800ëC): spinel + H2O + O2 ? hoÈgbomite + corundum + magnetite...Ti-free hoÈgbomite. X T hoÈgbomite, sapphirine, spinel, Mg-Al rock, metamorphic ¯uid, Palghat-Cauvery |  | | Journal (article/letter/editorial) | | anthophyllite, spinel-hercynite, and rutile. Hoegbomite has a chemistry similar to spinel in that it readily...wt%). Hoegbomite commonly forms by alteration of spinel (e.g. Friedman 1952; Zakrzewski 1977). However...hoegbomite and spinel, Hoegbomite: A n i o n s - 30 O + 2 OH, c a t i o n s = 2 2 ; spinel: Fe 3 + + A1...features in infrared spectra of hoegbomite from Tanzania. On the other hand, Gatehouse and Grey (1982)...0.5 as in spinel. However, hoegbomite actually consists of alternating layers of a spinel-like structure |  | | Journal (issue) | | Tobacco Homworm in the Southern Cigar-Tobacco District. By A. H. Madden and F . S. Chamberlin. Tech....and wrote a brief account of the geology of the district; in r836 Sir Roderick Murchison referred to fossils...hydro-geological surveys were made of the coastal region east and north-east of Accra, and of the Voltaian...evidence of widespread raised beaches, river and lake t erraces, and of the drowned mouths of some of...age. The crater, 391 sq. miles in area, in which Lake Bosumtwi (18 sq. miles) is situated, was formed |  | Owens, B. E., Belkin, H. E., Zerolis, J. M. (2013) Margarite, corundum, gahnite and zincohögbomite in a blackwall, Raleigh Terrane, Eastern Piedmont Province, USA. Mineralogical Magazine, 77 (7) 2913-2929 doi:10.1180/minmag.2013.077.7.03 | Journal (article/letter/editorial) | | across) that typically consist of ragged Zn-rich spinel grains surrounded by masses of randomly oriented...associated with spinel are smaller grains of corundum and högbomite. In most cases, spinel and högbomite...suggest that högbomite formed at the expense of spinel (although locally the reverse relationship holds)...holds), and högbomite compositions mimic those of spinel. Margarite appears to be a later phase, and textures...reactions with spinel, corundum and, possibly, chlorite. This occurrence of Zn-rich spinel and högbomite |  | | Journal (article/letter/editorial) | | Departmentof Geologyand Geophysics, Universityof Utah, Salt Lake City, Utah 84112 Abstract Tin andtin-bearingmineralsare...Regionaland district geology The Manitouwadgeminingdistrict,located80 km north-northeastof Lake Superior...Manitouwadge(Stockwell,1964). Numerousaccountsof the district geologyhave been published(Pye, 1957; Milne, 1969;...northof the orebody.Among the lithologiesin the district,onlythe cordierite-gedrite gneisses haveunusuallyhightin...samesolutionswhich leachedthe copper and zinc. The district cordierite-gedrite gneisses,which representconformablefootwall |  | | Journal (article/letter/editorial) | | al. 1978). In Yalgin's (1987) study, both the Zn spinel gahnite and h6gbomite were found, each in characteristic...platy habit parallel to the octahedral faces of the spinel. Selected microprobe analyses of gahnites are listed...Table 1. Ferric iron was calculated assuming ideal spinel stoichiometry, R2+R23+O~; the Ti contents are low...h6gbomite and the related phase nigerite along {111} of spinel were described by Schmetzer and Berger (1990) and...Fig. 6. Epitactic relationship between central spinel octahedron (shaded) and the overgrowth of eight |  | | Journal (article/letter/editorial) | | Springer-Verlag 1987 Lamellar nigerite in Zn-rich spinel from the Falun deposit, Sweden J.C. Schumacher...found in Zn-rich spinel from a sample that contains chiefly anthophyllite + spinel + cordierite, lesser...of spinel-like (R 2 +A1204) and nolanite-like ((Sn, Ti)Alg0s) structures. In nigerite, the spinel-like...spinel-like part is also compositionally related to spinel, but in the nolanite-like part only the structural...the breakdown of R22+ (Sn, Ti)O 4 and RZ+A1204 spinel components during more complex reactions. An experimental |  | | Journal (article/letter/editorial) | | Hdgbomite, a complex Fe-Mg-Al-Ti oxide related to the spinel group and once thought to be rare, has been reported...substantially higher than Fe3+-Feratios characteristicof spinel-hercynite and ferromagnesiansilicates,but similar...oxidation of magnetite results in exsolution of spinel-hercynite and oxidationexsolution of ilmenite....hiigbomite by alteration hand, development the other of spinel-hercynite or oxidation-exsolution of magnetite...formed from a metastable reaction of quartz and spinel in fluid-deficient conditions during the retrogradestageofa |  | | Journal (issue) | | postage • Vl Contents PAGE ARTICLES Variations in Lake Levels and Sunspots. By F. Dixey, C.M.G., O.B.E...