 | | Journal (article/letter/editorial) | | combeite- and götzenite-bearing nephelinite at Nyiragongo, Virunga Volcanic Province in the East African...a c t The lavas and pyroclastic rocks of Nyiragongo volcano (East African Rift) range in composition...combeite nephelinite. In peralkaline nephelinites at Nyiragongo, titanium is hosted in mineral assemblages with...melilite phenocrysts), recrystallized nepheline + kalsilite phenocryst aggregates and a range of late accessory...The compositions of coexisting nepheline and kalsilite in phenocryst aggregates and groundmass suggest |  | | Journal (article/letter/editorial) | | Kalsilite in the lavas of Mt. Nyiragongo (Belgian Congo) by TH. G. S AH AM A University of Helsinki,...(1942) and, later, by Sahama (1954). Subsequently, kalsilite was detected in a number of rocks from localities...within the Bunyaruguru field and, in addition, KALSILITE [Journal of Petrology, Vol. 1, Part 2, pp. 146-71...nephelinite lavas of the volcano Mt. Nyiragongo in the eastern Belgian Congo contains kalsilite as one of the main...leucite. Other important constituents of these kalsilite-bearing rocks are clinopyroxene, olivine, perovskite |  | | Journal (article/letter/editorial) | | Kalsilite in the lavas of Mt. Nyiragongo (Belgian Congo) by TH. G. S AH AM A University of Helsinki,...nephelinite lavas of the volcano Mt. Nyiragongo in the eastern Belgian Congo contains kalsilite as one of the main...leucite. Other important constituents of these kalsilite-bearing rocks are clinopyroxene, olivine, perovskite...The feldspars are lacking. Kalsilite occurs both as complex nepheline-kalsilite phenocrysts in which these...from those of nepheline. The complex nepheline-kalsilite phenocrysts exhibit a continuous series of progressing |  | | Report (issue) | | Data: Hexagonal. Point Group: 6: nepheline and kalsilite. Physical Properties: Extremely ¯ne-grained;...501(2) Z = n.d. X-ray Powder Pattern: Kabfumu volcanic °ow, Congo. 3.076 (100), 3.050 (95), 2.558 (45)...kaliophilite, kalsilite, and panunzite. Occurrence: In lava. Association: Nepheline, kalsilite. Distribution:...the Kabfumu volcanic °ow, between the Mt. Mikeno and Mt. Nyiragongo volcanos, Kivu Province, Congo (Zaire)...length of the [100] axis, three times that of kalsilite. Type Material: n.d. References: (1) Sahama |  | | Journal (article/letter/editorial) | | Aufs~itze Mineralogical composition of the Nyiragongo rod, s By TrL G. SArr~MA,Helsinki *) With 8 figures...figures and 2 tables Dedicated to Professor Dr. A. RITTMANNon the oeeasion of his 75. birthday Zusammenfassung...Gesteinsanalysen auf die Laven des Nyiragongo-Vulkans in Nord Kivu, Republik Congo (Kinsasha). In dem hetr. vulkanischen...Basanitgruppe (m~il3ig unters~ttigt) und das Nyiragongo-Gebiet mit Gesteinen der Leuzitit-NephelinitMelilitithgruppe...Entstehung des hauptsiichlich melilitithischen Nyiragongo-Magmas mSglicherweise mit karbonatischen Anteilen |  | | Journal (article/letter/editorial) | | NorES AND NEWS 287 ORDER-DISORDERIN KALSILITE J. V. Snrrn, Dept. of Mineral,ogy and, Petrology,Cambrid'ge...Geology,Helsinki', Finland. eno Tn. G. S.l.nau.o,, Kalsilite, the stable form of KAlSiO4 at ordinary temperatures...that the structure type of kalsilite is H2e (Gottfried, 1940) but kalsilite can truly belong to this structure...disordered structures would be small and crystals of kalsilite previously found have been too small to provide...avaiiable from a lava flow at Kabfumu, Nyiragongo area in North Kivu, Belgian Congo, which has been studied |  | | Journal (article/letter/editorial) | | nepheline (melilite nephelinites) from the Nyiragongo volcano of the Congo and a group rich in olivine (olivine...(the melilite nephelinite of the lava lake of Nyiragongo) through the Cameroons etindite (clinopyroxene...includes a number of lavas of the Nyiragongo Crater area of the Congo and an etindite from the Cameroons...nepheline-kalsilite surrounded by a nepheline margin (FEAE 83). The lava of the lava lake of Nyiragongo crater...is 1100°C-for the specimen of the lava lake of Nyiragongo. Sahama and Meyer (1958 p. 15) have recorded |  | | Journal (article/letter/editorial) | | between the alkali feldspars and the nepheline-kalsilite series would suggest existence of similar phenomena...of the specimens are from the Nyiragongo volcano in the Eastern Congo. Column 4 explains the mode of...or from intravolcanic sills and dykes. For the Nyiragongo area specimens, the exact petrographic definition...Uganda Baruta, Congo Nyiragongo, Congo 15 16 17 18 19 20 21 22 23 24 Nyiragongo, Nyiragongo, FEAE 86 Nyiragongo...FEAE 87 Nyiragongo, FEAE 88 Nyiragongo, FEAE 89 Nyiragongo, FEAE 92 Nyiragongo, FEAE 93 Nyiragongo, S77 |  | | Journal (article/letter/editorial) | | also for lava flows from one extensively sampled volcano. Hypotheses involving simple fractional crystallization...Birunga area at the junction of the Congo, south-west Uganda, and north-west Rwanda (see Fig. 1). The Birunga...Nyamlagira (Nyamuragira) and Nyiragongo in the Virunga province of the Congo. Most of the volcanoes in the...FIELD 2 - TORO-ANKOLE FELO 3 - SOUTH KIVU FIELD CONGO LAKE KIVU LAKE. TANSANYIKA\ INDIAN OCEAN FIG...Birunga field. The volcanic field to the south of Lake Kivu, however, consists largely of olivine and tholeiitic |  | | Journal (article/letter/editorial) | | and andremeyerite-bearing nephelinite from Nyiragongo volcano, East African Rift Tom Andersen a,⁎, Marlina...peralkaline leucite nephelinite from the active volcano Nyiragongo in the Virunga province of the East African...of uncommon minerals coexist with this glass (kalsilite, kirschsteinite, chlorbartonite, götzenite, delhayelite...mineral. Low-variance mineral assemblages in Nyiragongo nephelinite define a cooling trend from eruptive...East African Rift (Shombole, Oldoinyo Lengai, Nyiragongo). A number of rare minerals that are characteristic |  | | Journal (article/letter/editorial) | | January 1956.] Summary.--Three new analyses of kalsilite are given, with optical and X-ray data; two (K/(K-~-Na)...determining the ratio of potassium to sodium in kalsilite. In his pat)er mentioned above, Smith (loe. eit...gives the difference in 20 angle between the kalsilite lines 1012 and 1011. The mc'~surements were made...A-values were given by Smith for two synthetic kalsilite preparations that contained 90 and 100 % by weight...may be used for determining the composition of kalsilite. For natural kalsilitc, thc rarity of the mineral |  | Chakrabarti, Ramananda, Basu, Asish R., Santo, Alba P., Tedesco, Dario, Vaselli, Orlando (2009) Isotopic and geochemical evidence for a heterogeneous mantle plume origin of the Virunga volcanics, Western rift, East African Rift system. Chemical Geology, 259 (3) 273-289 doi:10.1016/j.chemgeo.2008.11.010 | Journal (article/letter/editorial) | | active Virunga volcanoes, Nyiragongo and Nyamuragira, are 15 km apart. Nyiragongo shows unusual compositions...major, trace elements and Nd–Sr–Pb isotopes in Nyiragongo and Nyamuragira lavas including samples from...from 2002, 2003 and 2004 eruptions. The youngest Nyiragongo lavas are ultrapotassic, ultrasodic and have...basanites and tephrites, distinct from the foiditic Nyiragongo lavas. Both volcanic products show enrichment...Dy/Yb suggests residual garnet in the source(s). Nyiragongo and Nyamuragira lavas show high Nb/U similar |  | | Journal (article/letter/editorial) | | Microstructures and high-temperaturephasetransitions in kalsilite