• Illustrations Variations in Lake Levels and Sutispots Plate I Lake Victoria and the Nile outlet •...Plate II Lake Nyasa and Upper Shire River . • • • Plate III Fluctuations in East African Lake Levels...Sociery,London, W. I. X 1 PLATE I [Ry courlt'S1 LAKE \l1C1'0RIA AND 'fHE 1 C.O.I., Lo11don ILl:...•me, no,v t1earing compleLio11. VARIA TI ONS IN LAKE LEVELS AND SUNSPOTS By F. DIXEY,C.M.G., O.B.E., |  | | Book | | "Broadly regarded, the depth ta which a metalliferous region has been eroded affects its present characteristics...Batholith near Arequipa, Toquepala-Cerro Verde district; in the centre, Morococha and in the north, Michiquillay)...pyroxene, amphibole, plagioclase, and possibly spinel. Eclogite transformation occurs beneath the depths... NORTH LAKE BALKHASH (PRIBALKHASH) REGION, KAZAKHSTAN, U.S.S.R. This is an outstanding region of Permo-Carboniferous...interpreted as marking the cores of stratovolcanoes. The region is densely mineralized and contains the principal |  | | Report (issue) | | and the Mumbwa District, the former including the valley proper in the Gwembe District and its flanks...discovery of a group of carbopatites in Feira District; the working out of the succession and structure...structure in the Katanga System in the Mumbwa-Lusaka District, and the demonstration of granitisation at the...deposits north of the Ruhuhu coalfields in Njombe District. Seven carbonatites have been located, and...apatite in the carbonatite of Nkombwa Hill, Isoka District, and some 25 to 30 million tons of coal in the |  | | Book | | "Broadly regarded, the depth to which a metalliferous region has been eroded affects its present characteristics...Batholith near Arequipa, Toquepala-Cerro Verde district; in the centre, Morococha and in the north, Michiquillay)...pyroxene, amphibole, plagioclase, and possibly spinel. Eclogite transformation occurs beneath the depths... NORTH LAKE BALKHASH (PRIBALKHASH) REGION, KAZAKHSTAN, U.S.S.R. This is an outstanding region of Permo-Carboniferous...interpreted as marking the cores of stratovolcanoes. The region is densely mineralized and contains the principal |  | | Journal (issue) | | much the same pattern of forces has acted in the region from the earliest (Ubendian) diastrophism and successive...intimate acquaintance witl1 the geology of the region. After some preliminar)r work on the northern portion...·complicated until the hills drop to the plains north of Lake Edward. To the west, where Ruwenzori overlooks the...Portal plateau region, and (3) the slope which rises gradually from the down-faulted area of Lake George. The...Basement Complex of the northern part of the Toro District, which strike NE-SW directly into the southern |  | | Report (volume) | | Vanadium-bearing magnetite-ilmenite deposits near Lake Sanford, Esse"!{ County, New York: U.S. Geol. Survey...base-metal vanadates, and the Colorado Plateau region, where vanadium-uranium deposits in sandstone are...geographic units, such as the Colorado Plateau region. "The Statesman's Yearbook," 19651966, 102d edition...Association Geologists, Annual Field Conference. Salt Lake City, Utah. Intermtn. Assoc. Petroleum Geologists...Geological and Mineralogical Survey Bulletin., Salt Lake City, Utah. Utah Geol. and Mineralog. Survey Spec |  | | Journal (volume) | | Rhexoxylon and Dadoxylon from the Lower Shire Region of Nyasaland and Portuguese East Africa . By Professor...British Guiana Occurrence of Helium- bearing Gases in Lake Province, Tanganyika 85 85 86 87 88 89 90 91 91...Rhexoxylon africanum Banc . Half the expanded Pith Region of a large Stem, with Shreds of normal Secondary...Evaporation, and Rate of Change of Sunspot Numbers for Lake Nyasa 159 161 162 163 page Method of Staining...River, about midway between the south 35 ern end of Lake Nyasa and the Shire -Zambezi conflu The ence ( |  | | Journal (article/letter/editorial) | | metamorphosed sedimentary iron deposits, Krivoy Rog and Lake Superior type, Magak'yan quotes an opinion that...stratigraphic sequence of Precambrian rocks of the region is favorable for the formation of thick highgrade...thus preventing its complete precipitation as a spinel during initial crystallization of the ultramafic...mining began to develop in the Urals, Karelia Tula region, and Khoper River valley. A little later exploitation...States reserves of high-grade ore in the Lake Superior region are largely exhausted. As a result, a considerable |
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