Mrcnnnr. A. CnnpnNTER AND DlNrnr,l CsLr,Ar Department...microscopy in natural kalsilite from volcanic and metamorphic rocks (Mount Nyiragongo, Z,aire; Alban Hills...er and singlecrystal X-ray diffraction. Pure kalsilite has P6rmc symmetry at high temptiratures but transformsto...involves the coexistenceof this phase with P6, kalsilite. High tetrakalsilite with composition -Ks,o reverts...atoms converge. At lower temperatures,pure P6, kalsilite appearsto have transformed during a metamorphic |  | | Journal (article/letter/editorial) | | 286 NOTESAND NEWS TRI-KALSILITE, A NEW MINERAL Tu. G. Sauaue, Institute of Geology,Helsinki, Finland...order-disorder in kalsilite is recorded in the following note. In addition to crystals of kalsilite-nepheline...kalsilite-nepheline microperthite, the lava from Kabfumu, North Kivu in Belgian Congo, contains parallel growths of a new...new mineral, tri-kalsilite, and nepheline. After heating to 1000o C. for two hours, one crystal consistedalmost...consistedalmost entirely of tri-kalsilite. Weak, slightly difiuse reflections revealed the presenceof nepheline |  | | Journal (article/letter/editorial) | | Exchange Between Tectosilicates with the Nepheline-Kalsilite Framework and Molten MNO3 or MCI (M--Li, Na, K...a synthetic Na-rich nepheline, and synthetic kalsilite were ion exchanged in molten MNO3 or MC1 ( M =...member (K,D)4[A13(A1,Si)Si4Oa6] which shows the kalsilite structure; there was no indication for the formation...correspondenceshould be addressed Introduction Nepheline and kalsilite are stuffed derivatives of tridymite D[Si204]...in order to compensate the charge deficit. In kalsilite K[A1SiO4], P63 a = 516 c= 869 pm Z = 2 , all cavities |  | | Journal (issue) | | Type Mineralogy of the Democratic Republic of the Congo................................................... Hickox, Jr. Wally Mann Keith and Diane Brownlee Dr. Nikolas Golosow William B. (Bill) Wray Herb & Monika...COLLECTIONS OF Kurt Hefendehl Jack Halpern Dr. Gene Meieran Dr. Steve Smale Dr. Vasco Trancoso Bill and Anne Cook...Type Mineralogy of the Democratic Republic of the Congo Florias Mees Department of Geology Royal Museum...for localities in the Democratic Republic of the Congo. A close look at how some of these species were |  | | Journal (article/letter/editorial) | | about 55 /kbar for the reaction nepheline kalsilite tetrakalsilite (K-rich nepheline) over the...K(1=2 : Introduction Nepheline, leucite, and kalsilite are the three most common anhydrous framework...thermodynamic properties of nepheline-, leucite-, and kalsilite-solid solutions 257 (ss) and integrated them...correctly predicts crystallization of nepheline-kalsilite and leucite solutions in numerous lava series...parameters of nepheline are roughly twice those of kalsilite, a P63 hexagonal stued derivative of tridymite |  | | Journal (article/letter/editorial) | | of interest since kalsilite quantities of the KAlSiOr polymorph callecl kalsilite is not a common mineral...presented for both the iron-rich mica and the kalsilite. INtnotructroN Attempts to grow single crystal...comparatively large quantities of the mineral kalsilite, the hexagonalform of KAlSiOa.Kalsilite is relatively...difficult to identify with assuratrcein thin section. Kalsilite was discovered in volcanic rocks from S.W. Uganda...clarify phase relations in the system nepheline-kalsilite and polymorphism in KAlSiOr. These studies indicate |  | | Journal (volume) | | (Eastern Congo) 8. TH. G. SAHAMA, Contact Microradiographic Distinction between Nepheline and Kalsilite in...Philippines Ojakangas, Richard, M. A., USA Dudek, Arnost, Dr., Czecho-Slovakia Clark, Alan, B. Sc., Great Britain...malmiesiintymistii. 40 Bulletin de la Commission g6ologiquc dr? Finlande N:o 196. Veikko Okko: Geologi-lehden ilmestymisen.... Lougee: Glacial Shoreline History in Eastern North America. A. Von Volborth: Vayryneniitistä. H. Stigzelius:...areas of molasse in Finland. Beginning from the north, the Kumpu formation has been thought to be a molasse |  | | Journal (volume) | | (Eastern Congo) 8. TH. G. SAHAMA, Contact Microradiographic Distinction between Nepheline and Kalsilite in...Philippines Ojakangas, Richard, M. A., USA Dudek, Arnost, Dr., Czecho-Slovakia Clark, Alan, B. Sc., Great Britain...malmiesiintymistii. 40 Bulletin de la Commission g6ologiquc dr? Finlande N:o 196. Veikko Okko: Geologi-lehden ilmestymisen.... Lougee: Glacial Shoreline History in Eastern North America. A. Von Volborth: Vayryneniitistä. H. Stigzelius:...areas of molasse in Finland. Beginning from the north, the Kumpu formation has been thought to be a molasse |  | | Journal (volume) | | Kirjeenvaihtajajäsenet Barth , Tom F. W ., Prof. Cloos, Ernst, Dr. von Eckermann, Harry, Prof. Flint, Richard, F ....F . J ., Prof. Ramdohr, Paul, Prof. Dr. Sander, Bruno, Prof. Dr. Szadeczky-Kardoss, Elemer, Prof. Vendl...Vendl, A., Prof. Wojno, Tadeusz, Prof. Öpik, Ar., Dr. MEMBERSHIP LIST H onorary Members Rakuunantie...0 218. Ulkomaiset jäsenet Adamson, Olge J., Fil. Dr. Armstrong, Herbert S., Prof. Barbour, George B.... Geolog Bem, Hansjürgen, Mag. Blake, Weston Jr., Dr. Bloomfield, Keith, M. Sc. Brognon, Georges, Inge |  | | Journal (volume) | | Kirjeenvaihtajajäsenet Barth , Tom F. W ., Prof. Cloos, Ernst, Dr. von Eckermann, Harry, Prof. Flint, Richard, F ....F . J ., Prof. Ramdohr, Paul, Prof. Dr. Sander, Bruno, Prof. Dr. Szadeczky-Kardoss, Elemer, Prof. Vendl...Vendl, A., Prof. Wojno, Tadeusz, Prof. Öpik, Ar., Dr. MEMBERSHIP LIST H onorary Members Rakuunantie...0 218. Ulkomaiset jäsenet Adamson, Olge J., Fil. Dr. Armstrong, Herbert S., Prof. Barbour, George B.... Geolog Bem, Hansjürgen, Mag. Blake, Weston Jr., Dr. Bloomfield, Keith, M. Sc. Brognon, Georges, Inge |  | | Book (volume) | | felspars we have been particularly fortunate in having Dr W. S. MacKenzie close at hand and are most grateful... . . .179 NEPHELINE GROUP.231 Nepheline, Kalsilite ....... 231 PETALITE.271 LEUCITE.276 SODALITE...nomenclatures we have been guided princip¬ ally by Dr. W. S. MacKenzie, whose assistance is gratefully...high-sanidine. Wyart (1947) obtained orthoclase (and kalsilite) by the interaction of muscovite, silica, and...424-C, p. 309. Wyart, J., 1947. Synthese de la kalsilite et de l’orthose. Paris, vol. 225, p. 944. Gompt |  | | Book (edition) | | co-author, teacher, mentor, colleague and friend, Dr. Joseph A. Mandarino. -Malcolm E. Back Fleischer's...they are: Dr. Peter Bayliss, Dr. Ernst A.J. Burke, Dr. Anton and hakhmouradian,Robert Gault, Dr. Julian...Låszl6 Horvåth, Dr. Uwe Kolitsch, Locock,Gaspare Malet.to,Dr. Roger Mitchell, Renato Pagano. Dr. Ole Petersen...Robert Ramik,Andy Roberts, hallit, Dr. Chris Stanley,Tony Steede and Dr. ThomasWitzke. upport and encouragementof...Red Sea covc, known as Sharm Abhur, about 30 km north of Jiddah. Saudi Arabia. 74, 500. 78. 235-236. CM |  | | Book (edition) | | This book is respectfully dedicated to the memory of Dr. John Sinkankas for his kind initiative and support...by Strunz (1996). Thanks to the kind permission of Dr. E. Nagele from the E. Schweizerbart'sche Verlagsbuchhandlung...(mountains), R. (river), Is. (island), Vole. (volcano), Penin. (peninsula), St. (Saint), Ste. (Sainte)...arisen with localities in Congo-Zaire: the country, named Democratic Republic of Congo since 1960, was changed...The former Kivu province is now divided to three regions: INTRODUCTION Nord-Kivu, Sud-Kivu, and Maniema |
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